Bioactive compounds of honey from different regions of Brazil: the effect of simulated gastrointestinal digestion on antioxidant and antimicrobial properties

Monofloral and multifloral honey produced in different regions may have different bioactive compounds and antioxidant capacities, resulting in changes in the antimicrobial activity of honey. However, many of these compounds degrade due to the extreme digestion conditions, which may inhibit the antimicrobial activity. Given this context, this study aimed to describe the bioactive compounds of honey produced in Brazil and verify if honey samples from different botanical and geographical origins differ in bioactive compounds, and if honey maintains its antimicrobial activity after digestion simulation. Multivariate analysis was used to identify characteristics that differentiated the honey samples according to the botanical and geographical origin criteria. The amount of the bioactive compounds varied significantly: the total phenolic compound content varied from 20.49 to 101.44 mg GAE per 100 g, flavonoids varied from 1.41 to 13.52 mg QE per 100 g, phenolic acids varied from 13.61 to 56.41 mg CAE per 100 g, and carotenoids varied from 0.66 to 4.27 mg β-carotene per g. Multifloral honey (H22) produced in the dry season of northeastern Brazil presented the highest bioactive compound concentration except for the carotenoid content. HPLC-MS analysis showed the presence of six hydroxybenzoic acids, four hydroxycinnamic acids, eight flavonols, three flavanones, two flavones and two isoflavonoids; Pterodon pubescens monofloral honey (H14) from midwestern Brazil stood out in terms of the carotenoid content. All analyzed honey samples exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria before digestive process simulation, and bacteria were inhibited during in vitro digestion; this activity decreased during the simulation of the oral phase, remained in the gastric phase, and disappeared in the intestinal phase.

Development, characterization and optimization of biopolymers films based on starch and flour from jabuticaba (Myrciaria cauliflora) peel

In this study, the influence of the concentration of flour from jabuticaba peel (FJP) and the concentration of glycerol (CG) on the physicochemical, barrier, mechanical, optical, spectroscopic and biodegradability properties of corn starch films was evaluated using response surface methodology. The increase in the concentrations of FJP and CG enhanced the thickness and permeability to water vapor, and made the films more hydrophilic. In addition to that, the interaction between the two variables caused reduction in the solubility of the films. High concentrations of FJP and CG reduced the maximum tensile strength, and increased CG increased the elongation and decreased the young's modulus of the films. Among the tests studied, the T1 film (15.80% FJP and 15.80% CG) was biodegradable, presenting the best mechanical and barrier properties such as low water vapor permeability, solubility and water holding capacity, showing great potential to be used as biodegradable packaging system.