Effect of Pretreatments and Drying Methods on Quality Attributes and Safety of Dried Shrimp (Pandalus borealis)

Abstract

This study was conducted to evaluate the quality attributes and safety assessment of dried shrimp treatments as affected by immersion process, type of immersion solution(sodium bisulphate and sodium tripolyphosphate) and drying methods (sun and oven drying) during storage at room temperature (25ºC±2ºC) up to 6 months. Keeping quality of these treatments during storage was evaluated by studying chemical composition, physicochemical, organoleptic properties and microbiological aspects. Results indicated that, fresh shrimp contained 79.20% moisture, 17.63% crude protein, 0.98 % crude fat and 2.19 % total ash. Also, significant differences (p> 0.05) were recorded in both chemical composition and all physicochemical properties between different dried shrimp treatments either at zero time or along storage periods. Sun dried samples had higher moisture content, TVN, TMAN and TBA values and were slightly lower in each crude protein, crude fat and pH values than shrimp samples dried by oven drying. Also, chemical composition of dried shrimp samples was not significantly affected by the type of immersion solution. Dried samples which immersed in sodium bisulfate had slightly higher TBA values and lower moisture content, pH values, TVN and TMAN than dried samples which immersed in sodium tripolyphosphate. Also, microbial load of dried shrimp samples was slightly affected by immersion process and the type of immersion solution. Dried shrimp samples which immersed in sodium bisulfate or sodium tripolyphosphate were lower microbial load (TBC, HB and yeast & mold) than samples prepared without immersion process. Moreover, dried shrimp samples which immersed in sodium bisulphate were slightly lower in both TBC and HB than that immersed in sodium tripolyphosphate. During storage periods, pH values, TVN, TMAN and TBA values and microbial load progressively increased as the period of storage increased for all dried shrimp samples. Finally, Sensory properties of fried sun dried shrimp samples were lower than those oven dried samples. Also, immersion in both sodium bisulfate and sodium tripolyphosphate led to improve the sensory properties of fried shrimp samples.