Effects of grain substitution and cooking methods on the quality characteristics and nutritional properties of traditional Korean Ssuk-Injeolmi (쑥인절미) for elderly consumers

Abstract Ssuk-injeolmi (쑥인절미), a traditional Korean glutinous rice cake containing Ssuk (mugwort) historically prepared by steaming, is nutritionally limited by its high glycemic index, low dietary fiber, and adhesive texture that poses dysphagia risk for elderly consumers. This study developed a modified Ssuk-injeolmi by partially substituting glutinous rice with brown rice and oat flour at four ratios (GR100, GR80, GR70, GR65) and evaluated the effects of grain substitution and cooking method (steaming vs. boiling) on colorimetric properties, texture profile, post-cooking moisture uptake, proximate composition, and predicted glycemic index. Steamed samples exhibited consistently higher lightness, greater moisture retention, and lower hardness and chewiness than boiled counterparts, attributed to more uniform starch gelatinization under indirect heat, scientifically validating steaming as the superior and traditionally appropriate cooking method for Ssuk-injeolmi . Among steamed formulations, GR70 (glutinous rice: brown rice: oat = 70:20:10) achieved the most favorable textural profile with the lowest chewiness, gumminess, and adhesiveness among substituted groups. Grain substitution progressively increased dietary fiber from 1.22 g/100 g (GR100) to 2.51 g/100 g (GR70) and reduced the predicted glycemic index from 82 to 77.6, consistent with the hypoglycemic effects of oat β-glucan and brown rice bran fiber. Caloric content remained comparable across formulations (224–235 kcal/100 g). Steamed GR70 Ssuk-injeolmi is identified as the most favorable reformulation, delivering reduced adhesiveness, more than double the dietary fiber of the control, and a lower predicted glycemic index while maintaining comparable caloric content. These findings demonstrate that evidence-based grain substitution and traditional steam cooking can synergistically improve the nutritional quality and textural safety of a culturally significant ethnic food without compromising its identity, offering a replicable reformulation framework for other traditional glutinous rice-based foods in Korean and East Asian cuisines targeting health-conscious and aging consumer populations globally.