Value Addition in Green Peas by Drying under Fluidized Bed Drying

Abstract

India's diverse climatic conditions provide advantages for the production of fruits and vegetables, ensuring year-round availability of various fresh produce. Pisum sativum (peas), a significant vegetable crop in India, contributes approximately 2.5% (3.86 million MT) to total vegetable production and accounts for 4.6% of the vegetable-growing area (NHB, 2014). However, due to their high moisture content, peas cannot be stored for extended periods and require preservation methods such as freezing, canning, cold storage, or drying (Chauhan and Srivastava, 2009). This study evaluates fluidized bed drying of green peas as a preservation method to enhance farmers' income, particularly in Gujarat. The investigation included two pre-treatments (unblanched and blanched), three bed heights (20, 40, and 60 mm), and three drying air temperatures (45°C, 55°C, and 65°C). Mature, fresh green peas were manually deshelled, blanched at 85°C for 1 minute, cooled under running water, and surface moisture was removed before drying. Results revealed that drying occurred entirely in the falling rate period, with the overall drying rate ranging from 0.0053 to 0.0158 kg water/kg dry matter/min. The maximum drying rate (0.0158 kg water/kg dry matter/min) was observed with the blanched sample at a bed height of 20 mm and 65°C. The highest protein content (17.87 g/100g) was recorded at 45°C, similar to 55°C (17.85 g/100g). The highest chlorophyll content (106.98 mg/100g) was observed in blanched samples dried at 40 mm bed height and 45°C, comparable to 55°C (106.68 mg/100g). The highest rehydration ratio (3.53) was achieved in blanched samples at 40 mm bed height and 55°C. It is concluded that blanching green peas at 85°C for 1 minute, followed by fluidized bed drying at 40 mm bed height and dry air temperature at 55°C, produces high-quality dried peas with good qualities.