Development and sensory evaluation of an improved beverage from Nigeria's Tamarind ( Tamarindus indica  L.) fruit

Tamarind (Tamarindus indica L.), an indigenous underutilised tree fruit, has many valuable properties and almost every part of the tree is utilised by rural and urban dwellers. Nigerian tamarind fruits are grossly underutilised, with the rural dwellers utilising some of the fruits in beverage production using ancient processing methods. The ancient processes of manufacture are cumbersome, slow, non-hygienic and highly subjective, often resulting in non-uniform and low quality products which are less preferred to commercial imported ones. Furthermore, traditional tamarind beverage is not as popular among the populace as other traditional beverages. There is therefore a need to develop simple and affordable process of producing standard tamarind beverage which would be widely accepted by Nigerians. A simple, improved processing method was developed based on the traditional method of manufacturing tamarind beverage using the modified one-factor-at-a-time method to determine the experimental levels of the various ingredients used in the formulation of the beverage. A pilot study was carried out to determine the acceptable range of pulp to water blend. The beverages were evaluated by the paired preference, hedonic rating and multiple comparison tests using 50 semi-trained assessors within the age range of 18 and 45 years. The results of the paired preference tests were expressed as levels of significance while the mean scores of hedonic rating tests were subjected to analysis of variance. Tukey′s test was used to separate the means. Samples of tamarind beverages produced by the traditional and improved processing methods were analysed for colour, pH, total acidity, soluble solids, ascorbic acid, total solids, browning index and cloudiness using standard methods. The colour (A _325nm ), cloudiness (A _660nm ), browning index (A _420nm ) and ascorbic acid (mg/100ml) of the traditional and improved beverages were 0.91±0.25, 0.68±0.16, 1.42±0.04, 9.5±0.69 and 0.60±0.01, 0.13±0.01, 0.19±0.01 and 10.4±0.21, respectively. While the traditional processing method took 10 hours to produce about 10 litres of beverage, the improved processing method took 2 hours to produce 250 litres of beverage. The improved beverage was rated much higher in terms of colour, aroma, taste and overall acceptability than the traditional beverage and compared favourably well with a similar commercial beverage. A beverage with more acceptable qualities than the traditional beverage was thus produced from the improved processing method.