Extraction of jojoba tannins and their role in protein-tannin complex formation and digestive proteases inhibition.

Abstract

Jojoba albumins and globulins were treated with jojoba tannins to study the protein-tannin complex formation. Trypsin and chymotrypsin were also treated with jojoba tannins to determine the change of enzymatic activity. The treated albumins and globulins were fractionated by gel filtration before and after treatment. Two albumin fractions did not appear after treatment, but a new fraction appeared with a shorter elution time. A precipitate was formed by addition of jojoba tannins to the jojoba globulins, and two globulin fractions did not appear after treatment. Trypsin was completely inhibited by 5.80 μg of tannin/ml. Chymotrypsin was completely inhibited by 36.44 μg of tannin/ml. Seven two-hour successive extractions with methanol were sufficient to obtain a jojoba meal which, when mixed at 15% in a ration with soybean, resulted in excellent growth of mice. Detannification of jojoba meal with methanol and acid methanol extracted other toxicants, because mice fed 15% of this jojoba meal gained more weight than the control. Acid methanol extraction was more effective than methanol or aqueous extraction in removing tannins; water extracted more protein and less tannin.