This study aimed to evaluate the milk clotting capacity (MCA), and caseinolytic activity (CA) of crude coagulant from the stomachs of adult rabbits (RC), and their influence on the composition, proteolysis, and textur...This study aimed to evaluate the milk clotting capacity (MCA), and caseinolytic activity (CA) of crude coagulant from the stomachs of adult rabbits (RC), and their influence on the composition, proteolysis, and texture of type Prato cheese. We tested two ways for salting the abomasum and three levels of pH and times for enzyme activation. The presence of enzymes and caseinolytic activity in RC was assayed by SDS-PAGE. The effects of three pH levels and the milk’s temperature on RC’s water-holding capacity (WHC) were evaluated. Brazilian Prato cheese type was developed and its proximate composition, texture, and change during ripening were assessed. The saturated NaCl solutions (37%, m/v) were more efficient for enzyme extraction from adult rabbit stomachs, and conditions of pH of 4.3 for 24 h showed better performance for enzyme activation into RC. An early and more active proteolytic reaction of RC on bovine caseinate was appreciated at the first 5 min of digestion when compared to commercial chymosin (CC). The water holding capacity of gel coagulated by RC was optimum at pH 6.4 and 37°C and is highly dependent on pH and temperature parameters. Total dry extract and fat were higher for treatment coagulated with RC. Conversely, hardness, gumminess, and chewability were lower in the same treatment. Yield, protein content, and changes that occurred during the ripening stage of cheeses were similar for both treatments, demonstrating that casein proteolysis was developed in a similar way. Coagulants from adult rabbits’ stomachs can be used to make semi-cooked curd cheeses.展开更多
BACKGROUND The evidence from observational studies has been inconclusive on the causal relationship between cheese intake and gestational hypertension or diabetes.AIM To determine whether cheese consumption was causal...BACKGROUND The evidence from observational studies has been inconclusive on the causal relationship between cheese intake and gestational hypertension or diabetes.AIM To determine whether cheese consumption was causally related to hypertension and diabetes during pregnancy.METHODS This was a two-sample Mendelian randomized(MR)study.Summary-level genetic data for cheese intake was exposure and corresponding outcome data for gestational hypertension and gestational diabetes were extracted from the IEU OpenGWAS database.MR analysis was conducted using inverse variance weighting.For sensitivity analyses,MR-Egger regression,weighted median,weighted mode,and leave-one-out methods were conducted.A fixed-effect model was used to meta-analyze two sample MR estimates.The traits of gestational hypertension were pregnancy hypertension(123579 individuals)and oedema,proteinuria and hypertensive disorders in pregnancy,childbirth and the puerperium(123579 individuals),and traits of gestational diabetes were gestational diabetes(123579 individuals)and diabetes mellitus in pregnancy(116363 individuals),respectively.RESULTS Cheese intake per standard deviation increase has causally reduced the risks of gestational hypertension[odds ratio(OR)=0.60,95%confidence interval(CI):0.47-0.76,P<0.001]and gestational diabetes(OR=0.41,95%CI:0.30-0.55,P<0.001)in inverse variance weighted analysis.Sensitivity analysis showed no heterogeneity(all P>0.05)nor horizontal pleiotropy(all P>0.05)in the relationship between cheese intake and gestational hypertension,but heterogeneity presented(all P<0.05)in relation to gestational diabetes in the two-sample MR analysis.CONCLUSION Cheese intake was inversely associated with gestational hypertension and gestational diabetes in MR analysis,suggesting that cheese consumption may be beneficial in preventing hypertension and diabetes during pregnancy.展开更多
Proteolysis is one of the most important biochemical reactions during cheese ripening.Studies on the secondary structure of proteins during ripening would be helpful for characterizing protein changes for assessing ch...Proteolysis is one of the most important biochemical reactions during cheese ripening.Studies on the secondary structure of proteins during ripening would be helpful for characterizing protein changes for assessing cheese quality.Fourier transform infrared spectroscopy(FTIR),with self-deconvolution,second derivative analysis and band curve-fitting,was used to characterize the secondary structure of proteins in Cheddar cheese during ripening.The spectra of the amide I region showed great similarity,while the relative contents of the secondary structures underwent a series of changes.As ripening progressed,the α-helix content decreased and the β-sheet content increased.This structural shift was attributed to the strengthening of hydrogen bonds that resulted from hydrolysis of caseins.In summary,FTIR could provide the basis for rapid characterization of cheese that is undergoing ripening.展开更多
Meltability is one of the most important properties of Mozzarella cheese, as it is generally used in pizza and other foods. Mozzarella was prepared by no salted and immature production technology, and the effect of di...Meltability is one of the most important properties of Mozzarella cheese, as it is generally used in pizza and other foods. Mozzarella was prepared by no salted and immature production technology, and the effect of different addition amounts of salt on the meltability of mozzarella cheese was measured by Schreiber method and small amplitude oscillatory shear analysis(SAOSA) method. The results showed that different adding amounts of NaCl had significant influence on the meltability of Mozzarella cheese, and 2% NaCl addition was the best condition. The results measured by the methods of Schreiber and SAOSA were basically same: adding different amounts of NaCl had significant influence on the hardness and elasticity of mozzarella cheese, but no significant influence on the sticky. It was a good microscopic structure arrangement of Mozzarella cheese with 2% NaCl addition. Scanning electron micrographs showed that a space grid structure formed by casein had changed, and formed many uniform molecular holes. The results indicated that different addition amounts of salt had influence on meltability of no salted immature Mozzarella cheese, and this technology could be drastically shorten the processing time.展开更多
Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and i...Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and in this respect, starter cultures consisting of autochthonous lactic acid bacteria strains are of particular interest. In the present study, we investigated lactic acid bacteria population diversity in San Simón da Costa cheese (PDO, Galicia, Spain) and found a predominance of the genus Lactobacillus, which by the end of ripening accounted for 78% of the strains isolated in Rogosa agar, around 40% of those in M17 agar and about 10% of those in MSE agar. The main species of lactic acid bacteria identified were Lactococcus lactis subsp. lactis, Lactobacillus casei subsp. casei, Lb. paracasei subsp. paracasei, Leuconostoc mesenteroides and Enterococcus faecalis. Virtually all the strains studied from a technological point of view yielded more than or equal to 0.24 g 100 mL-1 lactic acid. Lactococcus lactis subsp. lactis (SS 194), Lactobacillus paracasei (SS 1695 and SS 1689) and Enterococcus faecalis (SS 1378 and SS 1449) strains exhibited the greatest proteolytic capacity. Based on the overall technological aptitude of the tested strains, we can propose starter cultures and co-cultures that include different combinations of previous strains with a view to manufacturing San Simón da Costa cheese from pasteurised milk.展开更多
This study aimed at investigating the impact of adding microbial transglutaminase (MTGase) after rennet addition on some properties of fresh soft cheese made from camel milk. MTGase was added to milk at concentration ...This study aimed at investigating the impact of adding microbial transglutaminase (MTGase) after rennet addition on some properties of fresh soft cheese made from camel milk. MTGase was added to milk at concentration of 80, 100 and 120 U/L after 20 and 30 min of renneting. The chemical composition, yield, hardness, antioxidant activity and sensory properties of cheese were estimated. Enzymatic protein crosslinking was analyzed by SDS-PAGE. Results revealed that MTGase-treated cheeses were higher in moisture and lower in protein content compared to control. In addition, the concentration of MTGase and time of addition significantly (P 0.05) impacted these parameters. Among treated cheeses, samples with 80 U of MTGase and addition time of 20 min were the highest in total solids and protein content. Adding MTGase significantly (P 0.05) increased the cheese yield, however, increased MTGase concentration at any time of addition did not improve it. The electrophoretic patterns of MTGase-cheese proteins showed a reduction in the intensity of caseins bands and the appearance of new protein fractions with high molecular weights. However, the changes in the intensity of the whey proteins bands were not sufficiently clear as caseins. The cheese hardness was significantly (P 0.05) affected by adding MTGase. Cheese containing 80 U of MTGase had the highest hardness value compared to control and other treated samples. The antioxidant activity of cheese was negatively influenced by adding the enzyme. The use of MTGase enhanced the mouthfeel, texture and overall acceptability of cheese. However, the effect of MTGase concentration and addition time was not significant (P > 0.05) on the sensory attributes. In conclusion, adding MTGase to milk at concentration of 80 U after 20 min of renneting is recommended to improve the yield, textural and some sensory properties of fresh soft cheese made from camel milk.展开更多
Elevation of acid degree values (ADV) and peroxide value (POV) indicates deterioration of nutritional and sensory qualities of dairy products during storage. Iron fortification in bovine milk cheeses in relation to li...Elevation of acid degree values (ADV) and peroxide value (POV) indicates deterioration of nutritional and sensory qualities of dairy products during storage. Iron fortification in bovine milk cheeses in relation to lipolytic parameters and their correlations have been studied, while no such studies have been reported on caprine milk cheeses. The objectives of this study were to evaluate levels of ADV and POV of iron fortified [regular ferrous sulfate (RFS) and large microencapsulated ferrous sulfate (LMFS)] goat milk Cheddar cheeses compared to those of non-fortified control cheese (CC) and their correlations. Three batches of 3 types (CC, RFS and LMFS added) of goat milk cheeses were manufactured and stored at two temperatures (4°C and -18°C) for 0, 2 and 4 months. Iron was supplemented to RFS and LMFS cheeses by 8.23 g and 9.03 g per 9 kg, respectively. ADV and POV were determined using standard methods of examining dairy products (Richardson, 1985) and AOCS (1975) procedures. Results showed that ADV values for CC, RFS and LMFS cheeses for 0 and 4 month storage at 4°C were: 0.67, 0.73, 0.64;1.24, 1.78, 1.58, respectively, indicating significant (P < 0.05) elevations occurred in ADV for all three cheeses during 4 months storage. The cheese samples at 4 months storage showed significantly (P < 0.05) higher peroxide values compared to 0 and 2 month stored ones. The samples stored at refrigeration temperature (4°C) revealed slightly more lipid oxidation than those stored at frozen temperature (-18°C). Significant (P < 0.05) elevations in POV for all goat cheeses stored for 4 months and slight increases in POV at higher temperature implies that the longer time and higher temperature storage can elevate the rate of lipid oxidation in goat milk Cheddar cheeses. Correlations (r) between ADV and POV for the pooled data of three types of the caprine cheeses across storage periods were significant (P < 0.01), while r values of CC cheeses alone were negative. It was concluded that significant correlations exist between extents of lipolysis and lipid oxidation in the caprine milk Cheddar cheeses during 4 months storage.展开更多
Cheeses are characterized by several chemical-physical properties that make it difficult for the microorganisms growth, consequently. The actual European legislation allows the addition of few food additives in this t...Cheeses are characterized by several chemical-physical properties that make it difficult for the microorganisms growth, consequently. The actual European legislation allows the addition of few food additives in this type of food products. In this work, the entire procedure of extraction, purification, chromatographic separations and quali/quantitative determination of seven food additives (sorbic acid, benzoic acid, lactic acid, acetic acid, nitrites, nitrates and phosphates) was developed and applied for the analysis of different types of cheese (mozzarella, cheese spread, semi-hard and hard cheeses). Through validation procedure it was possible to evaluate the most important validation parameters. Extended calibration curves (r > 0.990) were obtained for all the analyzed compounds. Recovery values ranged from 72.8% to 98.4% and a good repeatability was obtained, with precision levels in the range of 0.03% - 0.11% (n = 6). The potential and feasibility of the method were tested by analysing real samples, such as mozzarella, cheese spread, semi-hard and hard cheeses, confirming that the method is well suited to satisfy the demands for accurate confirmation analyses of seven food additives in cheeses, which is especially valuable in official check analyses and in monitoring schemes.展开更多
Blueberry is a kind of wild berry with high nutrition values. It contains a great amount of anthocyanin, organic acid and fiber, which significantly affects sensory evaluation, pH value, texture profile analysis (TPA)...Blueberry is a kind of wild berry with high nutrition values. It contains a great amount of anthocyanin, organic acid and fiber, which significantly affects sensory evaluation, pH value, texture profile analysis (TPA) and microstructure. This study determined the effect of blueberry pulp on spreadable processed cheese through examining pH value, TPA, microstructure and color-difference. The results showed that increased blueberry content lowered pH value, remarkably transformed microstructure and TPA (P<0.05). Overloaded fiber in blueberry ruined the network structure of casein gel, thus 10% of blueberry performed better, more than that additive volume, sensory evaluation was worsen and gel structure was spoiled gradually. The blueberry sample lowered L*, b* and slightly increased a*, resulting in blueberry samples presented light amethyst, while sterilizing samples presented dark pink because of the lost of anthocyanin.展开更多
The aim of this study was to describe the compositional, functional and sensory properties of six traditional Mexican cheeses: Panela, Oaxaca, Manchego, Manchego Botanero, Tenate, and Morral. A total of 50 cheeses wer...The aim of this study was to describe the compositional, functional and sensory properties of six traditional Mexican cheeses: Panela, Oaxaca, Manchego, Manchego Botanero, Tenate, and Morral. A total of 50 cheeses were analysed. Relevant compositional parameters including pH, aw, proximate composition, NaCl, sugars, lactic and acetic acids, mineral contents, free-amino acid nitrogen, fat acid degree value and total fatty acids were determined. In addition, colour and texture profile analyses of unmelted cheeses and their meltability were investigated. Furthermore, other 30 cheeses were used for a descriptive sensory analysis. Properties of cheeses were described, compared between each cheese, and related to their respective making processes.展开更多
For a long time, ripened cheeses have been officially recognized as having human health beneficial properties. However, to date only a few studies have investigated the complex microbiota of S?o Jorge and Parmigiano-R...For a long time, ripened cheeses have been officially recognized as having human health beneficial properties. However, to date only a few studies have investigated the complex microbiota of S?o Jorge and Parmigiano-Reggiano cheeses in order to identify microorganisms with probiotic potential. Hence, with the purpose of analyzing the probiotic potential of autochthone bacteria from S?o Jorge and Parmigiano-Reggiano cheeses, lactic acid bacteria isolated from both products were isolated and their direct biotic interaction against three bacteria found in the human intestine evaluated. From a total of 225 bacterial autochthone isolates, 67 had synergetic behavior with Bifidobacterium animalis , 34 had no synergetic behavior with Shigella dysenteriae and 33 had antagonistic activity with this human pathogen. Biochemical tests were used to identify these cheese isolates with probiotic potential. Lactobacillus paracasei subsp paracasei Lactobacillus arhamnosus were found in São Jorge cheese and Lactobacillus rhamnosus , Lactobacillus buchneri and Lactobacillus curvatus in the Parmigiano cheese. Overall, initial exploratory studies with São Jorge cheese seem to show a higher number of potential probiotic agents than those found in the Parmigiano-Reggiano cheese. However, in order to better understand the functional potential of this traditional Portuguese cheese, further confirmatory studies should be pursued.展开更多
A randomized case control prospective method was adopted in this study in order to assess the health benefit associated with the Darfiyeh cheese, a traditional Lebanese raw goat milk cheese ripened in goat skin. 21 pa...A randomized case control prospective method was adopted in this study in order to assess the health benefit associated with the Darfiyeh cheese, a traditional Lebanese raw goat milk cheese ripened in goat skin. 21 participants were recruited and divided into 2 groups: test group (n = 10) and control group (n = 11). Venous blood and stools were collected at day 14, 21 and day 0 and 21 respectively. Flow cytometry was performed on blood sample. Fecal samples were plated on Plate Count Agar (PCA) and de Man, Rogosa and Sharpe Agar (MRS) agar in order to monitor any alteration in the gastrointestinal tract (GIT). At day 24, a significant increase by 27.67% (p = 0.043) in the bacterial count was seen on the MRS agar for the test group in comparison to no change in the total bacterial count. At day 14 a significant drop (p = 0.026) in CD3+/CD4+ population in the test group (35.67 vs 42.87), and a non-significant drop (p = 0.818) in CD8+ (24.76 vs 28.28) is seen when compared to control group. At day 24, no significant change (p = 0.20) in the CD3+/CD4+ population in comparison between both groups and no change in CD8+ or Geo means in both groups. In conclusion, an alteration in the GIT microflora could be hinted at by the lactobacilli bacterium, which was not reflected on the total bacterial count.展开更多
Cheddar and Kefalotyri cheese belong to the category of hard cheeses.Cheddar has an English origin,while Kefalotyri is a traditional cheese in Greece and a well-consumed dairy product in Cyprus.Discrimination of dairy...Cheddar and Kefalotyri cheese belong to the category of hard cheeses.Cheddar has an English origin,while Kefalotyri is a traditional cheese in Greece and a well-consumed dairy product in Cyprus.Discrimination of dairy products can be determined through several chemical methods.The aim of this study was to discriminate the samples of Cheddar and Kefalotyri cheese by analyzing various samples,from different brands.Two spectroscopic techniques namely proton nuclear magnetic resonance(1H-NMR)and Fourier-transformed infrared(FTIR)spectroscopy were chosen in order to chemically characterise the samples.The first step of the methodology was the freeze-drying process for lyophilisation of the samples.The number of samples reached 28,including 14 Cheddar samples and 14 samples of Kefalotyri cheese.After that,measurements for each sample have been obtained by FTIR(%transmittance-wavenumber in cm^-1)and ^1H-NMR(signal intensity-chemical shift in ppm)techniques.The data were analysed using SIMCA software.The proposed techniques along with chemometrics allow the discrimination of those two types of cheese.Both techniques employed are of significant importance,since they provide information about good classification of the samples when they are combined together.Interpretation of results and classification by using chemometric methods confirmed the different recipe of the two types of cheese.This study is the initial step of the future work.Future research will focus on discrimination based on the species’origin of milk of these and other cheese samples.展开更多
Four “cuajada” type fresh cheeses were evaluated by two trained panels in different regions from Oaxaca in Mexico (Instituto Tecnológico de Comitancillo (ITC) and Universidad del Mar (UMAR)). Each panel was int...Four “cuajada” type fresh cheeses were evaluated by two trained panels in different regions from Oaxaca in Mexico (Instituto Tecnológico de Comitancillo (ITC) and Universidad del Mar (UMAR)). Each panel was integrated by six judges. Analysis of variance (ANOVA) in conjunction with principal component analysis (PCA) and the Rv coefficient were used to identify similarities and consensus among trained judges and panels. The ANOVA results revealed that the judges from ITC performed significantly better (P < 0.05) in discrimination and repetitivity, while both panels showed a similar effect in discrimination. The PCA determined some similarities in the position of cheeses in the sensory space, while Rv revealed that judges and panels were consensual. In conclusion, statistical resources determined that both panels were discriminating and that similarities in the positioning of cheeses in the sensory space were found.展开更多
Natural starters have been extensively used for many centuries to make many different fermented food products from different raw materials: Milk, meat, roots, vegetables, etc. The industrialisation of food production ...Natural starters have been extensively used for many centuries to make many different fermented food products from different raw materials: Milk, meat, roots, vegetables, etc. The industrialisation of food production at the end of the 19th century necessitated the use of regular selected starters to standardize the organoleptic characteristics of the final product. As a consequence, during the 20th century, there was a decline in the use of natural starters in Western countries except in the production of local cheeses or sourdough breads. The beginning of this new millennium has witnessed a deep change in consumer demand, in pursuit of quality, safety and pleasure. In this context, natural starters could, in the future, play an important role in the development of fermented products. However, food producers and researchers have first to cope with fundamental problems in the understanding of these complex ecosystems. The dynamic evolution of the microbial population inside the natural starter (its resilience, its genetic and physiological aptitudes) and the consequences on the product are still partially unknown. This document reviews a broad range of articles concerning the use of natural starters with a specific focus on cheeses and breads, and discusses the major stakes for local food production and the consumption of typical products.展开更多
Compared to pasture based sistems, milk produced in confined dairy systems is characterized by a high saturated fat (SF) content with a lower concentration of healthy fatty acids (FA) such as vaccenic (VA, trans-11C18...Compared to pasture based sistems, milk produced in confined dairy systems is characterized by a high saturated fat (SF) content with a lower concentration of healthy fatty acids (FA) such as vaccenic (VA, trans-11C18:1), conjugated linoleic cid (cis-9, trans-11 C18:2, CLA), α-linolenic (cis-9, cis-12, cis-15C18: 3), eicosapentaenoic (EPA, C20:5) and docosahexaenoic (DHA, C22:6) whose presence in milk and dairy products can be increased by feeding polyunsaturated FA (PUFA). The aim of the study was to determine the differences in milk composition and FA profile between a regular (Reg) milk (Reg-Milk), a Reg-Dambo type cheese (Reg-DCh) and a Reg yogurt (Reg-Yog) with that obtained after including a blend (7:1) of soybean (SO) and fish (FO) oils in the total mixed ration (TMR) of lactating dairy cows. The experiment was carried out at the Talar Farm located at Laguna del Sauce, Maldonado Department, Punta del Este, Uruguay Republic during a period of 30 experimental days using a single production batch of 29 Holstein cows. Within this batch, one group of 8 cows (1.88 ± 0.99 calves) in early lactation (135 ± 19 days postpartum) was selected to individually measure milk yield and composition. During the first 7 days of the experiment, cows were fed a TMR without oil-blend inclusion to obtain the Reg-Milk, Reg-DCh and Reg-Yog. From the 8th day onwards, the oil blend was added to the TMR at 4% DM (1.0 kg oil blend cow-1 day-1) and after 23 days of feeding, the modified milk (Mod-Milk) was analyzed and collected to elaborate the modified Dambo-type cheese (Mod-DCh) and Mod-yogurt (Mod-Yog). Milk yield was recorded daily in the selected 8 cows and milk composition was determined over two consecutive days prior to the start of blend-oil supply (Reg-Milk) and at the end of oil supplementation (Mod-Milk) on days 29th and 30th. Milk-tank samples of Reg-Mi and Mod-Mi were also collected and analyzed for chemical composition and milk FA profile. Cheese and yogurt were assayed for its FA profile. Differences in milk yield and composition and in the FA profile before and after oil-feeding were stated using the Student T-test for paired observations. Milk production (kg·cow-1·day-1) slightly (-6.7%) decreased (P -1 g leading to a lower (P -1·day-1) of fat corrected milk (4%FCM) from 32.83 (before) to 29.63 after oil. Milk protein content (g 100 g-1) increased (P -1·day-1) (P -1 in Mod-Mi as it was observed (P -1). Yield of NFS tended (P -1·day-1after oil supply. Content of atherogenic FA (C12:0 to C16:0) was significantly (P -1 (Mod-Mi) with a concomitant decrease (P -1 FA) of elaidic (trans-9 C18:1) and trans-10 C18:1 FA was low in Reg-Mi (0.22 and 0.34 respectively) but tended (P -1 FA) of VA resulted higher (+110%, P -1 FA) increased (P -1) of α-linolenic were higher (P cis-9 C18:1) content (g 100 g-1) remained unchanged (P < 0.504) averaging 21.99 in Reg-Mi and 22.86 in Mod-Mi. Composition of FA of the Mod-DCh was highly correlated (R2 = 0.999) with FA profile from its original Mod-Mi. A serving of the M-DCh (30 g) theoretically involved a 12.1% reduction in total fat consumption with 16.9% less in SF intake compared to the Reg-Ch. A serving of the M-DCh could putatively increase total CLA consumption by 72.7% compared to the Reg-DCh. Compared to Reg-Yo, a portion (178 g) of the Mod-Yo could increase (69.4%) total CLA intake. The nutritional value of milk fat was improved by feeding a blend of PUFA oils to confined dairy cows and the consumption of the mofified dairy products obtained could promote a lower intake of the potentially atherogenic saturated FA and some increase in healthy FA ingestion.展开更多
At semi-industrial scale it was obtained two cheeses, one with aromatic culture (CHN) and the other with also L. helveticus (CHN + LH). Proteolysis during ripening was evaluated using proteolytic indices, electrophore...At semi-industrial scale it was obtained two cheeses, one with aromatic culture (CHN) and the other with also L. helveticus (CHN + LH). Proteolysis during ripening was evaluated using proteolytic indices, electrophoretic profile Urea-PAGE and release of free amino acids. Sensory evaluation was performed by acceptability test. It was observed a 5-fold increase in the fraction corresponding to αs1-I-casein in the CHN cheese and 6.5 times in the CHN + LH cheese and 7.2 and 8.2 increase respectively, for total amino acids. Prato cheese with the adjunct culture showed higher acceptability in terms of overall aroma and flavor.展开更多
The microbiological, chemical and sensory characteristics of licensed and unlicensed commercial Serrano cheese, a traditional product from the highlands of South Brazil, were studied. The average bacteria counts (log ...The microbiological, chemical and sensory characteristics of licensed and unlicensed commercial Serrano cheese, a traditional product from the highlands of South Brazil, were studied. The average bacteria counts (log CFU/g) were 8.8, 3.4, 3.4, 5.1, and 8.8, for mesophilic bacteria, fecal coliforms, staphylococci, yeasts and moulds, and lactic acid bacteria (LAB), respectively. Differences in microbiological quality were detected between licensed and unlicensed cheeses. However, the presence of potential gastroentheric bacteria in both kind of cheeses is disturbing and point out the necessity of alternative manufacturing process and good manufacturing practices to minimize consumers’ health risks. The most prevalent LAB were Lactobacillus (91%), followed Lactococcus and Enterococcus. Lactobacillus isolates comprised L. plantarum (57.7%), L. paracasei (19.2%), L. rhamnosus (7.7%), L. acidophilus (7.7%), and 3.8% of both L. curvatus and L. fermentum. Non-significant physico-chemical differences were detected between licensed and unlicensed cheeses. Cheeses that received the highest sensorial scores exhibited the presence of both L. plantarum and L. paracasei, indicating that mixed populations of these species positively contributed to flavor development.展开更多
Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a...Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a bulk milk from the mixed herd of Saanen, Alpine, and Nubian goat breeds. LF cheeses were made using LF milk after cream separation. FFAs of all cheeses were extracted in diisoprophyl ether using polypropylene chromatography column, and FFA concentrations were quantified using a gas chromatograph equipped with a fused silica capillary column. Moisture, fat, protein contents (%) and pH of fresh LF and FF cheeses were: 55.1, 52.3;1.30, 25.6;35.7, 22.5;5.40, 5.42, respectively. The FFA contents (mg/g cheese) of fresh FF and LF cheeses prior to storage treatments for C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C18:1, and C18:2 were: 0.020, 0.072;0.070, 0.035;0.061, 0.055;0.181, 0.167;0.073, 0.047;0.174, 0.112;0.579, 0.152;0.308, 0.202;0.521, 0.174;and 0.057, 0.026, respectively. The respective FFA to total fatty acid ratios for 0, 1 and 3 months aged FF and LF cheeses were 8.44, 12.4;6.31, 16.91;12.03, 14.19. The LF cheeses generated more FFA than FF cheeses, while actual FFA content in FF cheese was significantly higher than in LF cheese. The FFA contents of LF cheese at 0, 1 and 3 months storage were 48.0, 96.8 and 36.4% of those of FF cheese, respectively. It was concluded LF cheese generated higher amount of FFA than FF cheese, although total FFA content was significantly (P<0.05) lower in LF cheese than in FF cheese.展开更多
文摘This study aimed to evaluate the milk clotting capacity (MCA), and caseinolytic activity (CA) of crude coagulant from the stomachs of adult rabbits (RC), and their influence on the composition, proteolysis, and texture of type Prato cheese. We tested two ways for salting the abomasum and three levels of pH and times for enzyme activation. The presence of enzymes and caseinolytic activity in RC was assayed by SDS-PAGE. The effects of three pH levels and the milk’s temperature on RC’s water-holding capacity (WHC) were evaluated. Brazilian Prato cheese type was developed and its proximate composition, texture, and change during ripening were assessed. The saturated NaCl solutions (37%, m/v) were more efficient for enzyme extraction from adult rabbit stomachs, and conditions of pH of 4.3 for 24 h showed better performance for enzyme activation into RC. An early and more active proteolytic reaction of RC on bovine caseinate was appreciated at the first 5 min of digestion when compared to commercial chymosin (CC). The water holding capacity of gel coagulated by RC was optimum at pH 6.4 and 37°C and is highly dependent on pH and temperature parameters. Total dry extract and fat were higher for treatment coagulated with RC. Conversely, hardness, gumminess, and chewability were lower in the same treatment. Yield, protein content, and changes that occurred during the ripening stage of cheeses were similar for both treatments, demonstrating that casein proteolysis was developed in a similar way. Coagulants from adult rabbits’ stomachs can be used to make semi-cooked curd cheeses.
文摘BACKGROUND The evidence from observational studies has been inconclusive on the causal relationship between cheese intake and gestational hypertension or diabetes.AIM To determine whether cheese consumption was causally related to hypertension and diabetes during pregnancy.METHODS This was a two-sample Mendelian randomized(MR)study.Summary-level genetic data for cheese intake was exposure and corresponding outcome data for gestational hypertension and gestational diabetes were extracted from the IEU OpenGWAS database.MR analysis was conducted using inverse variance weighting.For sensitivity analyses,MR-Egger regression,weighted median,weighted mode,and leave-one-out methods were conducted.A fixed-effect model was used to meta-analyze two sample MR estimates.The traits of gestational hypertension were pregnancy hypertension(123579 individuals)and oedema,proteinuria and hypertensive disorders in pregnancy,childbirth and the puerperium(123579 individuals),and traits of gestational diabetes were gestational diabetes(123579 individuals)and diabetes mellitus in pregnancy(116363 individuals),respectively.RESULTS Cheese intake per standard deviation increase has causally reduced the risks of gestational hypertension[odds ratio(OR)=0.60,95%confidence interval(CI):0.47-0.76,P<0.001]and gestational diabetes(OR=0.41,95%CI:0.30-0.55,P<0.001)in inverse variance weighted analysis.Sensitivity analysis showed no heterogeneity(all P>0.05)nor horizontal pleiotropy(all P>0.05)in the relationship between cheese intake and gestational hypertension,but heterogeneity presented(all P<0.05)in relation to gestational diabetes in the two-sample MR analysis.CONCLUSION Cheese intake was inversely associated with gestational hypertension and gestational diabetes in MR analysis,suggesting that cheese consumption may be beneficial in preventing hypertension and diabetes during pregnancy.
基金financially supported by Beijing Municipal Commission of Education Co-Constructed Programand Chinese Universities Scientific Fund(2009-4-25)
文摘Proteolysis is one of the most important biochemical reactions during cheese ripening.Studies on the secondary structure of proteins during ripening would be helpful for characterizing protein changes for assessing cheese quality.Fourier transform infrared spectroscopy(FTIR),with self-deconvolution,second derivative analysis and band curve-fitting,was used to characterize the secondary structure of proteins in Cheddar cheese during ripening.The spectra of the amide I region showed great similarity,while the relative contents of the secondary structures underwent a series of changes.As ripening progressed,the α-helix content decreased and the β-sheet content increased.This structural shift was attributed to the strengthening of hydrogen bonds that resulted from hydrolysis of caseins.In summary,FTIR could provide the basis for rapid characterization of cheese that is undergoing ripening.
基金Supported by 12th Five-year Plan of National Ministry of Science and Technology(2011BAD09B02)National Ministry of Science and Technology(2009GJB20010)
文摘Meltability is one of the most important properties of Mozzarella cheese, as it is generally used in pizza and other foods. Mozzarella was prepared by no salted and immature production technology, and the effect of different addition amounts of salt on the meltability of mozzarella cheese was measured by Schreiber method and small amplitude oscillatory shear analysis(SAOSA) method. The results showed that different adding amounts of NaCl had significant influence on the meltability of Mozzarella cheese, and 2% NaCl addition was the best condition. The results measured by the methods of Schreiber and SAOSA were basically same: adding different amounts of NaCl had significant influence on the hardness and elasticity of mozzarella cheese, but no significant influence on the sticky. It was a good microscopic structure arrangement of Mozzarella cheese with 2% NaCl addition. Scanning electron micrographs showed that a space grid structure formed by casein had changed, and formed many uniform molecular holes. The results indicated that different addition amounts of salt had influence on meltability of no salted immature Mozzarella cheese, and this technology could be drastically shorten the processing time.
文摘Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and in this respect, starter cultures consisting of autochthonous lactic acid bacteria strains are of particular interest. In the present study, we investigated lactic acid bacteria population diversity in San Simón da Costa cheese (PDO, Galicia, Spain) and found a predominance of the genus Lactobacillus, which by the end of ripening accounted for 78% of the strains isolated in Rogosa agar, around 40% of those in M17 agar and about 10% of those in MSE agar. The main species of lactic acid bacteria identified were Lactococcus lactis subsp. lactis, Lactobacillus casei subsp. casei, Lb. paracasei subsp. paracasei, Leuconostoc mesenteroides and Enterococcus faecalis. Virtually all the strains studied from a technological point of view yielded more than or equal to 0.24 g 100 mL-1 lactic acid. Lactococcus lactis subsp. lactis (SS 194), Lactobacillus paracasei (SS 1695 and SS 1689) and Enterococcus faecalis (SS 1378 and SS 1449) strains exhibited the greatest proteolytic capacity. Based on the overall technological aptitude of the tested strains, we can propose starter cultures and co-cultures that include different combinations of previous strains with a view to manufacturing San Simón da Costa cheese from pasteurised milk.
文摘This study aimed at investigating the impact of adding microbial transglutaminase (MTGase) after rennet addition on some properties of fresh soft cheese made from camel milk. MTGase was added to milk at concentration of 80, 100 and 120 U/L after 20 and 30 min of renneting. The chemical composition, yield, hardness, antioxidant activity and sensory properties of cheese were estimated. Enzymatic protein crosslinking was analyzed by SDS-PAGE. Results revealed that MTGase-treated cheeses were higher in moisture and lower in protein content compared to control. In addition, the concentration of MTGase and time of addition significantly (P 0.05) impacted these parameters. Among treated cheeses, samples with 80 U of MTGase and addition time of 20 min were the highest in total solids and protein content. Adding MTGase significantly (P 0.05) increased the cheese yield, however, increased MTGase concentration at any time of addition did not improve it. The electrophoretic patterns of MTGase-cheese proteins showed a reduction in the intensity of caseins bands and the appearance of new protein fractions with high molecular weights. However, the changes in the intensity of the whey proteins bands were not sufficiently clear as caseins. The cheese hardness was significantly (P 0.05) affected by adding MTGase. Cheese containing 80 U of MTGase had the highest hardness value compared to control and other treated samples. The antioxidant activity of cheese was negatively influenced by adding the enzyme. The use of MTGase enhanced the mouthfeel, texture and overall acceptability of cheese. However, the effect of MTGase concentration and addition time was not significant (P > 0.05) on the sensory attributes. In conclusion, adding MTGase to milk at concentration of 80 U after 20 min of renneting is recommended to improve the yield, textural and some sensory properties of fresh soft cheese made from camel milk.
文摘Elevation of acid degree values (ADV) and peroxide value (POV) indicates deterioration of nutritional and sensory qualities of dairy products during storage. Iron fortification in bovine milk cheeses in relation to lipolytic parameters and their correlations have been studied, while no such studies have been reported on caprine milk cheeses. The objectives of this study were to evaluate levels of ADV and POV of iron fortified [regular ferrous sulfate (RFS) and large microencapsulated ferrous sulfate (LMFS)] goat milk Cheddar cheeses compared to those of non-fortified control cheese (CC) and their correlations. Three batches of 3 types (CC, RFS and LMFS added) of goat milk cheeses were manufactured and stored at two temperatures (4°C and -18°C) for 0, 2 and 4 months. Iron was supplemented to RFS and LMFS cheeses by 8.23 g and 9.03 g per 9 kg, respectively. ADV and POV were determined using standard methods of examining dairy products (Richardson, 1985) and AOCS (1975) procedures. Results showed that ADV values for CC, RFS and LMFS cheeses for 0 and 4 month storage at 4°C were: 0.67, 0.73, 0.64;1.24, 1.78, 1.58, respectively, indicating significant (P < 0.05) elevations occurred in ADV for all three cheeses during 4 months storage. The cheese samples at 4 months storage showed significantly (P < 0.05) higher peroxide values compared to 0 and 2 month stored ones. The samples stored at refrigeration temperature (4°C) revealed slightly more lipid oxidation than those stored at frozen temperature (-18°C). Significant (P < 0.05) elevations in POV for all goat cheeses stored for 4 months and slight increases in POV at higher temperature implies that the longer time and higher temperature storage can elevate the rate of lipid oxidation in goat milk Cheddar cheeses. Correlations (r) between ADV and POV for the pooled data of three types of the caprine cheeses across storage periods were significant (P < 0.01), while r values of CC cheeses alone were negative. It was concluded that significant correlations exist between extents of lipolysis and lipid oxidation in the caprine milk Cheddar cheeses during 4 months storage.
文摘Cheeses are characterized by several chemical-physical properties that make it difficult for the microorganisms growth, consequently. The actual European legislation allows the addition of few food additives in this type of food products. In this work, the entire procedure of extraction, purification, chromatographic separations and quali/quantitative determination of seven food additives (sorbic acid, benzoic acid, lactic acid, acetic acid, nitrites, nitrates and phosphates) was developed and applied for the analysis of different types of cheese (mozzarella, cheese spread, semi-hard and hard cheeses). Through validation procedure it was possible to evaluate the most important validation parameters. Extended calibration curves (r > 0.990) were obtained for all the analyzed compounds. Recovery values ranged from 72.8% to 98.4% and a good repeatability was obtained, with precision levels in the range of 0.03% - 0.11% (n = 6). The potential and feasibility of the method were tested by analysing real samples, such as mozzarella, cheese spread, semi-hard and hard cheeses, confirming that the method is well suited to satisfy the demands for accurate confirmation analyses of seven food additives in cheeses, which is especially valuable in official check analyses and in monitoring schemes.
基金Supported by Scientific Research Fund of Northeast Agricultural University
文摘Blueberry is a kind of wild berry with high nutrition values. It contains a great amount of anthocyanin, organic acid and fiber, which significantly affects sensory evaluation, pH value, texture profile analysis (TPA) and microstructure. This study determined the effect of blueberry pulp on spreadable processed cheese through examining pH value, TPA, microstructure and color-difference. The results showed that increased blueberry content lowered pH value, remarkably transformed microstructure and TPA (P<0.05). Overloaded fiber in blueberry ruined the network structure of casein gel, thus 10% of blueberry performed better, more than that additive volume, sensory evaluation was worsen and gel structure was spoiled gradually. The blueberry sample lowered L*, b* and slightly increased a*, resulting in blueberry samples presented light amethyst, while sterilizing samples presented dark pink because of the lost of anthocyanin.
文摘The aim of this study was to describe the compositional, functional and sensory properties of six traditional Mexican cheeses: Panela, Oaxaca, Manchego, Manchego Botanero, Tenate, and Morral. A total of 50 cheeses were analysed. Relevant compositional parameters including pH, aw, proximate composition, NaCl, sugars, lactic and acetic acids, mineral contents, free-amino acid nitrogen, fat acid degree value and total fatty acids were determined. In addition, colour and texture profile analyses of unmelted cheeses and their meltability were investigated. Furthermore, other 30 cheeses were used for a descriptive sensory analysis. Properties of cheeses were described, compared between each cheese, and related to their respective making processes.
文摘For a long time, ripened cheeses have been officially recognized as having human health beneficial properties. However, to date only a few studies have investigated the complex microbiota of S?o Jorge and Parmigiano-Reggiano cheeses in order to identify microorganisms with probiotic potential. Hence, with the purpose of analyzing the probiotic potential of autochthone bacteria from S?o Jorge and Parmigiano-Reggiano cheeses, lactic acid bacteria isolated from both products were isolated and their direct biotic interaction against three bacteria found in the human intestine evaluated. From a total of 225 bacterial autochthone isolates, 67 had synergetic behavior with Bifidobacterium animalis , 34 had no synergetic behavior with Shigella dysenteriae and 33 had antagonistic activity with this human pathogen. Biochemical tests were used to identify these cheese isolates with probiotic potential. Lactobacillus paracasei subsp paracasei Lactobacillus arhamnosus were found in São Jorge cheese and Lactobacillus rhamnosus , Lactobacillus buchneri and Lactobacillus curvatus in the Parmigiano cheese. Overall, initial exploratory studies with São Jorge cheese seem to show a higher number of potential probiotic agents than those found in the Parmigiano-Reggiano cheese. However, in order to better understand the functional potential of this traditional Portuguese cheese, further confirmatory studies should be pursued.
文摘A randomized case control prospective method was adopted in this study in order to assess the health benefit associated with the Darfiyeh cheese, a traditional Lebanese raw goat milk cheese ripened in goat skin. 21 participants were recruited and divided into 2 groups: test group (n = 10) and control group (n = 11). Venous blood and stools were collected at day 14, 21 and day 0 and 21 respectively. Flow cytometry was performed on blood sample. Fecal samples were plated on Plate Count Agar (PCA) and de Man, Rogosa and Sharpe Agar (MRS) agar in order to monitor any alteration in the gastrointestinal tract (GIT). At day 24, a significant increase by 27.67% (p = 0.043) in the bacterial count was seen on the MRS agar for the test group in comparison to no change in the total bacterial count. At day 14 a significant drop (p = 0.026) in CD3+/CD4+ population in the test group (35.67 vs 42.87), and a non-significant drop (p = 0.818) in CD8+ (24.76 vs 28.28) is seen when compared to control group. At day 24, no significant change (p = 0.20) in the CD3+/CD4+ population in comparison between both groups and no change in CD8+ or Geo means in both groups. In conclusion, an alteration in the GIT microflora could be hinted at by the lactobacilli bacterium, which was not reflected on the total bacterial count.
文摘Cheddar and Kefalotyri cheese belong to the category of hard cheeses.Cheddar has an English origin,while Kefalotyri is a traditional cheese in Greece and a well-consumed dairy product in Cyprus.Discrimination of dairy products can be determined through several chemical methods.The aim of this study was to discriminate the samples of Cheddar and Kefalotyri cheese by analyzing various samples,from different brands.Two spectroscopic techniques namely proton nuclear magnetic resonance(1H-NMR)and Fourier-transformed infrared(FTIR)spectroscopy were chosen in order to chemically characterise the samples.The first step of the methodology was the freeze-drying process for lyophilisation of the samples.The number of samples reached 28,including 14 Cheddar samples and 14 samples of Kefalotyri cheese.After that,measurements for each sample have been obtained by FTIR(%transmittance-wavenumber in cm^-1)and ^1H-NMR(signal intensity-chemical shift in ppm)techniques.The data were analysed using SIMCA software.The proposed techniques along with chemometrics allow the discrimination of those two types of cheese.Both techniques employed are of significant importance,since they provide information about good classification of the samples when they are combined together.Interpretation of results and classification by using chemometric methods confirmed the different recipe of the two types of cheese.This study is the initial step of the future work.Future research will focus on discrimination based on the species’origin of milk of these and other cheese samples.
文摘Four “cuajada” type fresh cheeses were evaluated by two trained panels in different regions from Oaxaca in Mexico (Instituto Tecnológico de Comitancillo (ITC) and Universidad del Mar (UMAR)). Each panel was integrated by six judges. Analysis of variance (ANOVA) in conjunction with principal component analysis (PCA) and the Rv coefficient were used to identify similarities and consensus among trained judges and panels. The ANOVA results revealed that the judges from ITC performed significantly better (P < 0.05) in discrimination and repetitivity, while both panels showed a similar effect in discrimination. The PCA determined some similarities in the position of cheeses in the sensory space, while Rv revealed that judges and panels were consensual. In conclusion, statistical resources determined that both panels were discriminating and that similarities in the positioning of cheeses in the sensory space were found.
文摘Natural starters have been extensively used for many centuries to make many different fermented food products from different raw materials: Milk, meat, roots, vegetables, etc. The industrialisation of food production at the end of the 19th century necessitated the use of regular selected starters to standardize the organoleptic characteristics of the final product. As a consequence, during the 20th century, there was a decline in the use of natural starters in Western countries except in the production of local cheeses or sourdough breads. The beginning of this new millennium has witnessed a deep change in consumer demand, in pursuit of quality, safety and pleasure. In this context, natural starters could, in the future, play an important role in the development of fermented products. However, food producers and researchers have first to cope with fundamental problems in the understanding of these complex ecosystems. The dynamic evolution of the microbial population inside the natural starter (its resilience, its genetic and physiological aptitudes) and the consequences on the product are still partially unknown. This document reviews a broad range of articles concerning the use of natural starters with a specific focus on cheeses and breads, and discusses the major stakes for local food production and the consumption of typical products.
文摘Compared to pasture based sistems, milk produced in confined dairy systems is characterized by a high saturated fat (SF) content with a lower concentration of healthy fatty acids (FA) such as vaccenic (VA, trans-11C18:1), conjugated linoleic cid (cis-9, trans-11 C18:2, CLA), α-linolenic (cis-9, cis-12, cis-15C18: 3), eicosapentaenoic (EPA, C20:5) and docosahexaenoic (DHA, C22:6) whose presence in milk and dairy products can be increased by feeding polyunsaturated FA (PUFA). The aim of the study was to determine the differences in milk composition and FA profile between a regular (Reg) milk (Reg-Milk), a Reg-Dambo type cheese (Reg-DCh) and a Reg yogurt (Reg-Yog) with that obtained after including a blend (7:1) of soybean (SO) and fish (FO) oils in the total mixed ration (TMR) of lactating dairy cows. The experiment was carried out at the Talar Farm located at Laguna del Sauce, Maldonado Department, Punta del Este, Uruguay Republic during a period of 30 experimental days using a single production batch of 29 Holstein cows. Within this batch, one group of 8 cows (1.88 ± 0.99 calves) in early lactation (135 ± 19 days postpartum) was selected to individually measure milk yield and composition. During the first 7 days of the experiment, cows were fed a TMR without oil-blend inclusion to obtain the Reg-Milk, Reg-DCh and Reg-Yog. From the 8th day onwards, the oil blend was added to the TMR at 4% DM (1.0 kg oil blend cow-1 day-1) and after 23 days of feeding, the modified milk (Mod-Milk) was analyzed and collected to elaborate the modified Dambo-type cheese (Mod-DCh) and Mod-yogurt (Mod-Yog). Milk yield was recorded daily in the selected 8 cows and milk composition was determined over two consecutive days prior to the start of blend-oil supply (Reg-Milk) and at the end of oil supplementation (Mod-Milk) on days 29th and 30th. Milk-tank samples of Reg-Mi and Mod-Mi were also collected and analyzed for chemical composition and milk FA profile. Cheese and yogurt were assayed for its FA profile. Differences in milk yield and composition and in the FA profile before and after oil-feeding were stated using the Student T-test for paired observations. Milk production (kg·cow-1·day-1) slightly (-6.7%) decreased (P -1 g leading to a lower (P -1·day-1) of fat corrected milk (4%FCM) from 32.83 (before) to 29.63 after oil. Milk protein content (g 100 g-1) increased (P -1·day-1) (P -1 in Mod-Mi as it was observed (P -1). Yield of NFS tended (P -1·day-1after oil supply. Content of atherogenic FA (C12:0 to C16:0) was significantly (P -1 (Mod-Mi) with a concomitant decrease (P -1 FA) of elaidic (trans-9 C18:1) and trans-10 C18:1 FA was low in Reg-Mi (0.22 and 0.34 respectively) but tended (P -1 FA) of VA resulted higher (+110%, P -1 FA) increased (P -1) of α-linolenic were higher (P cis-9 C18:1) content (g 100 g-1) remained unchanged (P < 0.504) averaging 21.99 in Reg-Mi and 22.86 in Mod-Mi. Composition of FA of the Mod-DCh was highly correlated (R2 = 0.999) with FA profile from its original Mod-Mi. A serving of the M-DCh (30 g) theoretically involved a 12.1% reduction in total fat consumption with 16.9% less in SF intake compared to the Reg-Ch. A serving of the M-DCh could putatively increase total CLA consumption by 72.7% compared to the Reg-DCh. Compared to Reg-Yo, a portion (178 g) of the Mod-Yo could increase (69.4%) total CLA intake. The nutritional value of milk fat was improved by feeding a blend of PUFA oils to confined dairy cows and the consumption of the mofified dairy products obtained could promote a lower intake of the potentially atherogenic saturated FA and some increase in healthy FA ingestion.
文摘At semi-industrial scale it was obtained two cheeses, one with aromatic culture (CHN) and the other with also L. helveticus (CHN + LH). Proteolysis during ripening was evaluated using proteolytic indices, electrophoretic profile Urea-PAGE and release of free amino acids. Sensory evaluation was performed by acceptability test. It was observed a 5-fold increase in the fraction corresponding to αs1-I-casein in the CHN cheese and 6.5 times in the CHN + LH cheese and 7.2 and 8.2 increase respectively, for total amino acids. Prato cheese with the adjunct culture showed higher acceptability in terms of overall aroma and flavor.
文摘The microbiological, chemical and sensory characteristics of licensed and unlicensed commercial Serrano cheese, a traditional product from the highlands of South Brazil, were studied. The average bacteria counts (log CFU/g) were 8.8, 3.4, 3.4, 5.1, and 8.8, for mesophilic bacteria, fecal coliforms, staphylococci, yeasts and moulds, and lactic acid bacteria (LAB), respectively. Differences in microbiological quality were detected between licensed and unlicensed cheeses. However, the presence of potential gastroentheric bacteria in both kind of cheeses is disturbing and point out the necessity of alternative manufacturing process and good manufacturing practices to minimize consumers’ health risks. The most prevalent LAB were Lactobacillus (91%), followed Lactococcus and Enterococcus. Lactobacillus isolates comprised L. plantarum (57.7%), L. paracasei (19.2%), L. rhamnosus (7.7%), L. acidophilus (7.7%), and 3.8% of both L. curvatus and L. fermentum. Non-significant physico-chemical differences were detected between licensed and unlicensed cheeses. Cheeses that received the highest sensorial scores exhibited the presence of both L. plantarum and L. paracasei, indicating that mixed populations of these species positively contributed to flavor development.
文摘Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a bulk milk from the mixed herd of Saanen, Alpine, and Nubian goat breeds. LF cheeses were made using LF milk after cream separation. FFAs of all cheeses were extracted in diisoprophyl ether using polypropylene chromatography column, and FFA concentrations were quantified using a gas chromatograph equipped with a fused silica capillary column. Moisture, fat, protein contents (%) and pH of fresh LF and FF cheeses were: 55.1, 52.3;1.30, 25.6;35.7, 22.5;5.40, 5.42, respectively. The FFA contents (mg/g cheese) of fresh FF and LF cheeses prior to storage treatments for C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C18:1, and C18:2 were: 0.020, 0.072;0.070, 0.035;0.061, 0.055;0.181, 0.167;0.073, 0.047;0.174, 0.112;0.579, 0.152;0.308, 0.202;0.521, 0.174;and 0.057, 0.026, respectively. The respective FFA to total fatty acid ratios for 0, 1 and 3 months aged FF and LF cheeses were 8.44, 12.4;6.31, 16.91;12.03, 14.19. The LF cheeses generated more FFA than FF cheeses, while actual FFA content in FF cheese was significantly higher than in LF cheese. The FFA contents of LF cheese at 0, 1 and 3 months storage were 48.0, 96.8 and 36.4% of those of FF cheese, respectively. It was concluded LF cheese generated higher amount of FFA than FF cheese, although total FFA content was significantly (P<0.05) lower in LF cheese than in FF cheese.
