Extraction, partial purification and some factors affecting milk clotting activity of a milk coagulant prepared from sunflower (Helianthus annus)‎ seeds

Abstract EN

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.