利用多醣膠體及不同來源之食用油脂供開發機能性低脂蛋黃醬之研究

Abstract

蛋黃醬中添加油脂的主要目的在賦予其特殊滑潤之口感，但因含大量油脂使蛋黃醬被視為一種易引起心血管疾病之食品。因此本研究嘗試利用富含膳食纖維之多醣膠質及不同來源之食用油脂供開發機能性低脂蛋黃醬。試驗第一部分探討用三仙膠 (xanthan gum, XG) 、關華豆膠 (guar gum, GG) 及柑橘纖維 (citrus fiber, CF) 相互搭配，並與去離子水混合後作為降低蛋黃醬中脂肪的可行性，再依據流變儀分析之結果來尋找最適複合膠體配方，期能在不改變蛋黃醬之流體特性的前提下，降低蛋黃醬配方中一半的油脂 (36.5％)；第二部分探討不同食用油脂 (包含大豆油、芥花油、葵花油、橄欖油及調合油) 與有無添加200 ppm抗氧化劑 (butyl hydroxy anisole, BHA) 對低脂蛋黃醬之黏稠度與氧化程度的影響。 第一部分結果顯示，利用1.5% XG + 1.0% GG或10% CF + 0.5% GG之複合膠體皆能使低脂蛋黃醬保有與對照組相似之流變特性。在成分分析方面，1.5% XG + 1.0% GG及10% CF + 0.5% GG能將蛋黃醬中膳食纖維含量分別提高至0.68與2.87%，且顯著降低熱量與脂肪含量 (P＜0.05) 。在理化特性方面，利用1.5% XG + 1.0% GG與10% CF + 0.5% GG能顯著提升蛋黃醬之亮度 (P＜0.05) 。1.5% XG + 1.0% GG與10% CF + 0.5% GG處理組之乳化安定性分別為90.7 ± 1.0及76.2 ± 3.8％，皆顯著高於對照組之43.9 ± 1.5% (P＜0.05)。進一步利用掃描式電子顯微鏡觀察，顯示低脂處理組之油滴分布有較多空隙，其中10% CF + 0.5% GG處理組與對照組油滴較小且大小一致，而1.5% XG + 1.0% GG處理組之油滴大小不一且小油滴夾雜於大油滴之間。最後利用官能品評試驗比較與市售產品間的差異，結果顯示使用1.5% XG + 1.0% GG處理組在外觀、香味、風味、油膩感及總接受度皆與對照組及市售產品沒有顯著差異 (P＞0.05) ，至於10% CF + 0.5% GG處理組在外觀、風味及總接受度則顯著低於對照組 (P＜0.05)。 第二部分結果顯示，除了使用調合油之處理組的黏稠度顯著低於其餘各組外 (P＜0.05) ，各處理組間無顯著差異 (P＞0.05) 。然而添加200ppm BHA之各處理組，在儲藏8周期間具有延緩酸價、過氧化價及硫巴比妥酸價上升的現象，至於添加不同食用油脂方面，含200 ppm BHA之橄欖油與調合油之處理組，其POV及TBA值皆顯著低於其它處理組 (P＜0.05) 。 綜合上述結果得知，1.5% XG + 1.0% GG與10% CF + 0.5% GG皆能扮演油脂在蛋黃醬中的功能性，且具有提高膳食纖維含量、降低油脂含量及降低熱量等優點；若以橄欖油或調合油作為原料油，能夠延長產品之保存期限，未來可進一步利用於各式低脂醬料中。

The purpose of adding lipid in mayonnaise is to give its special creaming taste. However, using a great quantity of lipid in mayonnaise may lead to cardiovascular complications, so it is regarded as an unhealthy product. Thus, the objective of this study is to develop low-fat mayonnaise containing functional ingredients by adding polysaccharide gum and different edible oil. The first part of this study combined xanthan gum (XG), citrus fiber (CF) and guar gum (GG) with deionized water and formulated the optimum ratios of polysaccharide gum as fat replacers. The lipid ratio in mayonnaise can be cut down by half and the product can maintain suitable rheological properties. The second part of this trial investigated the influence on steady shear viscosity and oxidation degree of low-fat mayonnaise by adding different edible oil and 200 ppm antioxidant (BHA). Results of the first part, the rheological parameters showed there were no significant differences of yield stress, viscosity and flow behavior index between 1.5% XG + 1.0% GG group, 10% CF + 0.5% GG group and control group (P>0.05). In section of chemical composition analysis, 1.5% XG + 1.0% GG and 10% CF + 0.5% GG groups could reduce half of caloric values and increase total dietary fiber percentage to 0.68 and 2.87 %, respectively. Lightness and stability of 1.5% XG + 1.0% GG and 10% CF + 0.5% GG groups were significantly higher than control group (P<0.05). Since quality of mayonnaise depends on oil droplets constitution, the texture of mayonnaise was observed by scanning electronic microscopy (SEM). The SEM micrographs showed the network of aggregated droplets in low-fat treatments contained a large number of interspaced voids of varying dimensions. The oil droplets polydispersed in 1.5% XG + 1.0% GG group, whereas monodispersed in 10% CF + 0.5% GG group Further compared sensory evaluation of low-fat treatments with commercial mayonnaise, there were no significant differences in all sensory scores between 1.5% XG + 1.0% GG group, control and commercial mayonnaise (P>0.05). However, there were significant differences of appearance, taste and overall acceptance between 10% CF + 0.5% GG group and control group (P<0.05). The results of second part show that the viscosity of extender oil group was significantly lower than other groups (P<0.05), and there were no significant differences between other groups (P>0.05). During storage period, 200 ppm BHA could postpone mayonnaise samples oxidation. Moreover, POV and TBA values of olive oil and extender oil groups containing 200 ppm BHA were significantly lower than other groups (P<0.05). In conclusion, 1.5% XG + 1.0% GG and 10% CF + 0.5% GG can substitute the functionality of lipid in mayonnaise. It can increase dietary fiber concentration, and also decrease fat and caloric values. The shelf life of mayonnaise can be postponed by using olive oil and extender oil. It might be used in variety of low-fat salad dressings for further application.