|a英文題名:Studies on the Antigenicity and Antioxidant Activity of Milk and Soy Proteins
|a牛乳與黃豆蛋白質具有良好的功能性質，然而同時也造成少數人體過敏反應。本研究目的為針對牛乳與大豆蛋白質之過敏蛋白質做為研究，探討樣品經由添加醣類、溫度及酵素水解之處理對於其組成、抗原性質與抗氧化性之影響。利用電泳分析系統觀察蛋白質結構組成之變化；藉由酵素連結免疫吸附法及西方轉漬系統來探討抗原與抗體之間的結合性變化及其抗體專一性；並以ABTS陽離子自由基清除法及抑制脂質過氧化試驗測定其抗氧化能力。結果顯示，酪蛋白經由胰蛋白酶 (trypsin) 水解可降低抗原性質，亦增加抗氧化能力，然而水解時間增加對抗氧化能力無顯著提升。在酪蛋白結合乳糖模式系統下，(1) 酪蛋白抗體：梅納反應對抗原性質無顯著影響，而梅納反應及酵素水解其作用順序皆可降低抗原性質，但抗氧化能力皆無顯著影響；(2) PKLAC抗體：酪蛋白結合20%乳糖在90℃時會顯著增加其抗原性，表示高溫加熱處理梅納反應產物越多，有助於增加醣基化生成。在酪蛋白結合寡木糖模式系統下，酪蛋白抗體：梅納反應對於抗原性質無顯著影響，酵素水解後可降低其抗原性質，酪蛋白結合20%寡木糖時，隨溫度升高抗原性增加。利用自行製備的SPI抗體，具有良好的專一性，可用於探討不同加工條件對黃豆蛋白抗原性質的影響。以TBARS方法探討牛血清白蛋白、牛血清白蛋白結寡木糖、酪蛋白、乳清蛋白於絞肉系統中的抗氧化性質，氧化安定性無顯著影響。綜合以上結果可以得知，樣品蛋白質經加糖、加熱及酵素水解的處理，可能會因蛋白質結構變化、聚合物生成量以及梅納反應產物有關，這些不同處理方式會導致蛋白質變性、抗原-抗體間的結合力的影響、抗原決定區 (epitopes) 的破壞，進而降低其抗原性。|uMilk and soy proteins possessed good functionalities but some are also general allergenic. This study aimed to investigate the structure, antigenicity and antioxidant activity of the allergens in milk and soy proteins which were treated using sugars, heat treatment and enzymatic hydrolysis. The changes of protein structure and antigenicity on milk and soybean proteins were investigated using electrophoresis, competitive ELISA and Western blot analysis. The ABTS radical scavenging ability and lipid peroxidation assay were used to determine the antioxidant activity of milk and soybean proteins. The results showed that the antigenicity of casein was decreased and the antioxidant activity of casein was elevated after trypsin-hydrolysis. In the casein combined with lactose model system, (1) Maillard reaction did not have significant effect on the antigenicity. Maillard reaction and enzymatic hydrolysis treatments could decrease of antigenicity, but had no effect on the antioxidant activity; (2) Treatment with 20% lactose at 90℃ significantly increase the antigenicity. These results suggested that Maillard reaction products might contribute to the formation of glycation. In the casein combined with xylooligosaccharide model system, Maillard reaction did not have significant effect on the antigenicity; the antigenicity was decreased after enzymatic hydrolysis; the antigenicity of casein combined with 20% xylooligosaccharide was significantly increased by the heating temperature. SPI antibodies prepared in this laboratory,show great specificity and might have potential in determination of the effects of different processing conditions on the antigenicity of soybean proteins. Bovine serum albumin (BSA), BSA combined with xylooligosaccharide, casein and whey protein had no significant effect on the antioxidant activity and oxidative stability of the ground meat system using TBARS method. In conclusion, the treatments such as adding sugar, heating and enzymatic hydrolysis on the protein samples might induce the changes of protein structure, formation of polymers and Maillard reaction products. These treatments further induced protein denaturation, changes of the antigen and antibody interaction and destruction of epitopes, and thus reduced the antigenicity.
|aStudies on the Antigenicity and Antioxidant Activity of Milk and Soy Proteins