In the present study, we preliminarily developed a processing procedure to manufacture dried dragon fruit. The objectives of the study were (1) to determine if it is advantageous to do osmotic dehydration (OD) before hot air drying, (2) to find out a suitable submerging time if OD was necessary, and (3) to evaluate stability of the product during storage with or without using sodium bisulfite. | 32 ESTABLISHMENT OF A PROCESSING PROCEDURE FOR MANUFACTURING DRIED DRAGON FRUIT Le Trung Thien1, Phan Tai Huan1, Katleen Raes2 1 Nong Lam University, Ho Chi Minh City 2 Ghent University, Kortrijk, Belgium Email: ABSTRACT In recent years, consumption of dragon fruits became an issue because of the dramatic increase in domestic production and the production in other countries. So it becomes urgent to develop new products, which can utilize the abundant amount of fresh dragon fruit, and provides a sustainable output for the domestic production. In the present study, we preliminarily developed a processing procedure to manufacture dried dragon fruit. The objectives of the study were (1) to determine if it is advantageous to do osmotic dehydration (OD) before hot air drying, (2) to find out a suitable submerging time if OD was necessary, and (3) to evaluate stability of the product during storage with or without using sodium bisulfite. The results showed that application of OD with a solution of 50% sucrose and citric acid led to higher in product yield, lower in volume contraction, and 3 hours shorter in subsequent hot-air drying. The use of sodium bisulfite by submersion of sample in % solution before processing was necessary to prevent the growth of mold and maintain sensorial quality (especially color) of the dried product. The processing procedure developed from this study can be implemented in industry. Keywords: dried dragon fruits, drying, osmotic dehydration, drying curves. TÓM TẮT Những năm gần đây việc tiêu thụ trái thanh long gặp nhiều khó khăn vì tốc độ tăng diện tích trồng trọt nhanh trong nước cũng như ở các nước khác. Việc chế biến thanh long trở nên cấp thiết để tận dụng nguồn trái thanh long tươi dư thừa không phù hợp tiêu thụ tươi, và góp phần tạo đầu ra ổn định hơn cho ngành trồng trái thanh long trong nước. Trong nghiên cứu này, quy trình chế biến thanh long sấy khô được bước đầu thiết lập. Mục tiêu
