Vitamina C y perfil fenólico de brócoli convencional e híbrido mínimamente procesado, tratado con agua electrolizada y recubrimientos comestibles

Abstract

Traditionally, edible coatings have been used as a barrier to minimize water loss and retard the natural senescence of horticultural products through selective permeability to gases. In this work, the effect of two edible coatings on quality of fresh-cut ‘Bimi’ broccoli during shelf life was studied. The broccoli was sanitized under neutral electrolyzed water (NEW) (ORP = 900 mV; 5 ºC; pH = 7; contact time = 2 min). Two edible coatings were applied: Naturcover® (5 % of sucroesters) and sodium alginate (2 g/100 mL) using glycerol as plasticizer and sunflower oil as emulsifier (contact time: 1 min; drying time: 1min). The product was then stored under modified atmosphere packaging throughout 15 days at 5ºC. As control, washing with cold tap water and no coating was used. 3 treatments were applied, NEW (NEW disinfection), NATURCOVER and ALGINATE. Vitamin C content, expressed as ascorbic acid, dehydroascorbic acid and total vitamin C and phenolics, expressed as caffeoyl-quinic derivatives, sinapic acid derivatives and ferulic acid derivatives, were analyzed for the two types of broccoli. The equilibrium gas partial pressure within the packages was 10-12 kPa CO2 and 5-12 kPa O2 and was reached after 3-4 days. Both varieties, `Parthenon´ and Bimi kept vitamin C during a cold storage (5ºC) of 15 days, at the end of this period the content was between 582.8-823.1 mg kg-1 fw for Bimi and 722.05-872.5 mg kg-1 fw for ´Parthenon´. The phenolics founded in larger quantities were caffeoyl-quinic acid derivatives (chlorogenic and neochlorogenic acid), Bimi showed the highest content of neochlorogenic acid of 384.5 mg kg-1 for control treatment at the end of the conservation.