Abstract:
Introduction & Objectives
Rice (Oryza sativa L.) is a staple in Asia; its high starch content can raise blood sugar, increasing
type 2 diabetes risk. This study investigated the impact of incorporating coriander (Coriandrum
sativum L.) leaf powder (CLP) (2.5% (w/w)) during cooking on the antioxidants and starch
digestibility of parboiled white rice (BG 360), widely consumed in Sri Lanka.
Methodology
Rice cooked with CLP (treated) and without CLP (control) were subjected to in vitro digestion
(gastric phase: pepsin, pH 1.2, 2 hours and intestinal phase: pancreatic α-amylase, pH 6, 5
hours). Digestive supernatants were analyzed at 30 min intervals for 2,2-diphenyl-1-
picrylhydrazyl (DPPH) radical scavenging activity (RSA), 2,2-azinobis(3- ethylbenzothiazoline-
6-sulfonate) (ABTS) RSA, ferric reducing antioxidant power (FRAP), total phenolic content
(TPC), total flavonoid content (TFC), and amylose content.
Results
The treated rice showed higher antioxidant activity than control, with a marked increase from the
gastric phase. DPPH and FRAP values rose steadily in the treated sample (DPPH from
167.97±0.63 to 200.50±0.38% and FRAP from 690.40±3.36 to 1166.04±2.69 μmol ascorbic acid
equivalent/100g, respectively), while the control showed only slight increases. ABTS activity
peaked between the gastric and intestinal phases for both; however, the treated rice consistently
outperformed the control. TPC and TFC remained slightly increased throughout digestion, with a
prominent increase in TFC observed after gastric digestion in the treated sample. Amylose
release was significantly lower in the treated rice, indicating slower starch
digestion.
Conclusion
In conclusion, enrichment with CLP yielded functional rice with antioxidant properties and
reduced starch digestibility. Further in vivo studies are needed to confirm these findings.
