Caracterização física e uso de análise de componentes principais, baseada na composição bioativa e características físico-químicas de diferentes resíduos de vinícolas do centro-oeste

Abstract

The production of juice and wine generates large quantities of waste, especially bagasse, the residue most produced in the processing, consisting of bark and seeds of grapes, most of which is still discarded without treatment, causing damage to the environment. Therefore, studies are necessary to solve this effect. In this work the physicochemical properties, phenolic compounds content, anthocyanin content, antioxidant capacity, structural analysis, rheological and thermal behavior and PCA were evaluated to classify residues from the Center-West region. SII, SIC, SIS, SPI, SPC, SPS, VII, VIC and VIS residues were tested. Skins and integral obtained values between 76.51% to 83% and 10.1 °Brix at 10.3 °Brix for moisture and soluble solids, respectively, which were significantly higher than the values found in the seeds that ranged from 32.79 % to 44.96 % and 1.1 °Brix to 1.2 °Brix. For pH the seeds stood out with the highest values (4.11 to 4.60), significantly deferring the skins and integral of the residues (3.39 to 3.76). For acidity the skins and integral of the Paraúna residues presented significantly higher values (27.51 % to 28.50 %) of the other residues (6.85 % to 13.83 %). Phenolic compounds contents in the residues differed statistically varying from 364.89 to 2250.88 mg.100g-1, and higher values were found in the seeds. Anthocyanin values differed statistically, varying from 3.18 to 65.80 mg. 100g-1, and the highest values were found in the skins and integral of the residues. For the antioxidant capacity by the ABTS and DPPH methods, all residues were statistically deferred, with the highest value detected in the VIS extract (11857 ± 705.32 and 22751.84 ± 155.67 μM. 100g-1 for DPPH and ABTS, respectively) and the lowest in SPC extract (2886.41 ± 203.46 and 3636.54 ± 355.72 μM. 100g-1 for DPPH and ABTS, respectively). By the PCA the wine residues differ in function of their processing and that the seed separates from the other residues. Structural analysis of wine residues revealed typical stretching bands of C-O bonds characteristic of ethers, C=C of aromatic ring, carboxylic acid, methylene and O-H of alcohol. For rheological analysis, the best fit of the experimental data was observed by the Ostwald-de-Waelle model and the rheological behavior of the extracts was non-Newtonian pseudoplastics, the activation energy ranged from 336.063 to 1280.862 kJ.g-1.mol-1, with the lowest values were found in the extracts of the Paraúna juice residues and the highest values in the extracts of Itaberaí juice residues. Thermal analysis revealed combustion profiles with three distinct zones corresponding to the release of moisture, devolatilization and decomposition. With this, it is concluded that the characteristics of the winemaking byproducts and their extracts varied according to their origin and region.