Influence of processing temperature and seasonal change in diet on lipase activity and lipolysis during the mechanical separation of bovine milk

1985 ◽  
Vol 52 (2) ◽  
pp. 255-266 ◽  
Author(s):  
Eric C. Needs ◽  
Malcolm Anderson ◽  
Stuart J. Payne ◽  
Elizabeth A. Ridout
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Seasonal Change ◽  
Lipase Activity ◽  
Bovine Milk ◽  
Skim Milk ◽  
Relative Activity ◽  
Heat Inactivation ◽  
Processing Temperature ◽  
Original Activity

SUMMARYThe effect of separating conditions on lipase activity and free fatty acid levels in preheated milk, cream and skim milk was measured on nine occasions during a 12-week period covering the seasonal change from winter feeding to summertime grazing. This change consisted of four periods each representing a different type of forage intake, namely: silage, kale, daytime grazing and 24 h grazing. Milk was separated at 30, 40, 50 and 60°C with preheating times of 10, 25 and 55 s. Results were expressed both as absolute values and in terms of changes relative to the original unheated milk. Lipase activity and free fatty acid concentration were significantly reduced as separation temperature increased but were not influenced by holding time. The loss of activity in cream was progressive so that at 60°C only 40% of the original activity remained. Up to 50°C little change occurred in preheated milk or skim milk activity, while at 60°C 83 and 76% respectively of the original activity remained. The amount of activity calculated to be associated with the fat fraction of the cream also decreased with temperature. Activity varied significantly with date; maximum values were observed during the first 3 weeks of summertime grazing. Relative activity values indicated that the susceptibility of milk lipase to heat inactivation also varied with date. Lipolysis was also significantly affected by date. Cream free fatty acid levels were lower during the period of daytime grazing and were significantly higher than those in preheated milk. The correlation between lipase activity and free fatty acid levels was generally poor, accounting for between 0 and 34% of the variance. Possible reasons for the effect of separating temperature on lipolysis in cream are discussed.

scholarly journals Clearing-factor lipase in adipose tissue. A possible role of adenosine 3′,5′-(cyclic)-monophosphate in the regulation of its activity

1968 ◽  
Vol 109 (5) ◽  
pp. 841-849 ◽  
Author(s):  
D. R. Wing ◽  
D S Robinson
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Cyclic Amp ◽  
Lipase Activity ◽  
Glucose Concentration ◽  
Free Fatty Acid Concentration ◽  
Epididymal Fat ◽  
Fat Bodies

1. The rise in clearing-factor lipase activity that occurs when epididymal fat bodies from starved rats are incubated in appropriate media in vitro is inhibited in the presence of 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP (1mm). 2. Inhibition occurs at a concentration of glucose in the incubation medium of 1·3mg./ml. or less, but not at a glucose concentration of 2·4mg./ml., unless caffeine (1mm), an inhibitor of 3′,5′-(cyclic)-nucleotide phosphodiesterase, is also present. Caffeine (5mm) alone inhibits the rise in clearing-factor lipase activity at a glucose concentration of 2·4mg./ml. of medium. 3. The concentration of free fatty acids in the epididymal fat bodies normally falls during incubations in vitro as the rise in clearing-factor lipase activity occurs. In the presence of 1mm-6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP, however, either the tissue free fatty acid concentration is increased or it does not fall to the same extent. The concentration of glucose in the incubation medium is important in determining the direction and extent of the changes in tissue free fatty acid concentration that occur in the presence of 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP. 4. Free fatty acid concentrations in epididymal fat bodies in vivo rise as the clearing-factor lipase activity of the tissue falls during starvation. 5. The possibility that the concentration of 3′,5′-(cyclic)-AMP in adipose tissue may regulate clearing-factor lipase activity, and that the regulation may occur through effects of the nucleotide on tissue free fatty acid concentrations, is discussed.

Heat Inactivation of Bile Salt-Stimulated Lipase Activity in Human Milk and Colostrum1

1983 ◽  
Vol 46 (6) ◽  
pp. 525-527
Author(s):  
S. H. L. PAN ◽  
C. W. DILL ◽  
E. S. ALFORD ◽  
R. L. RICHTER ◽  
C. GARZA
Keyword(s):  
Human Milk ◽  
Bile Salt ◽  
Lipase Activity ◽  
Bovine Milk ◽  
Heat Inactivation ◽  
Assay Procedure ◽  
Ph Stat

Time-temperature relationships for heat-inactivation of bile salt-stimulated lipase activity in human milk and colostrum were systematically measured using a pH-stat assay procedure with triolein as substrate. The enzyme was not affected in either menstruum at 45°C for 40 min. The enzyme was destroyed almost instantaneously at 60°C, and was slightly more heat-sensitive in colostrum than in milk. The bile salt-stimulated lipase(s) in human milk was more heat sensitive than lipase in bovine milk.

Observations on the influence of high cell count on lipolysis in bovine milk

1979 ◽  
Vol 46 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Amer M. A. Salih ◽  
Malcolm Anderson
Keyword(s):  
Cell Count ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Bovine Milk ◽  
Skim Milk ◽  
High Cell ◽  
Lipoprotein Lipase Activity ◽  
Milk Serum ◽  
Cell Counts ◽  
And Control

SummaryThe effect that changes in composition which occur in milks possessing high cell counts have on milk lipolysis has been investigated. High cell counts were produced either by intramammary infusion of Escherichia coli endotoxin or Streptococcus agalactiae or by addition of washed cells which were isolated from milk obtained from quarters infused with endotoxin. Free fatty acid levels in milk were measured in terms of acid degree value (ADV) either as initial ADV measured immediately after milking or ADV developed after a prescribed incubation period.There was an increase in initial ADV after the infusion either of endotoxin or of Str. agalactiae relative to a control quarter. This increase appeared to be associated with changes in cell count, but in absolute terms the influence of cells on ADV became less as cell count increased. Neither type of infusion had any effect on lipoprotein lipase activity. The addition of washed cells to normal milk resulted in an increase in developed ADV, but the increment was not as large as that produced by the addition of 1% blood serum. When cream and skim-milk from endotoxin-treated quarters and control quarters were mixed in different combinations with and without additional cells, developed ADV was higher in those samples containing endotoxin cream and those with added cells. Milk from a quarter treated with endotoxin was diluted with its own skim-milk to produce different cell counts and ADV was determined after various time intervals at 4 and 37 °C. Lipolysis increased with increasing cell count, but a depression in lipolytic rate was noted after incubation for 6 h at 4 °C and 20 min at 37 °C.The proportion of skim-milk lipoprotein lipase activity in milk serum was larger both in milks possessing high cell counts and in normal milk adjusted to between 5 and 20 mM-NaCl by addition of solid NaCl. These levels of NaCl inhibited lipolysis.The possible direct and indirect effects of high cell count on milk lipolysis are discussed.

Effect of prolactin on lipoprotein lipase in crop sac and adipose tissue of pigeons

1975 ◽  
Vol 228 (5) ◽  
pp. 1542-1544 ◽  
Author(s):  
MM Garrison ◽  
RO Scow
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Lipoprotein Lipase ◽  
Adult Female ◽  
Lipase Activity ◽  
Milk Lipid ◽  
Lipoprotein Lipase Activity ◽  
Omental Adipose Tissue ◽  
Chylomicron Triglyceride

The effect of prolactin on lipoprotein lipase activity of crop sac, omental adipose tissue, and esophagus was studied in adult female pigeons. Prolactin injected for 4 days, 1 mg/day, increased lipoprotein lipase activity from 17 to 177 U/g in crop sac and from 68 to 118 U/g in adipose tissue, but had no effect on the activity in esophagus, 4 U/g. (10 = 1 mumol of chylomicron triglyceride hydrolyzed to free fatty acid and glycerol per hour.? Prolactin increased the weight of crop sac from 1.4 to 7.2 G. The effect of prolactin on lipoprotein lipase activity and weight of crop sac occurred mostly during the 3rd and 4th days of treatment, whereas the effect on the activity of adipose tissue occurred later, during the 4th day of treatment. Crop "milk" collected from pigeons injected with 2 mg of prolactin daily for 4 days contained a small amount of lipoprotein lipase activity, 12 U/g, is smaller than 10% of that found in crop sac. The finding of markedly increased lipoprotein lipase activity in crop sac of prolactin-treated pigeons suggests that blood triglyceride may be used by crop sac for the formation of crop milk lipid.

Serum lipoprotein stimulation of lipolysis and its relevance to free fatty acid development in bovine milk

1983 ◽  
Vol 50 (3) ◽  
pp. 309-319 ◽  
Author(s):  
Malcolm Anderson ◽  
Eric C. Needs
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Blood Serum ◽  
Milk Fat ◽  
Bovine Milk ◽  
Serum Lipoprotein ◽  
Serum Lipoproteins ◽  
Cell Counts ◽  
Highly Correlated ◽  
And Control

SummaryThe role of blood serum lipoproteins in stimulating milk lipolysis was investigated by adding blood serum and heparin to the milk of normal cows and cows in which elevated somatic cell counts were induced by intramammary infusion of Escherichia coli endotoxin and Staphylococcus aureus. There was considerable variation between individual milks in the extent to which lipolysis was stimulated. In some milks there was almost no response. For values obtained from 29 cows during the first 6 months of lactation a relationship was observed between free fatty acid (FFA) levels in the untreated and serum-stimulated samples (r = 0·776). FFA values were higher after 18 h at 4 °C in milks from infused quarters than in those from control quarters, but this difference was not entirely due to higher values from the infused quarters at 0 h. Both blood serum and heparin stimulated lipolysis in high cell count milks and control milks. The response to heparin was greater than that to blood serum, but the response to both was highly correlated with FFA levels in the untreated milks. There were no differences in the ability of skim-milks prepared from infused and control quarters to promote lipolysis in recombined milks containing sterilized homogenized milk fat globules as a source of substrate. Incubation of blood serum with 2 μg/ml trypsin for 1 h at 37 °C reduced the ability of the serum to promote lipolysis. The importance of lipase activation by blood serum lipoproteins in relation to milk lipolysis is discussed.

scholarly journals The Lipolytic Activity of Antithrombin III

1977 ◽  
Author(s):  
M. Nakagawa ◽  
S. Okuda ◽  
M. Watada ◽  
H. Ijichi
Keyword(s):  
Myocardial Infarction ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Lipase Activity ◽  
Inhibitory Activity ◽  
Antithrombin Iii ◽  
Lipolytic Activity ◽  
Lipoprotein Lipase Activity ◽  
Coagulation Mechanism ◽  
The Relationship

Antithrombin III in the circulating blood is known to play an important role on the coagulation mechanism of the blood and is reported to be decreased in its amount on the cases of myocardial infarction and arteriosclerosis, in the meanwhile the arteriosclerosis has been considered to be one of thrombogenic factors. This research was designed to investigate the effects of antithrombin III on the relationship between fibrin formation and atherosclerosis.Antithrombin III was purified from human defibrinated plasma by Heparin Sepharose Affinity Chromatography. Using this antithrombin III as an enzyme, its lipolytic activity was assayed spectrophotometrically detecting the produced free fatty acid from various substrates, Intralipid, Triolein, and Human Chylomicron respectively. Lipoprotein lipase activity was detected in the purified antithrombin III. Intralipid was hydrolyzed to a greater extent than triolein or chylomicron and it is concluded that antithrombin III in the circulating blood has not only the inhibitory activity of thrombin but also has the lipolytic activity. From these observations it is considered that this lipolytic activity is beneficial for preventing the developement of atherosclerosis and also of thrombosis.

Effect of stage of lactation, stage of pregnancy, milk yield and herd management on seasonal variation in spontaneous lipolysis in bovine milk

1986 ◽  
Vol 53 (4) ◽  
pp. 529-538 ◽  
Author(s):  
Marie-Paule Chazal ◽  
Yves Chilliard
Keyword(s):  
Seasonal Variation ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Milk Yield ◽  
Bovine Milk ◽  
Physiological Factors ◽  
Stage Of Lactation ◽  
Lactation Stage ◽  
Bulk Tank ◽  
One Year

SummaryThe free fatty acid (FFA) levels after milking (initial FFA) and after 22 h storage at 4°C (FFA-22) were determined in milk from 57 cows every 2 weeks for one year. FFA levels which were higher in summer than in winter were explained by later stages of lactation occurring in summer. Initial FFA content increased regularly during lactation. FFA-22 content increased after 12 weeks, and further after 32 weeks of lactation. The first increase was due to stage of lactation. The second increase, which appeared in late lactation, was essentially due to the stage of pregnancy combined with the effect of milk yield. FFA-22 content increased in the second part of pregnancy, chiefly after 24 weeks. A low milk yield (≼ 5 kg) further increased lipolysis, but only after 16 weeks of pregnancy. The effect of stage of pregnancy may have been enhanced by management factors such as feeding conditions. In this investigation, the seasonal FFA variation in bulk tank milk could be explained entirely by physiological factors.

scholarly journals Free Fatty Acid Concentration and Carboxy methyl cellulase Activity of Some Formulas of Protected Fat-proteins Tested In Vitro

2015 ◽  
Vol 17 (2) ◽  
pp. 92
Author(s):  
Lilis Hartati ◽  
Ali Agus ◽  
Lies Mira Yusiati ◽  
Budi Prasetyo Widyobroto
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Acid Concentration ◽  
Palm Oil ◽  
Skim Milk ◽  
Fatty Acid Concentration ◽  
Free Fatty Acid Concentration ◽  
Second Stage

The aim of this study was to determine the levels of free fatty acids and carboxymethylcellulase activity (cmc-ase) activity of some protected fat-proteins base on in vitro Tilley and Terry method. Two sources of fat, i.e. crude palm oil and fish oil and three sources of protein i.e. skim milk, soybean flour and soybean meal were used in the formulation of protected fat-protein, and thus there were six treatment combinations. The filtrate from the in vitro test was analyzed for the levels of free fatty acids and  cmcase activity. The result of this research indicates that different combinations of feed materials and fat give different content of free fatty acid in first stage and second stage in vitro, with the best results in the combination treatment of skim milk and palm oil that give the lowest result of  free fatty acid concentration in fisrt stage in vitro (0.168%) and the highest result free fatty acid concentration in second stage in vitro ( 4.312%) . The activity of CMC-ase was not influenced by different  sources of fat and protein. It can be concluded was that the protection of the combination between skim milk and CPO gives the highest protection results.

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