EXTRACTION, PARTIAL PURIFICATION AND SOME FACTORS AFFECTING MILK CLOTTING ACTIVITY OF A MILK COAGULANT PREPARED FROM SUNFLOWER (Helianthus annus) SEEDS | ||
| Zagazig Journal of Agricultural Research | ||
| Article 16, Volume 46, Issue 2, March and April 2019, Pages 441-453 PDF (430.17 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/zjar.2019.33399 | ||
| Authors | ||
| Islam I. Ramadan* ; E. M. Abd El-Wahed; A. M. Rabie; A. A. Abdel Baky | ||
| Food Sci. Dept., Fac. Agric., Zagazig Univ., Egypt | ||
| Abstract | ||
| Crude extract of sunflower seeds was prepared using different extractants (distilled water, 5% NaCl in distilled water, 5% NaCl in acetate buffer pH 5.0) and certain mixing ratios (1:2, 1:5 and 1:10 seeds powder : extractant, respectively). Using of 5% NaCl in acetate buffer pH 5.0 at mixing ratio of 1:5 gave an extract with reasonable efficient clotting properties. Ammonium sulphate at 40-60% concentration was used in one single step for the partial purification of the extract. Ammonium sulphate, (40-60%) fraction showed milk clotting and specific activities of 440 sec and 2.30 U/mg protein, respectively. Meanwhile a yield percentage and a fold of purification of 28.58 and 2.02 were achieved. Clotting/proteolytic activity, water holding capacity and curd synersis of the partially purified extract approved those of commercial calf rennet indicating the suitability of the extract as a rennet substitute. The optimum temperature, pH, Cacl2 and GDL concentration of the resultant extracts were found to be 65°C, 5.0, 0.04 % and 0.4%, respectively. | ||
| Keywords | ||
| Sunflower seed; milk clotting activity; crude protein extracts; proteolytic activity; rheological analysis | ||
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