Edible coatings with antibrowning agents to maintain sensory quality and antioxidant properties of fresh-cut pears

Abstract

The effect of alginate-based (2%, w/v), pectin-based (2%, w/v) and gellan-based (0.5%, w/v) edible coatings containing N-acetylcysteine at 0.75% (w/v) and glutathione at 0.75% (w/v) on gas exchange, antioxidant properties, sensory quality and microbial stability of fresh-cut ‘Flor de Invierno’ pears, was investigated for 14 d at 4 ◦C. The use of polysaccharide-based edible coatings increased the water vapor resistance and reduced ethylene production of coated fresh-cut pears. The incorporation of N-acetylcysteine and glutathione into coating formulations not only reduced microbial growth compared with samples not containing antioxidants but also was effective in preventing fresh-cut pears from browning for 2 weeks without affecting firmness of fruit wedges. The increased vitamin C and total phenolic content observed in pear wedges coated with alginate, gellan and pectin including antioxidants contributed to maintain their antioxidant potential. In addition, coatings with alginate or pectin best maintained sensory attributes of pear wedges for 14 d.

This research was financed by the Ministerio de Ciencia y Tecnologıa (Spain) through the AGL 2003-09208-C01 project, the European Social Fund and the Departament d’Universitats Recerca i Societat de la Informacio of the Generalitat de Catalunya (Spain) that also awarded author G. Oms-Oliu a pre-doctoral grant.