Determination of the effect of frying temperature, time, added asparagine, glucose content and precursor content on the acrylamide formation in fish roll

Abstract

Food toxicants are formed in foods, during high temperatures (>120 ºC) associated with deepfrying, baking, and roasting. Acrylamide has been declared as a "probable human carcinogen" by the International Agency for Research on Cancer. Acrylamide formation is affected by intrinsic and extrinsic factors of the food. The objectives of this study were to identify the main acrylamide precursor content (asparagine and total reducing sugar (TRS)) of raw materials and analysing the effect of various factors on acrylamide formation in fish rolls. The effect of frying temperature (160-180 ºC), time (8-12 minutes), and added asparagine (0.3-0.9 g/100g flour) and glucose content (2.0-4.0 g/100g flour) on acrylamide formation in fish rolls were analyzed in this study. The raw materials were analyzed for their asparagine (chromatographic methods) and TRS (dinitro salicylic acid method) contents. The effect of studied factors on acrylamide formation was analyzed using the response surface methodology (RSM) and Box-Behnken method with 4 factors and 3 levels. The raw materials of fish roll: wheat flour, potato, B-onion, green chili, curry leaves, fish, bread crumbs and black pepper had asparagine contents about 0.22 ± 0.01, 14.24 ± 1.33, 1.41 ± 0.08, 3.03 ± 0.01, 6.76 ± 0.12, 0.27 ± 0.00, 0.08 ± 0.00, and 2.35 ± 0.06 mg/g (dry basis), respectively and TRS about 3.34 ± 1.30, 11.59 ± 0.60, 154.63 ± 16.61, 46.50 ± 0.70, 10.86 ± 1.63, 4.05 ± 0.87, 45.15 ± 0.96 and 2.49 ± 0.33 g/kg (dry basis), respectively. The raw materials were enriched with RS, and asparagine acted as the limiting factor in acrylamide formation. According to RSM, acrylamide content had shown a strong positive correlation with frying temperature (0.715), and a moderate positive correlation with time (0.424). Time and temperature were the most critical factors in acrylamide formation in fish rolls. The acrylamide content had shown a small positive correlation with the asparagine (0.309) and the glucose content (0.222). Asparagine was the limiting factor in acrylamide formation in fish rolls. Therefore, it is critical to use raw materials with lower acrylamide precursor contents, while frying at optimized frying conditions (at 170 ºC for 10 minutes).