A maca é uma raiz aromática com 52 a 76% de carboidratos e seu período de conservação pós-colheita é bastante longo, sem demonstrar sinais de deterioração. O mecanismo de degradação do amido e dos componentes da parede celular via ação enzimática não eram ainda conhecidos. O objetivo do trabalho foi caracterizar a ação de enzimas amilolíticas e pectinolíticas nessas raízes, bem como a morfologia do grânulo de amido e a composição centesimal. Os resultados mostraram que foi obtida a purificação parcial de β-amilase com peso molecular aproximado de 57 kDa, com atividade máxima a 40,7 ºC e pH de 5,1. A pectinesterase foi extraída a pH 6,0 com maior atividade a 49,4ºC e pH 6,6 a maior atividade da poligalacturonase foi a 46 ºC e pH 5,4, quando extraída a pH 8,5.O teor de amido total foi de 8,92%, os grânulos apresentaram morfologia oval em observados em microscopia eletrônica de varredura (MEV).

Maca is an aromatic root that contends 52 to 76 per cent of carbohydrates and is very stable for a long period without signals of deterioration. The degradation mechanisms of the reserve carbohydrates and the cell wall components by enzymatic way had not been described yet. The main objective of this study was the identification of inner enzymes which degrades the starch and the pectins; the others objectives were the analysis and the morphology of the starch grains as well as the root's contend composition. The results showed that was obtained the partial purification of a β- amylase, characterized by the molecular mass of 57 kDa, with a highest activity at 40.7 °C and pH 5.1. The pectinesterease was extracted with a pH of 6.0 and its maximum activity was at 49.4 °C and pH 6.6; the polygalacturonase was extracted with a pH of 8.5 and its top activity was achieved at 46 °C and pH 5.4. The total contend of starch was 8.92 % and the grains had an oval morphology observed by SEM.