Dehydration In Foods

2. REVIEW OF LITERATURE
Capsicum is members of the nightshade family, which also includes potatoes, tomatoes and eggplant. Capsicum locally known as simla mirch and used as a vegetable (Rakesh, et al., 2014). Due to high moisture content, the capsicum is highly perishable. Among the several techniques of preservation of high moisture foods, dehydration is one of the most appropriate methods of drying. There are many methods of drying/dehydration depending upon the heating sources such as solar drying that is the oldest methods another methods are hot air drying, vacuum drying, freeze drying, infrared drying, microwave drying, foam mat drying and superheated steam drying.
Drying refers to the removal of moisture from liquid to wet solid by

Transfer of internal moisture from surface of solid and its subsequent evaporation due to process one. In first stage process, the removal of water from surface as vapor depends, on the external condition of temperature, air humidity and flow area of exposed surface. In second stage process the movement of moisture, inside the solid is a function of physical nature of the solid, its moisture content and bed temperature. However, like other types of conventional convective dehydration processes, fluidized bed dehydration is a very intensive process in industry. Dehydration is an energy intensive operation, and a greater understanding of the dehydration process is important, if dehydration efficiency is to be increased and maintaining product quality. The main objective of any dehydration process is to be produced a dried product of desired quality at minimum cost and maximum output, and to optimize these factors reliably. Often good quality of products implies that, it undergoes several physical, chemical or biological changes to yield a product of desired specification. A brief review of literature is presented below.
2.2 Nutritive value and calories of

(2012) studied the physicochemical and microbial quality of dried pineapple by using foam-mat-dryer. Two foaming agents were used for foaming, the first one tricalcium phosphate (TCP) (0%, 0.25%, 0.50%, 0.75%, and 1.0%) and another egg white (EW) (0%, 0.50%, 1.0%, 1.50%, and 2.0%). Drying was carried out in tray dryer with 65, 75, and 85°C followed by pulverizing the dried foam mats in to fine powder and carboxy methyl cellulose (0.25%) was used as foam stabilizer. Various physicochemical quality parameters viz. total sugars, reducing sugars, ascorbic acid, total acid, pH, iron, phosphorus and calcium content, and bacterial and fungal load were analyzed from powdered samples. Statistical analysis done by using LSD, it revealed that sample dried using 1% TCP at 65°C was the best with 4.60% total sugars, 2.71% reducing sugars, 4.05mg per 100g ascorbic acid, 0.35% total acid, 0.29mg per 100g Iron, 2.24mg per 100g phosphorous, and 6.58 g per 100g calcium and zero bacterial and fungal