Abstract:
Dragon fruit (Hylocereus undatus L.), which is rich in vitamin C,
fiber and natural antioxidants, is one of the most popular commercial fruits
available in sri lanka. However, dragon fruit is still an underutilized fruit in
Sri Lanka as its high price and exotic taste don’t warrant consumption of the
fruit by average Sri Lankan consumers. The present study investigated the
possibility of developing a novel fruit-yoghurt incorporated with white
dragon fruit and evaluated its eating quality parameters. An initial survey
was conducted to find out the consumer preference for value-added dragon
fruit products in Sri Lanka. Pasteurized dragon fruit juice enriched yoghurt
(5%, 7.5%, 10% and12.5% w/w) were prepared with the suitable
concentrations of sugar and gelatin and sensory properties, pH, titratable
acidity, total solid, fat, solid-non-fat (SNF) and microbiological properties of
the product were determined. Sensory results were analyzed by Kruskal wallis non-parametric one way ANOVA method using STATISTIX software
(ver 2.0) for windows. Survey results showed that 90% of individuals were
eagerly waiting for the new product from dragon fruit in the near future.
Sugar (10%), gelatin (0.8%) and dragon fruit juice (10%; w/w) added
yoghurt mix was selected as the best product considering its highest mean
rank values recorded for sensory properties. The titratable acidity and pH of
the developed product during the storage period ranged from 0.8 to 1.0 %
and 4.08 to 3.9, respectively. Yeast and mould count did not exceed the Sri
Lanka Standards Institute (SLSI) recommended values during the 15-day
storage period. It can be concluded that dragon fruit can be successfully
European Scientific Journal January 2015 edition vol.11, No.3 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431
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used to develop a fruit-yoghurt with improved sensory and nutritive
properties.
