Desenvolvimento de filmes biodegradáveis a base de polímeros de fontes renováveis e polpa de guabiroba (Campomanesia xanthocarpa)

Abstract

The objective of this study was to evaluate the effect of guabiroba pulp merger (Campomanesia xanthocarpa) (PG) in barrier properties, mechanical and optical composite films and verify the antioxidant effect in olive oil packaging. This study was divided into three stages. In the first step they were prepared composite films of gelatin (GEL) 5 to 10% native corn starch (AMN) 2 to 4% and glycerol (GLY) 10% (relative to dry mass of AMN and GEL) as plasticizer in the proportions 2: 1, 1: 1 and 1: 2. It was characterized as: Visual and tactile analysis, humidity, water activity (aw), thickness, permeability to water vapor (PVA), water solubility (SOL), tensile strength (RT), percent elongation (ELO ) and opacity (OP). The film obtained best results as PVA, is selected for the second stage, which consisted of the preparation of films active compounds (with addition of PG to 10 and 20% w/v) and featuring the same properties as the first step. The film that won best result as the PVA in the second stage, was selected for the third stage, which consisted of preparing sachets to verify the antioxidant effect in extra-virgin olive oil packaging through the acid value (IA), index peroxide (IP), the presence of phenolic compounds (CF) and determination of TBARS for 15 days. The range of concentrations used both gel (5 to 10%) as AMN (2 to 4%), as well as the studied ratios (2: 1, 1: 1 and 1: 2) showed significant differences in properties analyzed. The composite film prepared with 5% GEL and 2% of AMN in the ratio 1:1, was selected for the second stage of labor, it stood out among the other formulations as the analysis of PVA (3.88 g.mm/m2.d.kPa) and SOL (19.78%). Addition of PG (10 and 20%) in the film compound caused reduction in RT and increasing PVA, SOL, ELO and OP. The film active compound with 10% PG was selected for the third stage of labor, as had lower amount of PVA (6.75 g.mm/m2.d.kPa) compared to the film active compound with 20% (12, 95 g.mm/m2.d.kPa). The composite films prepared in sachets with addition of 10% PG showed is weak compared to sachets without addition of PG. At the end of the conditioning period (15 days), the IA values and olive oil IP both the film prepared with PG and control not reached the maximum allowed by law. The CF values showed that in time to the time 0 days 7 days, there was a decrease in CF of olive oil, but on day 15, such values do not change significantly. Thus, we can conclude that the results obtained in this study may be useful for future studies and applications using active and biodegradable films for food products, as proved applicable in the extra-virgin olive oil packaging.