FERMENTATION OF MIXED BEETROOT JUICE WITH LACTIC ACID BACTERIA AND RECYCLING STARTER

Abstract

The purpose of this research was to studying the optimum formula of mixed beetroot juice for fermentation with Lactobacillus pentosus that acceptable of customers, studying the change of total soluble solid, percent of lactic acid, pH and viable cell of L. pentosus during beetroot juice fermentation, recycling, and storage of fermented beetroot juice at 4 o C, and studying the nutritional value of fermented beetroot juice. The result showed that, the optimum formula of beetroot juice for fermentation were as follows : 50 % (v/v) beetroot juice, 25 % (v/v) pineapple juice and 25 % (v/v) distilled water. During 48 hours of fermentation, total soluble solid was decreased from 15.00 to 14.10 o brix, lactic acid was increased from 0.214 to 0.612 %, pH value was decreased from 3.95 to 3.17, and viable cell of L. pentosus was increased from 9.40 x 10⁶ to 6.50 x 10¹⁰ colony/ml. The change of sixth recycling starter culture were as follows: total soluble solid was stable, lactic acid was increased, pH value was decreased, and viable cell of L. pentosus was increased from 10⁶ to 10¹⁰ colony/ml. The fermented beetroot juice had high nutritional value and suitable for probiotic beverage, such as carbohydrate include fiber, protein, energy, potassium and probiotic of L. pentosus, The fermented mixed beetroot juice can be storaged at 4 o C for 30 days.