Effect of cryoprotectants and frozen storage on Anisakis allergens in surimi processing

Surimi is a myofibrillar protein concentrate in which minced muscle is washed to remove sarcoplasmic proteins, lipids, etc, stabilized with cryoprotectants and mostly commercialized frozen stored. Many fish species heavily infected with Anisakis spp L3 larvae present a high allergen concentration in the muscle thus posing a potential problem for Anisakis sensitive patients even when larvae are killed by e.g. freezing. Previous results have shown that washing of muscle in surimi processing significantly reduced the allergen concentration, but raw surimi still can have residual allergens that may be carried on in the subsequent steps. To design strategies to reduce the allergenic capacity of processed products, it is necessary to know if additional factors related to surimi production can have an effect on the concentration of Anisakis allergens. The aim of this work was to determine the presence of Anisakis allergenic proteins in surimi as affected by the washing solutions, cryoprotectant blends, and frozen storage. Hake muscle infected under controlled conditions (50 L3 larvae/100 g mince) was washed [3 cycles, muscle:washing solution, 1:4 (w:v)] with water, sodium phosphate buffer, sodium bicarbonate, or sodium hypochlorite. Two cryoprotectant blends were added to each of these four raw surimis: 4% sucrose+4% sorbitol and 4% sucrose+4% sorbitol+0.2% sodium pyrophosphate, thus making a total of 8 combinations. The impact of these factors on the allergenic proteins was studied during frozen storage (-20°C) for 90 and 180 days, with chilled surimi (5°C) used as control. Ani s 4 and Anisakis simplex antigens were quantified by immunodetection (Dot blot). No significant differences (p