ABSTRACT
The presence of cyanogenic glycoside amygdalin and prunasin, and of ß-glucosidases which hydrolyze these molecules, causes potential toxicity in peach kernel by the possible hydrogen cyanide release, disabling the use of the kernel and their sub-products as foods. Until now, no data are available in the literature on the conditions of the enzymes hydrolysis present in this material. This study aimed to measure the amygdalin content, and the optimal conditions of pH, temperature and substrate concentration of ß-glucosidases crude extract for the enzymatic activity. The results showed the presence of the glycoside in peach almond in levels similar to those found for other almond kernels. Regarding the activity of ß-glucosidase, the enzyme showed Km and Vmax of 2.7 mmol L-1 of amygdalin and 0.1407 mmol of glicose.min-1.mg-1 of protein respectively, values ??that indicate lower affinity for amygdalin substrate than purified enzymes that catalyze the same reaction. The optimum pH of the enzyme was 7.0, but between 5.0, 6.0 and 8.0 high activity still occurs. The enzyme showed stability at the temperatures employed in this study, with maximum activity at 60 ° C. Thus, the use of these changes is not sufficient for enzyme inactivation and safe use of peach kernels.
Index terms
amygdalin; hydrogen cyanide release;
Prunus persica
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