"Chemical, physical and sensory analyses suggest that grape antioxidant dietary fibre is a highly active technological ingredient in frozen dark minced fish," wrote Isabel Sanchez-Alonso and Antonio Javier Borderias in the International Journal of Food Science & Technology.
The study builds on previous research published last year in the Journal of Food Science by the Instituto del Frio (CSIC) researchers.
Oxidation processes in food can lead to organoleptic deterioration in taste, colour and texture. And fish products are particularly susceptible to oxidation processes because of the high unsaturated lipid content.
The food industry has long been aware of this, and is increasingly seeking natural solutions rather than artificial additives, such as like butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT), to extend the shelf life of milder-tasting products.
The researchers looked at using grape antioxidant dietary fibre (GADF) as an ingredient in the minced muscle of horse mackerel (Trachurus trachurus). Concentrations of 0, 2 and 4 per cent GADF were tested.
Sanchez-Alonso and Borderias report that lipid oxidation was inhibited during frozen storage on addition of the fibre, compared to the control fish sample.
From a functional point of view, the fibre significantly increased water retention and increased the cooking yield of the minced fish meat. Texture was also affected by the fibre, with softness and cohesiveness decreasing with increasing GADF addition.
A sensory analysis of the samples showed that the minced fish meat formulated with two per cent GADF was "very acceptable, even more so than the fibre-free sample," wrote the researchers.
However, the higher GADF amount (four per cent), was "much less acceptable", they said.
"We therefore propose the use of GADF as a multipurpose technological ingredient in minced dark fish muscle, and one that might additionally offer physiological benefits to the consumers," they concluded.
A significant number of studies have reported that grape polyphenols such as gallic acid, caffeic acid, catechins, and anthocyanidins have potential benefits for heart health.
According to a 2003 report by Frost and Sullivan, the synthetic antioxidant market is in decline, while natural antioxidants, such as herb extracts, tocopherols (vitamin E) and ascorbates (vitamin C) are growing, pushed by easier consumer acceptance and legal requirements for market access.
Source: International Journal of Food Science & Technology (Wiley-Blackwell)
June 2008, Volume 43, Issue 6, Pages: 1009-1018
"Technological effect of red grape antioxidant dietary fibre added to minced fish muscle"
Authors: I. Sanchez-Alonso, A.J. Borderias