Desenvolvimento e caracterização de filmes compostos por resíduo de maracujá (Passiflora edulis f. Flavicarpa) com extrato das folhas de ora-pro-nóbis (Pereskia aculeata Miller).

Abstract

The development of biodegradable films based on agro-food waste combined with natural additives is a promising technology in the food industry and has grown in recent years. In this context, this study developed biodegradable films from the yellow Passion Fruit Peel Flour (FCM) (Passiflora edulis f. Flavicarpa) added from extract from the leaves of ora-pro-nóbis (Pereskia aculeata Miller), and characterized the physical, mechanical, barrier, microscopic, antioxidant, chemical and morphological properties. Initially, the MHR was obtained, so the passion fruit hull was subjected to dehydration in an oven with forced air circulation at 60 ± 5 ºC for 24 hours and fragmented in a blender. MF showed light coloration, heterogeneous granulometry, high carbohydrate content, carotenoids and total phenolic compounds with antioxidant activity. For the elaboration of ethanolextracts from the leaves of ora-pronóbis(Pereskia aculeata Miller), it was verified how different ultrasonic extraction times (10, 20, 30 and 40 minutes) can influence phytochemical profile, antioxidant and antibacterial activity. The extract obtained in ultrasonic extraction for 20 minutes (EO20) showed better results against bacterial inhibition. Thus, the EO20 was chosen as an additive to be incorporated in films prepared with FCM. In view of these results, a starch control film, a Standard Film (FPCM) was developed only with the FCM and three films with the FCM added extract from the leaves of ora-pro-nóbis at concentrations of 12.50% (FOR1); 6.24% (FOR2) and 3.10% (FOR3) w/w in relation to the filmogenic solution. Scanning electron microscopy revealed that the addition of the extract in the concentrations used was able to improve the homogeneity of the films, making them denser, with smaller cracks and smoother structure. The FPCM and the films with addition of extract did not differ statistically for thickness, solubility, tensile strength, elongation and puncture resistance, besides not showing major changes in the infrared spectrum of the films, which demonstrated low permeability to water vapor. Through paper spray mass spectrometry (EM-PS), 66 chemical compounds were identified in films developed in positive and negative ionization modes. The addition of the extract in the films allowed a significant increase in the content of total phenolic compounds and antioxidant activity. In view of the results, it was possible to infer that this research was able to evidence a great potential in the use of passion fruit bark, an agro-industrial residue and the leaves of ora-pro-nóbis, a plant still little explored technologically and in human food.