添加不同食用膠對愛玉凍離水性與組織特性之影響

Influence of Different Edible Hydrocolloids Addition on Jelly Fig (Ficus awkeotsang Makino) Jello Synaeresis and Textural Properties

本研究係探討於愛玉凍製程中添加不同濃度（0.1、0.3與0.5%）結蘭膠、刺槐豆膠與褐藻酸鈉等三種食用膠，並且貯存在不同溫度（35、45與55℃）之下，觀察其對愛玉凍離水性與組織特性之影響。結果顯示，不論添加何種濃度之三種食用膠及在何種溫度下貯存，經24小時後，pH值均會下降。添加食用膠後，亦會對愛玉凍之L、a、b值造成變化，其中，L值以添加0.5%結蘭膠者最高，a值與b值則均以對照組者最高，而添加0.5%結蘭膠者a值與添加0.5%刺槐豆膠者b值最低。對照組在55℃之下貯存24小時後，離水率可高達61.68%，但若添加結蘭膠、刺槐豆膠及褐藻酸鈉，則均能顯著(P < 0.05)改善此離水現象，且隨著食用膠濃度增加，離水率降低，其中更以添加0.5%結蘭膠之改善效果最佳，離水指數可降低至55.77。三種食用膠的添加也會對愛玉凍組織造成變化，其中，結蘭膠及刺槐豆膠可顯著(P < 0.05)提升愛玉凍之硬度、膠黏性與咀嚼性，至於在彈性及內聚性部分，所有樣品間無顯著差異(P > 0.05)。在感官品評方面，各處理組之色澤與對照組者之間無顯著差異(P > 0.05)；硬度以對照組與添加0.5％刺槐豆膠者最高；咀嚼感以添加0.1％結蘭膠、0.5％刺槐豆膠與對照組者最高；整體接受性以添加0.1％結蘭膠最高。整體而言，在添加不同濃度之三種食用膠及在不同溫度貯存下，都以結蘭膠對愛玉凍有最佳之抗離水效果，其中以0.5%結蘭膠效果最佳，但感官品評結果則以0.1%結蘭膠之整體接受性最佳。

The objective of this study was to investigate the effects of adding different concentrations (0.1, 0.3 and 0.5%) of three edible hydrocolloids (gellan gum, locust bean gum, sodium alginate) on the synaeresis and texture characteristics of jelly fig jello after storage at different temperatures (35, 45 and 55℃). The results indicated that the pH value was decreased for 24 hr storage no matter which concentration of the three edible hydrocolloids was added, and storage at different temperatures had no effect on the outcome. The addition of edible hydrocolloids affected the L, a, b values of jelly fig jello. The jelly fig jello containing 0.5% gellan gum had the highest L value. The control group had the highest a and b values, while the containers containing 0.5% gellan gum and 0.5% locust bean gum had the lowest a and b values, respectively. The control group has the highest synaeresis ratio (61.68%) when stored at 55℃ for 24 hr. However, the addition of gellan gum, locust bean gum and sodium alginate significantly improved (P < 0.05) the synaeresis phenomena of jelly fig jello, and the higher the concentration of edible hydrocolloids used, the amount of water lost decreased accordingly. Among the three edible hydrocolloids, the best synaeresis improvement was achieved by adding 0.5% gellan gum, achieveing a synaeresis index of 55.77, the lowest result obtained in this study. Adding the three edible hydrocolloids in jelly fig jello also caused changes in the texture characteristics of the jello. Among these, gellan gum and locust bean gum significantly improved (P < 0.05) the hardness, gumminess and chewiness of jelly fig jello. No significant differences (P > 0.05) on springiness and cohesiveness were found between all jello samples. In the sensory evaluation study, no significant difference (P < 0.05) in color was found between all jello samples. The highest hardness value was observed in the control group and the group with 0.5% locust bean gum added, while the highest chewiness value was observed from the control group, the group with 0.1% gellan gum added and the group with 0.5% locust bean gum added. The group with 0.1% gellan gum added had the highest overall acceptability among all jello samples. In summary, the best anti-synaeresis effect was obtained by adding 0.5% gellan gum (storing at different temperatures had no effect on this result). However, the adding 0.1% gellan gum had the highest score regarding overall acceptability.