Effect of parboiling on starch digestibility and mineral bioavailability in rice (Oryza sativa L.)

• Published in: Food science & technology Vol. 156; p. 113026
• Main Authors: Kumar, Awadhesh, Lal, Milan Kumar, Nayak, Sarangadhar, Sahoo, Upasana, Behera, Ajit, Bagchi, Torit Baran, Parameswaran, C., Swain, Padmini, Sharma, Srigopal
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.02.2022
• Subjects: bioavailability; digestible carbohydrates; Glycemic index; malnutrition; Mineral bioavailability; Oryza sativa; Parboiling; phytic acid; resistant starch; Rice; Starch digestibility; Glycemic index; Mineral bioavailability; Starch digestibility; Rice; Parboiling
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.113026

Parboiled rice is preferably consumed in many countries due to its nutritional superiority and lower starch digestibility. Parboiling affects rice cooking quality, starch digestibility and phytic acid which affects minerals bioavailability. Cooking quality was improved in parboiled brown (PB) and parboiled milled (PM) rice. Parboiling has significantly (P < 0.05) reduced glycemic index in both PB and PM rice with a proportionately increase in resistant starch. After milling, the phytic acid (PA) and Fe were reduced significantly (P < 0.05), however, parboiling further reduced PA but increased Fe content and bioavailability in PM rice due to its inward diffusion. Zn content was lower in PB and PM rice due to its outward movement during parboiling. The impact of Zn retention on its bioavailability was insignificant in parboiled rice as non-parboiled rice. This study provides better insights on rice parboiling as a method to reduce starch digestibility and improve mineral bioavailability which could be beneficial for diabetics and malnourished population. •Rice starch digestibility and mineral bioaavailability were affected by parboiling.•Parboiling lowered the glycemic index with increase in resistant starch content.•Parboiling reduced phytic acid with improved Fe and Zn bioavailability.•Pullulanase regulated resistant starch content during the grain filling stage.•MIPS1 and IPK1 regulated phytic acid content in the grain filling stage.