The Effects of Spray Drying Conditions on Water Absorption Index, Water Solubility Index, Solubility and Water Activity (aw) of Rice Milk Powder

Abstract

Cow’s milk has been widely consumed as it acts as an important source of protein. It also acts as a wholesome complete food providing all the major nutrients like fat, carbohydrates and proteins. Due to the lactose intolerance in some people in place of cow’s milk plant based milk products are becoming more popular due to its nutritional benefits same as that of cow’s milk. Broken rice has the nutritional benefits equal to raw rice and it can be processed into various value added products. In this study, the broken rice was used to prepare rice milk with the optimized process parameters. Rice milk was spray dried to enhance its shelf life at different inlet drying air temperatures and feed flow rates. Temperature and feed flow rate were optimized with desirability function which satisfied all the responses with required values to obtain optimum conditions for spray drying. The predicted optimum conditions were;T= 138°C, and Q= 35 mL/min. Under these conditions, the response values for water activity, water solubility index and water absorption index were 0.30, 72.8% and 21.7%, respectively.