Granola bars prepared with Agave tequilana ingredients: Chemical composition and in vitro starch hydrolysis

Abstract

The stem of Agave tequilana is used to obtain: agave syrup (AS) and native agave fructans (NAF). Ground-agave-fiber is the by-product from fructans production. These ingredients were used to design a food ingredient: agave dietary fiber (ADF), containing NAF (30 g/100 g) as soluble dietary fiber (DF) and ground-agave-fiber (70 g/100 g) as an insoluble DF. The objective of this work was to evaluate the effect of the incorporation of A. tequilana ingredients (AS, NAF, ADF) on the proximate composition, in vitro starch hydrolysis (HI) and predicted glycemic index (pGI) of oat-based granola bars. Total DF (82.03 g/100 g) was the main component in ADF, with 22.8 g/100 g soluble DF. Granola bars were prepared by substituting honey and wheat flour by AS and ADF. A sensory test was used to select the level of sugar substitution by NAF, where 62 g NAF/100 g was the preferred one. The effect of each ingredient on the chemical composition was evaluated using a 23−1 fractional design. Soluble DF in a granola bar containing a combination of three agave ingredients (AS, NAF and ADF) was 23.35 g/100 g, with HI and pGI values of 74 and 72%, respectively, pointing this product as a moderate GI food.