Novel mode of kafirin modification using combination of enzyme and thermal treatment to expand its food application.

Kafirin in sorghum inhibits starch digestion and exhibits antioxidant properties, however its potential in food
industry remains unexplored. Therefore, the study was aimed to explore and improve the potential of kafirin as
natural carbohydrate blocker using papain (6 NFU/mL) and/or infrared treatment (220 ◦C/3 min). Results
indicated that the combined treatment, PIR (infrared + papain) is the most efficient treatment to modify kafirin.
PIR generated a new ~37 kDa high molecular weight moiety in kafirin with a crystal size of 157.44 Å. All
samples showed superior antioxidant activity post-treatments, with PIR exhibiting highest scavenging activity
from 31.09 to 82.97%, 15.09 to 42.82%, and 25.92 to 38.58% for DPPH, FRAP, and ABTS, respectively. PIRmodified
kafirin limited malondialdehyde production, and increased α-amylase and α-glucosidase inhibition.
Incorporation of 7.5% kafirin in corn starch increased resistant starch from 5.09 to 21.04% after cooking, which
suggests potential of kafirin in development of diabetic-friendly food formulations.