Interaction between Casein Micelles and Whey Protein/κ-Casein Complexes during Renneting of Heat-Treated Reconstituted Skim Milk Powder and Casein Micelle/Serum Mixtures

2011 ◽  
Vol 59 (4) ◽  
pp. 1442-1448 ◽  
Author(s):  
Prashanti Kethireddipalli ◽  
Arthur R. Hill ◽  
Douglas G. Dalgleish
Keyword(s):  
Whey Protein ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Heat Treated

scholarly journals Staphylococcal Food Poisoning Associated with Spray-Dried Milk

1955 ◽  
Vol 53 (4) ◽  
pp. 387-397 ◽  
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.

QUALITY OF PROTEIN IN MILK REPLACERS FOR YOUNG CALVES. III. RENNET COAGULATION AND UNDENATURED WHEY PROTEIN NITROGEN CONTENT OF SKIM MILK POWDERS AND COMMERCIAL MILK REPLACERS

1976 ◽  
Vol 56 (2) ◽  
pp. 335-338
Author(s):  
D. B. EMMONS ◽  
E. E. LISTER ◽  
D. L. CAMPBELL
Keyword(s):  
Whey Protein ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Plant Proteins ◽  
Protein Nitrogen ◽  
Rennet Coagulation ◽  
Powder Samples ◽  
Milk Replacers

Reconstituted commercial skim milk powder samples which produced a firm (> 30 g) rennet curd had high levels (> 4 mg N/g) of undenatured whey protein nitrogen (WPN) as measured by the modified Harland–Ashworth test. However, similar samples which also had high levels of WPN (> 6 mg N/g) had low curd firmness or failed to coagulate. Of 24 commercial samples of milk replacers, 2 formed a soft curd; the rest did not coagulate. Five had high levels of WPN (> 6 mg N/g); one sample contained 17.8 mg N/g, well above normal levels of skim milk powder. Plant proteins may have caused high WPN values and interfered with the Harland–Ashworth test. It was concluded that WPN is neither an acceptable index of rennet coagulability of milk replacers, nor a reliable index for selecting commercially produced skim milk powders with good rennet coagulability.

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

1976 ◽  
Vol 56 (2) ◽  
pp. 327-333 ◽  
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.

A fluorimetric method for determination ofPseudomonas fluorescensAR11 lipase in skim milk powder, whey powder and whey protein concentrate

1984 ◽  
Vol 51 (4) ◽  
pp. 623-628 ◽  
Author(s):  
Donald Stead
Keyword(s):  
Whey Protein ◽  
Lipolytic Activity ◽  
Sodium Taurocholate ◽  
Milk Powder ◽  
Skim Milk ◽  
Milk Proteins ◽  
Skim Milk Powder ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Whey Powder

SummaryA method which was developed for assaying the extracellular lipases of psychrotrophic bacteria in milk (Stead, 1983, 1984) and which uses the fluorogenic substrate 4-methylumbelliferyl oleate has been adapted for use with skim milk powder (SMP), whey powder (WP) and whey protein concentrate (WPC). A five-fold increase in the concentration of sodium taurocholate (NaTC), in the mixture of NaTC and cetyltrimethylammonium bromide needed to dissociate lipase from milk proteins, removed the excessive sensitivity of the assay to variations in the concentrations of SMP, WP or WPC incorporated. Commercially available pancreatic lipase provided a suitable standard of lipolytic activity and as little as 1–2 μ could be detected in each assay system.

Predicting lactulose concentration in heat-treated reconstituted skim milk powder using front-face fluorescence

Food Control ◽  
2017 ◽  
Vol 73 ◽  
pp. 110-116 ◽  
Author(s):  
N. Ayala ◽  
A. Zamora ◽  
C. González ◽  
J. Saldo ◽  
M. Castillo
Keyword(s):  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Front Face ◽  
Heat Treated

scholarly journals Lactose crystallisation and early Maillard reaction in skim milk powder and whey protein concentrates

2005 ◽  
Vol 85 (4-5) ◽  
pp. 315-323 ◽  
Author(s):  
François Morgan ◽  
Corinne Appolonia Nouzille ◽  
Robert Baechler ◽  
Gilles Vuataz ◽  
Alois Raemy
Keyword(s):  
Whey Protein ◽  
Maillard Reaction ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Protein Concentrates ◽  
Whey Protein Concentrates

Denaturation, aggregation and heat stability of milk protein during the manufacture of skim milk powder

1991 ◽  
Vol 58 (3) ◽  
pp. 269-283 ◽  
Author(s):  
Harjinder Singh ◽  
Lawrence K. Creamer
Keyword(s):  
Spray Drying ◽  
Milk Powder ◽  
Skim Milk ◽  
Heat Stability ◽  
Skim Milk Powder ◽  
Casein Micelle ◽  
Commercial Plant ◽  
Preheat Treatment ◽  
Solids Content ◽  
Time Required

SummaryThe effect of preheat treatment, evaporation and drying in a commercial plant on the denaturation of βlactoglobulin and α-lactalbumin, their incorporation into the casein micelle and the heat stability characteristics of the milks and powders were determined. Preheat treatments between 110 °C for 2 min and 120 °C for 3 min denatured between 80 and 91% of β-lactoglobulin and between 33 and 45% of α-lactalbumin. Evaporation increased the extent of denaturation but spray drying did not increase it further. The incorporation of α-lactalbumin and βlactoglobulin into the micelles was markedly less than the amount that denatured and was not a constant ratio to it. Heat coagulation times at 140 °C of milks, concentrates and powders diluted to the original milk concentration were measured as a function of pH. In general, the greater the collective heat treatment, the shorter the time required to achieve coagulation. Spray drying shifted the peak positions in the pH-heat coagulation time profiles. In contrast, heat coagulation times (measured at 120 °C) of concentrates and powders diluted to 20% total solids content increased with the severity of the preheat treatment. Surprisingly, spray drying markedly increased the heat coagulation times of the diluted concentrates.

scholarly journals Karakteristik Fisikokimia Yogurt Tanpa Lemak dengan Penambahan Whey Protein Concentrate dan Gum Xanthan

2018 ◽  
Vol 38 (2) ◽  
pp. 178
Author(s):  
Mohamad Djali ◽  
Syamsul Huda ◽  
Lovita Andriani
Keyword(s):  
Whey Protein ◽  
Block Design ◽  
Milk Powder ◽  
Skim Milk ◽  
Chemical Properties ◽  
Skim Milk Powder ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Randomized Block Design ◽  
Physical And Chemical

Non-fat yogurt exhibited weak body, poor texture, and whey separation because of reduction of fat. The separation of whey in yogurt is not desired by consumer. The aim of present study was to evaluate the effect of adding whey protein concentrate (WPC) and xanthan gum on physical, chemical and sensory properties of non-fat yogurt. Physical and chemical properties were tested using randomized block design whereas the yogurts properties during 21 days of cold storage included syneresis index and organoleptic. There were 6 treatments : A (full fat yogurt = control 1); B (skim milk + skim milk powder (SMP) 3% = control 2); C (skim milk + SMP 3% + WPC 1%); D (skim milk + SMP 3% + WPC 1,25%); E (skim milk + SMP 3% + WPC 0,5% + xanthan 0,005%); F (skim milk + SMP 3% + WPC 0,5% + xanthan 0,004%). The fat content 0,12%-0,14% of non-fat yogurt with the addition of WPC and blend of WPC-xanthan could increased firmness, cohesiveness and consistency compared to control 1 and control 2. In the organoleptic properties, non-fat yogurt with the addition of WPC and blend of WPC-xanthan were gained color, flavor, aroma, and consistency of the panelists preferred higher than control yogurt. Non-fat yogurt with only addition of WPC gained the lowest syneresis index. ABSTRAKYogurt tanpa lemak memiliki kekuatan struktur yang rendah dan rentan terjadi pemisahan whey karena berkurangnya kandungan lemak. Pemisahan whey pada yogurt tidak disukai oleh konsumen. Tujuan penelitian ini adalah untuk mengevaluasi efek penambahan whey protein concentrate (WPC) dan gum xanthan terhadap karakteristik fisik, kimia sensori yogurt tanpa lemak. Karakteristik fisik dan kimia diuji menggunakan metode RAK, sedangkan karakteristik yogurt selama penyimpanan dingin 21 hari meliputi indeks sineresis dan organoleptik. Terdapat 6 perlakuan yaitu: A (susu segar = kontrol 1); B (susu skim + skim milk powder (SMP) 3% = kontrol 2); C (susu skim + SMP 3% + WPC 1%); D (susu skim + SMP 3% + WPC 1,25%); E (susu skim + SMP 3% + WPC 0,5% + gum xanthan 0,005%); F (susu skim + SMP 3% + WPC 0,5% + gum xanthan 0,004%). Kandungan lemak 0,12%-0,14% pada yogurt tanpa lemak dengan penambahan WPC dan kombinasi WPC-gum xanthan dapat meningkatkan firmness, cohesiveness, dan konsistensi dibandingkan kontrol 1 dan kontrol 2. Secara organoleptik, yogurt tanpa lemak dengan penambahan WPC dan kombinasi WPC-gum xanthan mendapatkan tingkat kesukaan panelis lebih tinggi untuk warna, rasa, aroma, dan kekentalan dibandingkan yogurt lemak utuh tanpa perlakuan. Yogurt tanpa lemak dengan penambahan WPC saja mendapatkan indeks sineresis lebih rendah dibandingkan perlakuan lainnya.

Sign in / Sign up

Export Citation Format

Share Document