ENZYMES ACTIVITY DYNAMICS AT AUBERGINE PROCESSING
BELINSKA Svetlana,
Doctor of Technical Sciences, Professor of KyivNational University of Trade and Economics
ENZYMES ACTIVITY DYNAMICS AT AUBERGINE PROCESSING
Background. Managing directions and speed of biochemical processes helps minimize the loss of biologically active substances inherent in plant material, stabilize color, smell and taste during freezing and low temperature storage. To prevent unwanted enzyme changes in the eggplant processing instead of blanching holding them in a salt solution prior to freezing was proposed. The effect of pre-treatment to reduce ascorbic acid ascorbic oxidase and polyphenol oxidase activity and preservation of color and vitamin C-value of frozen products has been studied.
The aim of the study is scientific substantiation of method of reducing the activity of eggplant enzymes to obtain frozen products with minimal loss of vitamin value and change of organoleptic properties.
Material and methods. Object of study – eggplant of Almaz variety. We determined ascorbic oxidase activity, polyphenol oxidase (in arbitrary units – mmol ascorbic acid oxidized for 1 min) by Pochynok [12], ascorbic acid content by standard [13]in eggplant without treatment (control sample) and soaked in a solution of sodium salt (research sample) prior to freezing and for 9 month low-temperature storage every 3 months.
Results. Duration of eggplant exposure and optimal concentration of salt solution was determined on the basis of experimental results and application of methods of correlation and regression analysis and mathematical modeling, namely 9 min in 3 % salt solution.
In eggplant during freezing and after 9 months low temperature storage losses without the use of ascorbic acid pretreatment are 39 %, with the use of it – 27%.
During freezing ascorbic oxidase activity in eggplant without treatment decreased 2.4 times, in soaked in salt solution – 5.3, and compared to the samples without pre-treatment –15.2 times.
After holding eggplant in a solution of salt polyphenol oxidase activity is reduced by 36.2 %, and after freezing compared to fresh raw materials by 58.9 %. In control sample eggplant enzyme activity is reduced to 35.6 % compared with fresh fruit.
Conclusion. The proposed method of polyphenoloxidase and ascorbic oxidase inactivation promotes preservation of color and vitamin value of frozen eggplant without substantial change of its consistency.
Keywords: quick-frozen eggplant, ascorbic oxidase, polyphenol oxidase, ascorbic acid.
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