The Effects of Spray Drying Conditions on Moisture Content, Water Activity, Bulk Density, and Tapped Density of Rice Milk Powder

Abstract

Cow's milk is usually consumed by the majority of the population and is well thought of as a wholesome complete food providing major nutrients like fat, proteins, and carbohydrates. Though milk is considered to be a complete food yet limited availability or near absence of certain minerals such as iron, and vitamins restricts its recommendation as a complete food for infants older than 12 months. To meet this requirement the rice milk was prepared by using the broken rice. Spray drying is a method applied to dry a wide variety of food extracts. The resulting powders are conveniently stored, transported, and handled. To increase the shelf life of the rice milk, spray drying of the rice milk was done by using the different inlet temperatures and feed flow rates. An experiment was conducted to study the effects of spray drying conditions on moisture content, bulk density, and tapped density of rice milk powder in 2019 at Bapatla, Andhra Pradesh, India. The broken rice was used to prepare rice milk with the optimized process parameters. Temperature and feed flow rate were optimized with the desirability function which satisfied all the responses with the required values to obtain optimum conditions for spray drying. The predicted optimum conditions were T=138°C and Q=35 MLM-1. Under these conditions, the response values for bulk density, moisture content, and water activity were 0.51 GML-1, 3.8% and 0.30.