Effects of Turmeric and Salt on Proximate Composition, Microbial Load and Organoleptic Quality of Treated Sun Dried Mystus gulio

Abstract

Drying is a common method of long term fish preservation. However, the study has been conducted for 60 days to assess the proximate composition (protein, lipid, moisture and ash) total bacterial load (CFU/g) and organoleptic quality of fresh Nuna Tengra (Mystus gulio), collected from local market, treated with 3% salt (by weight) and 3% salt and different levels of turmeric powder (2, 3 and 4% of body weight) prior to drying in solar-tent dryer were designated as T-1, T-2, T-3 and T-4 respectively. Proximate composition in every 10 days intervals for 60 days showed highest (P<0.05) protein content, among the treatments, in T-2 (58.97% ± 0.05) however, no difference (P > 0.05), with progress in storage duration, in T-2 was observed. Lipid and ash content, among the treatment, varied from 5.80% to 13.3% and 11.12% to 15.23% respectively that showed no significant difference (P > 0.05). Statistically (P < 0.05) lowest moisture content (12.56% ± 0.15) was also observed in T-2. Total bacterial load drastically lowered in all treatments than the fresh fish (8.63 × 10⁵ CFU/g). Control showed highest (P < 0.05) bacterial load in both 30ᵗʰ and 60ᵗʰ day of preservation (58.70 × 10³ and 62.80 × 10³ CFU/g respectively) than the others and that of the lowest (P < 0.05) was observed in T-4 followed by T-3 (1.78 × 10³ and 1.82 × 10³ and 2.14 × 10³ and 2.23 × 10³ CFU/g respectively). Total bacterial load gradually decreased in drying process and observed to decrease significantly (P < 0.05) with the increase in turmeric concentration together with salt prior to drying. However, organoleptic quality assessment of the treatments showed the highest score in T-2. Considering the nutritional value, bacterial load and organoleptic assessment it reveals that treated M. gulio with 3% salt and 2% turmeric prior to drying can retain it quality better for storage.