Reduction of the Glycemic Index in Thai Layer Cakes and Butter Cakes from Sago Flour

Foods with a low glycemic index (GI) help control blood glucose levels and are associated with a lower risk of adverse health effects. Sago flour is rich in polyphenols and resistant starch, which correlates with a low GI diet. The study developed Thai layer cakes and butter cakes by replacing high-GI flour with sago flour in proportions of 40% to 60%. This is experimental research. The main variable is replacing high-GI flour with sago flour. GI is measured by the in vitro method for rapidly available glucose (RAG). The proximate composition of Thai layer cakes had higher fat and ash content and significantly lower carbohydrate content than the standard cake ( p ≤ 0.05). Butter cakes had lower protein content ( p ≤ 0.05) and higher carbohydrate content ( p ≤ 0.05), and sago flour lowered the GI value in cakes from high to low compared with the standard formula. The total polyphenol content and antioxidant activity were higher when replaced by 50% sago flour compared with the standard formula, but without significant difference ( p > 0.05). Sensory evaluation was most acceptable when replaced with 50% sago flour. Sago flour has significant antioxidant activity, and its use in cake formulations may increase antioxidant activity, particularly in butter cakes. The results suggest that the ORAC method may not be suitable for detecting the antioxidant activity of Thai layer cakes. Using sago flour as an alternative ingredient may benefit individuals with diabetes or health-conscious individuals. Replacing 50% of cassava starch with sago flour in Thai layer cakes and 50% of wheat flour with sago flour in butter cakes reduced the GI from medium to low and high to medium. The levels of polyphenols and antioxidant activity remained unchanged after substitution. Keywords: butter cakes, glycemic index, food, sago starch, Thai layer cakes. DOI: https://doi.org/10.55463/hkjss.issn.1021-3619.62.74