Effects of Blanching and Natural Convection Solar Drying on Quality Characteristics of Red Pepper (Capsicum annuum L.)

Received Apr 19, 2017; Accepted Aug 8, 2017

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1. Introduction

Red pepper (Capsicum annuum L.) is used as a spice or major ingredient in dishes around worldwide and perhaps considered the first spice to have been used by man with archaeological evidence of pepper and other fossil foods dating back to 6000 years old [1]. Red pepper is generally known to be cholesterol free, have low sodium and caloric contents, and serve as good source of vitamins A and C [2]. Additionally, red pepper is known to possess antimicrobial activity [3] and reduces the risk of diseases such as arthritis, cancer, and diabetes [4–8]. In food processing, red pepper is also used as colouring and flavouring agent in sauces, soups, pickles, and pizzas [9].

Ghana contributes about 1% of world pepper production and was ranked the eleventh largest producer of pepper in the world and second in Africa with an estimated total production of 88,000 metric tons [10]. Like other fresh fruits and vegetables, fresh pepper is a perishable produce and deteriorates within a few days after harvest without proper storage or preservation measures. The perishable nature of pepper can lead to economic losses which is further aggravated by storage and marketing problems and lack of appropriate processing technologies [11]. To prevent losses due to postharvest deterioration, dehydration is one important method often adopted for preservation and value addition to perishable agricultural products through moisture control. The major goal in drying fruits and vegetables such as pepper is to reduce the moisture content to desirable levels, usually 5–10%, which allows for safe storage over an extended period of time [12].

Unlike many industrialized countries where mechanized drying of fruits and vegetables is practiced, traditional open-sun drying of fruits...