ABSTRACT: Vegetable oils are widely used in food preparation. Still, when subjected to high temperatures, they undergo physical and chemical degradation that compromises their quality and generates residues with high environmental impact. This study aimed to perform the physicochemical characterization of used cooking oils and propose reuse strategies aligned with the principles of the circular economy. Samples from households and restaurants were analyzed for acidity, peroxide value, iodine index, density, and soluble solids content. The results revealed significant degradation, particularly in terms of acidity and peroxide levels, rendering reuse in food applications unfeasible. Statistical tools were applied to group the samples into four distinct clusters, each with specific chemical profiles. Based on these profiles, targeted applications were proposed: the extraction of unsaturated and saturated fatty acids for the food, pharmaceutical, and chemical industries, and the production of biodiesel from highly degraded oils. The findings highlight the relevance of physicochemical analysis as a tool for efficient and sustainable management of residual oils.Keywords: Used cooking oil, Physicochemical characterization, Lipid oxidation, Waste management, Sustainable processes.
Growing social concern about health has increased interest in new functional foods. To meet this demand, hydrogels represent a promising alternative: semisolid structures with a high water-retention capacity that can act as drug-encapsulating systems. Hydrogels are composed of structuring agents, generally biopolymers, capable of promoting gelation. Xanthan gum (XG) can increase the medium's viscosity through molecular interactions with other components. Thus, evaluating its gelling behavior in the incorporation of B12 vitamin into hydrogels becomes essential. Hydrogels were prepared using four concentrations of xanthan gum: XG1 (0.5% w/v), XG2 (0.75% w/v), XG3 (1.0% w/v), and XG4 (1.5% w/v). Samples were analyzed for moisture content, gel fraction, swelling index, and Raman spectroscopy, and statistical significance was assessed. The moisture content of all samples remained between 98% and 99%. The highest gel fraction values were observed for XG2 and XG3 85.33% and 82.4%, respectively, indicating more efficient network formation. The swelling index ranged from 25.64 to 28.66 g/g across samples. Raman spectroscopy revealed characteristic peaks for all formulations, including C–H vibrations, ester groups, and asymmetric and symmetric CH₂ and CH₃ stretching modes. Overall, intermediate concentrations of xanthan gum proved more efficient for producing hydrogels suitable for future vitamin incorporation.
In lobster fisheries along the Brazilian coast, lobster cephalothorax is discarded overboard. The cephalothorax corresponds to 2/3 of the crustacean in weight, and its meat yields 26.6% of the total weight of the Panulirus argus lobster. This means that thousands of tons of meat are wasted in fishing. However, some fishing companies have taken the initiative to use the meat extracted from the cephalothorax, including the meat from the antennas, which corresponds to a yield of 5% in relation to the weight of the cephalothorax. The problem with using antennae meat lies in the fact that when cooked, after being stored frozen, it becomes different, "strange," tough, and therefore loses its commercial acceptance. This study aims to monitor some of these biochemical changes in the raw material and develop a simple, practical, and inexpensive methodology to promote its softening. Biochemical test results showed variations in pH, from 6.63 to 7.73, salt-soluble proteins, from 23.47 to 10.52 mg/g, and formaldehyde, from zero (freshly killed lobster) to 59.5 µg/g. Organoleptic tests showed that treatment III, consisted of a pre-softening with the commercial softener whose composition includes the enzyme papain, was the most efficient.
With the crescent interest of the industries in phenolic compounds-rich aqueous extract, new extraction methodologies must be evaluated on their technical and environmental efficiencies. In the current work, the extraction of phenolic compounds from yerba mate is evaluated using the non-isothermal subcritical water extraction technique. The extraction was conducted with a solid-liquid ratio of 0.5 g 100 mL-1, with a final temperature of 120 °C and a heating ramp of 5 °C min-1. Additionally, a conventional batch extraction at 70 °C was conducted in a non-pressurized system, and the energetic demand for the production of 1 m3 of crude yerba mate extract for both scenarios was estimated. Both the extraction methods presented a similar concentration of phenolic compounds (up to 527 mg GAE L-1), with a total extraction time of 161 and 128 min for the conventional and non-conventional extraction processes, respectively. The non-conventional process resulted in an increase of 111 % in the energy consumption of the conventional one, which suggests that the batch extraction conducted with water at 70 °C is more efficient in environmental aspects.
O objetivo deste trabalho foi avaliar a influência de concentrações de cloreto de cálcio como ingrediente, nas características físico-químicas, estruturais e de maturação de queijo prato, em diferentes períodos de maturação. Para isso foram elaborados queijos com adição de 0,04 (pc4) e 0,08% (pc8) de solução cacl2 50%, e como padrão foi produzido um lote sem adição de cacl2 50% (pc0). Os queijos foram embalados a vácuo e maturados em câmaras de maturação em temperatura de 12 ºc e umidade relativa de 85%. Os queijos foram avaliados nos períodos de 0, 25, 50 e 75 dias de maturação. Foram observadas diferenças significas entre as amostras com 75 dias de maturação em relação aos queijos p0, comparados com os queijos pc4 e pc8, com uma diferença de 2% para o parâmetro de ph, 9 % no teor de cinzas, 1% para atividade de água, e 10% para proteína. Para os parâmetros de umidade essa diferença foi de 2% entre as amostras p0 e pc4, e 3% entre as amostras p0 e pc8. Para os parâmetros do perfil de textura foram observadas diferenças significativas entre as amostras para mastigabilidade, dureza, coesividade e resiliência. Desta forma, recomenda-se a utilização de cloreto de cálcio na concentração de 0,04%, já que nesta concentração não foram observadas alterações significativas na composição físico-química, estrutural e maturação.
