Evaluation of drying characteristics, milling performance and nutritional quality: The case of aromatic rice

Abstract

This study aimed to investigate the effect of two-stage drying schemes (first stage: fluidized bed drying [FBD] at 90°C and second stage: (i) FBD at 50°C, (ii) Louisiana State University drying at 50°C, and (iii) sun drying) on drying characteristics, milling performance, nutritional and sensory quality of three popular local aromatic rice varieties (Chinigura, Kalizira, and Katarivog) in Bangladesh. Results indicated that shorter drying time (only 1.83 to 5 hr) required in the proposed two-stage drying schemes compare to the sun drying method (14 to 16 hr). All the proposed two-stage drying yielded higher or at least comparable percentage of head rice yield (54.13% ~ 64.27%) of the studied rice varieties. Amylose, fat, protein, and total ash content varied from 23% ~ 25.20%, 0.41% ~ 0.54%, 7.20% ~ 8.70%, and 0.38% ~ 3.37%, respectively. Mineral profile of the milled brown and white aromatic rice and the sensory attributes were not influenced by the two-stage drying methods. Practical applications Drying of aromatic rice is an important concern in maintaining milling yield and preserving the nutritional quality with its attractive fragrance. Moreover, paddy drying is an important issue during the rainy season, which requires quick and efficient drying techniques to reduce the drying time. Keeping this space, the present study was carried out to investigate the effect of two-stage drying options (fluidized bed drying [FBD] in the first stage at higher temperature followed by FBD at low temperature, Louisiana State University and sun drying in the second stage) on the drying behavior, milling recovery and nutritional quality of aromatic rice cultivars cultivated widely in Bangladesh. It is expected that the proposed two-stage drying technique would be helpful in reducing the drying time and maintaining the qualities of paddy especially aromatic rice.