Effect of postharvest handling processes on the nutrient, chemical composition and sensory properties of silver cyprinid powder

Abstract

Background; The proper post-harvest handling processing of the highly perishable silver cyprinid (Rastrineobola argentea) could contribute towards alleviation of food insecurity by directly acting as a food resource and through employment for income generation among vulnerable groups. Despite the many processing techniques used, the quality and value of silver cyprinid still remains low. This research was carried out to establish how effective different post-harvest handling processes are in improving the quality (nutrient content, chemical and sensory properties) of silver cyprinid powder. Methodology; The silver cyprinid was subjected to different conditions: soaking in varying concentrations of NaCl (0.5%, 1%, and 1.5%), varying concentrations of acetic acid (0.05%, 0.1% and 0.15%), blanching at varying temperatures (40oC, 50oC, 60oC) and sun-drying as control. Determined the proximate, chemical and sensory properties. Results; Results showed that the different postharvest handling processes had significant effects on the proximate, chemical and sensory properties of the silver cyprinid powered. Increasing the NaCl concentration led decrease in proximate composition (Total ash, crude fat, moisture content and crude protein). Increase in NaCl also caused increase in chemical properties (pH and Thiobarbituric acid reactive substances (TBARS) of the silver cyprinid powder. Increasing acetic acid concentration on the other caused variations in proximate composition; the moisture and ash content decreased while the protein and fat content increased. Increase in acetic acid concentration also led to a decrease in chemical properties, pH and TBARS. Increasing the blanching temperature on the other hand caused a decrease in all the proximate properties and pH but increased the thiobarbituric acid content. Soaking silver cyprinid in NaCl yielded sauces with higher consumer acceptability than those subjected to other treatments. Conclusion ; The study therefore revealed that treatment with 1% NaCl would be recommended to be used as preprocessing condition that maintains the nutrient and chemical quality of the fish and produces sauces with acceptable sensory characteristics.