Beetroot: Beta Vulgaris

Beetroot (Beta vulgaris) are considered as very important vegetables from nutritional view rich in valuable, active compounds such as carotenoids 4, glycine, betaine 3 saponins 2, betacyanines21, betanin, polyphenols and flavonoids 30. Therefore, beetroot ingestion can be considered a factor in cancer prevention 12. The preservation of fruits and vegetable by dehydration presents a unique challenge, because of the structural configuration of these products the removal of moisture must be accomplished in a manner that is the least detrimental to the product quality. Among the different methods of food preservation, convective dehydration is the most popular and efficient way to reduce the moisture content and preserve foods. Product quality

Therefore, there is a need for simple economic and technically feasible alternative drying processes, which have low capital cost and offer a method to save highly perishable products making them available to the regions away from production zones. Osmotic dehydration is one such method 26. Osmotic dehydration involves the partial removal of water from food, such as fruit or vegetables, by immersion in a hypertonic solution 15.This appears to improve the quality of the final product because it prevents oxidative browning and the loss of volatile flavouring constituents, reducing the fruit acidity and structural collapse during subsequent air-drying 4.Osmotic pretreatment can also minimise drying colour losses 23, as well as reducing nutrient losses

The cubes were mixed in a plastic container before drying and then divided into 175 g portions. The initial moisture content of Beetroot varied from 85.71 to 86.29% (w.b).Optimization of osmotic dehydration process was carried out with purpose of maximizing water loss, solute gain and quality of the product. The optimum conditions were 60oBx osmotic solution concentration, 55o C osmotic solution temperature and 180 min process duration at fruit to solution ratio 1:4 (w/w). Following osmotic pre treatment at optimum conditions, the moisture content of the Beetroot cubes reduced to 74.86 %(w.b) and the solid content increased up to 26%. To prepare a shelf stable product, the beetroot cubes were dehydrated up to final moisture content 9±1% (w.b.) (Singh, Kingly, & Jain, 2007) at an air temperature of 55, 65, 75 oC and air velocity of 1.6 m s-1.Inital moisture content was determined by the oven drying method, for the natural and osmosed Beetroot samples at a temperature of 1350C for 2 hours until constant weight was reached 1 with repetition in order to assure moisture content average