Laboratório de Química, Bioquímica e Biologia Molecular de Alimentos, Departamento de Alimentos e Nutrição Experimental, FCF, Universidade de São Paulo, Avenida Lineu Prestes 580, Bloco 14, CEP 05508-900, São Paulo (SP), Brazil.
J Agric Food Chem. 2011 Jun 22;59(12):6672-81. doi: 10.1021/jf201590h. Epub 2011 May 26.
Different banana cultivars were used to investigate the influences of starch granule structure and hydrolases on degradation. The highest degrees of starch degradation were observed in dessert bananas during ripening. Scanning electron microscopy images revealed smooth granule surface in the green stage in all cultivars, except for Mysore. The small and round granules were preferentially degraded in all of the cultivars. Terra demonstrated a higher degree of crystallinity and a short amylopectin chain length distribution, resulting in high starch content in the ripe stage. Amylose content and the crystallinity index were more strongly correlated than the distribution of amylopectin branch chain lengths in banana starches. α- and β-amylase activities were found in both forms, soluble in the pulp and associated with the starch granule. Starch-phosphorylase was not found in Mysore. On the basis of the profile of α-amylase in vitro digestion and the structural characteristics, it could be concluded that the starch of plantains has an arrangement of granules more resistant to enzymes than the starch of dessert bananas.
不同的香蕉品种被用来研究淀粉颗粒结构和水解酶对降解的影响。在成熟过程中，甜香蕉的淀粉降解程度最高。扫描电子显微镜图像显示，除了迈索尔香蕉外，所有品种的绿色阶段淀粉颗粒表面都很光滑。所有品种中，小而圆的颗粒优先降解。Terra 表现出更高的结晶度和较短的支链淀粉链长分布，导致成熟阶段淀粉含量较高。直链淀粉含量与结晶度指数的相关性强于支链淀粉分支链长分布的相关性。α-和β-淀粉酶以两种形式存在，一种在果肉中溶解，另一种与淀粉颗粒结合。在迈索尔香蕉中没有发现淀粉磷酸化酶。根据体外消化的α-淀粉酶图谱和结构特征，可以得出结论，大蕉淀粉的颗粒排列比甜香蕉淀粉更能抵抗酶的作用。
