activation of lactoperoxidase _lp_ system in milk and use of the lp

J.Sc. Tech ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬Vol. 10(1) 2009 ACTIVATION OF LACTOPEROXIDASE (LP) SYSTEM IN MILK AND USE OF THE LP-ACTIVATED MILK IN MANUFACTURE OF JIBNA-BEIDA (white cheese) By

Abdel Moneim E. Sulieman, Safa EL Zubier and Sirelkhatim B. El Hardallou Departmernt of Food Science and Technology, Faculty of Engineering and Technology, University of Gezira, P.O. Box 20 Wad-Medani, Sudan

ABSTRACT In the present study, lactoperoxidase system has been activated in fresh cow’s and goat’s milk and the effect of activation on the pH and acidity of milk has been investigated during storage at room (32°C), incubator (37°C) and refrigerator (5°C) temperatures by adding thiocyanate SCNֿ and H2O2 at different levels. In addition, the effect of activation on microbiological quality was investigated. All the treatments greatly improved the keeping quality of milk at ambient or higher temperatures compared to the untreated samples. The best results are achieved by adding 0.030 SCN: 0.030 H2O2 ml for cow’s milk and 0.035 SCNֿ: 0.040 H2O2 ml for goat’s milk. In addition, slight improvements in the keeping quality of the LP-activated milk were observed when the milk was kept in a refrigerator. Jibna-beida (white cheese) (a semi-indigenous Sudanese cheese) was made from control cows milk (CCJ), control goat milk (CGJ), LPactivated cow’s milk cheese (LP-CJ) and LP-activated goat’s milk cheese (LPGJ). Activation of LP system allowed the production of Jibna-beida (white cheese) with high value, good keeping quality and high cheese yield. This cheese is accepted by panelists.

@ @Z—‚ܽa