The Effect of Sesame Oil Contents on the Mechanical Properties of Gomatofu (Sesame Tofu)

Abstract

Gomatofu is a mixed gel consisting of kudzu (arrowroot) starch and sesame seeds. In this study the effect of sesame oil contents on the mechanical properties of gomatofu was investigated by rheological measurements under uni-axial compression and creep, SEM observation and sensory evaluation. Huskless (hereafter Muki) white sesame seeds were used. The gomatofu samples are as follows: a) Defatted gomatofu (oil content 0%), b) Defatted gomatofu (oil content 0.42%), c) Control gomatofu (oil content 3.4%), d)3% sesame oil added (oil content 6.4%), e) 6% sesame oil added (oil content 9.4%), were prepared and examined.
From the results of the texture measurement, the hardness increased with increasing oil content, but cohesiveness in the sample c), control gomatofu, showed the highest value on the first storage day. Conversely the adhesiveness of the sample c) was the lowest. With increase in the number of storage days, hardness of the sample increased. Cohesiveness and adhesiveness decreased with increasing oil content. From the result of the creep measurement, the coefficient of elasticity and viscosity of 4 elements model increased with the number of storage days. The size of air cells was found to become smaller with increasing content of oil by SEM (scanning electron microscopy) observation. In the sensory evaluation, the control sample c) and the sample d) were highly evaluated for total acceptance. From these results it was found that favorable oil content was 3.4˜6.4 % in the sample (gomatofu). The correlation between mouthfeel and oiliness (0.47, P<0.05), and between mouthfeel and total acceptance (0.94, P<0.001) of the sensory evaluation showed significant difference.