Improved shelf stability of mulberry juice by combination of preservatives

Abstract

Mulberry (Morus alba L.) fruit is rich in sugar and has high nutritional value. Commercial mulberry juice is available in China but not readily available in India. In India the mulberry fruit trees are generally grown for rearing silkworms and to a small extent for its fruits sold in local markets. This study was carried out to standardize the preservation protocol for shelf stable mulberry fruit juice using low cost technology so that small scale entrepreneurship may be developed in this area. Effect of chemical preservatives, viz. potassium meta bisulphite (KMS) and sodium benzoate (SB) treatment (alone or in combination) followed by pasteurization, on physico-chemical, microbial and sensory qualities of stored juice (9 months) was studied. The results revealed that among all the treatments, combination of KMS and SB (0.05% each) followed by pasteurization of bottles at 100°C for 20 min. resulted in shelf stable juice with least physicochemical changes in terms of TSS, acidity, vitamin C, antioxidants, anthocyanin content, reducing and total sugars. No microbial contamination could be detected after 9 months of storage with maximum sensory acceptability.