Effect of Drying Characteristics of Garlic-A Review

Abstract

Natural sun drying is one of the most common ways to preserve agricultural products. The main purpose in drying farm produce is to reduce its water activity from the harvest level to the safe storage level in order to extend its shelf life. Once the produce has been dried, its rate of deterioration due to respiration, insects, and microbial activity and biochemical reactions should diminish leading to maintenance of quality of the stored product. It is improve bargaining position of the farmer to maintain relatively constant price of his product. Drying reduces post-harvest losses and transportation costs since most of the water are taken out from the product during the drying process. In India, sun drying is the most commonly used method to dry the agricultural material like grains, fruits and vegetables. In sun drying, the garlic is spread in a thin layer on the ground and exposed directly to solar radiation, ambient temperature, wind velocity, relative humidity, initial moisture content, absorptive, exposure time and mass of product per unit exposed area. Direct sun drying has been a popular method of crop drying in the farms and villages. Sun drying allows for the production of a product rich in colour and translucent in appearance, but it has some disadvantages (e.g. it is a time-consuming process, weather depended, labour demanded and it is greatly exposed to possible environmental contamination. Solar driers using natural convection or forced circulation have been investigated to overcome these problems. For commercial applications, the ability of the dryer to process continuously throughout the day is very important to dry the garlic to its safe storage level and to maintain the its quality. Garlic (Allium sativum L.) is a nutritional herbaceous plant known for its medicinal as well as culinary benefits, which originated from the mountains of Central Asian regions Globally, China is by far the largest producer of garlic, producing over 75% of world tonnage followed by India, Korea, and the USA (FAOSTAT, 2005). Food drying is one of the oldest methods of preserving food for later use.