Antioxidant activities and physicochemical properties of chocolate fermented by Lactobacillus plantarum CK10

Abstract

In this study, antioxidant activities and physicochemical properties of chocolate fermented with Lactobacillus plantarum CK10 were investigated. The pH level decreased from 5.26±0.02 to 3.98±0.06 during fermentation while titratable acidity increased from 5.36±0.19 to 13.31±0.34. The total polyphenol and flavonoid contents slightly increased during fermentation, but it was numerically negligible. Slight increase and decrease in the radical scavenging activities of chocolate, against DPPH-, ABTS-, and alkyl-radical, were observed during 32 hr of fermentation, but the changes were not statistically relevant. Composition ratios (% area by GC analysis) of lactic acid, xanthosine, and theobromine increased with fermentation time while hydroxymethylfurfural (HMF) and caffeine decreased after 32 hr of fermentation, in the order of xanthine (22.7%), theobrome (20.0%), lactic acid (14.9%), HMF (9.1%) and caffeine (9.0%). However, there was no remarkable changes in theobromine and caffeine contents in chocolate during fermentation.