ESTIMATION OF LIPASE IN DAIRY PRODUCTS: I. AN EXTRACTION-TITRATION METHOD FOR THE ESTIMATION OF MILK LIPASE

A procedure has been outlined for the estimation of milk lipase. The method is based on the titration of an ether extract of butyric acid derived from the enzymatic hydrolysis of tributyrin under standardized conditions. Some of the fundamental factors involved in the procedure have been discussed. It is suggested that modifications of the method may be used to study lipase activity in other dairy products and in cultures of micro-organisms.

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ESTIMATION OF LIPASE IN DAIRY PRODUCTS: II. AN EXTRACTION–TITRATION METHOD FOR THE ESTIMATION OF BACTERIAL LIPASE

Canadian Journal of Research ◽

10.1139/cjr49f-052 ◽

1949 ◽

Vol 27f (12) ◽

pp. 491-498 ◽

Cited By ~ 1

Author(s):

D. J. Lubert ◽

L. M. Smith ◽

H. R. Thornton

Keyword(s):

Lipase Activity ◽

Dairy Products ◽

Skim Milk ◽

Reaction Medium ◽

Ether Extract ◽

Titration Method ◽

Wide Ph Range ◽

Ph Range

A method of estimating bacterial lipase is presented that is believed to be more nearly quantitative than any other at present available. The method is based on the titration of acids in an ether extract of a skim milk culture to following a 30 mm period of lipase activity at 37 °C. It is shown that ether-soluble acids carried into the reaction medium do not interfere with the measurements and that ether-soluble acids are not produced from protein or lactose during the test. The method is applicable over a sufficiently wide pH range to make it generally adaptable in bacteriology.

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ESTIMATION OF LIPASE IN DAIRY PRODUCTS: III. LIPASE ACTIVITY IN CULTURES OF MICRO-ORGANISMS AND IN CHEESE

Canadian Journal of Research ◽

10.1139/cjr49f-053 ◽

1949 ◽

Vol 27f (12) ◽

pp. 499-503 ◽

Cited By ~ 6

Author(s):

D. J. Lubert ◽

L. M. Smith ◽

H. R. Thornton

Keyword(s):

Lipase Activity ◽

Dairy Products ◽

Lipolytic Activity ◽

Skim Milk ◽

Preceding Paper ◽

Cheddar Cheese ◽

Titration Method ◽

Number Of Species ◽

The One ◽

Micro Organisms

The lipolytic activity in skim milk cultures of micro-organisms representing a number of species and genera were studied by the extraction–titration method described in the preceding paper. No evidence was found of a bacterial lipase having an activity optimum on the acid side of neutrality. No lipase active at approximately pH 5.0 was demonstrated in 20 samples of commercial cheddar cheese of varying age or one sample of blue veined cheese on measurement by the extraction–titration method or by the Peterson et al. method. Weak lipolytic activity was found in one sample of blue veined cheese by the extraction–titration method. No lipolytic activity at pH 8.5 was demonstrated by the extraction–titration method in the one sample of cheese tested at this pH.

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INVESTIGATION OF THE FAT FRACTION ENZYMATIC HYDROLYSIS OF THE WASTE FROM PRODUCTION OF HYDROGENATED FAT BY THE LIPASE RHIZOPUS JAPONICUS

Food Science and Technology ◽

10.15673/fst.v13i1.1332 ◽

2019 ◽

Vol 13 (1) ◽

Cited By ~ 1

Author(s):

V. Skliar ◽

G. Krusir ◽

V. Zakharchuk ◽

I. Kovalenko ◽

T. Shpyrko

Keyword(s):

Thermal Stability ◽

Enzymatic Hydrolysis ◽

Lipase Activity ◽

Lipolytic Activity ◽

Complete Loss ◽

Ph Stability ◽

Hydrogenated Fat ◽

Optimum Ph ◽

Fat Fraction ◽

Hydrolysis Of

. In the article the conditions of enzymatic hydrolysis of fat fraction of waste from production of hydrogenated fat by the lipase Rhizopus japonicus are considered, namely, the influence of pH of the medium (pH-optimum, pH-stability) and temperature (thermal optimum, thermal stability). The scope of applications of lipases in various branches of the national economy, including for utilization of numerous fatty waste and by-products of oil and fat industry, is disclosed. The main reasons of biotechnological potential of microbial lipases are considered. Objects of research were the lipase Rhizopus japonicus and waste from the demetallization stage of the hydrogenated fat production. Detected, that the optimum pH value for Rhizopus japonicus lipase is 7.0, reducing the pH of the medium from the optimum to pH 6.0 is accompanied by a decrease in activity by 30%, and an increase from 7.0 to 9.0 – decrease by 20%. The maximum activity of the enzyme is observed in the region of physiological values of the temperature. It has been established that the lipase optimal temperature is 40°C. The results of the Rhizopus japonicus lipase stability study showed that incubation of the enzyme at pH 2.5 resulted in a complete loss of lipolytic activity after 30 minutes, and at alkaline pH, the enzyme was more stable. Incubation of lipase Rhizopus japonicus for 30 min at pH 9.0 leads to loss of lipolytic activity by 25% of the maximum, and total loss of activity occurs after 2.5 h. The study of pH-stability of Rhizopus japonicus lipase at an optimal pH of 7 showed that after 60 min of incubation, the enzyme lost 15% of the lipolitical activity, and after 60 min – 50%. Complete loss of Rhizopus japonicus lipase activity at pH 7.0 takes place after 150 minutes of incubation. The results of the study of thermal stability of lipase showed that at a temperature of 40°C and 60°C, the lipase activity remained rather stable for 50 minutes and completely lost after 150 minutes of incubation. At 80°C and 100°C, lipase activity was lost after 40 minutes and 50 minutes of incubation, respectively. The results of the study indicate the prospect of enzymatic hydrolysis of fat fraction of waste by Rhizopus japonicus lipase. The results obtained should be used to improve the processing technology of waste oil and fat industry food and processing industries.

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Effect of Oligosaccharide Formation on the Cryoscopic Measurements of Enzymatic Hydrolysis of Lactose in Dairy Products

Journal of Food Science ◽

10.1111/j.1365-2621.1986.tb10886.x ◽

1986 ◽

Vol 51 (1) ◽

pp. 245-246 ◽

Cited By ~ 8

Author(s):

I.J. JEON ◽

S.R. SAUNDERS

Keyword(s):

Enzymatic Hydrolysis ◽

Dairy Products ◽

Hydrolysis Of

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Microwave-assisted enzymatic hydrolysis of starch

10.3390/ecsoc-13-00159 ◽

2009 ◽

Cited By ~ 1

Author(s):

Marcin Lukasiewicz ◽

Anna Osowiec ◽

Magdalena Marciniak

Keyword(s):

Enzymatic Hydrolysis ◽

Microwave Assisted ◽

Hydrolysis Of

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Analyses of enzymatic hydrolysis of bagasse cane of sugar for obtention of ethanol employing a cocktail of natives commercials enzymes.

10.3390/mol2net-04-05300 ◽

2018 ◽

Author(s):

Ángel Batallas ◽

Erenio González ◽

Carmen Salvador ◽

Jonathan Villavicencio ◽

Humberto González Gavilánez ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Hydrolysis Of

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Faculty Opinions recommendation of Enzymatic hydrolysis of pneumococcal capsular polysaccharide renders the bacterium vulnerable to host defense.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733387483.793547056 ◽

2018 ◽

Author(s):

Mattias Collin

Keyword(s):

Enzymatic Hydrolysis ◽

Host Defense ◽

Capsular Polysaccharide ◽

Hydrolysis Of

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Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

Current Nanoscience ◽

10.2174/1573413714666180611081759 ◽

2019 ◽

Vol 15 (3) ◽

pp. 296-303 ◽

Cited By ~ 5

Author(s):

Swapnil Gaikwad ◽

Avinash P. Ingle ◽

Silvio Silverio da Silva ◽

Mahendra Rai

Keyword(s):

Catalytic Activity ◽

Enzymatic Hydrolysis ◽

Immobilized Enzyme ◽

Free Enzyme ◽

Magnetic Nanomaterials ◽

Sugar Production ◽

Cellulase Enzyme ◽

Enzymatic Hydrolysis Of Cellulose ◽

Hydrolysis Of Cellulose ◽

Hydrolysis Of

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.

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