Ripening-related changes in ethylene production, respiration rate and cell-wall enzyme activity in goldenberry (Physalis peruviana L.), a solanaceous species

Abstract

Abstract The ripening of goldenberry (Physalis peruviana) is associated with a conspicuous climacteric rise in carbon dioxide and ethylene production. Its respiration rate and ethylene biosynthesis can be classified as extremely high. Ethylene yields between 7 and 24 nmol h−1 per g in the ripe/overripe stages thus compare favorably with production rates previously reported for tomato fruit. As the fruit color turns from green (chlorophyll) to yellowish orange (carotenoids) and a progressive softening occurs, several cell-wall enzyme changes arise. Pectinmethylesterase and α- and β-galactosidase reach activity levels similar to those in tomato fruit. Pectinmethylesterase and α-galactosidase increase toward the ripe stage. α-Arabinofuranosidase and β-glucosidase show lower activities but with an increasing pattern during ripening. On the other hand, polygalacturonase and α-glucosidase activities are hardly noticeable.