Effects of Redrying Methods on the Milling Potential, Crude Protein and Total Phenolic Content, and Antioxidant Activity of Stored Inorganic and Organically-Grown Paddy
Effects of Redrying Methods on Inorganic and Organically-Grown Paddy
Abstract
This study sought to determine the effects of redrying techniques (no redrying or Control, 2-h, 4-h, and 6-h redrying with stirring every 30 min, Farmer's Practice or 6-h redrying with one stirring) on grain quality of stored inorganic and organic paddy rice as well as the redrying method that gives the best quality rice. PSB Rc82 rice harvested in October 2016 was used in the experiment conducted in February 2017. Quality parameters evaluated were moisture content, brown rice, total milled rice, crude protein content in percent, total phenolic content, and 2-2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. PSB Rc82 paddy exposed to various redrying techniques had moisture contents ranging between 9.10% – 11.60% moisture content (wet basis) (MCw.b.). Brown rice (70.19% – 72.52%), total milled rice (66.37% – 69.12%), crude protein content (6.60% – 7.73%), total phenolic content (0.0783 – 0.0950 mg g-1 GAE), and % DPPH radical scavenging activity (19.53 – 26.87) of PSB Rc82 rice were all significantly influenced by redrying process and type of rice (p = 0.05). The 2-h redrying produced maximum brown and milled rice recoveries while removing the least amount of moisture from paddy samples. Control (no redrying) had the highest crude protein content. Inorganic rice had more crude protein and was more nutrient-dense than organic rice. Samples dried at 4-h redrying with 30-min stirring intervals produced the highest % DPPH radical scavenging activity. Moreover, DPPH radical scavenging activities were higher in inorganic rice than in organic rice. Variations between inorganically and organically-grown rice in terms of crude protein content and antioxidant activity with different redrying methods may be attributed to crop management. Findings from this study can help other researchers in determining the best redrying method to attain maximum grain quality and health benefits important to consumers.
