Comparison of Parbolling-Induced Changes in Starch Crystalinity and Functional Properties of Brown Rice for Functional Food Applications

¹ Agricultural Product Tecnology, Mulawarman University, Indonesia, 75119
² Indonesian Ministry of Higher Education, Research and Science, Indonesia, 10270
³ Department of Agroecotechnology, Faculty of Agriculture, Mulawarman University, East Kalimantan, Indonesia. 75119

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The Makan Bergizi Gratis program emphasizes the need for safe, affordable, and nutritionally complete foods that are easy to prepare and distribute. Brown rice, rich in dietary fiber and bioactive compounds with a low glycémie index, is a promising candidate for such programs. However, its functional properties can be enhanced through processing, particularly parboiling. This study investigated the effects of parboiling on the structural and functional properties of two local brown rice cultivars from East Kalimantan (SMC 279 and SMC 213). The focus was on starch crystallinity, swelling power, water absorption, oil absorption, specific gravity, and wettability to assess their suitability for biscuit production. Parboiling reduced starch crystallinity, as shown by X-ray diffraction (XRD), with weaker and broader peaks indicating a transition to more amorphous starch. Functionally, swelling power increased by approximately 7.5 times, water absorption nearly doubled (1.12–1.34% to 2.02–2.77%)), and wettability improved by 2.15–9.71 times. Oil absorption (2.15–3.60%)) and specific gravity (0.56–0.71 g/mL) showed minimal changes, reflecting their dependence on grain density and porosity. Cultivar-specific differences were observed, influenced by starch composition and granule architecture. In conclusion, parboiling enhances the functional and water-responsive properties of brown rice without compromising its density or oil-binding characteristics, making it a scalable, nutritious ingredient for biscuit production and other foods aligned with the Makan Bergizi Gratis initiative.