Project work

2.5 Determination of fat

          AOAC method 7.045(2000) was used to determine the fat content of the rice powder. Rice powder (5g) was taken into the thimble. The thimble was attached to the Soxhlet apparatus which was attached with a round bottom flask containing 200 ml ether. The fat was extracted for16 hours. The ether was evaporated at 80ºC until the flask completely dried.

Fat content was calculated by following formula:

% Fat = ×100

W₁ = weight of evaporated flask with powder

W₂ = weight of empty flask

W = weight of powder

2.6 Determination of acid insoluble ash

            AOAC method 14.006(1975) was used to determine the total ash content. Rice powder (5g) was weighed and transferred into a clean, dry and pre-weighted crucible.Then the crucible was kept into muffle furnace at 550ºC for 6 hours. It was cooled at desiccator and weighed.

The ash content was calculated by the following formula:

% Ash = ×100

w₁ = weight of ash with crucible

w₂ = weight of crucible

 w = weight of powder

2.7 Determination of Water Absorption Index (WAI)

          Water absorption index (WAI) was determined by Anderson method (1982) with some modification. Dried powder (0.83g) was suspended with 10 ml of water into a 30 ml of tared centrifuge tube. Then it was stirred intermittently over a 30 min. and centrifuged at 4000 rpm for 15 min. The supernatant was poured carefully into a tared dish. The residue was weighed.

Water absorption index was determined by following formula:

WAI (g/g) = ×100

w₁ = weight of tube with residue

w₂ = weight of the tube

w = weight of powder

2.8 Determination of Water Solubility Index (WSI)

          Water solubility index (WSI) was determined by Anderson method (1982) with some modification. Dried powder (0.83g) was suspended with 10 ml of water into a 30 ml of tared centrifuge tube. Then it was stirred intermittently over a 30 min. and centrifuged at 4000 rpm for 15 min.The supernatant was poured carefully into a tared dish. The supernatant was dried at 70ºC until a constant weight was obtained. Then it was cooled and weighed.

Water solubility index was calculated by following formula:

Water Solubility Index (%) = ×100

w₁=weight of dish and dried liquid

w₂=weight of dish

w=weight of dry powder