AIM:To assess whether there is a possible causal link between the intake of cheese and the risk of diabetic retinopathy(DR)utilizing a two-sample Mendelian randomization(MR)analysis.METHODS:The research data were obta...AIM:To assess whether there is a possible causal link between the intake of cheese and the risk of diabetic retinopathy(DR)utilizing a two-sample Mendelian randomization(MR)analysis.METHODS:The research data were obtained from summary statistics of genome-wide association studies(GWAS).Genetic loci closely related to cheese intake were extracted as instrumental variables(IVs),and DR was the outcome variable.The data were extracted from individuals of European ethnicity.The data of cheese intake consisted of 451486 samples with 9851867 single nucleotide polymorphisms(SNPs),while the DR data consisted of 206234 samples with 16380446 SNPs.Sixty-one genetic loci closely related to cheese intake were selected as IVs.MR analysis was performed by inverse-variance weighted(IVW)method and MR-Egger regression respectively.The causal relationship between cheese intake and DR was evaluated using odds ratios(ORs)and 95%confidence intervals(CIs).Egger-intercept test was used to test horizontal pleiotropy and sensitivity analysis was performed by leave-one-out test.RESULTS:The P value of the IVW method was less than 0.05,indicating a significant negative correlation between cheese intake and DR.MR-Egger regression showed that the intercept was 0.01 with a standard error of 0.022,and a P-value of 0.634,indicating no evidence of horizontal pleiotropy affecting the IVs related to the exposure factors.Besides,heterogeneity tests confirmed the absence of heterogeneity,and the“leave-one-out”sensitivity analysis demonstrated that the results were stable.CONCLUSION:Cheese intake is causally negatively correlated with the occurrence of DR,and cheese intake could reduce the risk of DR.展开更多
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
In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, ...In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, acid value of cheese, fat, salt, titratable acidity, pH levels in Mud cheeses were variable according to whey characteristics used in their production. Wide variations were found in the total bacteria, Coliform bacteria, Staphylococcus aureus, yeast-mould, Lactobacillus spp. and Streptococcus spp. counts of cheese samples. The presence of coliforms, Staph. aureus and yeast-moulds indicate poor hygienic conditions of cheese production.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
The Inca peanut, a plant native to the Peruvian Amazon, has an important nutritional contribution to 53% oil and 33% protein [ 1, 2], high content of Omega 3 and 6, Vitamin E. Recent research suggests the nutritional ...The Inca peanut, a plant native to the Peruvian Amazon, has an important nutritional contribution to 53% oil and 33% protein [ 1, 2], high content of Omega 3 and 6, Vitamin E. Recent research suggests the nutritional and therapeutic significance of consumption for the control of free radicals [3], being an alternative food to reduce nutritional deficiencies of macro and micronutrients in the diet. The results show that the cheese made from a mixture of milk and Inca peanut （70：20 v/v） 0.15 M of Ca sulphate is of firm consistency, with a clotting time of 9 min and yields 14.56% at 80 ℃, is similar to fresh milk cheese sensory characteristics determined by the test of acceptability. Respect to nutrition cheeses present values of protein and fat （16.3% and, 25.05%, respectively）. Sensory evaluation process cheese 70：30 v/v showed an acceptance of 67% relative to a commercial cheese. The texture profile of the finished product, applying a deformation of 30%, have hardness values for 1.88 N, elasticity 0.08, cohesiveness 0.86, adhesiveness 0.36, gumminess 1.62 and chewiness 0.13.展开更多
This study investigates the properties of cheeses made from camel milk, sheep milk and their mixtures. Cheeses were made using Camifloc enzyme as a coagulant after addition of calcium chloride. Camel＇s milk was mixed...This study investigates the properties of cheeses made from camel milk, sheep milk and their mixtures. Cheeses were made using Camifloc enzyme as a coagulant after addition of calcium chloride. Camel＇s milk was mixed with sheep＇s milk at the levels of 25%, 50% and 75%. Then, the cheeses were stored for 21 days in the whey at room temperature （37-40 ~C）. The study revealed that fortifying camel＇s milk with sheep＇s milk improved the processing properties of camel milk for cheese making. The addition of 50% sheep＇s milk to camel＇s milk reduced the coagulation time to about 46.15%. The addition of 25%, 50% and 75% sheep＇s milk to camel＇s milk revealed yield of 13.76%, 21.33% and 26.2%, respectively. However, the cheese made from pure camel＇s milk and sheep＇s milk revealed yield of 10.66% and 23.53%, respectively. There were significant （P 〈 0.001） differences in total solids, protein, fat, ash, acidity and overall acceptability among the cheeses made from different types of milk. The cheeses made from camel＇s milk after addition of 75% and 50% sheep＇s milk were the most acceptable compared to other cheeses. Hence sheep＇s milk could be added to camel＇s milk for improvement of cheese properties.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 colordifference. The results showed that increased blueberry content lowered pH value, remarkably transformed microstrucmre 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
The objective of this work was to study the influence of cooking time and cooling rate on functionality and microstructure of processed cheese spreads. When the cooking time was 20 min, the hardness and apparent visco...The objective of this work was to study the influence of cooking time and cooling rate on functionality and microstructure of processed cheese spreads. When the cooking time was 20 min, the hardness and apparent viscosity were increased, and formed a homogenous, dense, and three-dimensional protein network, and a stronger gel was formed at this time. The slow cooling can increase the hardness and apparent viscosity of products, protein wall was thicker, and network was closer, so products can formed a stronger gel structure. The influence of cooking time on the functional properties was more significant than the influence of rapid cooling.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
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
基金Supported by the National Natural Science Foundation of China(No.81960174)the Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2023GXNSFAA026154)the Youth Science Foundation of Guangxi Medical University(No.GXMUYSF201912).
文摘AIM:To assess whether there is a possible causal link between the intake of cheese and the risk of diabetic retinopathy(DR)utilizing a two-sample Mendelian randomization(MR)analysis.METHODS:The research data were obtained from summary statistics of genome-wide association studies(GWAS).Genetic loci closely related to cheese intake were extracted as instrumental variables(IVs),and DR was the outcome variable.The data were extracted from individuals of European ethnicity.The data of cheese intake consisted of 451486 samples with 9851867 single nucleotide polymorphisms(SNPs),while the DR data consisted of 206234 samples with 16380446 SNPs.Sixty-one genetic loci closely related to cheese intake were selected as IVs.MR analysis was performed by inverse-variance weighted(IVW)method and MR-Egger regression respectively.The causal relationship between cheese intake and DR was evaluated using odds ratios(ORs)and 95%confidence intervals(CIs).Egger-intercept test was used to test horizontal pleiotropy and sensitivity analysis was performed by leave-one-out test.RESULTS:The P value of the IVW method was less than 0.05,indicating a significant negative correlation between cheese intake and DR.MR-Egger regression showed that the intercept was 0.01 with a standard error of 0.022,and a P-value of 0.634,indicating no evidence of horizontal pleiotropy affecting the IVs related to the exposure factors.Besides,heterogeneity tests confirmed the absence of heterogeneity,and the“leave-one-out”sensitivity analysis demonstrated that the results were stable.CONCLUSION:Cheese intake is causally negatively correlated with the occurrence of DR,and cheese intake could reduce the risk of DR.
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.
文摘In this study, the basic composition and microbiological properties of traditional Mud （Gamur） cheese produced in Tire region of Turkey was evaluated. The total solids, fat, protein, water soluble nitrogen （WSN）, acid value of cheese, fat, salt, titratable acidity, pH levels in Mud cheeses were variable according to whey characteristics used in their production. Wide variations were found in the total bacteria, Coliform bacteria, Staphylococcus aureus, yeast-mould, Lactobacillus spp. and Streptococcus spp. counts of cheese samples. The presence of coliforms, Staph. aureus and yeast-moulds indicate poor hygienic conditions of cheese production.
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The Inca peanut, a plant native to the Peruvian Amazon, has an important nutritional contribution to 53% oil and 33% protein [ 1, 2], high content of Omega 3 and 6, Vitamin E. Recent research suggests the nutritional and therapeutic significance of consumption for the control of free radicals [3], being an alternative food to reduce nutritional deficiencies of macro and micronutrients in the diet. The results show that the cheese made from a mixture of milk and Inca peanut （70：20 v/v） 0.15 M of Ca sulphate is of firm consistency, with a clotting time of 9 min and yields 14.56% at 80 ℃, is similar to fresh milk cheese sensory characteristics determined by the test of acceptability. Respect to nutrition cheeses present values of protein and fat （16.3% and, 25.05%, respectively）. Sensory evaluation process cheese 70：30 v/v showed an acceptance of 67% relative to a commercial cheese. The texture profile of the finished product, applying a deformation of 30%, have hardness values for 1.88 N, elasticity 0.08, cohesiveness 0.86, adhesiveness 0.36, gumminess 1.62 and chewiness 0.13.
文摘This study investigates the properties of cheeses made from camel milk, sheep milk and their mixtures. Cheeses were made using Camifloc enzyme as a coagulant after addition of calcium chloride. Camel＇s milk was mixed with sheep＇s milk at the levels of 25%, 50% and 75%. Then, the cheeses were stored for 21 days in the whey at room temperature （37-40 ~C）. The study revealed that fortifying camel＇s milk with sheep＇s milk improved the processing properties of camel milk for cheese making. The addition of 50% sheep＇s milk to camel＇s milk reduced the coagulation time to about 46.15%. The addition of 25%, 50% and 75% sheep＇s milk to camel＇s milk revealed yield of 13.76%, 21.33% and 26.2%, respectively. However, the cheese made from pure camel＇s milk and sheep＇s milk revealed yield of 10.66% and 23.53%, respectively. There were significant （P 〈 0.001） differences in total solids, protein, fat, ash, acidity and overall acceptability among the cheeses made from different types of milk. The cheeses made from camel＇s milk after addition of 75% and 50% sheep＇s milk were the most acceptable compared to other cheeses. Hence sheep＇s milk could be added to camel＇s milk for improvement of cheese properties.
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 colordifference. The results showed that increased blueberry content lowered pH value, remarkably transformed microstrucmre 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.
基金Supported by Tackle Problem Project of Science and Technology Department of Heilongjiang Province (GC05B404)
文摘The objective of this work was to study the influence of cooking time and cooling rate on functionality and microstructure of processed cheese spreads. When the cooking time was 20 min, the hardness and apparent viscosity were increased, and formed a homogenous, dense, and three-dimensional protein network, and a stronger gel was formed at this time. The slow cooling can increase the hardness and apparent viscosity of products, protein wall was thicker, and network was closer, so products can formed a stronger gel structure. The influence of cooking time on the functional properties was more significant than the influence of rapid cooling.
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.
