In general, fishery waste consists of liquid and solid waste. Liquid waste can be blood, mucus, and fat, while solid waste is in the form of heads, fins, skin, bones, and scales. Currently, fishery waste is mainly used as fish meal, the primary raw material in the manufacture of animal feed. However, fishery waste has high added value, as it can be used in various processed products. From the processing of Pangasius alone, a large percentage of the waste is produced. This waste comes from the yield in the Pangasius filet processing process, which only utilizes about 45% of the fish.
In comparison, the remaining 55% of the contents of the stomach, abdominal fat, bones, skin, and trimmings have not been utilized optimally. This waste has caused new problems in human life, even though it has great potential to be used or reprocessed. Many studies have been conducted related to the utilization of Pangasius waste. Pangasius waste can be processed into economically valuable products, such as products from Pangasius innards which are converted into animal feed. In addition, fish waste can also be processed as material for pharmaceuticals. The following are the types of utilization of Pangasius waste that have been developed:
1. Fish protein hydrolyzate (HPI)
Fish protein hydrolyzate (HPI) is a liquid product made from fish with the addition of proteolytic enzymes to accelerate the hydrolysis process under controlled conditions, resulting in a mixture of protein components (Piggot and Tucker 1990). Fish protein hydrolyzate can be used as a dietary supplement or consumed directly as food to increase protein intake. Protein hydrolyzate is composed of bioactive peptides with calcium-binding activity, maximizing calcium absorption in the body. Pangasius waste is a filet, particularly the head and bones, which can be processed into protein hydrolyzate with calcium-binding activity. In a study conducted by Nurilmala from the Department of Aquatic Products Technology, Faculty of Fisheries and Marine Sciences, IPB, it was proven that fish protein hydrolyzate from Pangasius filet waste has calcium-binding activity. The highest calcium activity was found in hydrolysis, with a six percent concentration.
2. Fish oil from Pangasius extraction
Based on research conducted by the Department of Marine Affairs and Fisheries of East Java Province, it is known that fish oil extracted from Pangasius is a source of unsaturated fatty acids, including omega-3 fatty acids, which have positive functions for human health. In addition, raw Pangasius oil (crude oil) can add nutrients to animal feed, food-grade lubricants, and other products. It has been believed that consuming fish oil can benefit humans, including preventing heart rhythm disorders, helping to lower high blood pressure, inhibiting plaque buildup in blood vessels, and providing several other health benefits.
3. Animal feed
Animal feed can be made from cheap materials, such as Pangasius offal waste. Its availability is abundant and has not been used optimally, resulting in environmental pollution. This waste can be seen as an opportunity to be reused into economic value products. The innards of Pangasius consist of the stomach, intestines, liver, gallbladder, pancreas, gonads, spleen, and kidneys. According to Hossain and Alam (2015), fish offal contains 14.01% protein, 60.62% water, 4.75% ash, and 20% fat. Fishery industry waste, such as offal, has high protein levels and unsaturated fat. This indicates that Pangasius offal can be used as an alternative source of protein feed for our livestock.
