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In the cheese industry, whey, which is rich in lactose and proteins, is underutilized, causing adverse environmental impacts. The fractionation of its components, typically carried out through filtration membranes, faces operational challenges such as membrane fouling, significant protein loss during the process, and extended operating times. These challenges require attention and specific methods for optimization and to increase efficiency. A promising strategy to enhance industry efficiency and sustainability is the use of enzymatic pre-treatment with the enzyme transglutaminase (TGase). This enzyme plays a crucial role in protein modification, catalyzing covalent cross-links between lysine and glutamine residues, increasing the molecular weight of proteins, facilitating their retention on membranes, and contributing to the improvement of the quality of the final products. The aim of this study is to review the application of the enzyme TGase as a pretreatment in whey protein filtration. The scope involves assessing the enzyme's impact on whey protein properties and its relationship with process performance. It also aims to identify both the optimization of operational parameters and the enhancement of product characteristics. This study demonstrates that the application of TGase leads to improved performance in protein concentration, lactose permeation, and permeate flux rate during the filtration process. It also has the capacity to enhance protein solubility, viscosity, thermal stability, and protein gelation in whey. In this context, it is relevant for enhancing the characteristics of whey, thereby contributing to the production of higher quality final products in the food industry. © 2023 Society of Chemical Industry.

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Heavy metals contamination present risks to ecosystems and human health. Bioremediation is a technology that has been applied to minimize the levels of heavy metals contamination. However, the efficiency of this process varies according to several biotic and abiotic aspects, especially in environments with high concentrations of heavy metals. Therefore, microorganisms immobilization in different materials, such as biochar, emerges as an alternative to alleviate the stress that heavy metals have on microorganisms and thus improve the bioremediation efficiency. In this context, this review aimed to compile recent advances in the use of biochar as a carrier of bacteria, specifically Bacillus spp., with subsequent application for the bioremediation of soil contaminated with heavy metals. We present three different techniques to immobilize Bacillus spp. on biochar. Bacillus strains are capable of reducing the toxicity and bioavailability of metals, while biochar is a material that serves as a shelter for microorganisms and also contributes to bioremediation through the adsorption of contaminants. Thus, there is a synergistic effect between Bacillus spp. and biochar for the heavy metals bioremediation. Biomineralization, biosorption, bioreduction, bioaccumulation and adsorption are the mechanisms involved in this process. The application of biochar-immobilized Bacillus strains results in beneficial effects on the contaminated soil, such as the reduction of toxicity and accumulation of metals in plants, favoring their growth, in addition to increasing microbial and enzymatic activity in soil. However, competition and reduction of microbial diversity and the toxic characteristics of biochar are reported as negative impacts of this strategy. More studies using this emerging technology are essential to improve its efficiency, to elucidate the mechanisms and to balance positive and negative impacts, especially at the field scale.

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The food industry is always looking for new strategies to extend the shelf life of food. In recent years, the focus has been on edible films and coatings. These play an essential role in the quality, safety, transport, storage, and display of a wide variety of fresh and processed foods and contribute to environmental sustainability. In this sense, this study aimed to carry out a bibliometric analysis and literature review on the production of whey-based films for application in food packaging. Whey-based films have different characteristics when compared to other biopolymers, such as antimicrobial and immunomodulatory capacity. A wide variety of compounds were found that can be incorporated into whey films, aiming to overcome their limitations related to high solubility and low mechanical properties. These compounds range from plasticizing agents, secondary biomacromolecules added to balance the polymer matrix (gelatin, starch, chitosan), and bioactive agents (essential oils, pigments extracted from plants, and other antimicrobial agents). The most cited foods as application matrix were meat (fish, chicken, ham, and beef), in addition to different types of cheese. Edible and biodegradable films have the potential to replace synthetic polymers, combining social, environmental, and economic aspects. The biggest challenge on a large scale is the stability of physical, chemical, and biological properties during application. © 2022 Society of Chemical Industry.

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This research carried out a bibliometric analysis and literature review on the production of gelatin-based films for application as food packaging, addressing the main advances and limitations. The search for articles was performed in the Scopus database, and bibliometric data were obtained using the Bibliometrix tool (RStudio software). It was observed that a wide variety of compounds can be incorporated into gelatin films to overcome the limitations related to their high solubility and low mechanical properties, as well as to obtain active or smart functions. Among the most reported compounds were essential oils, pigments extracted from vegetables, and other antimicrobial agents. The most reported foods as an application matrix were meat (fish, chicken, and shrimp), milk, cheese, and minimally processed fruits. Even with promising trends, the biggest challenge for large-scale applications is to obtain easily degradable biopolymers with structural and functional stability similar to synthetic polymers. Thus, a greater focus on this theme in research may favor significant advances in the use of these packages and positively impact several of the Sustainable Development Goals, as recommended by the United Nations.

Este estudo objetivou realizar uma análise bibliométrica e revisão de literatura acerca da produção de filmes à base de gelatina para aplicação como embalagens alimentícias, abordando os principais avanços e limitações. A busca de artigos foi realizada na base de dados da Scopus e os dados bibliométricos obtidos pela ferramenta Bibliometrix (RStudio software). Verificou-se uma grande variedade de compostos que podem ser incorporados nos filmes de gelatina, a fim de superar suas limitações relacionadas à alta solubilidade e baixas propriedades mecânicas, bem como para obtenção de funções ativas ou inteligentes. Dentre os compostos mais reportados, têm-se: óleos essenciais, pigmentos extraídos de vegetais e outros agentes antimicrobianos. Os alimentos mais reportados como matriz de aplicação foram: carnes (peixe, frango e camarão), leite, queijo e frutas, minimamente processadas. Mesmo com tendências promissoras, o maior desafio no âmbito das aplicações reais em larga escala é a obtenção de biopolímeros facilmente degradáveis, com estabilidade estrutural e funcional similar aos polímeros sintéticos. Dessa forma, o maior enfoque dessa temática em pesquisas poderá favorecer avanços significativos para o uso dessas embalagens, impactando positivamente diversos dos Objetivos para o Desenvolvimento Sustentável, preconizados pela Organização das Nações Unidas.

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ABSTRACT: This research carried out a bibliometric analysis and literature review on the production of gelatin-based films for application as food packaging, addressing the main advances and limitations. The search for articles was performed in the Scopus database, and bibliometric data were obtained using the Bibliometrix tool (RStudio software). It was observed that a wide variety of compounds can be incorporated into gelatin films to overcome the limitations related to their high solubility and low mechanical properties, as well as to obtain active or smart functions. Among the most reported compounds were essential oils, pigments extracted from vegetables, and other antimicrobial agents. The most reported foods as an application matrix were meat (fish, chicken, and shrimp), milk, cheese, and minimally processed fruits. Even with promising trends, the biggest challenge for large-scale applications is to obtain easily degradable biopolymers with structural and functional stability similar to synthetic polymers. Thus, a greater focus on this theme in research may favor significant advances in the use of these packages and positively impact several of the Sustainable Development Goals, as recommended by the United Nations.

RESUMO: Este estudo objetivou realizar uma análise bibliométrica e revisão de literatura acerca da produção de filmes à base de gelatina para aplicação como embalagens alimentícias, abordando os principais avanços e limitações. A busca de artigos foi realizada na base de dados da Scopus e os dados bibliométricos obtidos pela ferramenta Bibliometrix (RStudio software). Verificou-se uma grande variedade de compostos que podem ser incorporados nos filmes de gelatina, a fim de superar suas limitações relacionadas à alta solubilidade e baixas propriedades mecânicas, bem como para obtenção de funções ativas ou inteligentes. Dentre os compostos mais reportados, têm-se: óleos essenciais, pigmentos extraídos de vegetais e outros agentes antimicrobianos. Os alimentos mais reportados como matriz de aplicação foram: carnes (peixe, frango e camarão), leite, queijo e frutas, minimamente processadas. Mesmo com tendências promissoras, o maior desafio no âmbito das aplicações reais em larga escala é a obtenção de biopolímeros facilmente degradáveis, com estabilidade estrutural e funcional similar aos polímeros sintéticos. Dessa forma, o maior enfoque dessa temática em pesquisas poderá favorecer avanços significativos para o uso dessas embalagens, impactando positivamente diversos dos Objetivos para o Desenvolvimento Sustentável, preconizados pela Organização das Nações Unidas.

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Alkaline hydrolysis of chromium-tanned leather wastes (CTLW) is a well-known process that allows the extraction of its most valuable portion: the protein. However, alkaline hydrolysis is time-consuming. It usually takes from 2 to 10 h to be completed. In this work, alkaline hydrolysis was performed in a steam explosion reactor, using CaO as the alkalinizing agent and aiming at a short-time process. Three different temperatures and residence times were tested: 130, 140, and 150°C; 5, 10, and 15 min. When performed at 140°C for 10 min, the steam explosion in alkaline medium resulted in the optimum combination of protein extraction yield (30%) and gelatine quality (viscosity of 2.4 cP at 25°C in a 24.6 g/L protein solution - 39 kDa of molecular mass [Formula: see text]w). Not only a high extraction yield was achieved, but when compared to traditional methods, steam explosion in alkaline medium reduced the process time by a factor that varied from 12 to 36 times. It also reduced chromium content in the gelatine by a factor that varied from 16 to 96 times. Finally, to produce a high quality product, the ash content of the gelatine was reduced from 11.8% (dry basis) to 1.2% (dry basis) through diafiltration. This purification allows the application of the gelatine, for example, in the production of polymeric films.

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BACKGROUND: The technological advances in agriculture, driven by the increased demand for food attributed to population growth, have led to the search for technologies that allow greater control over the variables that interfere in crop yield. Several techniques stand out for optimizing yield capacity, including cultivation in a protected environment, mulching and low tunneling. To expand the use of these techniques, synthetic petroleum-based polymers are employed due to their low cost, easy processing, and lightness. However, they take a long time to degrade, and, since they are discarded at the end of each cycle of cultivation, end up accumulating in the environment causing irreversible damage. RESULTS: The use of biodegradable films, made of starch and/or a protein source such as gelatin, has been studied as a promising alternative. Both stand out because of their film-forming ability, and because they come from abundant sources and are biodegradable. CONCLUSION: This study aimed to review the current findings on starch and gelatin films that can be used as alternatives to conventional plastics in agricultural crops. © 2019 Society of Chemical Industry.

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Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10%w/v. The results were compared to those of commercial lactose. A scale-up test in a 4L bioreactor was done at 35°C, 750rpm, 7L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11g/L.h, and for polymer yield, (YP/S), 1.08g/g. The bioreactor experiment resulted in lower p and YP/S. PHB showed maximum degradation temperature (291°C), melting temperature (169°C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality.

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Tobacco stems waste underwent steam explosion pulping for nanofibrillated cellulose (NFC) production. In order to obtain NFC hydrogels, the pulp obtained by steam explosion was bleached and refined in a grinder employing specific energy of up to 5067kWh/t. Eucalyptus kraft pulp was processed under the same conditions to produce NFC hydrogels, later used in order to compare with NFC hydrogels from tobacco stems waste. According to statistical analysis, the optimum tobacco stems pulping condition was obtained with a severity index of log3.0 and active alkali of 16.25%. These conditions allowed obtaining a bleached pulp with Schopper Riegler degree of 46. Electronic microscopy with field emission showed a higher presence of nanofibers in the tobacco stems pulp than in commercial eucalyptus kraft pulp, both after refining. Thermal analysis indicated that tobacco stems pulp degrade at lower temperatures than eucalyptus kraft pulp. FTIR analysis did not indicate chemical bonding differences between the two pulps.

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In this work is described the isolation of a new proteases-producing strain of Bacillus subtilis, screened from aerobic tannery sludge, to be applied in leather production. The optimization of culture conditions to enhance the proteolytic activity was carried out using central composite design. The enzymatic extract was characterized and the hide unhairing and the inter-fibrillary removal capabilities of the enzymatic extract were evaluated by scanning electron microscopy and by the determination of proteoglycans and glycosaminoglycans. The leather quality obtained with this enzymatic preparation was assessed for possible damages to hide collagen by measuring the amount of hydroxyproline released into the reaction medium. Temperature was the most significant factor for culture conditions optimization. The crude enzymatic extract showed the best values for proteolytic activities at pH 9 and 10, temperature between 37 and 55 °C, and showed good thermal stability up to 45 °C. The treated hides presented few remaining hairs; for the enzymatic process, the removal of inter-fibrillary proteins was approximately fourfold for glycosaminoglycans and sixfold for proteoglycans, when compared with the conventional unhairing process. The enzyme application was successful for hide treatment, suggesting that this enzymatic preparation can be used in an environment-friendly leather production to replace the conventional chemical process.

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