STUDYING ON THE FERMENTATION USING IMMOBILIZED YEAST IN ALGINATE GEL IN THE DRYING PROCESS OF MIRACLE FRUIT POWDER (Synsepalum dulcificum)

Abstract

Miracle fruit with a miraculin component can modify the taste perception of food. The research investigated the possibility of processing miracle fruit powder that retains the above interesting properties and is convenient when added to other foods. Removing sugars by fermentation to support the drying process of fruit powder is a simple, economical method and still maintains the activity of miraculin. The fruit juice fermentation used immobilized yeast on alginate gel with the yeast particle ratio of 0.5, 1.0 and 1.5% to ferment fruit juice for 30, 60 and 90 minutes at environmental temperature. The fermented fruit juice was freeze-dried into fruit powder. The recovery efficiency, sugar decreasing efficiency, powdering ability, and miraculin activity through the change in the recognition threshold for basic tastes when using miracle fruit powder were determined. The fruit powder with the suitable parameters of the fermentation was mixed with pure orange juice product at the ratios of 0, 0.25, 0.5, 0.75 and 1%. The consumer acceptability of the product was evaluated. The results showed that using 1.5% of immobilized yeast to ferment the fruit juice for 30 minutes produced a high-quality miracle fruit powder product, high miraculin activity maintained through the results of a decrease in the sweet taste threshold, an increase in the sour and bitter taste threshold and almost no effect on the salty taste threshold. The addition of 0.5 – 0.75% of miracle fruit powder significantly improved consumer acceptability of pure orange juice products by up to 90%.