Hydrolysis of Milk Fat with Lipase in Reversed Micelles

1991 ◽  
Vol 56 (1) ◽  
pp. 234-237 ◽  
Author(s):  
JYH-PING CHEN ◽  
HONG PAI
Keyword(s):  
Milk Fat ◽  
Reversed Micelles ◽  
Hydrolysis Of

486. The action of the lecithinase of Bacillus cereus on the globule membrane of milk fat

1952 ◽  
Vol 19 (3) ◽  
pp. 311-315 ◽  
Author(s):  
M. Jean Stone
Keyword(s):  
Bacillus Cereus ◽  
Culture Filtrate ◽  
Microscopic Examination ◽  
Milk Fat ◽  
Marked Effect ◽  
Whole Milk ◽  
Free Choline ◽  
Fat Globule ◽  
Hydrolysis Of ◽  
Qualitative Estimation

An effect simulating broken cream in whole milk was produced when Bacillus cereus was grown in washed cream at 22° C. A similar but less marked effect was obtained when a concentrated culture filtrate of B. cereus was added to washed cream.Microscopic examination of washed cream to which B. cereus or its concentrated filtrate had been added showed that the fat-globule membranes had been broken down. The hydrolysis of lecithin in washed cream in which B. cereus had grown was demonstrated by qualitative estimation of free choline.Since these results could not be reproduced when a non-lecithinase-producing strain of B. cereus or its concentrated culture filtrate was added to washed cream, it appears that the hydrolysis of the lecithin of the fat-globule membrane is at least partly responsible for the formation of broken cream.

An automated enzymic micromethod for the measurement of fat in human milk

1987 ◽  
Vol 54 (4) ◽  
pp. 487-492 ◽  
Author(s):  
Alan Lucas ◽  
Geoffrey J. Hudson ◽  
Peter Simpson ◽  
Timothy J. Cole ◽  
Brian A. Baker
Keyword(s):  
Human Milk ◽  
Small Mammals ◽  
Milk Fat ◽  
Enzymic Hydrolysis ◽  
Sample Throughput ◽  
Human Milk Fat ◽  
Hydrolysis Of

SummaryMost (98%) of the fat in human milk is present as triglycerides. This paper describes the use of a clarification procedure that enables the level of human milk fat to be determined by measurement of glycerol released by enzymic hydrolysis of triglycerides. The method requires only 10–50 μl milk, thus presenting a possible technique for work with small mammals, and is suitable for use with autoanalysers, permitting rapid sample throughput.

THE MODE OF ACTION OF PANCREATIC LIPASE ON MILK FAT GLYCERIDES

1965 ◽  
Vol 43 (11) ◽  
pp. 1799-1805 ◽  
Author(s):  
A. Boudreau ◽  
J. M. deMan
Keyword(s):  
Fatty Acids ◽  
Pancreatic Lipase ◽  
Milk Fat ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Specific Distribution ◽  
Hydrolysis Rates ◽  
Hydrolysis Of ◽  
Palmitic Acids ◽  
Chain Fatty Acids

Hydrolysis of tricaprylin by pancreatic lipase resulted in a stepwise hydrolysis, triglyceride to diglyceride to monoglyceride, as has been obtained with long-chain triglycerides. However, hydrolysis rates were much faster and considerable amounts of free glycerol were formed. Hydrolysis of an equimolar mixture of tricaprylin and triolein indicated that some of the short-chain fatty acid was released from the 2-position before all of the oleic acid was released from the 1-position. Hydrolysis of genuine and randomized milk fat resulted in preferential hydrolysis of glycerides containing short-chain fatty acids. This phenomenon was not dependent on a specific distribution of these acids, since it also occurred with the randomized fat. It was concluded that part of the short-chain fatty acids of milk fat is located in the 2-position. The distribution of caprylic and capric acids between the 1- and 2-positions is approximately at random. Lauric, myristic, and palmitic acids are predominantly located in the 2-position, and stearic and oleic acids in the 1-position, of milk fat glycerides.

Preparation and properties of rennets from lamb's and kid's abomasa

1980 ◽  
Vol 47 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Emmanuel Anifantakis ◽  
Margaret L. Green
Keyword(s):  
Milk Fat ◽  
Ph Value ◽  
Lipolytic Activity ◽  
Agar Gel ◽  
Milk Clotting ◽  
Ph Values ◽  
Cathepsin Activity ◽  
Maximum Stability ◽  
Hydrolysis Of ◽  
Gel Diffusion

SummaryLamb and kid rennets were prepared by extraction of dried abomasa with 6% (w/v) NaCl-2% (w/v) H3BO3 and activation of the proenzymes at pH 2·0. Each gave one zone of precipitation on casein-agar gel diffusion, enabling them to be differentiated from calf rennet and pig pepsin. After agarose gel electrophoresis, the proteinase activity of lamb rennet occurred in chymosin and pepsin bands only, whereas kid rennet contained an additional proteinase of intermediate mobility. Relative to their milk-clotting activities, lamb and kid rennets contained less pepsin and were less proteolytic on both haemoglobin at pH 1·8 and casein at pH 5·3 than calf rennet. The milk-clotting activities of lamb and kid rennets increased less with decrease in pH and were more stable to storage at both the pH value of maximum stability and lower pH values than that of calf rennet. Neither cathepsin activity nor lipolytic activity on milk fat was detected in any of the 3 rennets, but lamb rennet caused slight hydrolysis of tributyrin.

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