不同去乙醯度幾丁聚醣乳化性質之比較及其應用於沙拉醬之研究

Comparison of Emulsifying Properties of Chitosans of Different Deacetylation Degrees and Their Application on Producing Salad Dressing

阮進惠(Jin-Hwei Rwan) ； 沈家弘(Jia-Hong Shen)

《臺灣農業化學與食品科學》 44卷1期 (2006/02) Pp. 41-53

https://doi.org/10.6578/TJACFS.2006.006

摘要

本研究以20-30、40-50、60-70及80-90%去乙醯度之幾丁聚醣(chitosan)為乳化劑分別於不同濃度（0.5、1.0、1.5及2.0%）及pH（3.0、4.0、5.0及6.0）下進行乳化並比較其乳化能力、乳化液之黏度、安定性和類型及乳滴大小之分布。此外，將上述不同去乙醯度之幾丁聚醣取代蛋黃製備法式沙拉醬，並比較這些沙拉醬與傳統者的官能評估、黏度、安定性及菌生長問題。結果發現，在乳化能力方面，20-30%去乙醯度幾丁聚醣之乳化能力最低，80-90%去乙醯度者最高，而40-50%及60-70%去乙醯度者介在上述兩組中間。幾丁聚醣濃度愈高其乳化能力愈低，而幾丁聚醣溶液之pH近於6.0時有較高之乳化能力。乳化液之黏度及安定性方面，無論去乙醯度之高低，濃度愈高者乳化液之黏度愈高且安定性愈佳；低去乙醯度者於低pH或高去乙醯度者於接近pH 6.0下乳化，其乳化液黏度較高且安定。乳化液之乳滴大小分布情形則隨著乳化液之安定性愈佳其油滴直徑在0.02 cm內之數量愈多。此外，無論幾丁聚醣去乙醯度之高低，其乳化型態均為W/O/W (water-in-oil-in-water)。在沙拉醬應用方面，由官能品評結果得知，除了40-50%去乙醯度組表現較差外，其餘去乙醯度組的口感、風味、顏色似乎均略優於傳統組，惟稍有澀味，但其總接受性與傳統組並無明顯差異。此外，幾丁聚醣乳化液均比傳統者較安定（不分層），且雜菌不易生長。

關鍵字

不同去乙醯度之幾丁聚糖 ； 乳化性質 ； 沙拉醬

並列摘要

Emulsification of chitosan was carried on at different deacetylation degrees (20-30, 40-50, 60-70 and 80-90%), concentrations (0.5, 1.0, 1.5, and 2.0%) and pHs (3.0, 4.0, 5.0, and 6.0). Their emulsifying capacity and stability, emulsion viscosity, droplet distribution and emulsion type were determined. Also, chitosan salad dressings and conventional one were compared on the sensory evaluation, viscosity, stability and microbial growth. As result, on the emulsifying capacity, 80-90% deacetylated chitosan had a highest value, 20-30% deacetylated chtitosan presented lowest, where 40-50% and 60-70% deacetylated chitosans were between the 80-90% and 20-30% samples. The higher the chitosan concentration, the lower the emulsifying capacity. Chitosan solutions slanted toward pH 6.0 had a higher emulsifying capacity. On the emulsion viscosity and stability, the higher chitosan concentration the higher viscosity and stability in all emulsions; low deacetylated chitosans emulsified at low pH or high deacetylated chitosans emulsified at near pH 6.0 showed highly viscous and stable emulsions and gave a high droplet distribution in small size (less than 0.02 cm). The chitosan emulsions were water-in-oil-in-water type. Salad dressings were prepared from 20-30%, 60-70%, and 80-90% deacetylated chitosans appeared better mouth-feel, flavor, and color than that of traditional one, and gave a similar score of total acceptability as the latter although they had some astringent taste. Chitosan salad dressings also showed more stable, and less microbial growth than traditional one.

並列關鍵字

Chitosan of different degree of deacetylation ； Emulsifying properties ； Salad dressing