Factors affecting milk clotting activity of sweet leavening extract involved in coagulation of a yoghurt-like product

1996 ◽  
Vol 55 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Ching-Yun Kuo ◽  
Feng-Sheng Wang ◽  
Chin-Wen Lin
Keyword(s):  
Factors Affecting ◽  
Milk Clotting ◽  
Milk Clotting Activity

A novel milk-clotting enzyme from Aspergillus oryzae and A. luchuensis is an aspartic endopeptidase PepE presumed to be a vacuolar enzyme

2022 ◽  
Author(s):  
Yoko Takyu ◽  
Taro Asamura ◽  
Ayako Okamoto ◽  
Hiroshi Maeda ◽  
Michio Takeuchi ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Proteolytic Activities ◽  
Homologous Enzyme ◽  
Traditional Fermentation ◽  
Enzyme Source ◽  
Cheese Production ◽  
Milk Clotting Activity ◽  
Aspartic Endopeptidase

Abstract Aspergillus oryzae RIB40 has 11 aspartic endopeptidase genes. We searched for milk-clotting enzymes based on the homology of the deduced amino acid sequence with chymosins. As a result, we identified a milk-clotting enzyme in A. oryzae. We expected other Aspergillus species to have a homologous enzyme with milk-clotting activity, and we found the most homologous aspartic endopeptidase from A. luchuensis had milk-clotting activity. Surprisingly, two enzymes were considered as vacuole enzymes according to a study on A. niger proteases. The two enzymes from A. oryzae and A. luchuensis cleaved a peptide between the 105Phe-106Met bond in κ-casein, similar to chymosin. Although both enzymes showed proteolytic activity using casein as a substrate, the optimum pH values for milk-clotting and proteolytic activities were different. Furthermore, the substrate specificities were highly restricted. Therefore, we expected that the Japanese traditional fermentation agent, koji, could be used as an enzyme source for cheese production.

Milk clotting activity and production of bioactive peptides from whey using Maclura pomifera proteases

LWT ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Maria Alicia Corrons ◽  
Juan Ignacio Bertucci ◽  
Constanza Silvina Liggieri ◽  
Laura María Isabel López ◽  
Mariela Anahí Bruno
Keyword(s):  
Bioactive Peptides ◽  
Maclura Pomifera ◽  
Milk Clotting ◽  
Milk Clotting Activity

Measurement of milk clotting activity by rotational viscometry

2011 ◽  
Vol 78 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Mandy Jacob ◽  
Martin Schmidt ◽  
Doris Jaros ◽  
Harald Rohm
Keyword(s):  
Standard Method ◽  
Small Amplitude ◽  
Clotting Time ◽  
Milk Clotting ◽  
Rotational Viscometry ◽  
Milk Gelation ◽  
Reconstituted Milk ◽  
Flocculation Time ◽  
Milk Clotting Activity

Standard method for the determination of the activity of milk coagulants is the rotating bottle method, where clotting time is defined as the time when visually observable flocculation starts. Aim of this study was to verify whether it is possible to determine milk clotting time by rotational viscometry. Using three different coagulants and reconstituted milk of different pH and temperature, flocculation time and viscosity in steady shear was determined, and milk gelation was monitored by small amplitude oscillating shear rheometry. The results show that, independent of pH and temperature, milk clotting time is related to an apparent viscosity of 7·24±0·45 mPa.s, indicating that rotational viscometry can be used for the screening of flocculation time with an accuracy of approximately 6%.

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