Influence of Lipid Content and Blanching on Capelin (Mallotus villosus) Drying Rate and Lipid Oxidation under Low Temperature Drying

Abstract The drying characteristics and lipid oxidation in brined and blanched whole capelin were studied during controlled low temperature drying to establish the influence of lipid content and blanching. Drying characteristics (moisture content, drying rate and water activity) and lipid oxidation indicators ( PV , TBARS and color) were determined. Drying was influenced by blanching as well as the lipid level. Moisture content at equilibrium for brined and blanched high lipid dried capelin was 20 and 13% (a w , 0.69 and 0.62), whereas counterpart low lipid groups had 19 and 11% ( A w , 0.67 and 0.59) accordingly after 184 h of drying. Changes in PV , TBARS and color were observed as drying progressed with brined capelin exhibiting more stability in the attributes than blanched capelin. Blanched and low lipid capelin dried faster; however, blanching resulted to increased yellowness color making it unpopular for capelin drying. Practical Applications Capelin is one of the important pelagic fisheries in northern hemisphere with sustained catch stock; nonetheless, small quantities are used fresh, dried or salted for human food. In this paper, effects of lipid content and blanching on capelin drying characteristics and lipid oxidation are assessed. The study shows that lipid content affected drying characteristics as capelin with low lipid recorded reduced moisture at equilibrium. Blanching as practiced prior to drying of other small fish products in the intended markets for dried capelin affected capelin muscle water holding thereby enhancing drying but led to undesirable yellowness color and oxidation. It was recommended that dried brined capelin with low lipid content is tested for consumer acceptability prior to commercialization.