A combination process to ensure microbiological safety, extend storage life and reduce anti-nutritional factors in legume sprouts

Sprouts are consumed worldwide as a highly nutritive food. However, the sprouting process is quite supportive of microbial and pathogenic growth. This makes the sprouts such as mung (Vigna radiata), lucerne (Medicago sativa) and chickpea (Cicer arietinum), potential sources of foodborne infections and intoxications. Their microbiological analyses showed substantial microbial loads including presumptive coliforms. Around 25-42% of the presumptive coliforms showed the IMViC pattern typical to E. coli. Similarly 40-62% of the presumptive Staphylococcus species showed coagulase and catalase positive reactions indicating S. aureus contamination. To address these concerns, a combination treatment including ultrasonication, blanching, ascorbate dip and gamma irradiation was developed which ensured the microbial safety of sprouts and extended the shelf life up to 35 days for mung and chickpea, and 21 days for lucerne sprouts at 4 +/- 1 degrees C. Nutritional, physico-chemical and sensory attributes were found to be well retained during storage. Anti-nutritional factors such as phytate, trypsin inhibitors, cyanogenic glycosides and oxalate were found to be significantly reduced up to 80%. The combination treatment developed could be an effective commercial strategy for ensuring safety and, thereby, promoting greater marketability.