Result of analysis shows that there was recorded significant differences in WI and YI of all UBF samples with different pretreatment across varying concentrations. Generally for all UBF samples, it was observed that the YI of all ascorbic acid treated samples was significantly higher (p < 0.05) than YI of citric and lactic acid pretreated samples while the WI of ascorbic acid pretreated UBF was significantly lower than those of citric and lactic acid pretreatment (Fig 1). WI of food produce generally measures consumers’ preference for white colours. It indicates the degree of whiteness of the food product thereby indicating the level of discolouration during processing. WI is derived from the combination of lightness and yellow-blue into a single term (Hsu, Chen, Weng, & Tseng, 2003; Pathare et al., 2013). YI of food products is used to quantify foods derived from degradation process of scorching, soiling, exposure to light and chemical processing. YI has also found application in measuring clear and near-colourless liquids