The influence of GDL concentration on milk pH change during acid coagulation

Skim milk powder was reconstituted to obtain milk A (with 8.01% TS). Milk A was standardized with 3% of skim milk powder and 3% of demineralized whey powder (DWP), respectively, to obtain milk B (with 11.15% TS) and milk C (with 11.10% TS). Milk samples were heat treated at 85?C/10 min, 90?C/10 min and 95?C/10 min, respectively. Untreated milk was used as control. Acidification was carried out at 25?C, 35?C and 45?C during 240 min with GDL (glucono-d-lactone), namely with the amount of 0.5%, 0.75%, 1.0%, 1.25% 1.5%, 1.75%, 2.0% and 3.0% of GDL, respectively. The results showed that all investigated factors, explicitly GDL concentration, acidification temperature and applied heat treatment of milk as well as added DWP influence the change of pH during acidification. Milk samples standardized with DWP had smaller buffer capacity and faster change of pH than samples standardized with skim milk powder. Only at acidification temperature of 25?C, added DWP did not influence the change of milk buffer capacity regardless of the change of casein:whey protein ratio. Under this acidification condition, both milk samples standardized with skim milk powder and DWP had similar final pH values.

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Viscosity of set-style yogurt as influenced by heat treatment of milk and added demineralized whey powder

Journal of Agricultural Sciences Belgrade ◽

10.2298/jas0201045d ◽

2002 ◽

Vol 47 (1) ◽

pp. 45-56 ◽

Cited By ~ 4

Author(s):

Jelena Djurdjevic-Denin ◽

Ognjen Macej ◽

Snezana Jovanovic

Keyword(s):

Heat Treatment ◽

Milk Powder ◽

Skim Milk ◽

Matter Content ◽

Lactobacillus Delbrueckii ◽

Dry Matter Content ◽

90 C 10 ◽

Milk Samples ◽

Whey Powder ◽

Heat Treated

Skim milk powder was reconstituted to obtain milk A (with 8.44% TS). Milk sample A was standardized with different amounts of demineralized whey powder (DWP) to obtain milk B (with 9.71% TS) and milk C (with 10.75% TS). Milk samples were heat treated at 85?C/20 min and 90?C/10 min, respectively. Untreated milk was used as control. Milk samples were inoculated with 2.5% of commercial yogurt culture (containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the ratio 1:1) at 43?C. Samples were incubated until pH 4.6 was reached. Samples were immediately cooled to 4?C and held at that temperature until analyses. Measurements of viscosity were done with Brookfield DV-E Viscometer. Spindle No 3 at 20 rpm was used for all samples. After 1 day of storage, set-style yogurt samples produced from untreated milk had the highest, while samples produced from milk heat treated at 90?C/10 min the smallest initial viscosity, regadless of the dry matter content and composition. Average viscosity of set-style yogurts decreased with intensifying temperature of applied heat-treatment. During storage, set-style yogurt samples produced from milk heat treated at 90?C/10 min had the least pronounced decrease of viscosity during shearing. After 14 days of storage, set-style yogurt samples produced from milk standardized with demineralized whey powder had higher viscosity than samples produced from basis milk.

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Staphylococcal Food Poisoning Associated with Spray-Dried Milk

Epidemiology and Infection ◽

10.1017/s0022172400000899 ◽

1955 ◽

Vol 53 (4) ◽

pp. 387-397 ◽

Cited By ~ 39

Author(s):

P. H. R. Anderson ◽

Doris M. Stone

Keyword(s):

Spray Drying ◽

Clinical Features ◽

Milk Powder ◽

Food Poisoning ◽

Skim Milk ◽

Skim Milk Powder ◽

Large Numbers ◽

Heat Treated ◽

Drying Chamber ◽

Spray Dried

SummaryEight explosive outbreaks of food poisoning, occurring in school canteens in England during 1953 and affecting 1190 known cases, are described. The clinical features were characteristic of the toxin type of illness. No deaths occurred.The food causing all of these outbreaks was prepared from spray-dried skim milk powder. It was not subsequently heat-treated and was usually consumed 3–4 hr. after preparation.The spray-dried milk powder proved to contain a high content of bacteria, including large numbers of Staph. aureus, of a phage pattern often associated with food poisoning. The assumption was therefore made that these outbreaks were caused by staphylococcal enterotoxin.Because the food was often consumed within 3–4 hr. of reconstitution of the milk powder—before, in fact, the staphylococci had had time to grow—it is concluded that the poisoning must have been due mainly to pre-formed toxin.Consideration is given to the opportunities for the formation of toxin in a spray-drying plant, and reasons are brought forward for believing that it is formed mainly in the balance tank where the warm milk is kept, sometimes for several hours, before passing into the final drying chamber.The processing of the milk and the precautions for preventing contamination of the finished product are discussed.

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ANALYSIS OF MILK QUALITY, ADULTERATION AND MASTISIS IN FOUR DIFFERENT MILK SAMPLES

Kongunadu Research Journal ◽

10.26524/krj131 ◽

2016 ◽

Vol 3 (1) ◽

pp. 67-69

Author(s):

Sudhasaravanan R ◽

Binukumari S

Keyword(s):

Nutritive Value ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Milk Quality ◽

Milk Samples ◽

Appearance Quality ◽

Health Related ◽

Yellowish White ◽

Better Than

The present study is aimed to analyze the milk quality, adulteration and mastitis infection in milk Samples available in market. Four different milk samples were analyzed for physical appearance, quality, adulterants and mastitis infection. 90% milk samples were white in color and 10 % were yellowish white. pH ranged between 6.5 – 6.9. Analysis of milk quality showed that Arokya milk appears to be better than the other three milk samples. Out of 4 milk samples analyzed for adulteration, adulterants found were glucose (80%), skim milk powder (58%), salt (51%) and urea (35%) while found negative for formalin, salicylic acid, boric acid, starch, soap and ammonium sulphate. All the samples were free from mastitis infection. The adulterants decrease the nutritive value of milk and may also cause serious human health related problems.

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The influence of investigated factors on viscosity of stirred yogurt

Journal of Agricultural Sciences Belgrade ◽

10.2298/jas0202219d ◽

2002 ◽

Vol 47 (2) ◽

pp. 219-231 ◽

Cited By ~ 1

Author(s):

Jelena Denin-Djurdjevic ◽

Ognjen Macej ◽

Snezana Jovanovic

Keyword(s):

Milk Sample ◽

Skim Milk ◽

Streptococcus Thermophilus ◽

Matter Content ◽

Lactobacillus Delbrueckii ◽

Dry Matter Content ◽

90 C 10 ◽

Milk Samples ◽

Heat Treated ◽

Control Milk

Skim milk was reconstituted to obtain milk with 8.44% DM, which was standardized with demineralized whey powder (DWP) to obtain milk sample A (9.71% DM) and milk sample B (10.75% DM). Milk samples were heat treated at 85?C/20 min and 90?C/10 min, respectively. Untreated milk was used as control. Milk samples were inoculated with 2.5% of commercial yogurt culture (containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the ratio 1:1) at 43?C. Samples were incubated until pH 4.6 was reached. Samples were immediately cooled to 4?C and held at that temperature until analyses. Samples of acid casein gels were stirred after 1, 7 and 14 days of storage. Measurements of viscosity were done with Brookfield DV-E Viscometer. Spindle No 3 at 30 rpm was used for all samples. Duration of fermentation decreased when DWP was used for standardization of milk dry matter content. Yogurt samples produced from milk heat treated at 85?C/20 min, obtained by stirring of gel 1 day after production had a higher viscosity than sample produced from milk heat treated at 90?C/10 min. On the other hand, samples produced from milk heat treated at 90?C/10 min had a greater viscosity after 7 and 14 days of storage, which indicates a greater hydrophilic properties and a more pronounced swelling of casein micelles.

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NUTRITIONAL EVALUATION OF AN ENSILED PRODUCT FROM FISH

Canadian Journal of Biochemistry ◽

10.1139/o65-206 ◽

1965 ◽

Vol 43 (11) ◽

pp. 1879-1883 ◽

Cited By ~ 3

Author(s):

M. A. Krishnaswamy ◽

S. B. Kadkol ◽

G. D. Revankar

Keyword(s):

Protein Efficiency Ratio ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Efficiency Ratio ◽

Protein Ratio ◽

Protein Utilization ◽

Streptococcus Lactis ◽

Available Lysine ◽

Net Protein

Ensiled fish was prepared from a local variety of freshwater fish (Barbus carnaticus) by fermentation with a pure culture of Streptococcus lactis, commercial lactose being used as a source of fermentable carbohydrate. The fermented material (pH 4.7) was roller dried. The finished product was cream colored and had a somewhat aromatic odor. It had a protein content of about 72%. Total lysine, available lysine, methionine, cystine, and tryptophan of the ensiled fish (expressed as g/16 g N) were 10.1, 8.1, 3.6, 1.1, and 1.2%, respectively. Hygienically, the product, being free from coliforms, enterococci, Salmonella, coagulase-positive staphylococci, and pathogenic anaerobes, was satisfactory. The biological value of the product as determined by protein efficiency ratio (3.3), net protein utilization (82.3%), and net protein ratio (4.2) was not significantly different from that of skim milk powder, which has a protein efficiency ratio of 3.2, net protein utilization of 82.8%, and net protein ratio of 4.9.

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QUALITY OF PROTEIN IN MILK REPLACERS FOR YOUNG CALVES. IV. RENNET (CHYMOSIN, RENNIN) COAGULATION OF RECONSTITUTED SKIM MILK POWDER CONTAINING ADDED PROTEINS, FAT, CALCIUM, PHOSPHATE AND CITRATE

Canadian Journal of Animal Science ◽

10.4141/cjas76-040 ◽

1976 ◽

Vol 56 (2) ◽

pp. 339-345 ◽

Cited By ~ 4

Author(s):

D. B. EMMONS ◽

J. D. JONES ◽

E. E. LISTER

Keyword(s):

Soy Protein Isolate ◽

Milk Powder ◽

Skim Milk ◽

High Heat ◽

Skim Milk Powder ◽

Protein Isolate ◽

Active Principle ◽

Total Solids ◽

Ph Values ◽

Milk Replacers

The effects of added nutrient sources on curd firmness of reconstituted skim milk powder (10% total solids) were studied. Defatted rapeseed flour (4%) had little effect whereas whey powder (4%) and fish protein concentrate (2%) decreased gel strength of the reconstituted skim milk by approximately 30%. Soybean meal (4%) and soy protein isolate (2%) markedly reduced curd firmness; addition of CaCl2 restored coagulability and curd firmness. However, addition of CaCl2 did not restore gel firmness in reconstituted, severely heated skim milk powder to that of a low-temperature product. Addition of 0.1% CaCl2 slightly increased firmness of reconstituted low- and high-heat powder at pH 6.1; further addition to 0.4% CaCl2 decreased firmness slightly. It appears that when there is sufficient available Ca, further additions have no effect on curd firmness. The results indicate that milk replacers which coagulate with rennet (containing chymosin or rennin as active principle) can probably be produced even when some of the skim milk protein is replaced by other less expensive proteins. Addition of citrate (14 mM), followed by adjustment of the pH, prevented coagulation at pH 6.1 and markedly reduced firmness at pH 5.6 and 5.2. Addition of citrate at 5.7 mM did not prevent coagulation at those pH values. Addition of phosphate had little effect on curd firmness at these pH values. Addition of fat to skim milk containing 15 or 20% total solids, followed by homogenization, had little effect on curd firmness at pH 6.1. Fat additions, however, decreased curd firmness of skim milk containing 10% total solids and nearly prevented coagulation in skim milk containing 5% total solids.

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QUALITY OF PROTEIN IN MILK REPLACERS FOR YOUNG CALVES. II. EFFECTS OF HEAT TREATMENT OF SKIM MILK POWDER AND FAT LEVELS ON CALF GROWTH, FEED INTAKE AND NITROGEN BALANCE

Canadian Journal of Animal Science ◽

10.4141/cjas76-038 ◽

1976 ◽

Vol 56 (2) ◽

pp. 327-333 ◽

Cited By ~ 8

Author(s):

E. E. LISTER ◽

D. B. EMMONS

Keyword(s):

Nitrogen Balance ◽

Dry Matter ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Milk Replacer ◽

Heat Treated ◽

Fat Level ◽

Forming Characteristics ◽

Suitable Index

Three spray-dried powders were prepared after heating skim milk for 30 min at 60 C (LT), 73.9 C (MT) or 85 C (HT). Each was reconstituted to two concentrations of dietary fat and fed to five or six calves for 26 days after purchase at approximately 1 wk of age. Calves receiving the HT skim milk had significantly (P < 0.05) higher incidence of diarrhea and slower rate of gain over 19 days on test as compared with those fed the MT and LT skim milks. Subsequently growth rate was unaffected by the skim milk source and there were interactions of fat level with skim milk source. The high fat level (22.2% of dietary dry matter) resulted in a higher incidence of alopecia than in calves receiving the low fat level (16.2% of dietary dry matter). Nutrient digestibilities and nitrogen balance, measured from day 20 to day 26, were unaffected by skim milk treatments or fat concentrations. This experiment indicated that young calves, less than 3 wk of age, require a diet based on skim milk that has not been severely heat-treated and the curd formation is a suitable index of quality for such milk replacer diets. Where control diets for milk-replacer studies are designated "all milk protein," it is important for correct interpretation to define their curd-forming characteristics. For older calves, coagulation appears not to be a requirement.

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