Sensory and Physicochemical Analyses on Commercial Taro Ice Products
TING-JANG LU 1, CHIH-WEN CHUANG 2 AND YUNG-HO CHANG 2*
1.Graduate Institute of Food Science and Technology, National Taiwan University 59, Lane 144, Kee-Lung Road, Sec. 4, Taipei, Taiwan 106, R.O.C.
2.Department of Food and Nutrition, Providence University 200 Chung-Chi Road, Shalu, Taiwan 43301, R.O.C.
(Received: June 19, 2001; Accepted: November 2, 2001)
ABSTRACT
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.
Keywords: taro ice products, commercial products, sensory evaluation, principal component analysis