Amid fears of falling fish stocks, adding moisture-releasing ingredients like diced vegetables or milk could boost acceptance of less desirable but abundant fish to consumers, suggests new research.
The healthy reputation of omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), has exploded into consumer consciousness, based largely on evidence that it can aid cognitive function, may help protect the heart against cardiovascular disease, and could reduce the risk of certain cancers.
However, fears about dwindling fish stocks and the presence of pollutants have pushed some academia and industry to start producing omega-3s from alternative sources, such as algae extraction or transgenic plant sources.
Atlantic mackerel a good alternative
The researchers behind the current research report that Atlantic mackerel (Scomber scombrus) has abundant stocks but is not commercially exploited because of its dark flesh colour, oily flesh, difficulty in boning, and poor market acceptance. It has also been labelled as an "undesirable fish rather than a health fish rich in omega-3 fatty acids for human consumption," they said.
But the fish is reported to be the richest source of omega-3 fatty acids among marine fish species (2,6 percent, giving 0,9 percent EPA, and 1,6 percent DHA), making it an interesting species for exploitation to a consumer base that is increasingly health aware.
Writing in the Journal of Food Science, Chong Lee and co-workers from the University of Rhode Island and Kyung Hee University in Korea reports on the addition of moisture-releasing ingredients to a minced fish product. The sensorial properties of the finished product were evaluated after moulding, battering, frying, freezing, and subsequent re-cooking.
"The present study was attempted to develop an innovative fish mince-based seafood product that is acceptable to food-service, institutional, and retail sectors, as well as to domestic ethnic and overseas markets," wrote the researchers.
How the study was done
Lee and co-workers used three approaches to improve the moistness of the resulting fish nuggets – by varying the added water level (0 to 35 percent), varying the added water–moisture-releasing vegetable combination (onion, mushroom, green pepper and zucchini), and varying the milk–water combination.
They report: "Milk was more effective than water in rendering moistness and tender texture. Vegetables were effective in forming and making the cooked product moist with less liquid added by holding moisture release during forming and liquid cells after cooking."
For the added water, the optimum water addition was found to be 28 percent, while the milk addition was most effective when a 14:7 milk-water combination was used.
"Milk was chosen as one of the moisture-releasing ingredients [because] it not only provides moisture but also serves as a fishy flavour neutraliser," explained Lee. "The mackerel meat has an inherently strong fishy flavour. It is desirable to neutralise this fishy flavour using milk since milk protein is known to have the ability to bind the prominent flavour compounds."
For the vegetables, the samples containing seven percent diced onion was found to be the softest, most moist and preferred ingredient.
"The mackerel nugget could potentially provide 260mg omega-3 fatty acids (10mg LNA, 90mg EPA, and 160mg DHA) per piece (approximately 20g containing 10g mince)," said Lee. - (Decision News Media, March 2007)
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