Caio Cesar Nemer Martins

The research responds to the limited availability of technical data on native Brazilian woods, which constrains their industrial application and sustainable management. The commercial use of timber from native Brazilian species is hindered by a scarcity of data on fundamental properties related to wood quality, limiting its use in the wood industry. This study sought to characterize the timber of ten native Brazilian species using X-ray densitometry and colorimetric analysis. Timber samples of various ages and 2 mm thickness were evaluated. The X-ray images enabled the identification of anatomical characteristics such as wood porosity and parenchyma. Densitometric profiles showed woods with high densities (ranging between 550 kg/m³ and 1000 kg/m³). Variations were identified in each sample due to transitions between earlywood and latewood, with latewood presenting higher density, and parenchyma and pore areas showing lower density values. Standard deviation values ranging from 84,6 (Tabebuia) to 162,8 (Bowdichia) indicated differing homogeneity in wood density across the samples. Colorimetric characterization using the CIELAB system allowed the identification of desirable visual characteristics, with species ranging from lighter (L*46,7) to darker (L*25,7) tones and significantly different colors from yellow to purple. Thus, the techniques used in this study proved effective in characterizing native timber through novel analytical methods, contributing to their better utilization.

Attempts have been made to replace conventional plastics in food packaging with biodegradable materials as a promising alternative because they are natural, renewable, and low-cost. This study aimed to develop biodegradable and resistant films from cellulose nanofibrils (CNFs) from sugarcane bagasse when used as reinforcement in starch films. Sugarcane bagasse pulps were subjected to alkaline treatment, with the residual lignin remaining. Part of the material was subjected to a bleaching process with H₂O₂. The pulps were subjected to the mechanical fibrillation process, and unbleached and bleached CNFs were produced. Percentages of 10%, 20%, 30%, and 50% CNF were added to a solution containing 2.5% starch (m/m) solids to make the films. The addition of unbleached CNF promoted an average increase in the tensile strength and Young’s modulus values, especially for films with higher percentages of CNF (30% and 50%). The contact angle values increased with the CNF concentration, with all films being classified as hydrophobic (>90°), except for the films with 30% and 50% unbleached CNF. The 50% unbleached and bleached CNF samples showed low water vapor permeability (2.17 g.mm/Kpa⁻¹ day⁻¹ m²), indicating a good vapor barrier. Although the influence of residual lignin on the test results was not identified for the other samples, treatments with 50% CNF of sugarcane bagasse (unbleached or bleached) should be highlighted among the properties evaluated for reinforcing the structure and improving the barrier properties of cassava starch-based films. Furthermore, this study proposes using sugarcane bagasse, which is a waste widely available in Brazil, placing the study in line with three Sustainable Development Goals (SDGs).

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

Charcoal fines are co-products of the wood carbonization process, unwanted because they reduce the gravimetric yield of the main product, charcoal. It can be produced due to the carbonization process, during the storage and transport of charcoal. Pelletizing charcoal fines increases the energy density of this material, producing a homogeneous fuel with lower moisture content, enabling burning in equipment with high energy efficiency, in addition to desirable properties in energy products such as high fixed carbon content and low moisture content. This study evaluated the effect of moisture content and drying time on the production of black pellets from charcoal fines bound with rice starch (Oryza sativa) on the physicochemical and mechanical characteristics. Black pellets were produced using two proportions of water (10 or 20%) and a drying time of 4 or 6 hours. Black pellets were evaluated for their proximate analysis, elemental composition, moisture content, size, apparent density, calorific value and energy density. The addition of water did not affect the content of volatile matter, ash, and fixed carbon, while the treatment with addition of 20% water and four hours of drying showed a higher moisture content (3.34%). The addition of water allowed for better heat conduction and particle arrangement, producing pellets with a durability greater than 98%. The better arrangement promoted by the addition of 20% water also increased the density of the pellets, resulting in greater energy density. Black pellets can be considered an alternative for residential heating, with T3 treatment (20% - 4h) with a high energy density and better performance in terms of desirable properties for use and commercialization according to the standard EN 14961-6.

The use of X-rays non-destructive technique in color scale in 2D and 3D needs further studies to understand variations in the apparent density of wood stored under natural conditions. The objective of this study was to evaluate, by digital X-ray images and to test the rainbow scale in digital X-ray images in 2D and 3D, the apparent density of eucalyptus wood after storage in the field during 365 days. Trees of two diametric classes were randomly distributed at three heights in a pile in direct contact with the soil. The apparent density of the wood and its diametric profiles in the radial direction were determined using digital X-ray images in gray scale, and converted to a rainbow scale and the density variations plotted on a 3D surface.