Banana starch structure and digestibility
It is well known that raw banana starch is a good source of resistant starch. Less is known, however, regarding the digestion property of gelatinized banana starch. In this study, banana starch cooked for 20 min in excess water had a significant fraction of slowly digestible starch (19%), as well as resistant fraction (27%). Amylopectin is thought to be responsible for its slow digestion property, since banana starch studied here has a relatively low amylose content of 11.2%. Chain-length distribution analysis revealed that banana amylopectin has a significantly different structure from corn or potato amylopectin in that it has a higher proportion of very long chains. Retrogradation studies support the view that banana starch retrogrades at a substantially faster rate than corn or potato starch leading to less digestible cooked starch. Additionally, banana starch has unique pasting properties making it behave like a chemically lightly cross-linked starch. Banana starch is unique, both nutritionally and functionally, to warrant further investigation on potential commercial uses. âº Cooked banana starch had a significant fraction of slowly digestible starch. âº Banana starch has unique pasting properties behaving like a cross-linked starch. âº Banana amylopectin has a significantly different structure from corn or potato amylopectin. âº Retrogradation studies support that banana amylopectin retrogrades at a faster rate. âº Banana starch is unique both nutritionally and functionally.