Diarrhea has become the leading cause of illness and death among infants and young children in developing countries.Clinically,patients with diarrhea showed damaged intestinal epithelial villi,usually accompanied by l...Diarrhea has become the leading cause of illness and death among infants and young children in developing countries.Clinically,patients with diarrhea showed damaged intestinal epithelial villi,usually accompanied by lactase deficiency.In this study,we evaluated the therapeutic effects of lactose-free milk powder on rats and children with diarrhea.Antibiotic-associated diarrhea(AAD)model was established by gavage with antibiotic mixture in SD rats,followed by administration of milk powder containing lactose or not.The results showed that lactose-free milk powder ameliorated A AD-related diarrhea symptoms,and accelerated the recovery from diarrhea.And 16S sequencing results indicated lactose-free milk powder contributed to increase theα-andβ-diversity of intestinal flora,and restore the intestinal microbiota disorder.In conclusion,our data demonstrate that lactose-free milk powder could alleviate diarrhea by restoring gut microbiota and intestinal barrier function.展开更多
Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS f...Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS for the simultaneous quantification of 2 and 3-MCPD esters in infant milk powder and edible vegetable oils. The developed protocol included fat fraction in infant milk powder and edible vegetable oils samples was extracted and treated with sodium methylate-methanol to cleave the ester bonds of the 2- and 3-MCPD esters, moreover, standard samples of deuterium isotope-labeled 2- and 3-MCPD palmitic acid double esters and stearic acid double esters were used as the internal standards. Furthermore, this method was validated when it was applied to food products, concrete manifestation in its good accuracy (the recovery of MCPD esters ranged from 86% to 114%), high sensitivity (the LOD of 3-MCPD and 2-MCPD esters were 0.025 and 0.020 mg/kg, LOQ were 0.075, 0.060 mg/kg, respectively) and satisfactory repeatability (RSD below 6.8%) for all analytes. In the 150 commercial edible vegetable oils and infant formula milk powder samples, we obtained a preliminary profile of MCPD ester contamination.展开更多
Recycling of junks is positive for the environmental protection.Along with the proposal of three-child policy,purchase volume of milk powder surely will experience a drastic growth,and the milk powder spoon as an affi...Recycling of junks is positive for the environmental protection.Along with the proposal of three-child policy,purchase volume of milk powder surely will experience a drastic growth,and the milk powder spoon as an affiliated product will win the attention of parents.Against the background of consumption upgrading,consumers have had higher requirements on the humanization and safety design of products.Most of milk powder spoons on the market are plastic,and the disposal of waste milk powder spoon has gradually become a burden for the environment.Based on the environment-friendly and developmental concept,and also the characteristics of infant development,this paper proposed the“in-one”design,applied color and tactile designs into the milk powder design,chose food grade silicone to make the milk powder spoon not only a spoon but also a baby teether toy,so as to expand the service life and functions of the product,meet the requirements of saving energy,protecting environment and developing circular economy,which also to some extent reduces the burden on environment brought by plastics,improves the efficiency of junk recycling,and meet the individualized needs of consumers.展开更多
[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the...[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.展开更多
To detect urea content in milk powder, a nonlinear chemical fingerprint technique was developed. In our study, Belousov-Zhabotinsky oscillatory chemical reaction (B-Z) was performed using milk powder and malonic acid ...To detect urea content in milk powder, a nonlinear chemical fingerprint technique was developed. In our study, Belousov-Zhabotinsky oscillatory chemical reaction (B-Z) was performed using milk powder and malonic acid as main dissipative substances. The same dosage of milk powder with or without artificially added urea was introduced to “H+ + Ce4+ + + malonic acid” oscillating system, respectively, and nonlinear chemical fingerprints of different milk powder were thus obtained. The proposed method was based on a linear relationship between inductive time of non-linear chemical fingerprints and urea content in milk powder, which held when urea content in milk powder was in the range of 0 - 40 mg/g. A detection limit of 7.8 × 10<sup>-3</sup>mg/g was also obtained. Our results showed that the method could be used to certify urea content in milk powder without pretreatment of samples, which was more simple and economical compared with traditional methods.展开更多
Zinc is one of the trace elements necessary to the human body. It can produce an important effect on the growth of the human body, the intelligence, immunity, and the functions of internal secretion and metabolism. Be...Zinc is one of the trace elements necessary to the human body. It can produce an important effect on the growth of the human body, the intelligence, immunity, and the functions of internal secretion and metabolism. Bezoar acid is one of the amino acid necessary to the body, especially to babies. It plays an important part in helping the growth of the brains, the work of the nervous system, and the functions of the eyes.展开更多
Qingshan brand milk powder with teais produced by the Inner Mongolia QingshanMilk Holdings Co.Ltd.It is prepared on thebasis of the original taste of Inner Mongolianmilk with tea and a folk tonic prescription.The fres...Qingshan brand milk powder with teais produced by the Inner Mongolia QingshanMilk Holdings Co.Ltd.It is prepared on thebasis of the original taste of Inner Mongolianmilk with tea and a folk tonic prescription.The fresh milk and fine pressed tea areprocessed into a powder through sterilizing,vacuum-condensing and dry spraying.展开更多
Major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined by ICP OES method, from these elements 9 elements determined by INAA. The determination of...Major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined by ICP OES method, from these elements 9 elements determined by INAA. The determination of trace element contents of foodstuffs, especially milk as daily drink for all peoples age which being a complex food has great importance. The elemental analysis of milk is important both as an indicator of environmental contamination and because milk is a significant pathway for toxic metal intake and a source of essential nutrients for humans. The major elements are Ca, K, Mg, Na, P and S. While trace element are B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se, Sn, Sr, V, W and Zn. ICP OES technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the milk powders mentioned and comparative results of other direct technique such as instrumental neutron activation analysis. Analysis of both standard reference material A 11 milk powder and NBS Orchard leaves for quality accurance had been completed, and used for a relative method calculate. The importance of the major and trace elements to human health was discussed.展开更多
A FAST (fluorescence of advanced Maillard products and Soluble Tryptophan) method for identification of recon- stituted milk made from skim milk powder in the fresh milk was developed. Considering milk and skim milk p...A FAST (fluorescence of advanced Maillard products and Soluble Tryptophan) method for identification of recon- stituted milk made from skim milk powder in the fresh milk was developed. Considering milk and skim milk powders variations from different seasons and countries, milk was collected from different dairy farms in different seasons and skim milk powders were collected from different countries to measure the Tryptophan (Trp), advanced Maillard products (AMP) fluorescence values. The results showed that there were differences (P<0.01) between raw and reconstituted milk. The plot of values in each mixed level of raw and reconstituted milk had a correlation coefficient >0.97. The FAST method is a simple, rapid, low-cost and sensitive method enabling the detection of 5% reconstituted milk in fresh milk. The measurement of the Trp, AMP fluorescence values and calculation of the FAST index is a suitable method for large-scale monitoring of fresh milk samples.展开更多
Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive a...Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.展开更多
At present,heavy metal pollution in food occurs frequently,which requires a novel method for rapid detection. Laser induced breakdown spectroscopy( LIBS) is a new technique for rapid and environmental friendly detecti...At present,heavy metal pollution in food occurs frequently,which requires a novel method for rapid detection. Laser induced breakdown spectroscopy( LIBS) is a new technique for rapid and environmental friendly detection,but it lacks high sensitivity and stability which restrict its development. In this study,Cr-polluted infant milk powder was used as experimental material to explore the feasibility of the application of LIBS technique in food safety detection. Aiming at improving the precision and accuracy of Cr detection by LIBS technique,LIBS spectra of samples were collected by a spectrometer with an intensified charge-coupled device( ICCD) using three gratings with different resolutions to comprehensively compare and analyze the stability,sensitivity and quantitative analysis accuracy of LIBS detection. The results showed that average relative standard deviation( RSD) of LIBS spectral intensity was below 10%,indicating good stability. LIBS signals were collected by three gratings for quantitative analysis,and the results demonstrated that the linear correlation coefficient R^2 of fitting curves was0. 248 87,0. 903 12 and 0. 992 81,respectively; the relative errors between actual and predicted concentrations were 38. 23%,8. 84% and 7. 43%,respectively,indicating that gratings with higher resolutions could lead to higher linear correlation coefficient and better detection accuracy. According to the results,high-resolution spectrometer could significantly improve the accuracy of LIBS detection of Cr concentration in milk powder,suggesting that it is feasible to detect heavy metals in food by LIBS technique with the improvement of core device performance.展开更多
The objectives of this study were to develop a probiotic milk powder containing Lactobacillus plantarum NCIMB 8826 immobilized with prebiotic Hi-maize starch and to analyze cell viability after spray drying and exposu...The objectives of this study were to develop a probiotic milk powder containing Lactobacillus plantarum NCIMB 8826 immobilized with prebiotic Hi-maize starch and to analyze cell viability after spray drying and exposure to simulated gastric and intestinal conditions.Milk powders containing free L.plantarum and cells immobilized with Hi-maize starch were assessed.Powders were evaluated during storage at 4°C for 15 days.After spray drying,at 0 and 15 days of storage both treatments had over 8 log CFU/g of viable cells and there were higher viable counts found for immobilized cells compared to free cells after 120 min in simulated gastric fluid.At 15 days of storage,immobilized cells had higher viable counts than free cells after exposure to simulated intestinal fluid for 120 min.The combined probiotic and prebiotic milk powder had stable viable cell counts at refrigerated storage conditions and under simulated gastric and intestinal transit.展开更多
The exposure to perfluorinated compounds (PFCs) through the diet for humans is of great concern. Among the diet, dairy products are in great demand. This paper reports the study on the levels of 9 perfluorinated acids...The exposure to perfluorinated compounds (PFCs) through the diet for humans is of great concern. Among the diet, dairy products are in great demand. This paper reports the study on the levels of 9 perfluorinated acids and 2 fluorotelomer acids in milk, milk powder and yoghurt purchased from Chinese markets from 2008 to 2009. The analytes were quantitated by high performance liquid chromatography/electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). In milk samples, perfluoroheptanoic acid (PFHpA) and perfluorononanoic acid (PFNA) were detected frequently, both in 68% of samples. In milk powder samples, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and PFNA were the only detected PFCs and none of them was observed in more than 35% of samples. In yoghurt, PFOA was the most frequently detected compound, found in 69% of samples. None of fluorotelomer acids was observed in any samples. The mean concentrations of total PFCs were 178 pg/g (wet weight) in milk, 98 pg/g (dry weight) in milk powder and 42 pg/g in yoghurt (wet weight). It is notable that the data of this study indicate significant differences (P<0.001) among three kinds of packaging of milk in the concentration of total PFCs. A preliminary human health risk assessment of milk and dairy products consumption was conducted in this study. For adults, the mean daily intake of PFOS and total PFCs was equal to or lower than 23 and 167 pg kg-1 d-1 (body weight), respectively.展开更多
Infant formula provides the largest, if not sole, source of nutrition for an extended interval;the nutritional adequacy of the formula must be confirmed and the indications for its use were well understood. Both iron ...Infant formula provides the largest, if not sole, source of nutrition for an extended interval;the nutritional adequacy of the formula must be confirmed and the indications for its use were well understood. Both iron deficiency and iron excess during the fetal and neonatal period bode poorly for developing organ systems. Voltammetry is analytical method based on current potential measurements in electrochemical cells. In this study the concentration of iron in four brands of powder milk and baby food (based on rice and based on wheat) was analyzed with DPASV and voltammeter device. Total Means ± SE of Iron in baby foods and powder milk (n = 40) were 8.55 ± 1.18 mg/100g, 5.21 ± 0.66 respectively. Iron level in baby food type I and II was lower than labeled value (p p < 0.05).展开更多
基金supported by the project of two children’s dairy products (201704810610483)。
文摘Diarrhea has become the leading cause of illness and death among infants and young children in developing countries.Clinically,patients with diarrhea showed damaged intestinal epithelial villi,usually accompanied by lactase deficiency.In this study,we evaluated the therapeutic effects of lactose-free milk powder on rats and children with diarrhea.Antibiotic-associated diarrhea(AAD)model was established by gavage with antibiotic mixture in SD rats,followed by administration of milk powder containing lactose or not.The results showed that lactose-free milk powder ameliorated A AD-related diarrhea symptoms,and accelerated the recovery from diarrhea.And 16S sequencing results indicated lactose-free milk powder contributed to increase theα-andβ-diversity of intestinal flora,and restore the intestinal microbiota disorder.In conclusion,our data demonstrate that lactose-free milk powder could alleviate diarrhea by restoring gut microbiota and intestinal barrier function.
文摘Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS for the simultaneous quantification of 2 and 3-MCPD esters in infant milk powder and edible vegetable oils. The developed protocol included fat fraction in infant milk powder and edible vegetable oils samples was extracted and treated with sodium methylate-methanol to cleave the ester bonds of the 2- and 3-MCPD esters, moreover, standard samples of deuterium isotope-labeled 2- and 3-MCPD palmitic acid double esters and stearic acid double esters were used as the internal standards. Furthermore, this method was validated when it was applied to food products, concrete manifestation in its good accuracy (the recovery of MCPD esters ranged from 86% to 114%), high sensitivity (the LOD of 3-MCPD and 2-MCPD esters were 0.025 and 0.020 mg/kg, LOQ were 0.075, 0.060 mg/kg, respectively) and satisfactory repeatability (RSD below 6.8%) for all analytes. In the 150 commercial edible vegetable oils and infant formula milk powder samples, we obtained a preliminary profile of MCPD ester contamination.
基金Sponsored by 2022 Teaching Reform Project of Lingnan Normal University(000302201830)2022 Model Course of Lingnan Normal University(LingShiJiaoWu(2014)No.125)2023 Undergraduate Students’Innovation and entrepreneurship Planning of Lingnan Normal University(X202310579049X).
文摘Recycling of junks is positive for the environmental protection.Along with the proposal of three-child policy,purchase volume of milk powder surely will experience a drastic growth,and the milk powder spoon as an affiliated product will win the attention of parents.Against the background of consumption upgrading,consumers have had higher requirements on the humanization and safety design of products.Most of milk powder spoons on the market are plastic,and the disposal of waste milk powder spoon has gradually become a burden for the environment.Based on the environment-friendly and developmental concept,and also the characteristics of infant development,this paper proposed the“in-one”design,applied color and tactile designs into the milk powder design,chose food grade silicone to make the milk powder spoon not only a spoon but also a baby teether toy,so as to expand the service life and functions of the product,meet the requirements of saving energy,protecting environment and developing circular economy,which also to some extent reduces the burden on environment brought by plastics,improves the efficiency of junk recycling,and meet the individualized needs of consumers.
文摘[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.
文摘To detect urea content in milk powder, a nonlinear chemical fingerprint technique was developed. In our study, Belousov-Zhabotinsky oscillatory chemical reaction (B-Z) was performed using milk powder and malonic acid as main dissipative substances. The same dosage of milk powder with or without artificially added urea was introduced to “H+ + Ce4+ + + malonic acid” oscillating system, respectively, and nonlinear chemical fingerprints of different milk powder were thus obtained. The proposed method was based on a linear relationship between inductive time of non-linear chemical fingerprints and urea content in milk powder, which held when urea content in milk powder was in the range of 0 - 40 mg/g. A detection limit of 7.8 × 10<sup>-3</sup>mg/g was also obtained. Our results showed that the method could be used to certify urea content in milk powder without pretreatment of samples, which was more simple and economical compared with traditional methods.
文摘Zinc is one of the trace elements necessary to the human body. It can produce an important effect on the growth of the human body, the intelligence, immunity, and the functions of internal secretion and metabolism. Bezoar acid is one of the amino acid necessary to the body, especially to babies. It plays an important part in helping the growth of the brains, the work of the nervous system, and the functions of the eyes.
文摘Qingshan brand milk powder with teais produced by the Inner Mongolia QingshanMilk Holdings Co.Ltd.It is prepared on thebasis of the original taste of Inner Mongolianmilk with tea and a folk tonic prescription.The fresh milk and fine pressed tea areprocessed into a powder through sterilizing,vacuum-condensing and dry spraying.
文摘Major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined by ICP OES method, from these elements 9 elements determined by INAA. The determination of trace element contents of foodstuffs, especially milk as daily drink for all peoples age which being a complex food has great importance. The elemental analysis of milk is important both as an indicator of environmental contamination and because milk is a significant pathway for toxic metal intake and a source of essential nutrients for humans. The major elements are Ca, K, Mg, Na, P and S. While trace element are B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se, Sn, Sr, V, W and Zn. ICP OES technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the milk powders mentioned and comparative results of other direct technique such as instrumental neutron activation analysis. Analysis of both standard reference material A 11 milk powder and NBS Orchard leaves for quality accurance had been completed, and used for a relative method calculate. The importance of the major and trace elements to human health was discussed.
基金Project (No. 2002BA518A06) supported by the Hi-Tech Researchand Development Program (863) of China
文摘A FAST (fluorescence of advanced Maillard products and Soluble Tryptophan) method for identification of recon- stituted milk made from skim milk powder in the fresh milk was developed. Considering milk and skim milk powders variations from different seasons and countries, milk was collected from different dairy farms in different seasons and skim milk powders were collected from different countries to measure the Tryptophan (Trp), advanced Maillard products (AMP) fluorescence values. The results showed that there were differences (P<0.01) between raw and reconstituted milk. The plot of values in each mixed level of raw and reconstituted milk had a correlation coefficient >0.97. The FAST method is a simple, rapid, low-cost and sensitive method enabling the detection of 5% reconstituted milk in fresh milk. The measurement of the Trp, AMP fluorescence values and calculation of the FAST index is a suitable method for large-scale monitoring of fresh milk samples.
基金supported by the National Natural Science Foundation of China (No: 81230079, 81102414, 81227802)the Natural Science Basic Research Plan in Shaanxi Province of China (Program No. 2017JQ8024)
文摘Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.
文摘At present,heavy metal pollution in food occurs frequently,which requires a novel method for rapid detection. Laser induced breakdown spectroscopy( LIBS) is a new technique for rapid and environmental friendly detection,but it lacks high sensitivity and stability which restrict its development. In this study,Cr-polluted infant milk powder was used as experimental material to explore the feasibility of the application of LIBS technique in food safety detection. Aiming at improving the precision and accuracy of Cr detection by LIBS technique,LIBS spectra of samples were collected by a spectrometer with an intensified charge-coupled device( ICCD) using three gratings with different resolutions to comprehensively compare and analyze the stability,sensitivity and quantitative analysis accuracy of LIBS detection. The results showed that average relative standard deviation( RSD) of LIBS spectral intensity was below 10%,indicating good stability. LIBS signals were collected by three gratings for quantitative analysis,and the results demonstrated that the linear correlation coefficient R^2 of fitting curves was0. 248 87,0. 903 12 and 0. 992 81,respectively; the relative errors between actual and predicted concentrations were 38. 23%,8. 84% and 7. 43%,respectively,indicating that gratings with higher resolutions could lead to higher linear correlation coefficient and better detection accuracy. According to the results,high-resolution spectrometer could significantly improve the accuracy of LIBS detection of Cr concentration in milk powder,suggesting that it is feasible to detect heavy metals in food by LIBS technique with the improvement of core device performance.
文摘The objectives of this study were to develop a probiotic milk powder containing Lactobacillus plantarum NCIMB 8826 immobilized with prebiotic Hi-maize starch and to analyze cell viability after spray drying and exposure to simulated gastric and intestinal conditions.Milk powders containing free L.plantarum and cells immobilized with Hi-maize starch were assessed.Powders were evaluated during storage at 4°C for 15 days.After spray drying,at 0 and 15 days of storage both treatments had over 8 log CFU/g of viable cells and there were higher viable counts found for immobilized cells compared to free cells after 120 min in simulated gastric fluid.At 15 days of storage,immobilized cells had higher viable counts than free cells after exposure to simulated intestinal fluid for 120 min.The combined probiotic and prebiotic milk powder had stable viable cell counts at refrigerated storage conditions and under simulated gastric and intestinal transit.
基金supported by the Major Research Program of Chinese Academy of Sciences (Grant No. KZCX2-YW-420-1)National High-Technology Research and Development Program of China (Grant No. 2007AA06Z405)+1 种基金National Natural Science Foundation of China (Grant Nos. 20837003 and 20890111)the National Basic Research Program of China (Grant No.2009CB421605)
文摘The exposure to perfluorinated compounds (PFCs) through the diet for humans is of great concern. Among the diet, dairy products are in great demand. This paper reports the study on the levels of 9 perfluorinated acids and 2 fluorotelomer acids in milk, milk powder and yoghurt purchased from Chinese markets from 2008 to 2009. The analytes were quantitated by high performance liquid chromatography/electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). In milk samples, perfluoroheptanoic acid (PFHpA) and perfluorononanoic acid (PFNA) were detected frequently, both in 68% of samples. In milk powder samples, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and PFNA were the only detected PFCs and none of them was observed in more than 35% of samples. In yoghurt, PFOA was the most frequently detected compound, found in 69% of samples. None of fluorotelomer acids was observed in any samples. The mean concentrations of total PFCs were 178 pg/g (wet weight) in milk, 98 pg/g (dry weight) in milk powder and 42 pg/g in yoghurt (wet weight). It is notable that the data of this study indicate significant differences (P<0.001) among three kinds of packaging of milk in the concentration of total PFCs. A preliminary human health risk assessment of milk and dairy products consumption was conducted in this study. For adults, the mean daily intake of PFOS and total PFCs was equal to or lower than 23 and 167 pg kg-1 d-1 (body weight), respectively.
文摘Infant formula provides the largest, if not sole, source of nutrition for an extended interval;the nutritional adequacy of the formula must be confirmed and the indications for its use were well understood. Both iron deficiency and iron excess during the fetal and neonatal period bode poorly for developing organ systems. Voltammetry is analytical method based on current potential measurements in electrochemical cells. In this study the concentration of iron in four brands of powder milk and baby food (based on rice and based on wheat) was analyzed with DPASV and voltammeter device. Total Means ± SE of Iron in baby foods and powder milk (n = 40) were 8.55 ± 1.18 mg/100g, 5.21 ± 0.66 respectively. Iron level in baby food type I and II was lower than labeled value (p p < 0.05).
