Storage and packaging of roasted quality protein maize (QPM) bar: physical, chemical and microbial studies

Abstract

Microbial safety of cereals products is essential due to its extensive utilization as staple food for humans. Aiming at increased shelf-life of staples, nutritious bar was developed using roasted QPM and assessed for its shelflife stability in view of different packaging materials (aluminum (AL) and High-density polyethylene (HDPE)) at diverse storage intervals i.e. 0, 30, 60, 90, and 120 days, respectively. For this, physical, chemical and microbial analyses were performed. The stored bar was ‘liked moderately’ till 60 days and ‘liked slightly’ during the storage period of 90 and 120 days, in both AL and HDPE pouches. The moisture content of the bar was increased by 12.82 per cent and 11.17 per cent in AL and HDPE pouches, correspondingly which affected bar’s texture. The value of browning index (OD) was significantly (p> 0.001) declined at 30th and 120 days. The free fatty acid content (% oleic acid) was different in HDPE and AL packaged bars; however, this difference was nonsignificant at 5% level. The microbial load was within the safest limits in the bar stored in HDPE pouches for 120 days and in AL pouches for 90 days, respectively. The bar stored in HDPE pouches was highly acceptable and shelf-stable till four months at refrigerated conditions.