Producing beetroot powder by using foaming agent maltodextrin and milk protein concentrate in foam mat-microwave drying method

Abstract

Introduction: Beetroot (Beta vulgaris L.) is a good source of dietary fibers, minerals, vitamins, antioxidants, betalains and phenolic compounds. Drying is one of the oldest ways to preserve food and increase its shelf life. Drying with normal methods causes a lot of damage to the flavor and nutrients due to the long time of the drying process and high temperature. Drying with microwave can significantly remove these disadvantages. The use of microwaves in drying significantly reduces the process time and improves the reabsorption and shrinkage characteristics of the product. Foam \mat drying is a new method that takes place in a shorter and faster time than the traditional method of drying with hot air. This method is used to dry liquid or semi-liquid food such as fruit juice and fruit puree or vegetables. The subject of this research is to produce beetroot powder using the foammat method in order to improve the nutritional value and increase the shelf life.Materials and methods: 15 treatments were defined using Design Expert version 11 software and considering three independent variables [maltodextrin (MD), milk protein concerate (MPC], microwave power). The foam produced from maltodextrin and MPC with the same concentration (0-10%) was dissolved in 100 ml of distilled water and then added to 200 g of chopped beet pulp and the mixture and prepared foam was spread in a special tray with a thickness of 1 cm. Drying operation was done in a microwave with power intensity (400-800). Then the produced powder of beetroot was evaluated in terms of some physicochemical characteristics and the responses of the treatments were analyzed by the response surface method (RSM) and the central composite design (CCD) and the optimal sample was obtained.

Keywords

• beetroot powder
• milk protein concentrate
• maltodextrin
• foam mat
• microwave