Open AccessFermentation of red pitahaya extracts using Lactobacillus spp. and Saccharomyces cerevisiae for reduction of sugar content and concentration of betacyanin content
Author(s) -
Ashwini Gengatharan,
Garys A. Dykes,
Wee Sim Choo
Publication year - 2021
Publication title -
journal of food science and technology/journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.656
H-Index - 68
eISSN - 0975-8402
pISSN - 0022-1155
DOI - 10.1007/s13197-021-05116-2
Subject(s) - fermentation , food science , sugar , chemistry , lactobacillus casei , yeast , lactobacillus plantarum , lactic acid , lactobacillus acidophilus , lactobacillus brevis , brix , bacteria , biology , probiotic , biochemistry , genetics
A study was conducted to concentrate the betacyanin in red pitahaya extracts by removing the coexisting sugars by fermentation. Four lactic acid bacteria ( Lactobacillus acidophilus , L. casei , L. rhamnosus and L. plantarum ) and a yeast species ( Saccharomyces cerevisiae ) were screened to determine their efficiency to reduce sugar content in red pitahaya extracts for concentration of their betacyanin content. A reduction of sugar content (19.8-56.4%) and increase in the yield of betacyanins were observed in all extracts as compared to the control, which was not innoculated with any microorganisms after 1 day of fermentation. The lowest total sugar content (26.40 g/L) was observed in extracts fermented by S. cerevisiae . Extracts fermented by S. cerevisiae also showed greater numbers of microbial cells (10.75 log CFU/mL) and a lower pH value (3.54) compared to those (6.89-8.48 log CFU/mL and pH 4.64-5.42) of the Lactobacillus spp. after 1 day of fermentation. An optimization step using response surface methodology (RSM) was then conducted using S. cerevisiae. Temperature, time and agitation speed were found to have a significant effect on the total sugar content and BC of concentrated betacyanins from red pitahaya, while the yield of betacyanins was significantly influenced by temperature and agitation speed.