Abstract:
Fruit yoghurts are becoming popular in the world due to their different flavours, tastes as well
as high nutritional properties. Therefore, yoghurt manufacturers now-a-days add different fruit
species to produce fruit yoghurts with improved nutritional and sensory properties. Star fruit
{Averrhoa carambola L.) is an underutilized fruit growing well in Sri Lanka, India, Malaysia
and Indonesia. Star fruit has a number of medicinal properties, besides being rich in vitamins
and minerals. Researchers have demonstrated that Star fruit juice is capable of reducing blood
pressure and moreover can be used as a remedy for diabetes. Therefore, the objectives of this
study were to develop a value-added fruit yoghurt using Star fruit and to determine its
sensory, physicochemical and microbiological properties. Properly washed golden color Star
fruits were cut into small pieces, steamed for 3 min and oven-dried at 60°C for 3 h. Further,
fruit pieces were introduced to saturated sugar solutions and dehydrated for 24 h before being
used to produce fruit yoghurts. Three types of new yoghurts with Star fruit were produced
and they were Star fruit jelly yoghurt, Star fruit stirred yoghurt, Star fruits on-top of yoghurt
and plain se# yoghurt (control). A panel of 30 sensory panelists was used to evaluate the
sensory attributes of newly prepared yoghurts such as appearance, aroma, taste, texture and
overall acceptability on a 5-point hedonic scale. The statistical analysis of sensory evaluation
results was carried out by using Kruskal Wallis one-way ANOVA test with the use of
STATISTIX computer software (Ver 2.0) for windows. Star fruit jelly yoghurt had a mean
rank sum of 49 for overall acceptability thus showing significantly higher (£<0.05) sensory
properties and was selected as the best fruit yoghurt. The pH of the Start fruit jelly yoghurt
decreased from 4.07 to 3.81 whereas the titratable acidity increased from 1% to 1.23% during storage for four weeks. The shelf-life of the Star fruit jelly yoghurt was 21 days. Redox
potential (£h) of the Star fruit jelly yoghurt increased from +105.3 mV to +153.6 mV during storage. Microbiological tests revealed that E. coli was absent in the Star fruit jelly yoghurts.
The results of the present study suggest that Star fruit jelly yoghurt conformed to the Sri
Lanka Standards Institution (SLSI) standards and thus Star fruit jelly yoghurt can be produced
as a high value, health promoting fruit yoghurt with improved sensory properties.
