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Changes in the microflora and physicochemical characteristics in Serra da Estrela cheese were examined using a three-way factorial design over a 35 day ripening period, throughout the lactation period, and for several slices taken...
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Changes in the microflora and physicochemical characteristics in Serra da Estrela cheese were examined using a three-way factorial design over a 35 day ripening period, throughout the lactation period, and for several slices taken normal to the cheese axis. Lactic acid bacteria were the major components of the microflora during ripening throughout the lactation period, but no statistically significant differences were detected between the surface and the interior of the cheese. Both enterobacteriaceae and staphylococci in the curd were at maximum numbers during the first week and were still at significant numbers towards the end of the maturation period. The numbers of staphylococci were statistically different between slices and at different times within the lactation period, whereas the numbers of enterobacteriaceae showed statistically significant variations only throughout the lactation period. Ripening time, lactation period and axial location significantly affected the number of yeasts. All factors studied had statistically significant effects on pH, salt and moisture content; the hypotheses that ripening time, lactation period, and axial location had effects on salt and moisture contents were accepted, in this order, at increasingly lower levels of significance; the hypotheses that ripening time, axial location, and lactation period had effects on pH were accepted, in this order, at increasingly lower levels of significance.
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Ewe raw milk composition, rennet coagulation parameters, and curd texture were monitored throughout the milk production season in 11 commercial flocks reared under a part-time grazing system. Milking season lasted from February to...
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Ewe raw milk composition, rennet coagulation parameters, and curd texture were monitored throughout the milk production season in 11 commercial flocks reared under a part-time grazing system. Milking season lasted from February to July. During that period, the diet of the animals shifted from indoor feeding, consisting of concentrate and forage, to an outdoor grazing diet. Lean dry matter, fat, protein, calcium, and magnesium contents increased throughout the milking season, as did rennet coagulation time, curd firmness, and curd resistance to compression. However, lean dry matter, protein content, and curd resistance to compression stabilized when sheep started to graze. Principal component analysis correlated curd resistance to compression and proteins, whereas curd firmness was highly correlated with fat content and minerals. Discriminant analysis distributed milk samples according to the feeding management. Curd firmness, fat, and magnesium turned out to be discriminant variables. Those variables reflected the evolution of the composition and coagulation parameters when fresh pasture prevailed over other feeds in the diet of the flocks. The present study shows that seasonal changes associated with feeding management influence milk technological quality and that milk of good processing quality can be obtained under part-time grazing.
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk...
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk was determined using GC and individual CLA isomers were analysed using Ag+-HPLC. Fat from Azeitao, Nisa and Evora cheese varieties showed some differences in FA composition, in particular contents of oleic were 15.4, 17.1 and 19.7 g/100 g, respectively, for Azeitao, Evora and Nisa cheese varieties with extended ripening. Also, some differences were observed in CLA isomer contents, with total CLA concn. reaching 1.15 g/100 g for Nisa cheese, while Azeitao cheese had a lower total CLAconcn. of 0.90 g/100 g. Contents of oleic and stearic acids, monounsaturated fatty acids (MUFA) and CLA were significantly higher for Nisa cheese. Also, significant differences were found between milk and cheese samples, especially for MUFA (21.0 g/100 g for milk and 17.5 g/100 g for 3 month old cheese) and trans fatty acids (3.98 g/100 g for milk and 4.57 g/100 g for 3 month old Azeitao cheese). Contents of the 2 major CLA isomers (cis-9,trans-11 and trans-7,cis-9) were also affected by cheesemaking, particularly for Nisa cheese, as suggested by the significant differences obtained for cis-9,trans-11 levels (68.7 mg/g of fat for milk and 73.8 mg/g of fat for 3 month old cheese) and for trans-7,cis-9 levels (15.8 mg/g of fat for milk and 10.1 mg/g of fat for 3 month old cheese). In addition, the relatively high contents of CLA and low values for the n-6/n-3 ratio suggest good health-related parameters. However, the PUFA/saturated fatty acids (PUFA/SFA index) ratio of 0.06 was consistently below recommended guidelines for the human diet (0.45).
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摘要 :
The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk...
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk was determined using GC and individual CLA isomers were analysed using Ag+-HPLC. Fat from Azeitao, Nisa and Evora cheese varieties showed some differences in FA composition, in particular contents of oleic were 15.4, 17.1 and 19.7 g/100 g, respectively, for Azeitao, Evora and Nisa cheese varieties with extended ripening. Also, some differences were observed in CLA isomer contents, with total CLA concn. reaching 1.15 g/100 g for Nisa cheese, while Azeitao cheese had a lower total CLAconcn. of 0.90 g/100 g. Contents of oleic and stearic acids, monounsaturated fatty acids (MUFA) and CLA were significantly higher for Nisa cheese. Also, significant differences were found between milk and cheese samples, especially for MUFA (21.0 g/100 g for milk and 17.5 g/100 g for 3 month old cheese) and trans fatty acids (3.98 g/100 g for milk and 4.57 g/100 g for 3 month old Azeitao cheese). Contents of the 2 major CLA isomers (cis-9,trans-11 and trans-7,cis-9) were also affected by cheesemaking, particularly for Nisa cheese, as suggested by the significant differences obtained for cis-9,trans-11 levels (68.7 mg/g of fat for milk and 73.8 mg/g of fat for 3 month old cheese) and for trans-7,cis-9 levels (15.8 mg/g of fat for milk and 10.1 mg/g of fat for 3 month old cheese). In addition, the relatively high contents of CLA and low values for the n-6/n-3 ratio suggest good health-related parameters. However, the PUFA/saturated fatty acids (PUFA/SFA index) ratio of 0.06 was consistently below recommended guidelines for the human diet (0.45).
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摘要 :
The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk...
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk was determined using GC and individual CLA isomers were analysed using Ag+-HPLC. Fat from Azeitao, Nisa and Evora cheese varieties showed some differences in FA composition, in particular contents of oleic were 15.4, 17.1 and 19.7 g/100 g, respectively, for Azeitao, Evora and Nisa cheese varieties with extended ripening. Also, some differences were observed in CLA isomer contents, with total CLA concn. reaching 1.15 g/100 g for Nisa cheese, while Azeitao cheese had a lower total CLAconcn. of 0.90 g/100 g. Contents of oleic and stearic acids, monounsaturated fatty acids (MUFA) and CLA were significantly higher for Nisa cheese. Also, significant differences were found between milk and cheese samples, especially for MUFA (21.0 g/100 g for milk and 17.5 g/100 g for 3 month old cheese) and trans fatty acids (3.98 g/100 g for milk and 4.57 g/100 g for 3 month old Azeitao cheese). Contents of the 2 major CLA isomers (cis-9,trans-11 and trans-7,cis-9) were also affected by cheesemaking, particularly for Nisa cheese, as suggested by the significant differences obtained for cis-9,trans-11 levels (68.7 mg/g of fat for milk and 73.8 mg/g of fat for 3 month old cheese) and for trans-7,cis-9 levels (15.8 mg/g of fat for milk and 10.1 mg/g of fat for 3 month old cheese). In addition, the relatively high contents of CLA and low values for the n-6/n-3 ratio suggest good health-related parameters. However, the PUFA/saturated fatty acids (PUFA/SFA index) ratio of 0.06 was consistently below recommended guidelines for the human diet (0.45).
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摘要 :
The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk...
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk was determined using GC and individual CLA isomers were analysed using Ag+-HPLC. Fat from Azeitao, Nisa and Evora cheese varieties showed some differences in FA composition, in particular contents of oleic were 15.4, 17.1 and 19.7 g/100 g, respectively, for Azeitao, Evora and Nisa cheese varieties with extended ripening. Also, some differences were observed in CLA isomer contents, with total CLA concn. reaching 1.15 g/100 g for Nisa cheese, while Azeitao cheese had a lower total CLAconcn. of 0.90 g/100 g. Contents of oleic and stearic acids, monounsaturated fatty acids (MUFA) and CLA were significantly higher for Nisa cheese. Also, significant differences were found between milk and cheese samples, especially for MUFA (21.0 g/100 g for milk and 17.5 g/100 g for 3 month old cheese) and trans fatty acids (3.98 g/100 g for milk and 4.57 g/100 g for 3 month old Azeitao cheese). Contents of the 2 major CLA isomers (cis-9,trans-11 and trans-7,cis-9) were also affected by cheesemaking, particularly for Nisa cheese, as suggested by the significant differences obtained for cis-9,trans-11 levels (68.7 mg/g of fat for milk and 73.8 mg/g of fat for 3 month old cheese) and for trans-7,cis-9 levels (15.8 mg/g of fat for milk and 10.1 mg/g of fat for 3 month old cheese). In addition, the relatively high contents of CLA and low values for the n-6/n-3 ratio suggest good health-related parameters. However, the PUFA/saturated fatty acids (PUFA/SFA index) ratio of 0.06 was consistently below recommended guidelines for the human diet (0.45).
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摘要 :
The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk...
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The composition and nutritional quality of fat in 3 Protected Designation of Origin (PDO) Portuguese ewe cheese varieties, namely Azeitao, Nisa and Evora, were determined. Fatty acids (FA) composition of cheese and raw cheese milk was determined using GC and individual CLA isomers were analysed using Ag+-HPLC. Fat from Azeitao, Nisa and Evora cheese varieties showed some differences in FA composition, in particular contents of oleic were 15.4, 17.1 and 19.7 g/100 g, respectively, for Azeitao, Evora and Nisa cheese varieties with extended ripening. Also, some differences were observed in CLA isomer contents, with total CLA concn. reaching 1.15 g/100 g for Nisa cheese, while Azeitao cheese had a lower total CLAconcn. of 0.90 g/100 g. Contents of oleic and stearic acids, monounsaturated fatty acids (MUFA) and CLA were significantly higher for Nisa cheese. Also, significant differences were found between milk and cheese samples, especially for MUFA (21.0 g/100 g for milk and 17.5 g/100 g for 3 month old cheese) and trans fatty acids (3.98 g/100 g for milk and 4.57 g/100 g for 3 month old Azeitao cheese). Contents of the 2 major CLA isomers (cis-9,trans-11 and trans-7,cis-9) were also affected by cheesemaking, particularly for Nisa cheese, as suggested by the significant differences obtained for cis-9,trans-11 levels (68.7 mg/g of fat for milk and 73.8 mg/g of fat for 3 month old cheese) and for trans-7,cis-9 levels (15.8 mg/g of fat for milk and 10.1 mg/g of fat for 3 month old cheese). In addition, the relatively high contents of CLA and low values for the n-6/n-3 ratio suggest good health-related parameters. However, the PUFA/saturated fatty acids (PUFA/SFA index) ratio of 0.06 was consistently below recommended guidelines for the human diet (0.45).
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The volatile profile of the Spanish soft cheese of the Protected Designation of Origin (PDO) Torta del Casar, made from raw ewes' milk, was studied in four different stages of ripening (1, 30, 60 and 90 days) by the method of SPME...
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The volatile profile of the Spanish soft cheese of the Protected Designation of Origin (PDO) Torta del Casar, made from raw ewes' milk, was studied in four different stages of ripening (1, 30, 60 and 90 days) by the method of SPME-GC-MS. A total of 46 compounds were detected: 13 acids, 9 esters, 4 ketones, 7 alcohols, 3 aldehydes, 7 aromatic compounds and 3 compounds which could not be classified into those groups. Carboxylic acids were the most abundant group isolated; their levels significantly increased during ripening and comprised 61.5% of the total aroma extract at the end of ripening. At day 90, acids of microbial origin were the most abundant, followed by acids derived from amino acids while acids from lipolysis of triglycerides were the least abundant. Esters were the next most important group and their amount also increased significantly during maturation, as did ketones, while alcohols content slightly decreased at the end of the ripening. At day 90, the compounds at highest levels were acetic acid, 3-methylbutanoic acid, butanoic acid propyl ester and 2-butan-one; so these compounds, due to their high levels and their low threshold value could play an important role in the final aromatic profile of this cheese.
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The formation of volatile compounds in fresh cheese by 10 Enterobacteriaceae strains of dairy origin (4 Hafnia alvei, 2 Serratia liquefaciens, 1 Enterobacter cloacae, 1 Enterobacter sakazakii, and 2 Escherichia coli strains) was i...
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The formation of volatile compounds in fresh cheese by 10 Enterobacteriaceae strains of dairy origin (4 Hafnia alvei, 2 Serratia liquefaciens, 1 Enterobacter cloacae, 1 Enterobacter sakazakii, and 2 Escherichia coli strains) was investigated. Small cheeses were made from pasteurized cow's milk separately inoculated with 1-3 x 10(3) CFU/ml of each of the Enterobacteriaceae strains, with glucono-delta-lactone added to achieve a pH value of 5.2 in the curds. All strains reached counts close to 10(8) CFU/g in 1-day-old cheeses and survived well from day 1 to day 8. Cheeses were analyzed for volatile compounds by gas chromatography-mass spectroscopy, after extraction by dynamic headspace using a purge and trap apparatus. Sixty-one volatile compounds were determined in cheeses, 31 of which were further investigated. Significant increases of aldehydes, sulfur compounds, and aromatic compounds were recorded from 2-h curd to 1-day-old cheese, and of ketones, alcohols, and acids from 2-h curd to 8-day-old cheese. Acetaldehyde, 2-methyl propanal, and 3-methyl butanal predominated among aldehydes; 2,3-butanedione, 2,3-pentanedione, and 3-hydroxy 2-butanone among ketones; ethanol, 2-methyl propanol, and 3-methyl butanol among alcohols; and ethyl acetate among esters. Hierarchical cluster analysis of strains using the data of 31 volatile compounds separated clearly the strain of E. sakazakii, which produced high amounts of volatile compounds, from the other Enterobacteriaceae strains.
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The aim of this study was to map the actual iodine status and its seasonal differences in raw milk of dairy cows, sheep and goats from various regions of Slovakia. Iodine concentrations were determined in 457, 78 and 16 samples of...
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The aim of this study was to map the actual iodine status and its seasonal differences in raw milk of dairy cows, sheep and goats from various regions of Slovakia. Iodine concentrations were determined in 457, 78 and 16 samples of raw milk from dairy cows, sheep and goats collected in various regions of Slovakia from 2002-07. Among the 457 samples of bovine milk, iodine content below 50 micro g/litre was recorded in 114 samples (24.94%). Moreover, 294 samples (64.33%) had an iodine content rangingfrom 50 to 200 micro g/litre, and 19 samples (4.16%) had an iodine content ranging from 200 to 500 micro g/litre. 17 samples (3.72%) had iodine contents between 500 and 1000 micro g/litre, and 13 samples (2.85%) showed iodine concentrations over 1000 micro g/litre. Regional concentrations showed the highest values in the western Slovakia, followed by the middle and eastern Slovakia and the lowest values in northern Slovakia (p<0.05, p<0.01). In sheep and goat milk samples, iodine concentrations were below 80 micro g/litre in 49 sheep (62.8%) and below 60 micro g/litre in 6 goats (37.5%), indicating iodine deficiency. When comparing seasonal differences, sheep and goat milk had higher iodine content during the winter feeding period. However, the opposite ratio was recorded in dairy cows. Except for goat milk (p<0.01), the seasonal differences were insignificant.
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