Some biochemical properties of trypsin inhibitor type antinutrients derived from extracts of wheat grain, Beta variety

✍ Scribed by Mossor, G. ;Skupin, J.

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 486 KB
• Volume: 29
• Category: Article
• ISSN: 0027-769X
• DOI: 10.1002/food.19850290527

✦ Synopsis

Some biochemical properties of trypsin inhibitor type antinutrients derived from extracts of wheat grain, Beta variety.

G. M o s s o ~ and J. Skupin Trypsin inhibitors were isolated and partially purified from wheat grain, Beta variety. The procedure for determination ofthe inhibitory activity was simplified. This pertains shortening ofthe reaction time as well as quantitative decrease of components in the incubation mixture.

The inhibitory fraction was salted out at 30 -65 ":,ammonium sulfate saturation. The experimental material has not been initially defatted. For isolation of the inhibitors pH 4.4 was demonstrated to be optimal. The trypsin inhibitor was characterized by relatively low activity against trypsin (1.5 "/,of soya inhibitory activity). Preparations showing inhibitory properties when stored at -I8 'C retained their original activity for 40 days, whereas at 4 "C only for 10 days, respectively. Storage at 18 "C for 10 days resulted in 50% loss ofthe original activity.

Among various factors stabilizing the inhibitory activity being studied, 2-mercaptoethanol at 0.0 I 7; final concentration was found to be most effective. Study on the effect of temperature on the antitrypsin activity revealed that the preparation retained its initial activity up to 80 'C. It has been demonstrated by wheat proteins fractionation that both albumin and globulin fractions were accompanied by the antitrypsin activity. Moreover gluten was also shown to exhibit some inhibitory activity. Variations in the inhibitory activity were evidenced during germination of wheat grain. After 2 days period of germination it tended to decrease, disappearing completely at the fifth day, respectively. The inhibitory activity appeared in coleoptile and root at fourth day of germination, being higher in coleoptile than in the roots.