Insights into the digestive processes of normal and high-amylose rice using realistic boluses formed in the bio-inspired oral mastication simulator (iBOMS-III)

Abstract

Mastication is essential for preparing food bolus for swallowing and digestion. This study employed the bio-inspired oral simulator (iBOMS-III) to investigate the effects of mastication on physical properties and starch hydrolysis of normal rice (NR) and high-amylose rice (HR), while validating its results through comparison with in vivo data from human subjects. The median particle size (d₅₀) of NR (1.266, 0.931, 0.776 mm) and HR (1.32, 1.04, 0.928 mm) boluses from iBOMS-III at 12, 14, and 20 cycles closely matched human boluses at the swallowing threshold, particularly after 14 and 20 cycles. Starch hydrolysis in NR increased from 76.6 % to 91.3 %, while HR hydrolysis ranged from 63.4 % to 73.3 %. Boluses from iBOMS-III with 14 and 20 cycles showed starch digestibility consistent with in vivo data (84.2 % for NR, 71.3 % for HR). These findings demonstrate that iBOMS-III effectively replicated human mastication behaviors, producing boluses comparable to those observed in vivo.