Abstract:
The busy life styles of Sri Lankans demand traditional food items on instant
preparation category. Therefore this study was conducted to identify best processing
method for string hopper flour with it’s promised quality characteristics as demanded by
the peoples.
Various processing conditions and treatments were tested to identify best processing
conditions. Deferent preheater temperature(3 5°C, 60°C, 70C°, 80°C, 85°C), different
water amounts (1000ml, 15Q0ml,2000ml/50kg of rice) in deferent soaking time
(30min.,45min., 60min.) was tested to identify gelatinization effect. The roasting effect
on gelatinization is tested at several temperature levels (,60°C, 70C°, 80°C, 90°C) for
different times(2min., 5min., 10min.,15min. ). Chemical treatments were given using
vinegar, citric acid, sodium carbonate, sodium bicarbonate, calcium carbonate, calcium
bicarbonate, hydrogen peroxide, phosphoric acid at the range of 0.01-0.2% . The plate
milling, hammer milling and there combinations were used to check effect milling.
Different kind of parboiled rice were also used in the preparation of rice flour for string
hopper. Sensory tests were conducted in comparison of parboiled rice flour with two
commercial available rice flour mixtures (Type I and Type III) to evaluate the functional
properties of string hoppers.
Temperature in the range of 70 - 80°C found to be the best preheater temperature for
string hopper flour manufacturing process; and with 2-5 min. and 70-80°C found to be
the ideal time temperature combination during roasting. Hydrogen peroxide and
phosphoric acid in the range of 0.01- 0.2 % given good texture and colour. Results
revealed that flour prepared using parboiled rice could able to make dough with cold
water while maintaing required quality characteristics. A combination of parboiled rice
and water spray is the most efficient and cheapest method to prepare string hopper. The
sensory evaluation related that there is a significant difference of functional properties
(e.g. colour, smell, texture, taste, appearance and overall quality) between three samples.
All of functional properties of parboil rice flour was best than type I flour. Hydration
capacity about 3.2-4.0 level suitable for string hopper preparation.
