Evaluation of the Effects of Preservation Methods on the Physical, Sensory Quality Attributes and Microbial Activity of Eri Silkworm (Samia ricini D.) Pupae

Abstract

Eri silkworm pupae, Samia ricini (Donovan), are a nutrient-rich by-product of eri silk production and are traditionally consumed in parts of North-East India. However, their high perishability limits storage, utilisation, and value addition. The present study evaluated the effects of three preservation methods on the physical, sensory, and microbial quality attributes of eri pupae during 30 days of ambient storage. The experiment was conducted in a completely randomised design (CRD) with three treatments and three replications. Physical and sensory attributes were assessed by a trained five-member panel at five-day intervals using a five-point hedonic scale, while microbial quality was evaluated through colony enumeration and Gram staining. All treatments maintained high sensory acceptability up to 10 days of storage. Thereafter, quality declined more rapidly in T₁ and T₂, whereas T₃ (10% brine cooking + 5% salt + 10% vinegar) retained superior quality throughout the storage period. T₃ recorded the highest overall sensory score (4.44 ± 0.90), significantly higher than T₁ (3.06 ± 1.73) and T₂ (3.00 ± 1.70). Preliminary microbial assessment after 30 days indicated lower colony development in T₃ compared with the other treatments. The results indicate that the combined use of brine, salt, and vinegar can effectively improve the short-term preservation and sensory quality of eri silkworm pupae under ambient storage conditions. Further studies involving detailed microbial quantification and large-scale validation are required before commercial application.