Some physico-chemical characteristics of four Kenyan tropical fruits and acceptability of blends of their beverage nectars

Purees were produced by simple manual extraction methods from passion fruit, mangoes and papaya, and juice from pears. These products were analyzed for yield, pH, total titratable acidity, total soluble solids and reduced ascorbic acid. Sugar/acid ratio was also calculated for each product. The products were then used to prepare beverage nectars using standard procedures. The nectars were blended in pairs: passion fruit + papaya, mango + papaya, passion fruit + pear, mango + pear and papaya + pear, to contain 10-50% (v/v) of the first fruit and 50-90% (v/v) of the second fruit. The blends were subjected to sensory evaluation on a 7-point hedonic rating scale using a trained laboratory panel in order to determine the most preferred blend in each group in terms of colour, appearance, taste and overall acceptance. The most preferred blends were then ranked. The yields of the products averaged 27.3 +/- 2.0% for passion fruit puree, 63.0 +/- 3.0% for mango puree, 67.5 +/- 2.4% for papaya puree and 68.5 +/- 3.0% for pear juice. The pH was lowest at 3.0 for passionfruit puree and highest at 5.1 for papaya puree. The total soluble solid content was lowest for papaya puree and highest for mango puree, while reduced ascorbic acid content was highest at 21.3 +/- 4.5 mg/100 ml in papaya puree and lowest at 0.3 +/- 0.1 mg/100 ml in pear juice. Papaya puree had an exceptionally high sugar/acid ratio due to the high soluble solids levels and very low acid levels. The most acceptable nectar blends in order of their decreasing ranking were found to be passion fruit + papaya (10 + 90), mango + papaya (10 + 90), passion fruit + pear (50 + 50), mango + pear (50 + 50) and pear + papaya (10 + 90). such blends should be affordable and would be of higher nutritional value than popular soda beverages.