Proteolysis of milk heated at high temperatures by native enzymes analysed by trinitrobenzene sulphonic acid (TNBS) method
Autor: | Lucy M. Chove, Michael J Lewis, Ison, Abdulsudi Issa Zacharia, Alistair S. Gr |
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Rok vydání: | 2013 |
Předmět: |
Marketing
chemistry.chemical_classification Economics and Econometrics Heat resistant medicine.diagnostic_test Plasmin General Chemical Engineering Proteolysis Food spoilage food and beverages Pasteurization Raw milk law.invention Enzyme Isoelectric point chemistry law medicine General Materials Science Food science medicine.drug |
Zdroj: | African Journal of Food Science. 7:232-237 |
ISSN: | 1996-0794 |
Popis: | Native enzymes play a significant role in proteolysis of milk during storage. This is significant for heat resistant native enzymes. Plasmin is one of the most heat resistant enzymes found in milk. It has been reported to survive several heat treatments, causing spoilage during storage. The aim of this study was to assess susceptibility of high temperature heated milk to proteolysis by native enzymes. The trinitrobenzene sulphonic acid (TNBS) method was used for this purpose. Raw milk was heated at 110, 120, 130,142°C for 2 s and 85°C for 15 s and milk processed at low temperature (85°C /15s) was selected to mimic pasteurisation. TNBS method confirmed that raw milk and milk processed at 85°C /15s were the most proteolysed, whereas treatment of milk at high temperatures (110, 120, 130 and 142°C for 2 s) inactivated the native enzymes. It may thus be concluded that high temperature processing positively affects proteolysis by lowering its susceptibility to spoilage during storage. Key words: Plasmin, proteolysis, trinitrobenzene sulphonic acid (TNBS), heat treatment, isoelectric precipitation. |
Databáze: | OpenAIRE |
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