Physico-chemical properties of instant Kheer mix

摘要

Certain cereal-based, traditional Indian desserts comprise a sweetened cooked mixture of partially concentrated milk and rice flour. However, such products have a very limited shelf life with the result that they cannot be commercially marketed. In order to render the product shelf-stable, it was converted into a reconstitutable powder by using a pilot-scale spray drying system with an integrated fluidized bed dryer and a provision for recycling of powder fines from the cyclone separator back into the drying chamber. The process involved standardization of buffalo milk followed by vacuum concentration, addition of ground rice flour and part sugar, pre-heating the slurry for gelatinization of starch, and finally spray-bed drying (inlet-air temperature 170 degreesC and outlet-air temperature 86 degreesC for the spray dryer and inlet-air temperature 88 degreesC and outlet-air temperature 80 degreesC for the fluidized bed dryer). The powder was then mixed with ground sugar through dry blending. The instant kheer mix thus obtained was analyzed for its physico-chemical properties. The freshly prepared powder had a good flowability (angle of repose, 40.09degrees) and fairly high loose and packed bulk densities (0.69 g.cm(3) and 0.81 g.cm(3), respectively) corresponding to a particle density of 1.25 g.cm(-3), occluded air content of 6.63 cm(3). 100 g(-1), interstitial air content of 45.00 cm(3).100 g(-1) and porosity of 44.80%. It showed an insolubility index of 4.00 mL, wettability of 2.00 min, and dispersibility of 75.38%.