Comparison of super and common bags for storage of Rastrineobola argentea

Abstract

The silver fish (Rastrineobola argentea) is an important source of income and nutrition to the population. However, R. argentea value chain incurs physical and quality losses due to spoilage resulting from porousness of conventional bags which freely allow pests, moisture and oxygen. The study evaluated the efficacy and commercial viability of super bags (two layers), pic (three layered) and conventional bags (one layer) for storage of R. argentea. Samples of pests were collected, identified and characterized based on morphological features from stores at Kiyindi landing site, Lake Victoria. Sensory changes (color, smell, texture) and acceptability were assessed weekly for 5 weeks. Results revealed that moisture, pests and residue differed significantly (p<0.05) among the storage bags decreasing with increasing layers of bags. The changes in weight among the bags didn’t differ significantly (p>0.05).The most dominant residing pest was Necrobia rufipes (62.6%), followed by the visiting pests Megaporea foetens 15%, Lardoglyphus spp. (9.4%),Linepithema humile (8.8%), Musca domestica (2.7%) and Periplaneta americana (1.0%). Sensory test scores and acceptability were relatively high for layered bags compared to none layered and these differed significantly except for color(p<0.05). Extrapolations of attained losses with costs for full sack in the same storage duration indicated that least losses (weight and financial) would be incurred with layered bags than non-layered ones. The layered bags provided limitation for moisture, pests which accounted for fewer residues however the changes in weight weren’t significant due to the slightly less number of pests and moisture in the overall storage duration to cause significant weight changes through feeding and residue formation from softening and fragmentation by moisture. Overall, the multilayered bags were more effective than none layered in safe storage of R. argentea. Visiting pests and residing pests affected stored R.argentea. Salting, separate storage of new and old processed catch alleviate cross infestations, adoption of layered bags, insulated storage room and storage off ground on pellets would potentially mitigate both physical and quality losses and extend shelf life.