Recycling protein from that is usually discarded in surimi processing water could provide an additional source of fish protein ingredients for the food industry, say researchers.
The study – published in the Journal of Food Quality – investigated methods to recover ‘lost’ fish protein from waste waters that are usually discarded. The research team, led by Professor Jesse Stine from the USDA’s Subarctic Agricultural Research Unit, revealed that it is solids from surimi wash-water could be successfully recovered using a pilot unit containing a membrane ultrafiltration system that concentrated protein from the surimi wash-water.
“It was demonstrated that the recoverable material is nutritionally similar to the final surimi product and that the overall yield can be increased using membrane technology,” explained Stine and colleagues.
“The recovered wash-water protein could be used to obtain a fish protein ingredient or added back at a low percentage to surimi products,” they said.
The team explained that using such a method to effectively recover proteins from waste water “would not only reduce the negative environmental impact and the cost of waste disposal, but could also lead to new ways to generate profit.”
“Recovered protein could be returned to the process to increase final surimi yield,” they suggested.
Surimi is made up of concentrated protein that has been obtained from extensively washed fish flesh.
As an ingredient, surimi and fish proteins are used in a variety of products. The authors noted that many surimi products “have become increasingly popular due to their unique textural properties, storage properties and high nutritional value.”
As part of the surimi manufacturing process, minced fish flesh is repeatedly washed with chilled water to remove non essential proteins, lipids, and other water soluble materials – leaving a tasteless and odorless pure protein product.
However, the researchers noted that surimi wash-water from this process typically contains between 0.5–2.3% protein.
They suggested that “new and different technologies are needed to recover these proteins economically.”
In order to increase productivity and improve utilization of seafood resources, the argued that processors and manufacturers should looking at alternative technologies to recover proteins and other material from the waste water.
The new study aimed to evaluate the potential of membrane filtration technology for the recovery of protein from surimi wash-water by recovering and characterising the properties of recoverable waste solids.
Stine and co-workers revealed that solids from surimi wash-water “were successfully recovered using an ultrafiltration system.”
They revealed that protein concentrates recovered in the trial “had a significantly higher moisture and lipid content when compared with surimi,” and had a higher number of lower molar mass proteins than surimi.
“From the results of this study, it is possible that the recovered wash-water protein could be used to obtain a fish protein ingredient or added back at a low percentage to surimi products,” said the team
Source: Journal of Food Quality
Published online ahead of print, doi: 10.1111/j.1745-4557.2011.00424.x
“Recovery and utilization of protein derived from surimi wash-water”
Authors: J.J. Stine, L. Pedersen, S. Smiley, P.J. Bechtel