New value from seafood

Innovation in processing and product development is identifying new opportunities to increase the value of waste in the seafood sector

By Catherine Norwood

Doing more with the seafood we already harvest is the aim of an FRDC-funded project focusing on new opportunities for seafood processing.

Curtin University researcher Janet Howieson is leading the research, which has two main themes. One is to maximise the economic returns from the existing catch with products
for human consumption. This includes using trimmings and other fish ‘waste’ to make new edible products.

The other is to reduce the cost of disposal where food products are not an option, through either conversion to a saleable product, such as fertiliser, or into a form with a reduced environmental impact and lower disposal costs. Any reduction in costs is a step towards improved profitability for individual operators, and for the industry as a whole.

Seafood graphic

Taking stock

An audit of what waste is produced, and from where, was the first step in the ‘New opportunities for processing waste’ project, says Janet Howieson, who is based at Curtin University’s Centre for Excellence in Science, Seafood and Health (CESSH).

“In Australia we have a diverse range of fish and seafood caught and processed right around the coast. This makes it difficult to get detailed information,” she says. “From a processing perspective, it also makes it difficult to get the quantity of scale needed to make investment in new processes or equipment, or make new products worthwhile.”

The audit identified more than 55,000 tonnes of waste generated during processing. Although Janet Howieson says there are still gaps in this data, white fish were found to be the most significant source of waste, adding up to an estimated 35,000 tonnes.

The project is also working with individual businesses, developing case studies to come up with new ways to use or add value to fisheries waste.

Total utilisation

These case studies build on work CESSH is undertaking with Western Australian fisher and processor Peter Jecks of Abacus Fisheries, through the FRDC-funded project ‘Waste transformation methods for value-added products for the catering market’.

Peter Jecks believes better use of the fish and seafood already harvested could net an additional $1 billion for the Australian seafood industry. “That’s big money without catching a single fish more,” he says.

He has made “total utilisation” the mantra for his Carnarvon-based family business, Abacus Fisheries, where he now produces 1.2 kilograms of Blue Swimmer Crab product for each kilogram of crab harvested. This includes using the water in which the crabs are cooked for stock, which is then incorporated into a range of products such as crab cakes. He also sells the shell for further processing, to extract chitin – a long-chain polymer that has a range of uses, from fertiliser to a finish on surgical thread that adds flexibility and strength.

Peter Jecks’ latest waste transformation project is focused on reclaiming as much protein as possible from fish and processed fish frames for use in a reconstituted product.
“I was given 100 kilograms of Atlantic Salmon frames to process, and I extracted 30 kilograms of meat from the frames,” he says. “When you consider some processors are dealing with 30 tonnes of fish a week, there’s a lot of seafood protein that can be reclaimed,” he says.

“Other species may not produce good fillets, but the flesh could be removed, minced and reconstituted into meat portions for catering,” he says.  

Work with CESSH and the CSIRO has developed a cold-set binding process, testing a range of setting agents, including alginate – a setting agent derived from algae – that has allowed him to create fish portions from the reconstituted meat with an acceptable taste and texture. This work has been undertaken with the needs of the aged-care sector in mind.
Based on the results so far, Peter Jecks has already invested in four processing machines, each of which strips as much flesh as possible from fish frames, but with variations in the processing settings, to cater for different final products.

Further work at the CSIRO facility in Werribee, Victoria, later this year will test an extrusion process for the development of other fish products.

New products

Southern Bluefin Tuna offal is transformed into liquid fertiliser and other products.
Photo: Janet Howieson

Using a similar approach to that taken by Peter Jecks, the FRDC’s ‘New opportunities for processing waste’ project is also investigating a seafood snack. Food science research student Duc Minh Nguyen has developed a seafood biscuit containing five per cent dried minced snapper frames.

Sensory trials to evaluate consumer acceptance of the snack, including taste, texture and odour, will be conducted later this year. The target end product is a long-life, high-protein snack for Asian markets.

Other human food products being assessed include new products from existing resources, such as fish minces, soups, stock, sauces, snacks and caviar. Extracting high-value, functional chemicals such as omega 3 oils and potentially collagen and gelatin, is another avenue of inquiry.

Pearl meat and swim bladders

Janet Howieson says for products targeting human consumption there are additional hurdles, including the need to ensure the ‘trimmings’ are treated as a food product with appropriate handling from point of harvest and through processing.

The process is easier in vertically integrated companies that deal with their product from harvest to market. In fragmented supply chains, once ‘waste’ moves beyond the first point of processing, it becomes more difficult to ensure the appropriate handling, food safety and cold-chain management have been applied.

She says the development of a premium pearl oyster meat product for the domestic and export food service industry is an example where entire supply chain focus is needed.

Pearl oyster meat is a recognised food product in many Asian countries. An earlier project funded through the Australian Seafood Cooperative Research Centre identified changes required in the shucking, cooling, packaging and freezing of the meat on board harvesting vessels to enhance quality. Kerri Choo, from CESSH, has been working with Paspaley Pearls to develop this product, undertaking shelf-life and quality studies on fresh and frozen products to support plans to target premium markets.

Janet Howieson is also developing drying techniques for Barramundi air bladders, which are normally removed and may be discarded when fish are gutted. However, there is a growing Asian demand for swim bladders for use as ‘food therapy’, and a similar product is already being supplied from Iceland.

Machine-dried Australian Barramundi air bladders are being tested against traditional Asian sun-dried products. Sanitisers and enzymes are being trialled to ‘clean up’ the bladders before drying, rather than requiring fishers to remove the blood and membrane as the fish are harvested and processed.

Several other projects underway are investigating the potential for fish roe products, and abalone viscera, and possible uses for fresh, but damaged shellfish.

Janet Howieson says overall, it’s clear that processors are interested in value-adding to their businesses and to the industry as a whole.  

Chefs’ challenge

It is not just producers and processors who are keen to maximise the use and returns from seafood while minimising waste. In the hospitality trade, some restaurants use pre-processed fillets to minimise waste, while others trim their own seafood, usually dealing with waste through normal food waste disposal.

However, there is a growing trend among savvy chefs for a similar total utilisation of the whole animal, extracting every gram of value out of their purchase. The proportion of fish recovered varies from species to species, but for larger fish fillets, the cheeks, liver, roe and wings are all usable. Further options include scraping the bones to get a fine mince, using skins for a ‘crunch’ element, and making fish stock from the frames.

But at some point there will be parts that cannot be used for food, and the quantities of this waste are generally larger and more costly to deal with for fishmongers and processors than they are for restaurants.

Small-scale retail

Fish and seafood waste can be disposed of as landfill, usually at a cost to the processor. Some companies sell or donate waste for use in plant fertilisers, pet food, fish feed or even roadfill. The FRDC project is working to develop simple and easily adopted value-adding options for both large and smaller operators, including seafood retailers.

The initial waste audit found that generally only 50 to 65 per cent of a white fish is recovered for sale during processing, leaving 35 to 50 per cent of the fish as ‘waste’, depending on the species and processing technique.

Industry advice has also indicated that of all white fish harvested, about half was processed at major facilities, and half was sold as whole fish and processed at food service, retail outlets, or by the consumer.

“Many smaller businesses have to store their waste in fridges or freezers because it’s only collected for disposal once a week. These smaller operations require a different strategy, because they don’t have the volumes that would make investment in a more complex product worthwhile,” Janet Howieson says.

“So we are designing a small, standalone processing unit that fish trimmings can be added to each day. A commercial enzyme is used to break down the proteins and liquify it, so that it could be used as a fertiliser, or some other product, rather than going to landfill. “That leaves the bones, and we’re looking at ways to liquify those as well, as well as for other uses of the liquid.”

Processing units with two to four-litre capacity have worked well in benchtop trials, she says. A larger, 50-litre prototype unit will be built and trialled with a business whose waste largely consists of snapper and salmon trimmings.

SBT Kingfish conversion

This proposed system is essentially a simpler version of that used by Port Lincoln fish waste processor SAMPI to transform about 2000 tonnes of Southern Bluefin Tuna and Yellowtail Kingfish waste and offal into hydrolysate each year.

SAMPI’s managing director Charles Franchina says that for his company this waste is “a high-value raw material with lots of nutrient value”.

The fish hydrolysate that SAMPI produces is organically certified and is sold as a biological soil conditioner and aquafeed ingredient, with growing demand in both markets. It currently supplies aquafeed markets in Indonesia, Malaysia, South Korea and the Philippines, and trials of the higher-quality hydrolysate now being produced are underway with an Australian aquafeed manufacturer.

The company previously used an acid, buthas switched to an enzyme process, which it has been refining in conjunction with the FRDC project. The result is faster hydrolysis and a higher-quality, homogenised liquid product, with higher protein levels and about 10 per cent oil. The new hydrolysis process results in a 100 per cent conversion of all material into a saleable product.

Bone matter separated out is used to make recreational fishing berley, and there is further research into higher-value uses for calcium extracted from the process, which could even potentially be used for human consumption.

Charles Franchina says while SAMPI currently handles material only from Port Lincoln, the plant has the capacity to process waste from other regions.

The ‘New opportunities for processing waste’ is part of the FRDC’s National R&D Priority 2: “By 2020 deliver RD&E for fishing and aquaculture to increase productivity and profitability consistent with economic, social and environmental sustainability.”

National survey

Food research scientist Stephen Pahl at the South Australian Research and Development Institute (SARDI) is coordinating a national survey to develop a more detailed picture of waste in Australia’s seafood sector. The survey, conducted online will seek information about the different types of waste, quantities, location and current methods of management or disposal.

Stephen Pahl says the survey will also provide an opportunity for the sector to help identify and prioritise future research and product-development opportunities. “Reducing waste can reduce our environmental footprint, while also improving the profitability of the industry.”

More information

Stephen Pahl, 08 8303 9333,

Low-impact ocean disposal

Austral Fisheries has been involved in a case study trying to streamline operational efficiencies by ‘transforming’ Patagonian Toothfish waste into a product that could be more easily disposed of at sea, or, alternatively, reclaiming the oil components for use or sale.

On board, the toothfish are headed and gutted but the offal can’t be disposed of on the fishing grounds because of the potential to attract seabirds and whales.

Austral Fisheries CEO David Carter says seabird mortality has reached near-zero levels in toothfish fisheries in recent years, thanks to a suite of mandatory mitigation methods, including offal retention.  “The offal is stored on board for as long as possible, and we try to make only one or two runs per trip to the edge of the fishing zone,” he says. For Austral, this offal is expected to total 500 to 600 tonnes in 2016.

In the Heard Island and McDonald Islands Patagonian Toothfish Fishery, vessels are required to travel outside the 200-nautical-mile fishing zone to dispose of their waste, which is expensive in terms of both operating costs and lost fishing time.

“We’ve been looking at some kind of waste-digesting approach that will break down the offal into components that would make it unattractive to whales and seabirds if it was disposed overboard. If there were additional uses, such as reclaiming oil to use in the engine, that would be a bonus,” David Carter says.

Initial trials investigated both an acid and an enzyme-based approach to break down the offal in a process known as hydrolysis. However, acid was deemed a potential environmental hazard.

The commercial enzyme tested was effective in breaking down the proteins, but required temperatures of 40 to 50ºC to work – conditions that are too difficult to maintain on a vessel where the temperature averages 2ºC. Patagonian Toothfish waste is also being examined for potential functional food ingredients that could be extracted. Researcher Ranil Coorey and post-graduate student Ahmad Jauhari are testing extracts from hydrolysed toothfish for food properties such as foaming, gelling and water holding.

More information

Austral Fisheries, 08 9217 0100

FRDC Research Codes: 2013-711.40, 2014-704, 2016-223, 2016-22

More information:

Stephen Pahl, 08 8303 9333

Janet Howieson, 08 9266 2034

Charles Franchina, 08 9335 1812