QUALITY OF PROTEIN IN MILK REPLACERS FOR YOUNG CALVES. I. FACTORS AFFECTING IN VITRO CURD FORMATION BY RENNET (CHYMOSIN, RENNIN) FROM RECONSTITUTED SKIM MILK POWDER

1976 ◽  
Vol 56 (2) ◽  
pp. 317-325 ◽  
Author(s):  
D. B. EMMONS ◽  
E. E. LISTER
Keyword(s):  
Heat Treatment ◽  
Milk Powder ◽  
Skim Milk ◽  
High Heat ◽  
Skim Milk Powder ◽  
Factors Affecting ◽  
Fresh Milk ◽  
Milk Solids ◽  
Milk Replacers

Fresh milk coagulates with chymosin (rennin) in the calf stomach to form relatively strong curds. With respect to calf milk replacers it is of interest to study factors affecting curd formation of reconstituted skim milk powder by this enzyme. Curd firmness was increased by lower pH of the skim milk over a range of 5.6–6.6, higher concentration of skim milk solids over a range of 5–20%, higher concentrations of chymosin, lower temperatures of heat treatment of skim milk prior to spray drying, and higher temperature of coagulation, 37 vs. 30 C. Reconstitution of powder in water above 56 C for 2 min remarkedly reduced the firmness of the curd. The following coagulation conditions were selected for comparison of powders and milk replacers: addition of 1 ml of a 1:50 dilution of standard strength commercial rennet to 100 ml of milk previously adjusted to pH 6.1, 10% of nonfat solids in the aqueous nonfat phase, temperature of 37 C, and measurements of firmness 30 min after adding rennet. Commercially produced skim milk powders designated high-heat, medium-heat and roller products yielded soft curds. Commercial low-heat powders yielded strong curds. All coagulated in less than 4 min at pH 6.1, the time being relatively independent of heat treatment.

SOME IN VITRO OBSERVATIONS ON FACTORS AFFECTING RENNET (CHYMOSIN) CLOTTING OF CALF MILK REPLACERS

1981 ◽  
Vol 61 (2) ◽  
pp. 393-401 ◽  
Author(s):  
K. J. JENKINS ◽  
J. R. LESSARD ◽  
D. B. EMMONS
Keyword(s):  
Milk Powder ◽  
Skim Milk ◽  
Total Solid ◽  
Skim Milk Powder ◽  
Factors Affecting ◽  
Total Solids ◽  
Rennet Coagulation ◽  
High Concentrations ◽  
Milk Replacers

The formation of a firm rennet (chymosin) curd in the abomasum appears to have a useful physiological function in the newborn calf. The results of in vitro experiments with calf milk replacers conducted to study the effect of various factors on rennet clot formation demonstrated that low-pressure (L) dispersion of lipid into skim milk powder replacers resulted in markedly higher (P < 0.05) curd firmness values with rennet than homogenization (H) at all total solid (10, 15 and 20%) and lipid (10, 20, 30 and 40% TS) levels tested. At higher total solids levels, curd firmness, clot weight and percentage of replacer lipid in clot were significantly (P < 0.05) increased. The L dispersion method also promoted rennet coagulation and firmer curds than H when skim was partially replaced by mixtures offish protein-whey or Promine D-whey. The results indicate that reconstitution of milk replacers at high total solids levels (e.g., 20%), in conjunction with L dispersion of lipid, would be beneficial for promoting rennet coagulation, curd firmness and high concentrations of protein and lipid in the clot.

scholarly journals The effect of heat treatment on the nutritive value of milk for the young calf

1969 ◽  
Vol 23 (4) ◽  
pp. 763-782 ◽  
Author(s):  
H. Tagari ◽  
J. H. B. Roy
Keyword(s):  
Heat Treatment ◽  
Nutritive Value ◽  
Milk Powder ◽  
Skim Milk ◽  
Sampling Period ◽  
Skim Milk Powder ◽  
Protein Nitrogen ◽  
High Ph ◽  
N Concentration

1. Four Ayrshire bull calves between 8 and 34 days of age and fitted with duodenal and ileal re-entrant cannulas were used to study the effect of heat treatment of the milk they received on the pH and nitrogen composition of the pyloric outflow and ileal contents.2. Milk A contained a spray-dried skim-milk powder pre-heated during the drying process at 74° for 30 min and milk B a similar powder pre-heated at 77° for 15 sec. In milk A about 50% of the non-casein protein N had been denatured.3. Milk B resulted in a lower pH than milk A in the pyloric outflow throughout the sampling period of 6.5 h after feeding. It resulted also in an increased volume of outflow during the 1st h after feeding, a reduced output of undigested protein, an increased output of non-protein nitrogen (NPN) and a different pattern of flow of NPN during the first 4 h after feeding.4. These differences between milk A and milk B were associated largely with different clotting characteristics, which were demonstrated in vitro at two levels of addition of rennet with or without the addition of calcium. The buffering capacity of the two milks was similar.5. Variation between calves in their response to these two milks was attributed to the age of the calves and to differences in inherent clotting or proteolytic activity.6. In the ileal outflow, bacterial activity, as measured by dehydrogenase activity, was positively related to N concentration, but the N concentration when milk A was given did not appear to differ from that when milk B was given.7. One calf had diarrhoea when given milk A at a young age. This was associated with an increased pyloric outflow, an increased outflow of undigested protein but little difference in the rate of proteolysis, and a high pH. In the ileal outflow the volume and amount of N was much increased although the N concentration was reduced.8. It is concluded that the detrimental effect of milk A, found in earlier experiments, was largely associated with high pH and poor digestibility of protein in the abomasum, conditions which allow multiplication of coliform organisms in the intestine.

REDUCTION OF β-CONGLYCININ ANTIGENICITY AND RATE OF ACID-PEPSIN PROTEOLYSIS OF PROTEINS IN EXTRUDED OR RUMEN FLUID-TREATED SOYBEAN MEAL

1989 ◽  
Vol 69 (3) ◽  
pp. 727-734 ◽  
Author(s):  
P. S. MIR ◽  
J. H. BURTON ◽  
B. N. WILKIE ◽  
F. R. VAN DE VOORT
Keyword(s):  
Soybean Meal ◽  
Rumen Fluid ◽  
Milk Powder ◽  
Skim Milk ◽  
In Vitro Digestion ◽  
Skim Milk Powder ◽  
Negative Control ◽  
Fermented Soybean Meal ◽  
Milk Replacers

The effect of processing commercial soybean meal (HSBM) by either extrusion (ExSBM) or fermentation with microbes in rumen fluid (FSBM) on rate of protein hydrolysis and the activity of the antigen β-conglycinin was evaluated. Ethanol-extracted soybean meal (EtSBM) and skim milk powder (SMP) were included as positive controls while HSBM was the negative control, with regard to antigen content. The rates of proteolysis were determined by acid pepsin hydrolysis and the activity of β-conglycinin in the soluble fraction of the digestion mixtures at 0, 2, 4, 6 and 8 h of in vitro proteolysis was determined by radial immunodiffusion in agar gel containing antibody specific for the antigen. Susceptibility of FSBM and ExSBM to proteolysis by pepsin was greater than that of EtSBM. β-Conglycinin content was greatest in HSBM (1.0 ± 0.2 g dL−1) and only 0.3 ± 0.03 g dL−1 in ExSBM at the beginning of in vitro digestion. The antigen was not detected in either FSBM or EtSBM, therefore these products could be used in milk replacers for calves. Key words: In vitro pepsin proteolysis, extruded soybean meal, fermented soybean meal, antigen, β-conglycinin

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

1976 ◽  
Vol 56 (2) ◽  
pp. 339-345 ◽  
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.

IN VITRO OBSERVATIONS ON FACTORS AFFECTING CALF PREGASTRIC ESTERASE ACTIVITY

1979 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
K. J. JENKINS
Keyword(s):  
Lipolytic Activity ◽  
Milk Powder ◽  
Skim Milk ◽  
Coconut Oil ◽  
Skim Milk Powder ◽  
Enzyme Hydrolysis ◽  
Factors Affecting ◽  
Ph Range ◽  
Hydrolysis Of

Three in vitro experiments were conducted to determine the efficacy of calf pregastric esterase (PGE) for hydrolyzing various fats and the influence of various factors on its lipolytic activity. Calf PGE was effective in hydrolyzing butterfat and coconut oil, hydrolyzed smaller amounts of the other plant oils tested and had a very limited capacity for lard and the six grades of tallow studied. The esterase retained good lipolytic activity for butterfat over the pH range normally encountered in the calf abomasum after feeding liquid diets. Rennet clotting of reconstituted skim-milk at pH 6.1 reduced enzyme hydrolysis of butterfat by 30%, presumably due to fat occlusion in the clot. Lecithin, skim-milk powder, casein, and lactalbumin markedly increased PGE activity; Ca++ had no effect. The bile salts taurodeoxycholate, glycochenodeoxycholate and taurochenodeoxycholate markedly inhibited PGE lipolysis, whereas others (taurocholate, deoxycholate, cholate, glycocholate) had little or no effect.

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.

Dry heat treatment of skim milk powder greatly improves the heat stability of recombined evaporated milk emulsions

2021 ◽  
Vol 112 ◽  
pp. 106342
Author(s):  
Jianfeng Wu ◽  
Simin Chen ◽  
Ali Sedaghat Doost ◽  
Qurrotul A’yun ◽  
Paul Van der Meeren
Keyword(s):  
Heat Treatment ◽  
Milk Powder ◽  
Skim Milk ◽  
Heat Stability ◽  
Skim Milk Powder ◽  
Dry Heat ◽  
Dry Heat Treatment

USE OF THE WILLEMS POLYTRON® TO HOMOGENIZE FAT AND DISPERSE INSOLUBLE INGREDIENTS IN HIGH-FAT LIQUID MILK REPLACERS

1972 ◽  
Vol 52 (3) ◽  
pp. 477-484 ◽  
Author(s):  
A. D. L. GORRILL ◽  
J. W. G. NICHOLSON
Keyword(s):  
Dry Matter ◽  
Soybean Lecithin ◽  
Milk Powder ◽  
Skim Milk ◽  
Nitrogen Retention ◽  
Liquid Mixtures ◽  
Skim Milk Powder ◽  
High Fat ◽  
Liquid Milk ◽  
Milk Replacers

The operation of the Willems Polytron® to prepare batches of high-fat (27–35%, air dry basis) milk replacers is described. Most milk replacers were mixed at 40% solids to minimize foaming, and were diluted prior to feeding. The Polytron homogenized fat in liquid mixtures at 55 or 65 C, and partially dispersed insoluble ingredients in soybean, rape-seed, and fish flours. The inclusion of 25% or more of partially delactosed acid whey powder increased the viscosity of the mixtures, and held insoluble ingredients in suspension for several hours. Homogenization of a milk replacer containing 73% skim milk powder and 27% bleachable fancy tallow (3% soybean lecithin added) markedly improved growth (425 vs. 190 g/day), dry matter, nitrogen, and energy digestion (92 vs. 73% for energy) and nitrogen retention (44 vs. 24%) by calves. Calf responses were similar when the liquid diet was homogenized at either 55 or 65 C. Homogenization with 3% soybean lecithin in the tallow increased digestion of dry matter, nitrogen, and energy by chives by 5–6% units (P < 0.2), and Ca by 16% units (P < 0.05) compared with no lecithin. Bleachable fancy or crude tallow and 3% soybean lecithin or 0.2% glyceryl monostearate in the fat gave similar calf responses.

scholarly journals Mass spectrometry data of in vitro and in vivo pig digestion of skim milk powder

Data in Brief ◽  
2018 ◽  
Vol 21 ◽  
pp. 911-917 ◽  
Author(s):  
Lotti Egger ◽  
Patrick Schlegel ◽  
Christian Baumann ◽  
Helena Stoffers ◽  
Dominik Guggisberg ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Mass Spectrometry Data
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