Changes in Microbial and Functional Properties of Lima Bean (Phaseolus lunatus) Flour During Storage

Abstract

Lima bean is a nutritious food legume. In addition to nutritional value of food product, its keeping quality and functional properties during storage are also important in determining the quality of the food for consumption. The study aimed at evaluating the microbial and functional properties of lima bean flour during storage. Lima bean was processed into flour, packaged in low density polyethylene bag and stored at ambient (28 ± 2 o C) temperature for twenty-four weeks. The stored samples were evaluated for microbial (Total viable count and mold count) and functional properties (Bulk density, water and oil absorption capacity, foaming capacity, emulsion capacity and dispersibility). Total viable count (TVC) increased from 1.60 log cfu/g at week 0 to 4.25 log cfu/g at week 24 of storage. There was no mold growth till week 12 of storage. Mold count increased from 1.77 log cfu/g in week 12 to 3.77 log cfu/g in week 24. Both TVC and mold counts in the lima flour were far lower than the recommended limit of 10 6 cfu/g for TVC and 10 3 cfu/g for mold count respectively by International Microbiological Standards. There was no significant difference (p>0.05) in the bulk density of the lima bean flour at storage. Water absorption capacity, oil absorption capacity, foam capacity, emulsion capacity and dispersibility decreased slightly with storage time. The study showed that lima bean flour is safe for consumption and can serve as a potential functional food ingredient in food products formulation without much changes in its functional properties over a period of twenty-four weeks.