INTELLIGENT PACKAGING WITH STARCH, PURPLE CABBAGE EXTRACT AND WHEY

The use of active and intelligent films for packaging has attracted the interest of researchers due to an increase in the protection of the food while at the same time informing the consumer about the quality of the product. The objective of the study was to develop films with starch, glycerol, whey and purple cabbage extract, with characteristics of intelligent packaging, which due to changes in pH caused by deterioration of food, would change color, informing the consumer about the quality of food. Eleven trials were carried out to prepare the films using a central rotational composite (DCCR). The evaluated responses were: thickness, moisture content (MC), water vapor permeability (WVP), water solubility (WS), mechanical properties, color, total phenolic content (TPH), total anthocyanins, ABTS and DPPH. The variations in thickness were between 0.07 mm and 0.20 mm, respectively for the treatment 7 with 50% anthocyanin and 0% whey and 3, with 35.81% anthocyanin and 25.63% whey. The moisture content ranged from 10.67% to 22.95%, where the treatment 1 with 35.81% anthocyanin and 4.36% whey thickness had the lowest moisture content and the treatment 2 with 64.18% anthocyanin and 4.36% whey had the highest moisture content. It was noted that the water vapor permeability values ranged from 0.112 (g.mm.h-1.m-2.kPa-1) to 0.543 (g.mm.h-1.m-2. kPa-1), during the first 12 hours of analysis, both treatment (10 and 8) had the same amount of anthocyanin (50%) and different amount of whey (15% and 30%, respectively), which caused a greater restriction to the passage of water molecules and decreasing WVP. The films presented solubility in water between 26.14% (treatment 7) and 42.08% (treatment 1). The film that obtained the highest tensile strength and highest Young's modulus was the 70% anthocyanin and 15% whey (treatment 6) and the highest elongation was observed in treatment 3. It was verified that the films became darker as the anthocyanin concentration increased (treatment 2) and the color of the films being illuminated with the incorporation of the whey. The mean total phenolic compounds varied from 323.31 ± 9.04 to 2055.62 ± 43.29 mg gallic acid / 100 g sample and total anthocyanins from 0.51 to 3.4 mg of cyanidin 3-glycoside / 100 g of the sample, being the treatment 2 the highest content of anthocyanins. The results of the antioxidant capacity by the DPPH method were considered low, however the highest value found were treatment 1 and 2. By the ABTS method the antioxidant capacity of the films cannot be quantified, showing that although these methods have the same mechanism of action, as the free radicals used are different, the action of the antioxidants in front of them becomes different as well. The results of this study show that films with properties for application as intelligent packaging in foods based on renewable sources were developed, it was possible to establish that the treatment 2, 7 and 10 were more effective for production of intelligent films, due to high antioxidant and anthocyanin content, low permeability and solubility.