Fortification of zinc in a parboiled low-amylose rice: effects of milling and cooking

J Sci Food Agric. 2019 May;99(7):3434-3442. doi: 10.1002/jsfa.9561. Epub 2019 Feb 6.

Abstract

Background: Rice is a staple diet for many people, however, it is not a good source of micronutrients. The process of parboiling induces several desirable changes in rice: it improves the retention of available micronutrients, and in the case of low-amylose varieties it eases the cooking requirement. During parboiling of brown rice, when soaking is conducted in micronutrient-rich solutions, it affects fortification. This study is aimed at examining the suitability of the method of zinc fortification by a brown rice parboiling process in a low-amylose rice.

Results: Application of the method of zinc fortification by a brown rice parboiling process increased the zinc content in unmilled rice. Milling caused a reduction in zinc content per gram of grain, indicating a high concentration of zinc at the outer layer. Both milled and unmilled rice could retain more than 86% of zinc upon cooking. Changes in colour values in uncooked rice, due to zinc fortification, were non-significant at P ≤ 0.05. Rehydration of zinc-fortified rice at 60 °C for 25 min yielded hardness values similar to that of its cooked form.

Conclusion: The method of zinc fortification by brown rice parboiling is a pragmatic way to produce zinc-fortified parboiled rice to combat zinc deficiency with a reduced cooking requirement from a low-amylose rice variety. © 2019 Society of Chemical Industry.

Keywords: brown rice; colour; ready-to-eat; texture; zinc fortification.

Publication types

  • Evaluation Study

MeSH terms

  • Amylose / analysis*
  • Color
  • Cooking / methods*
  • Food Handling / methods
  • Food, Fortified / analysis*
  • Hardness
  • Oryza / chemistry*
  • Seeds / chemistry
  • Trace Elements / analysis
  • Zinc / analysis*

Substances

  • Trace Elements
  • Amylose
  • Zinc