Efficient three phase partitioning of actinidin from kiwifruit (Actinidia deliciosa) and its characterization.

Three phase partitioning (TPP) method was effectively utilized for the extraction and purification of milk clotting protease (actinidin) from the kiwifruit pulp. The different purification parameters of TPP such as ammonium sulfate saturation, ratio of the crude kiwifruit extract to tert-butanol, and the pH value of extract were optimized. The 40% (w/v) salt saturation having 1.0:0.75 (v/v) ratio of crude kiwifruit extract to tert-butanol at 6.0 pH value exhibited 3.14 purification fold along with 142.27% recovery, and the protease was concentrated exclusively at intermediate phase (IP). This fraction showed milk-clotting activity (MCA), but there was no such activity in lower aqueous phase (AP). The enzyme molecular weight was found to be 24 kDa from Tricine SDS-PAGE analysis. Recovered protease demonstrated greater stability at pH 7.0 and temperature 50 °C. The Vmax and Km values were 121.9 U/ml and 3.2 mg/ml respectively. Its cysteine nature was demonstrated by inhibition studies. This study highlighted that the TPP is an economic and effective method for extraction and purification of actinidin from kiwifruit, and it could be used as a vegetable coagulant for cheesemaking.

Extraction and process optimization of bael fruit pectin.

Pectin was extracted at temperature of 100 and 120°C with two different pH conditions each, pH 1.5 and pH 2 along with different extraction ratios, ER1:1, 1:1.5 and 1:2 respectively. Data obtained were analyzed statistically using ANOVA (no blocking) at 5% level of significance, which showed that there was significant difference (p < 0.05) between the pectin extracted at 100°C, pH 1.5 and extraction ratios of 1:1, 1:1.5, and 1:2, respectively, whereas there was not any significant difference between extraction at 120°C, pH 1.5 and extraction ratios of 1:1, 1:1.5, and 1:2 respectively. Also, there was no any significant difference between pectin extracted at 100°C, pH 2, extraction ratios 1:1, 1:1.5, and 1:2 and also at 120°C, pH 2, 1:1, 1:1.5, and 1:2 respectively. Best yield of pectin was found at temperature 120°C, pH 1.5 and ER 1:1.5.