市售芋冰品之官能與物理化學分析   全文下載

Sensory and Physicochemical Analyses on Commercial Taro Ice Products

本研究針對市售14種不同品牌的芋冰品，依產品形式分為冰磚（冰棒，8品牌）及冰淇淋（6品牌）兩類，分別測定其外觀色澤、水分含量、脂肪含量、膨脹率、黏度、質地、融化速率及游離糖組成等理化性質，並以官能品評及主成分分析法探求其重要官能品評指標項目。結果顯示，整體而言不同品牌冰淇淋類產品間之色澤差異較小，膨脹率則較高。而兩類產品中以冰磚類產品之堅實度較冰淇淋者為高且融化速率較慢；冰品之游離糖組成則大多以蔗糖及乳糖為主。官能品評結果顯示，冰磚類產品之口感堅實度顯著（p<0.05）高於冰淇淋類者；不同品牌間之甜度與細滑度的品評結果較為一致，整體感亦普遍高於冰淇淋類者。進一步分別針對兩類冰品之官能品評結果進行主成分分析，結果顯示研究中所採之官能品評項目較能評估出冰淇淋類樣品間之差異。對芋冰磚類主成分分析結果之第一主成分具顯著（p<0.05）影響程度的官能品評項目依序為甜度、黏稠感、堅實度、色澤；對第二主成分具顯著（p<0.05）影響程度的項目則為油膩感。而對冰淇淋類者的分析結果具顯著（p<0.05）影響程度的官能品評項目則依序為色澤、細滑度、甜度、黏稠感（第一主成分）及整體感、芋香味（第二主成分）。綜合比較冰磚及冰淇淋類產品之主成分分析結果，得知冰品之甜度、色澤及黏稠感等官能品評項目為市售芋冰品官能性質中的差異指標項目，故應可作為芋冰品開發時之參考指標。

Fourteen commercial taro ice products, including 8 ice-bar products and 6 ice-cream products, were used as the samples in the present study. The physicochemical properties of the commercial taro ice products such as color, moisture content, fat content, overrun, viscosity, texture, melting rate and free-sugar composition were measured. Sensory evaluation and principal component analysis (PCA) methods were also employed to investigate the important sensory factors. Results indicated that the ice creams showed lower levels of differences in color and higher overrun values, whereas the ice bars had a higher value of hardness and lower melting rate. Sucrose and lactose were the major free-sugar components for most of the commercial taro ice products studied. Ice-bar samples showed a significantly (p<0.05) higher value of firmness in sensory evaluation, and the sweetness and creaminess scores of ice bars were less diverse than those of the ice creams. Results of PCA indicated that the sensory evaluation method distinguished the differences between the ice cream products in a more sensitive manner than that of the ice-cream products. The significant (p<0.05) attributes of the sensory evaluation to the first principal component of ice bars were sweetness, thickness, firmness and color whereas fattiness was the significant (p<0.05) item to the second principal component. For the ice creams, on the other hand, the significant (p<0.05) sensory evaluation items were color, creaminess, sweetness, thickness (for the first principal component), overall score and taro flavor (for the second principal component). Based on the results of PCA, the evaluation of sweetness, color and thickness were the important sensory factors, which then could be used as a reference index in the development of taro ice products. 本研究針對市售14種不同品牌的芋冰品，依產品形式分為冰磚（冰棒，8品牌）及冰淇淋（6品牌）兩類，分別測定其外觀色澤、水分含量、脂肪含量、膨脹率、黏度、質地、融化速率及游離糖組成等理化性質，並以官能品評及主成分分析法探求其重要官能品評指標項目。結果顯示，整體而言不同品牌冰淇淋類產品間之色澤差異較小，膨脹率則較高。而兩類產品中以冰磚類產品之堅實度較冰淇淋者為高且融化速率較慢；冰品之游離糖組成則大多以蔗糖及乳糖為主。官能品評結果顯示，冰磚類產品之口感堅實度顯著（p<0.05）高於冰淇淋類者；不同品牌間之甜度與細滑度的品評結果較為一致，整體感亦普遍高於冰淇淋類者。進一步分別針對兩類冰品之官能品評結果進行主成分分析，結果顯示研究中所採之官能品評項目較能評估出冰淇淋類樣品間之差異。對芋冰磚類主成分分析結果之第一主成分具顯著（p<0.05）影響程度的官能品評項目依序為甜度、黏稠感、堅實度、色澤；對第二主成分具顯著（p<0.05）影響程度的項目則為油膩感。而對冰淇淋類者的分析結果具顯著（p<0.05）影響程度的官能品評項目則依序為色澤、細滑度、甜度、黏稠感（第一主成分）及整體感、芋香味（第二主成分）。綜合比較冰磚及冰淇淋類產品之主成分分析結果，得知冰品之甜度、色澤及黏稠感等官能品評項目為市售芋冰品官能性質中的差異指標項目，故應可作為芋冰品開發時之參考指標。