Microbial Stability of Mango (Mangifera indica L.) Juice Preserved by Combined Application of Mild Heat and Extracts of Two Tropical Spices

Abstract

The microbial stability of mango (Mangifera indica L.) juice (pH 4.9) supplemented with extracts of ginger (Zingiber officinale) and nutmeg (Myristica fragrans) was investigated during 3 months of ambient-temperature storage. Heating at 55°C for 15 min markedly reduced the levels of non-spore-forming bacteria and produced a product with acceptable taste. Supplementing mango juice with an agueous extract of ginger (15%, vol/vol) or nutmeg (20%, vol/vol) inhibited the growth of challenge microorganisms, but produced a product with unacceptable taste. Heating the mango juice at 55 °C for 15 min and supplementing with nutmeg (4%, vol/vol) and ginger (4%, vol/vol) markedly inhibited microbial growth and produced a product with acceptable taste. Tropical spices may prove useful in preservation of fruit juices by hurdle technology.