For years, fish processing industries worldwide have struggled with the vast volumes of byproducts they generate. In fact, studies estimate that roughly two-thirds of every fish caught is ultimately discarded, creating significant environmental and economic challenges. This so-called “fishery waste” comes in two forms: liquid and solid. The liquid fraction includes blood, mucus (slime) and fats, while the solid fraction consists of heads, fins, skin, bones and scales. Although mostly thrown away now, these byproducts are rich in proteins and other valuable compounds. Experts note that compounds from fish byproducts (for example, collagen from skins and bones) can command high commercial value, serving diverse uses in food, cosmetics and pharmaceuticals. In short, with the right technology, today’s fish waste could be turned into tomorrow’s valuable ingredients.
In Southeast Asia, the pangasius catfish (ikan patin) is a major freshwater aquaculture commodity—and it produces an unusually large share of waste. When pangasius are filleted, only about 45 % of the fish ends up as edible fillet. The remaining 55 % – comprising stomach contents, belly fat, bones, skin and the so‑called “trimmings” (the unwanted cut‑off parts such as bones, spines, skin and excess fat) – is typically discarded. Left untreated, these leftovers can foul waterways with odors and contamination. However, researchers now report that pangasius byproducts can be transformed into eco‑friendly, value‑added products. For example, recent Indonesian studies have shown that pangasius offal can be processed into fish protein hydrolysates, oils and other extracts suitable for use as animal feed supplements, nutritional additives or even pharmaceutical ingredients. In other words, innovative science is now turning pangasius waste from a pollution problem into a promising resource.
1. Fish Protein Hydrolyzate (HPI)
Researchers have turned the pangasius waste into an opportunity by developing fish protein hydrolyzate (HPI). This liquid concentrate is made by adding proteolytic enzymes to fish byproducts under controlled conditions, which breaks down the proteins into smaller peptides and amino acids. In practice, attention often focuses on pangasius heads and bones – rich sources of collagen and calcium. By subjecting these parts to hydrolysis, scientists extract an HPI rich in calcium-binding peptides, molecules that latch onto calcium ions. The result is a water-soluble blend of protein fragments of high nutritional value, essentially converting low-value byproducts into high-quality nutrition. Compared to traditional fish meal, these hydrolyzed proteins are more readily absorbed, since the enzymatic process yields tiny, nutritive peptides.
In fact, laboratory tests by Prof. Mala Nurilmala at IPB University confirmed that pangasius HPI exhibits exceptionally strong calcium-binding activity. The study found that the binding activity was highest when the proteins were about 6% hydrolyzed, indicating that this level of processing produces the optimal mix of peptides for capturing calcium. These calcium-binding peptides improve calcium bioavailability (the fraction of dietary calcium absorbed into the bloodstream) by keeping calcium soluble and aiding its transport across the intestinal wall.
This finding has practical implications. Pangasius HPI is thus more than an easily digested protein; it actively enhances mineral absorption. That matters because certain groups—growing children, pregnant or nursing women, and older adults—have especially high calcium needs (often around 1,000–1,500 mg daily). Calcium deficiency can lead to serious problems like osteoporosis, bone fractures, and impaired growth in children. Adding HPI to foods or supplements could help these populations meet their requirements by making more of the calcium they consume available for use.
One byproduct of the pangasius fish processing industry is fish oil, extracted and refined for use in consumer applications including, ice cream: BPPSDM KKP
Beyond bone health, pangasius-derived HPI carries other potential benefits. Fish-derived bioactive peptides are known to act as antioxidants (protecting cells from damage), antihypertensive agents, and even antimicrobial or immune-modulating substances. These multifunctional properties make HPI attractive to the nutraceutical and pharmaceutical industries. In the future, pangasius HPI might be formulated into health supplements, functional beverages, or specialized medical nutrition formulas, turning once-discarded fish parts into a valuable resource for human health.
2. Fish oil from pangasius extraction
In Southeast Asia’s pangasius processing plants, the fatty tissue clinging to the belly cavity and under the skin is often discarded along with the head and bones. For years this oily byproduct was treated as waste. Now researchers and industry experts see new value in what was once tossed aside. They have discovered that this leftover fat can be extracted and transformed into fish oil rich in polyunsaturated fatty acids (PUFAs), including omega-3 fatty acids like EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
A recent analysis found that the extracted oil contained roughly 6.32% DHA and 2.11% EPA. These figures suggest pangasius-derived oil could be a promising alternative source of omega-3s, as demand for health supplements rises. Omega-3 fatty acids are known to support cardiovascular health by reducing the risk of arrhythmias, lowering blood pressure, and preventing arterial plaque buildup.
From this extracted oil, producers can develop two main products: crude oil and refined oil. The crude oil, still unpurified, is often added to animal or aquaculture feed, where its rich nutrients can promote faster growth and improve feed efficiency. The refined oil undergoes additional purification and finds uses in the food and pharmaceutical industries. It can become a human dietary supplement, a food-grade lubricant, or a natural ingredient in cosmetics.
Refining the oil involves several steps: degumming, neutralization, bleaching, and deodorization. These processes strip away the fishy odor and remove impurities, yielding a high-quality oil that is safe to consume and stable in storage. Studies indicate that refined fish oil has better oxidative stability and delivers its benefits more effectively, especially when encapsulated in softgel capsules.
Turning pangasius fat into fish oil also yields environmental benefits. Discarded fish fat can cause pollution – the oily residue creates foul odors and can contaminate water and soil around processing plants. By converting this waste into a useful product, fish processors not only gain additional revenue but also cut down on organic waste, supporting a zero-waste approach in the fisheries industry.
3. Animal feed from pangasius entrails
The waste entrails of pangasius catfish—comprising the stomach, intestines, liver, gallbladder, pancreas, gonads, spleen, and kidneys—are emerging as a valuable livestock feed resource. Fish viscera can be an important source of protein and energy for animal feed, making their use an innovative solution with high economic and ecological value. Processing is straightforward: the waste can be fermented, dried, or directly mixed into feed formulations. For example, fermentation with lactic bacteria (such as Lactobacillus spp.) breaks down proteins into microbial biomass and peptides, increasing the nutrient content while suppressing foul odors. Likewise, drying the viscera into powder lowers moisture and preserves nutrients, dramatically extending shelf life. (If the raw gut material is simply added to feed, it must first be fully dried and ground to ensure stability and hygiene).
Pangasius waste holds promise as an alternative protein source for aquaculture feed, offering a sustainable pathway to reduce reliance on imported and costly fish meal: Badan Mutu KKP Medan II
Small and medium enterprises in fisheries and livestock can adopt these low-cost methods to make quality alternative feeds. A study by Hossain and Alam (2015) found pangasius viscera contained about 14.01% protein, 20.00% fat, 4.75% ash and 60.62% water, confirming it as a rich source of animal protein and lipids. Such waste-based ingredients can be blended with inexpensive supplements—rice bran, cornmeal or mineral concentrates—to balance the diet’s nutrients. In effect, farmers are reclaiming the nutrients from waste: turning a disposal problem into a value-added feed ingredient.
Beyond nutrition, this recycling also cuts costs in a sector where feed dominates expenses. Feed can constitute roughly 50–70% of total operational costs, so a low-cost feed made from local processing residue can greatly ease the financial burden on small-scale producers. In short, using pangasius entrails for animal feed is a win–win: it yields a nutritious, low-cost ration while advancing a more sustainable, circular approach to aquaculture and farming.
