Revestimentos de amido, nanofibras de celulose e metabissulfito de sódio em goiabas (Psidium guajava L.) minimamente processadas

Abstract

The application of starch-based coatings on fruit has been used to promote increased life. Cellulose nanofibers have mechanical characteristics desirable as reinforcement in starch films. Sodium metabisulfite, one of the derivatives of sulphites, is one of the most conservative used in food in relation to its broad spectrum of action and to be considered safe. The aim of this study was to determine the effects of biopolymers produced films with corn starch, reinforced with cellulose nanofibers and sodium metabisulfite under products minimally processed guavas 'Pedro Sato'. We evaluated 5 treatments on minimally pr ocessed guava, used to control (without coating), starch coated, starch coating + sodium metabisulfite, starch coating + cellulose nanofibers and starch coating + sodium metabisulphite + cellulose nanofibers. The fruits were fresh-cut into slices, stored at 4 ° C for 15 days. The biopolymers films were characterized with spectroscopic analysis in the infrared Fourier transform (FTIR), diffraction X-ray (XRD), scanning electron microscopy (SEM) and field emission source (EGF), test traction and puncture. Analyses in minimally processed guavas were performed every three days as to their physical and chemical characteristics (firmness of flesh, color placental region (pulp) and soluble solids, titratable acidity, pH and ascorbic acid (vitamin C)), mass loss and microbiological (total and fecal coliforms).