Physicochemical properties and composition of Snakehead fish (Channa striatus) whole fillet powder prepared with pre-filleting freezing treatments

Channa striatus (“haruan”) fish destined for fillet preparation was subjected to two freezing treatments, freezing with distilled water (FW) or freezing directly without distilled water (DF). Fish that was freshly processed without freezing served as control (C). Fillet yield (%) was in the range 33.8% to 35.3% and the highest yield was recorded in FW samples. Whole Fillet Powder (WFP) was prepared from the fillets through low temperature vacuum oven drying (50°C) and its composition and physicochemical properties were assessed. There was no significant difference in moisture and protein contents of all samples (p > 0.05). All WFP were generally dark in colour with whiteness indices ranging from 55.23 63.98. The redness (a*) values were 4.33, 11.12, 8.83 whilst the yellowness (b*) were 19.31, 23.04, 21.20 for C, WFPFW and WFP-DF respectively. WFPs were generally high in histidine, arginine, threonine and tyrosine when compared to egg whites and these (except histidine) and other amino acids (serine, glycine, methionine and phenylalanine) were significantly higher (p < 0.05) in WFPFW compared to other samples. Overall, freezing treatments affected the composition and physicochemical properties of WFPs.