Storage stability of a stimulant coconut water-acerola fruit juice beverage

The objective of this work was to study the stability of a beverage formulated with acerola fruit juice and green coconut water with added caffeine. The beverage was prepared with 25% acerola pulp, 75% green coconut water and sugar up to 12 degrees Brix, and caffeine (125 mg L-1), heat processed at 90 degrees C for 30 s and packed in 250-mL glass bottles. Chemical, physicochemical, microbiological and sensory analyses of the beverage were performed just after processing and during 6 months of storage at room temperature (27 degrees C). The vitamin C content decreased significantly throughout storage, from 399.5 to 189.6 mg 100 mL(-1), although it has remained relatively high. The anthocyanins initially present (0.025 mg 100 mL(-1)) were completely lost during the storage at a mean rate of 4 mu g 100 mL(-1) month(-1). The product was microbiologically stable during storage. Colour changes were also observed with absorbance at 420 nm, with average values ranging from 0.19 to 0.24. However, according to the sensory analyses the product was acceptable during the 6 months of storage, presenting sensory scores (colour, taste and global acceptance) from 6.5 to 5.5, which suggests its potential for market.