Properties of Flour and Starch from Unripe Banana ‘Kluai Khai’ Flesh and Their Application in Tong Muan

Abstract

This study aims at investigating the chemical and physical properties of flour and starch from unripe banana cultivar, Musa AA group ‘Kluai Khai’ (45 days after stabbing banana blossom) and sensory attributes of flour and starch based Tong Muan products. Flour and starch from unripe bananas had a dry basis yield of 51.42% and 19.10% and amylose content of 31.45% and 38.98%, respectively. The chemical compositions of unripe banana flour (UBF) (moisture, protein, lipid, ash and crude fiber contents) were higher than that of unripe banana starch (UBS). The swelling power and the solubility of UBF and UBS increased by increasing temperature.  At temperatures above 75ºC, the swelling power and the solubility of UBF were 11.38 g/g and 4.70% respectively, which were lower than that of UBS were 13.32 g/g and 5.45% respectively. The peak and final viscosity of UBF (317 and 368 RVU, respectively) was lower than that of UBS (362 and 523 RVU, respectively) and also the setback values of UBS (203 RVU) was higher than that of UBF (102 RVU). To utilise the UBF and UBS, the Tong Muan flour mixtures were prepared by mixing rice flour and cassava starch at a weight ratio of 50:50 (control), and the flour mixtures was substituted with the flour mixtures of UBF and UBS at weight ratios of 50:50, 100:0 and 0:100. The result of sensory evaluation indicated that the Tong Muan products made from the mixture of UBF and UBS at the ration of 0:100 had the highest acceptability with a score of 8.05 (9-point hedonic scale). The results showed that the colour values of Tong Muan products were lightness (L*) = 56.95, redness (a*) = 10.41 and yellowness (b*) = 19.94, respectively. The hardness values of Tong Muan products made from the mixture flour between UBF and UBS had the highest hardness values (316.32 g force). In addition, Tong Muan product of this recipe yielded higher crude fiber content (3.23 % dry basis), but lower protein (0.34 % dry basis) and fat content (2.45 % dry basis) than that of the control (P<0.05). Therefore, it can be concluded that the unripe banana flour and starch can be used as the ingredients in flour mixtures of Tong Muan products.