In three different dairies (A, B and C) located in Peloponess region (Southern Greece), traditional Feta cheese trials took place February to March using mixtures of sheep's and goat's milk. Only ...small variations in the evolution of microbial groups were observed during the whole ripening period. The main groups, such as thermophilic cocci, mesophilic lactococci, thermophilic lactobacilli, nonstarter lactic acid bacteria (NSLAB), presumptive
Leuconostoc, enterococci and micrococci, reached their highest levels during the first 16 days, and then declined approximately 1–2 log units until the end of ripening. The remaining groups investigated, comprising yeasts, coliforms and
Escherichia coli, were highest at day 4. The yeasts remained constant, while coliforms and
E. coli decreased sharply and were not detectable after 120 days of ripening. A number of 146 isolates (dairy A) taken from all stages of the manufacturing and ripening process were purified and studied.
Lactobacillus plantarum (58/146) and isolates of related species
Lactobacillus pentosus and
Lactobacillus paraplantarum (16/146) were the most common microorganisms found during cheese ripening.
Streptococcus thermophilus (23/146) and
Lactobacillus delbrueckii subsp.
bulgaricus (20/146) were detected in high levels up to 20 days, and then gradually reduced.
Enterococcus faecium (29/146) was found in all manufacturing and ripening stages.
Teleme cheese was made from ovine, caprine and bovine milk with thermophilic, mesophilic, and mixed thermophilic–mesophilic cultures. Nine lots of cheese each time were made in order to study the ...physico-chemical and sensory changes of cheeses throughout ripening and storage up to 6 months. The rate of pH decrease was the fastest in cheeses made with the mesophilic culture and the slowest in cheeses made with the thermophilic culture, regardless of the kind of milk used. Moisture was higher in cheeses made from cows’ milk than in cheeses made from the other two kinds of milk. The highest fat content and yield were in cheeses made from ewes’ milk not being affected by starter culture used, the highest protein content was in cheeses made from goats’ milk whereas salt content was not affected by either the kind of milk or starter culture used. The use of mesophilic or mixed cultures resulted in cheeses of higher flavour scores than those of cheeses made with thermophilic culture. It is concluded that all three kinds of milk may be used in making Teleme cheese preferably by using a mesophilic or a mixed thermophilic and mesophilic starter culture.
The objective of this work was to study the characteristics of the gastric aspartic proteinases chymosin and pepsin which are constituents of the kid rennet. The two enzymes were extracted from ...abomasal tissue of one kid from a local indigenous breed, separated from each other by DEAE-cellulose chromatography and then were purified by gel filtration and anion-exchange chromatography. The molecular weights of the purified kid chymosin and pepsin as determined by gel filtration were 36 kDa and 40 kDa respectively. The isoelectric point of kid chymosin was as multiple forms of 3-6 zones at pH 4.6-5.1, while that of kid pepsin was at pH less than or equal to 3.0. Kid pepsin contained 0.37 molecules phosphorous per molecule and was totally inhibited by 5 micromolar pepstatin A, being more sensitive than kid chymosin. Both enzymes were almost equally as proteolytic as calf chymosin on total casein at pH 5.6. Kid pepsin activity was more pH and temperature dependent than kid chymosin activity. In comparison with the calf chymosin temperature sensitivity, the order of increased sensitivity was: calf chymosin <kid chymosin <kid pepsin.
Acid whey filtrates from the bulk milk of different indigenous greek ovine and caprine breeds were investigated for the quantitative and qualitative characteristics of
α-lactalbumin (
α-LA) and
...β-lactoglobulin (
β-LG). For comparison reasons acid wheys from bovine milk and from Saanen and Alpine caprine breeds were included. The main characteristic of ovine acid wheys was the low
α-LA percentage. The
β-LG/
α-LA ratio of ovine acid wheys ranged from 3.91 in Chios breed to 6.65 in Boutsiko breed. It was higher than the estimate for bovine acid wheys which ranged from 3.09 to 3.37. The chromatographic and isoelectric focusing profiles of ovine
β-LG and
α-LA from the different breeds were also variable. The
β-LG percentage of caprine acid wheys was lower compared to ovine and bovine acid wheys. Their
β-LG/
α-LA ratios ranged from 2.02 in Saanen breed to 3.04 in the indigenous breed Skopelos.
The relative amounts of the major caseins in the total casein fraction from bulk milks of four different caprine breeds (two indigenous Greek and the highly selected Alpine and Saanen) were ...determined by alkaline urea polyacrylamide gel electrophoresis and by reversed-phase HPLC. Both methods revealed differences with regard to the α
s1-casein fraction of the different breeds. The estimated values, expressed as percentage of total caseins, ranged as follows: for α
s1-casein from 9.9% to 25.6%, for α
s2-casein from 12.5% to 18.9%, for β-casein from 51.1% to 58.4% and for κ-casein from 9.9% to 13.5%. The lowest α
s1-casein and the highest β-casein and κ-casein percentages were found in the casein fraction of the Saanen breed.
The separation of cows', sheep's and goats' milk casein components by HPLC on a strong anion-exchange (P.L-SAX 8 mu 1000A) column is described. During HLPC, whole caseins of the three kinds of milk ...behaved differently from conventional separations. The casein components of the three kinds of milk were well resolved under the chromatographic conditions used. HPLC resolved the kappa-caseins better than did ion-exchange chromatography on DEAE cellulose, and was particularly efficient in the case of goats' milk. Goats' and sheep's milks had almost similar chromatographic profiles but these differed considerably from that of cows' milk. Caseins from the sheep and the goat were also similar in that a shallower NaCl gradient was required for the separation of casein components than for cows' milk.
The objective of this work was to study the decrease of alkaline phosphatase (ALP) activity during heat treatment of ovine and caprine milk in comparison to that of bovine milk. For this purpose, ...different samples from the three milk kinds were subjected to heat treatment at 59
°C under different time conditions and the residual ALP activity was determined using the IDF reference method and the automated fluorimetric IDF method. The heat treatment reduced the ALP activity in bovine milk slower (
P
<
0.05) compared to that of the other two milk kinds, whereas the fastest decrease was observed in ovine milk. The lowest absolute values of ALP activity were observed in caprine milk before and after heat treatment. The results for ovine and caprine milk obtained by the two methods (reference and automated fluorimetric) were linearly correlated. This preliminary study indicates that the automated fluorimetric method can be used to analyze a high number of ovine and caprine milk samples taken at different stages of lactation period, with the aim to define the acceptable limits of residual ALP activity in pasteurized ovine and caprine milk.
Characteristics of goat milk collected from seven small and medium enterprises (SMEs) in Greece, France and Portugal were compared. Results of microbiological, biochemical and technological ...characteristics (whey draining capacity after lactic or rennet coagulation, acidification aspects, and heat stability) of goat milk with identical and standardised techniques are discussed in relation to effects on technological processes and quality of final products. Results revealed variability of goat milk characteristics collected from the different European areas. Hygienically, goat milk production conditions in Greece and Portugal, under extensive breeding systems were: total bacteria—3.6×10
7 and 4×10
7
CFU/ml; coliforms—1.8×10
6 and 2.5×10
6
CFU/ml; staphylococci coagulase+—1.7×10
5 and 7.6×10
4
CFU/ml, respectively. For France, using intensive breeding systems, microbiological quality was: total bacteria—1.08×10
5
CFU/ml; coliforms—1.40×10
2
CFU/ml; staphylococci coagulase+—2.75×10
2
CFU/ml. Goat milk from Greek farms had the highest fat and protein contents: 51.4 and 37.0
g/kg, compared to goat milk in France: 36.5 and 32.5
g/kg, respectively. Portuguese goat milk was intermediate: 42.7 and 34.9
g/kg, respectively.
Regarding technological aspects, Greek and Portuguese milks showed poor whey draining capacity and Greek milks presented low heat stability (100.5
°C on average) but a good propensity to acidify. Systems of production of goat milk, ways of transport of raw goat milk, and the procedures applied inside factories regarding receiving and storage of the raw goat milk are discussed and should be useful for the definition of technological adaptations, that are necessary for best milk and product quality.
