Protein Content of Fish Waste and Fish Protein Powder from Clupeapallasii Valenciennes (“Tamban”)

Abstract

Fish waste, consisting of the head, bones, tail, and entrails, comprises of around 38% of the total fish material. The food processing industry uses only the flesh of the fish to produce their fish food products, and the fish wastes are often left unused, if not added as an ingredient to low-market-value products such as animal feeds or fertilizers. Improper disposal of fish waste can be hazardous to the surroundings where it is being disposed, particularly to other living things, because of the high biological oxygen demand in the biodegradation of these wastes, which would cause oxygen depletion in its disposal area. There is therefore a need to utilize fish wastes. One method is conversion of fish waste to fish protein powder (FPP). The resultant powder could be used as an additive in drugs, cosmetics, among other applications. For Clupeapallasii Valenciennes, known in the Philippines as tamban and is one of the known local alternatives for sardines, the properties of fish waste, including its protein content, have not been subject to much scientific study and is therefore inconclusive. This study determines the amount of protein in the head, bones, and viscera of C. pallasii and compares the amount to processed sardines. The results of this study could be useful in determining their possible uses in pharmaceutics and could help increase the economic value of fish waste. The fish wastes were blended into a homogenized fish paste and underwent acid hydrolysis in order to extract hydrolysate. This hydrolysate, which had a clear yellow color, underwent freeze-drying to convert it into powder. Biuret test colorimetry was used to determine the percentage of protein in the powder. The same method was utilized for unhydrolyzed fish paste for comparison on the amount of protein yielded. As a result, two averages were made. The average concentration of protein in fish protein powder was 38.45% ± 1.92 (mg/mL), while that of the homogenized (unhydrolyzed) fish paste was 25.01% ± 2.20(mg/mL). Both figures are significantly less than as is known in past studies on the amount of soluble protein in the flesh of sardines.