Resumen

BEDOYA GOMEZ, Angela M et al. Design extraction method pectin methylesterase (EC 3.1.1.11) in sapodilla fruit. Agronomía Trop. [online]. 2014, vol.64, n.3-4, pp.155-164. ISSN 0002-192X.

Sapodilla (Manilkara zapota [L.] ‘Prolific’) is a fruit whose difficulties of post-harvest management have limited its commercialization. During ripenning of these fruits the most dramatic change is the loss of firmness, which causes the decrease in quality. This softening is associated with the action of the pectin methylesterase (PME, E.C. 3.1.1.11), which is an enzyme that induce degradation of the cellwall. The objective was to design a method for effi cient extraction of PME, with high quality, fast and using few reagents. Physiologically ripen Sapodilla fruits from the Germplasm Bank INIACENIAP, Maracay, Aragua state, were used. They were stored at -20 °C. Five methods of extraction Buffer Tris HCl; Buffer PBS; Liquid nitrogen (N₂L); Buffer Tris HCl + N₂L and NaCl, were designed. Methods were evaluated according to enzyme quality, amount (mg mL^-1 protein) and extraction. The analysis of variance showed highly significant differences (P<0.01) among the methods and Duncan mean comparisons determined that the liquid nitrogen method extracted more protein (231 mg ml^-1) with a catalytic activity of 1.97 μmol acid min^-1, excelling the other methods and the control with values ranging from 0.13 μmol acid min^-1 up to 0.6 μmol acid min^-1. Therefore, the C method is the most efficient, with higher protein yield and lower time (two hours). However, purification and characterization of PME for either agroindustrial purposes or biotechnological application is recommended.

Palabras clave : Manilkara zapota; softening; sapodilla; PME; enzymes activity.

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