Effects of Turmeric and Salt on Proximate Composition, Microbial Load and Organoleptic Quality of Treated Sun Dried Loitta (Harpadon nehereus)

Abstract

Studies were conducted to produce good quality of dried loitta fish (Harpadon nehereus) by combining the effect of salt (by weight) salt and 3% salt and different levels of turmeric powder (2, 3 and 4% of fish body weight) prior to drying in solar-tent dryer were entitled as T-1, T-2, T-3 and T-4 respectively. Quality changes in dried products under different treatments were assessed at every 10 days intervals of 60 days storage periods through proximate composition (protein, lipid, ash and moisture), microbial load (CFU/g) and organoleptic aspects. The highest and lowest level of protein, lipid, moisture and ash were found 62.82±0.29 to 56.64±.03, 11.12±0.02 to 7.039±0.05, 17.09±0.08 to 13.33±0.12 and 14.52±0.07 to 10.12±0.09 respectively with 60 days of storage. Statistics showed highest level of protein content on T-2 significantly varies (P <0.05) from other treatments at 20ᵗʰ, 30ᵗʰ, 40ᵗʰ and 50ᵗʰ day of preservation. However, at 60ᵗʰ day of preservation the highest value of protein percentage found 62.24±0.10 on T-2 and 60.94±0.30 on T-3 showed no significant difference (P >0.05) to between the treatments. The lipid content was highest 10.16±0.02 and 10.11±0.12 at T-3 and T-4 varies significantly (P<0.05) from other treatments at 60 days of preservation. Statistically (P <0.05) lowest moisture content (13.96±0.08) was also observed in T-2. At 60ᵗʰ day of preservation the highest value of ash content found 14.13±0.04 in T-4 varies significantly (P <0.05) with other treatments. Effect of salt and turmeric was investigated on the bacteriological properties of dried fish. Control showed highest (P < 0.05) bacterial load in both 30ᵗʰ and 60ᵗʰ day of preservation (6.740±0.07×10⁴ and 7.33±0.07×10⁴ CFU/g respectively) than the others and that of the lowest (P <0.05) was observed in T-4 (1.96±0.08×10³ and 2.22±0.08×10³ CFU/g) followed by T-3 (2.43±0.05×10³ and 2.56±0.04×10³ CFU/g) and T-2 (3.26±0.04×10³ and 2.79±0.05×10³ 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. Among the all other treatments salt and turmeric treated fish, T-2 showed top most scores for skin appearance, color, texture and odor. Considering the nutritional value, bacterial load and organoleptic assessment it reveals that treated Loitta (Harpadon nehereus) with 3% salt and 2% turmeric prior to drying can maintain it quality better for storage.