Osmotic Dehydration Lab Report

Chapter 1

Introduction

Osmotic dehydration is a process of water removal from fruits and vegetables, because the cell membranes are semi-permeable and allow water to pass through them than sugar (Ponting, 1973). The basic purpose of food dehydration is to lower the water content to minimize rates of chemical reactions and to facilitate distribution and storage. In osmotic dehydration, foods are dipped or soaked in a salt or sugar solution. This shows three types of counter mass transfer phenomenon (Ponting, 1973). First, water flows out from the food tissue to the osmotic solution, second, a solute transfer to the food tissue from the osmotic solution, third, a leaching out of the food tissue solutes (sugars, organic acids, minerals, vitamins

100 g of taro root provides 112 calories. Nonetheless, the roots are very low in fats and protein than in cereals and pulses. Their protein levels can be comparable to that of other tropical food sources like yam, cassava, potato, plantain etc. The corms, however, are free from gluten protein. They carry high-quality phyto-nutrition profile comprising of dietary fiber, and antioxidants in addition to moderate proportions of minerals, and vitamins. Taro is one of the finest sources dietary fibers; 100 g flesh provides 4.1 g or 11% of daily-requirement of dietary fiber. Together with slow digesting complex carbohydrates, moderate amounts of fiber in the food help gradual rise in blood sugar levels. Yellow-fleshed roots and young, tender leaves have significant levels of phenolic flavonoid pigment antioxidants such as ß-carotenes, and cryptoxanthin along with vitamin A. 100 g fresh taro leaves provide 4825 IU or 161% of RDA of vitamin A. Altogether, these compounds are required for maintaining healthy mucus membranes, skin and vision. Consumption of natural foods rich in flavonoids helps protect from lung and oral cavity cancers.It also contains good levels of some of the valuable B-complex group of vitamins such as pyridoxine (vitamin B-6), folates, riboflavin, pantothenic acid, and thiamin.Further, the corms provide healthy amounts of some of important minerals like zinc, magnesium, copper, iron, and

Vitamin C (mg) 4.5 7 Vitamin E (mg) 2.38 20 Vitamin K (µg) 1 1 Minerals Calcium (mg) 43 4 Copper (mg) 0.172 19 Iron (mg) 0.55 7 Magnesium (mg) 33 8 Zinc (mg) 0.23 2 Source (Brown and Deni,