Abstract

This work was aimed at producing juice from soursop (Annona muricata L.) and understudying its storage stability at refrigeration (4°C) and ambient (28°C) temperatures. Physicochemical, microbiological and sensory qualities of the juice were analysed before they were stored for 8 weeks. Changes in physicochemical quality and microbiological quality were analysed regularly during the period of storage. Results showed that processing affects the physical and chemical composition of the soursop pulp. The soursop juice was found to be microbiologically safe for consumption. Results showed that the soluble solid of the pasteurized juice was more stable at 4°C than at 28°C. More acid was produced in the juice at higher temperature (28°C) than at lower temperature (4°C) during storage. Results have shown that pasteurisation of soursop juice reduced microbial counts from 3 x 10⁵ to < 10x10¹ cfu/g for mesophilic aerobic counts and 27.5 x 10⁶ to < 10 x 10¹ cfu/g for moulds and yeasts.

Key words: Soursop juice, storage stability, physicochemical quality, microbiological quality.