Study On The Effect Of Okara On The Characteristics Of Cakes

Okara is the main by-product of soybean processing industry. Its main ingredient is the dietary fiber which accounts for more than half of the dry matter. The production of okara is huge every year in China, but the most were discarded as a kind of waste which caused the waste of resources and environmental pollution. Okara was used as dietary fiber in this study and the effects of different levels and particle sizes of okara on the physical properties of cake were investigated by measuring batter density, the rheological properties of cake batters, specific volume of the cakes, crumb moisture, crust and crumb color, and texture. The results were as follows:1. Effects of different levels of okara on the physical properties of cake were studied. The results showed that the batter density added with okara was significantly different (P<0.05) from that without okara, but no significant difference between the two groups of10%and15%. As the levels of okara increased, specific volume of the cakes was decreased. Specific volume of the sample with20%okara was2.25ml/g which was the lowest. When the levels of okara were no less than10%, there were significant differences (P<0.05) among samples. The crumb moisture was significant differences (P<0.05) when the levels of okara were more than5%and there was no significant differences (P>0.05) between the group of0%and5%. The colour of crust cake with0%okara had the lowest L*values and the highest a*and b*values. The crumb colour with20%okara had the highest L*、a*and b*. With increasing okara levels, hardness, chewiness increased whereas springiness, cohesiveness, resilience values revealed an opposite trend. The addition of okara had negative effect on the sensory properties of cake. As the levels of okara increased, the colour, chewiness, taste, odour, springiness and overall acceptability scores decreased. However, the organoleptic indicators were little affected when the levels of okara was5%.2. Batter density increased with the reduction of particle sizes of okara and there were significant differences (P<0.05) among the batter density with the largest particle size (>40mesh) of okara and other samples. The specific volume of the cake with the smallest (<80mesh) okara is the largest compared with other samples and there were significant differences (P<0.05). The crumb moisture of the cake was affected (P<0.05) by the reduction of particle sizes of okara. The crumb moisture of the largest particle size (>40mesh) of okara is the highest, reaching36.58%. The L*values of the crust cake decreased with the reduction of particle sizes of okara whereas a*values increased, and the b*values of the crust cake was not affected (P>0.05). The L*values of the crumb cake was not affected (P>0.05) and the b*values decreased with the reduction of particle sizes of okara. With particle sizes of okara decreasing, hardness, chewiness, cohesiveness decreased whereas springiness, resilience values increased. The appearance, chewiness, taste, odour, springiness and overall acceptability scores increased with the reduction of particle sizes of okara.3. The rheological properties of cake batter was affected by the different levels and particle sizes of okara. The storage modulus and loss modulus of cake batters with okara were higher than sample without okara. The G’and G" values of cake batter increased with the increasing of particle sizes of okara. In early heating stages, the G" values were higher than G’values, after a period of time the G’values were higher than G" values.