ARS | Publication request: STARCH/PULP-FIBER BASED PACKAGING FOAMS AND CAST FILMS CONTAINING ALASKAN FISH BY-PRODUCTS (WASTE)

Submitted to: BioResources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 17, 2008
Publication Date: August 2, 2008
Citation: Imam, S.H., Chiou, B., Wood, D.F., Shey, J., Glenn, G.M., Orts, W.J., Narayan, R.R., Avena Bustillos, R.D. 2008. Starch/pulp-fiber based packaging foams and cast films containing alaskan fish by-products (waste). BioResources. 3(3):758-773.

Interpretive Summary: The seafood industry produces large quantities of fish waste globally. Most of the fish waste, also known as fish by-product, is generated during the large-scale fish processing operations carried out onboard by big trawlers. According to the Food & Agricultural Organization of the United Nations, roughly, over 100 million metric tons of fish waste or discard is generated worldwide annually resulting from both sea and land-based fishing operations, of which only a small portion is used in the production of fishmeal and fish oil. Fish waste is a source of many useful natural polymers, fuels, and other industrially important chemicals. It is critical that we seek new and novel ways to use this abundant resource of raw material and at the same time prevent environmental degradation. Single-use packaging presents one of the most promising applications for inherently biodegradable natural polymers. In this regard, research from our laboratory have successfully shown that starch polymers, derived from a variety of botanical sources, can be expanded into foams via thermal treatment (extrusion, as well as baking processes) in the presence of other biopolymers such as cellulose, poly(vinyl alcohol) (PVOH), polylactic-acid (PLA) and polyhydroxybutyrate-co-valerate, etc. However, fish waste, which mostly contains proteins (including collagen), CaCO3, oil and water, has never been used in conjunction with starch and/or fiber for making foam packaging material. Thus, this is the first report which describes our efforts to use processed fish waste in baked starch/pulp foams and starch-PVOH cast film formulations. The foams and films were produced and evaluated to examine their properties for use in packaging applications.

Technical Abstract: Baked starch/pulp foams were prepared from formulations containing 0-25% (wt%) of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads and pollock frames (bones and associated remains produced in the filleting operation). Fish by-products thermoformed well along with starch and pulp fiber, and the foam product (panels) exhibited useful mechanical properties. Foams with all three fish by-products, ranging between 10 and 15% (wt%), showed the highest flexural modulus (500-770 Mpa). Above 20% fiber content, the modulus dropped considerably in all foam samples. Foam panels with pollock frames had the highest flexural modulus at about 15% fiber content (770 Mpa). Foams with salmon heads registered the lowest modulus at 25% concentration. Attempts were also made to cast starch-glycerol-poly (vinyl alcohol) films containing 25% fish by-product (salmon heads). These films showed a tensile strength of 15 Mpa and elongation at break of 78.2%. All foams containing fish by-product degraded well in compost at ambient temperature (24oC), loosing roughly between 75-80% of their weight within 7 weeks. The films degraded at a much higher rate initially. When left in water, foams without fish by-product absorbed water much more quickly and deteriorated faster, whereas, water absorption in foams with fish by-product was initially delayed and/or slowed for about 24 h. After this period, water absorption was rapid.