Effect of hydrocolloids and egg content on sensory quality of coated fried yam chips

Abstract

This study investigated the role of hydrocolloid and egg content as coating ingredients on the sensory quality of fried yam chips (FYC). The independent variables studied include hydrocolloid type (xanthan gum, gum tragacanth and carboxymethyl cellulose (CMC)), hydrocolloid concentration (0.5-1.5%) and egg content (egg white or whole egg). The coated chips were evaluated for appearance, texture, taste, flavour and overall acceptability using nine-point hedonic scale. Descriptive sensory evaluation of the samples using generic method was also conducted. FYC without coating were used as the control samples. Hydrocolloid type, concentration and egg content had significant (p˂0.05) effects mainly on the appearance and texture of the FYC. Only the hydrocolloid concentration significantly influenced the overall acceptability of the samples. Samples containing CMC plus egg-white were more acceptable in terms of appearance and texture. Generally, the acceptability scores decreased significantly with increased hydrocolloid concentration (p<0.05). Also, coated fried chips were rated better than the control. Appearance had highest significant correlation (p<0.01, r=0.764) with overall acceptability. Out of over 50 descriptors generated by the trained panelists, eight of them were agreed upon as non-redundant, discriminatory attributes of the coated fried yam chips. Similarity map of the descriptors were defined by two principal components (1 and 2) accounting for 53.06 % and 40.18 %, respectively, of total variance of rotation sums of squared loadings. Puffiness had significant negative correlation with overall acceptability (p<0.05, r=-0.986). This study shows that careful selection and formulation of coating ingredients could help to improve on consumer acceptability of coated fried yam chips. Information generated could be used in further optimization of the processing variables for the production of consumer acceptable coated fried yam chips.