Spray drying of mango juice - Buttermilk blends

Abstract

In India both dairy and fruit sectors face problems of lack of basic infrastructure for handling peaks in production. Mango is considered as king of the fruits, but its production is highly seasonal. Lack of adequate infrastructure in many places results in huge losses due to low keeping quality. In the dairy industry, buttermilk, a by-product of butter production, is mostly left unutilized. Buttermilk is a good source of valuable milk proteins and lactose; its high phospholipids content makes dried buttermilk a good functional ingredient in food formulations. In this study, blends with different levels of mango juice and buttermilk were spray dried viz., 5:95, 10:90, 15:85 and 20:80 at feed temperature of 40-55 °C and compressed air pressure of 68-170 kPa. It was observed that the various processing parameters such as outlet air temperature, total solids and blend proportions had a profound effect on the characteristics of the resultant powder. The viscosity of blends increased with an increase in the mango juice proportion in the blend. High acid content of the blends had no negative effect on thermal stability of the blends before and after spray drying. This is probably due to the fact that a relatively low feed temperature (45 °C) was used and the exposure of the blends to high temperatures was only momentary during drying process. It was found that increments in the inclusion of mango solids had a positive effect on the resultant yield of powder. An increase in solid content of the blends up to 35% resulted in a steep increase in yield, which was adjudged as the optimal total solids for drying. Further increase in total solids of the blends resulted in reduced yields. The outlet air temperatures of the spray drier were optimized at a range of 85-90 °C for all the blends. Sensory evaluation studies by an in-house panel affirmed that the blend with 20:80 ratio of mango juice: buttermilk, respectively, possessed the desired sensory characteristics. © INRA, EDP Sciences, 2005.