Development of low estimated glycemic index (eGI) rice noodles from broken jasmine rice (KDML 105) starch modified by microwave and acid treatments

Jasmine rice (KDML 105) is widely consumed worldwide as a major source of dietary carbohydrates; its highly digestible starch contributes to a high postprandial glycemic response. This study aimed to modify the starch from broken KDML 105 and develop the estimated glycemic index (eGI) rice noodles. KDML 105 was processed into broken rice flour (BRF), from which we subsequently isolated broken rice starch (BRS). Modified starches (MWS, CAS, AAS) were prepared using microwave for 5–20 min and acid concentrations (10–25%), citric acid, acetic acid, and propionic acid. MWS significantly (p < .05) improved the swelling power (SP), water absorption capacity (WAC), and solubility. BRS, MWS, CAS, and AAS also increased the amylose (27–29%) compared with BRF (17.09%). MWS-20 reduced eGI (55.11), while CAS-25% also decreased eGI (53.86). MWS-20 and CAS-25% were selected to develop low eGI noodles and were compared with BRS and BRF noodles. MWS-20 noodles showed better texture and the highest tensile strength, while CAS-25% noodles had a softer texture and required a longer cooking time. CAS-25% noodles had the lowest eGI (52.07), while MWS noodles had the highest sensory acceptability. These findings suggest that modified starch from broken KDML 105 can be developed into low‑eGI products and increase the value of rice-milling by-products.