Functional improvement of fish myofibrillar protein by conjugation with alginate oligosaccharide.

鱼肉具有良好的成胶性、乳化性、保水性等食品功能。然而，与其他脊椎动物相比，鱼肌原纤维蛋白(MF)的热稳定性和化学稳定性较差，其功能特性随着蛋白质变性的进展而迅速受损。为了改善海藻酸低聚糖的功能性质和热稳定性，在控制湿度条件下，通过美拉德反应将海藻酸低聚糖(AO：平均聚合度=6)偶联到海藻酸低聚糖上。结果表明：(1)微球在低盐浓度(~lt；0.16M)中的溶解度明显提高，完全不受离子强度的影响。(2)所得的水溶性微球具有良好的热稳定性(在80℃下3h无团聚现象)。(3)微球的乳化性能也得到了一定的改善。(4)接合后MF仍保持良好的消化率。进行了细菌致突变试验和动物剂量试验，以评价MF-AO结合物的食品安全性。(1)REC-Assey和Ames试验均未证实MF-AO偶联物的致突变性。(2)MF-AO偶联物经口给药对大鼠无毒，本研究结果表明，通过Maillard反应将其与褐藻低聚糖偶联，是改善鱼肉食品功能的一种很好的方法。

Fish meat has excellent food functionalities such as gel-forming ability, emulsifying ability, and water-holding ability. However, fish myofibrillar ptotein (Mf) is thermally and chemically less stable than that of other vertebrates and its functional properties are rapidly impaired with progress of protein denaturation. To improve the functional properties and the thermal stability, Mf was conjugated with alginate oligosaccharide (AO : Mean degree of polymerization=6) through the Maillard reaction under controlled humidity states.1. The improved functional changes of Mf by the conjugation with AO are as follows : (1) The solubility of Mf in low salt concentration (<0.16M) was significantly improved by conjugation with AO and the ionic strength dependence of the solubility was completely lost. (2) The water soluble Mf thus obtained had excellent thermal stability (no aggregation at 80 ℃ for 3h). (3) The emulsifying properties of Mf was also improved by conjugation with AO. (4) Good digestivity of Mf was remained after the conjugation.2. Bactertial mutagenesis tests and animal dose test were examined to evaluate the food safety of Mf-AO conjugate. (1) No mutagenecity of Mf-AO conjugate was confirmed by rec-assey and Ames-test. (2) Mf-AO conjugate was nontoxic for oral administration to rats.The results of this study indicate that the conjugation with AO with alginate oligosaccharide through the Maillard reaction is a good manner to improve food functionalities of fish meat as a foodstuff.