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Agriculture and food science literature on waste-to-value applications that allow upcycling of by-product ingredients is increasing. However, this stream of research rarely takes an international trade and sustainability systems perspective. This focused review defines the term of waste-to-value and the sustainable development goals connected to it, and points to the tensions and questions arising when international trade is involved. Further, it exemplifies the challenges and opportunities of waste-to-value in tropical fruit trade through five cases of tropical fruit from South America: Green coconut, açaí, maracujá, cambuci, and jabuticaba. We present a model of the international supply chain that indicates where the opportunities of waste-to-value applications in international tropical fruit trade are situated, and discuss which future research questions need to be addressed to tackle the challenges of waste-to-value in global tropical fruit chains. Establishing the waste-to-value approach in the export of yet-underused tropical fruits can amongst others improve local employment, preserve natural resources, allow favorable use of side-streams in local energy production, environmentally friendly packaging material for transport, and add health functionalities to the end-consumer products, but challenges have to be solved in order to ensure these environmental and social benefits materialize.
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Comércio , Frutas , Internacionalidade , AgriculturaRESUMO
The aim of this research was to investigate the effect of Holder pasteurization (HoP; 62.5°C, 30 min) on the protein profile and activities of glutathione peroxidase (GPx) and lysozyme (LZ) in human milk. Over 6 mo of lactation, human milk samples were analyzed before (raw) and after HoP for GPx and LZ activity and electrophoresis protein profile. Holder pasteurization reduced human milk lactoferrin, immunoglobulin fractions, and GPx activity. In addition, GPx activity, which is high in colostrum and transitional milk, was naturally reduced over the 6-mo lactation period. In contrast, HoP did not affect human milk LZ activity. Besides its critical cellular antioxidant role in protecting the organism from oxidative damage, GPx decreases the redox potential of milk, stimulating the growth of anaerobic microorganisms, such as the probiotic Bifidobacterium. Considering the role of lactoferrin in infant health, we conclude that an important part of its function has been inactivated by pasteurization. These compounds should be replaced by human milk banks after the HoP step to recover lost functionality. Otherwise, an alternative technology to HoP that better retains human milk properties should be used by milk banks to eliminate the risk of transmission of infectious agents.
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Leite Humano/enzimologia , Pasteurização , Antioxidantes , Feminino , Glutationa Peroxidase , Humanos , Lactação , Lactoferrina/metabolismo , Muramidase , Pasteurização/métodosRESUMO
Osmoporation is an innovative method that can be used with food-grade yeast cells of Saccharomyces cerevisiae as natural encapsulating matrices. This technique overcomes barriers that difficult encapsulation and enables the internalization of fragile bioactive molecules such as fisetin into yeasts. In the present study, we assessed the effects of concentration, osmotic pressure, and temperature on the encapsulation efficiency (EE) and internalized fisetin content (IF). Two different quantification strategies were investigated: direct extraction (DE) without cell washing or freeze-drying steps and indirect extraction (IE) performed after washings with ethanol and freeze-drying. Our results showed that osmoporation improved EE (33 %) and IF (1.199 mg). The best experimental conditions were found by using DE. High-resolution images showed that the yeast cell envelope was preserved during osmoporation at 30 MPa and 84 % of yeast cells remained viable after treatment. Washing cells with organic solvent led to decreased EE (0.65 %) and IF (0.023 mg). This was probably due to either damages caused to yeast cell envelope or fisetin dragged out of cell. Overall, the results demonstrated the adequacy and relevant biotechnological potential of yeasts as encapsulating matrices for hydrophobic compounds. This fresh biotechnological approach has proven to be a promising tool for the production of bioactive-rich food products.
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Biotecnologia , Cápsulas/química , Flavonoides , Saccharomyces cerevisiae/fisiologia , Fosfatos de Cálcio , Cápsulas/análise , Cápsulas/metabolismo , Flavonoides/análise , Flavonoides/química , Flavonóis , Liofilização , Interações Hidrofóbicas e Hidrofílicas , Pressão Osmótica , Saccharomyces cerevisiae/ultraestrutura , TemperaturaRESUMO
The main goal of this work was to study the bacterial adaptive responses to antibiotics induced by sublethal concentration of citral on first-and second-generation cells of Listeria monocytogenes serovar 4b (CECT 4032) and Salmonella enterica serovar Typhimurium (CECT 443). The first-generation cells were not pretreated with citral, while the second-generation cells were obtained from cells previously exposed to citral during 5 h. The trials were conducted at 37°C. The presence of citral in the culture medium and the antibiotic strips resulted in a reduced minimum inhibitory concentration (MIC) for the first-generation cells of Listeria monocytogenes serovar 4b and Salmonella Typhimurium. This result was observed for almost all the antibiotics, compared with the same microorganisms of the control group (without citral), which could represent an additive effect. For Listeria serovar 4b, the second-generation cells of the test group maintained the same susceptibility to antibiotics compared with cells in the control group and in the test group of the first generation. The second-generation cells of the control group indicated that the Salmonella Typhimurium maintained the same sensitivity to the antibiotics tested compared with the first generation of this group, except in the case of erythromycin, which exhibited an increased MIC value. With respect to the second-generation cells of Salmonella Typhimurium, the presence of citral determined a decrease in the antibiotic susceptibility for almost all of the antibiotics, except colistin, compared with the first-generation of the test group, which can be seen by increase of MIC values. In conclusion, the presence of citral in the culture medium of Listeria 4b and Salmonella Typhimurium increased the antibiotic susceptibility of the first generations, while we observed an increase in antibiotic resistance in the second generation of Salmonella Typhimurium.
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Farmacorresistência Bacteriana/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Listeriose/microbiologia , Monoterpenos/farmacologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/efeitos dos fármacos , Monoterpenos Acíclicos , Antibacterianos/farmacologia , Contagem de Colônia Microbiana , Meios de Cultura , Humanos , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/fisiologia , Testes de Sensibilidade Microbiana , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/fisiologiaRESUMO
BACKGROUND: The isolated application of high hydrostatic pressure (HHP) and ultraviolet-C (UV-C) radiation may induce physicochemical changes, thus jeopardizing fish quality attributes during refrigerated storage, which could be minimized by the use of synergistic treatments. Therefore, this study investigated the combined effect of UV-C at 0.103 ± 0.002 J cm−2 and HHP at 220 MPa for 10 min on quality parameters of tilapia fillets stored at 4 °C for 15 days. RESULTS: HHP and UV-C+HHP showed higher myoglobin concentration, higher metmyoglobin-reducing activity, and lower a* than control and the UV-C treatment (P < 0.05), reaching 2.49, 2.58, 1.62, 1.54 mg myoglobin g−1 , 13.30, 13.81, 2.29, 2.29%, and 2.32, 2.58, 4.29, 3.98 respectively on the last day of storage. UV-C, HHP, and UV-C+HHP increased water-holding capacity and decreased the pH levels, hardness, and chewiness (P < 0.05). HHP retarded lipid oxidation and UV-C increased protein oxidation compared with control (P < 0.05), achieving 0.81 and 2.80 mg malondialdehyde per kilogram of fish tissue, and 5.50 and 4.15 nmol carbonyl per milligram of protein respectively on 15th day of the storage. CONCLUSION: Both technologies (alone or together) enhanced texture parameters and water-holding capacity. UV-C did not induce color changes and lipid oxidation, whereas HHP showed high potential to prevent meat discoloration, lipid oxidation, and protein oxidation. In addition, this combination of methods could be an alternative to prevent protein oxidation induced by UV-C.
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Produtos Pesqueiros/análise , Irradiação de Alimentos/métodos , Conservação de Alimentos/métodos , Animais , Cor , Produtos Pesqueiros/efeitos da radiação , Conservação de Alimentos/instrumentação , Pressão Hidrostática , Oxirredução , Tilápia , Raios UltravioletaRESUMO
Food processing includes operations that transform raw materials into new products, ensuring the preservation and supply of safe food; however, this view is not always understood by consumers who tend to associate any type of processing with something negative and harmful to health. Given this, the objective of this study was to explore the associations of Brazilian consumers in relation to healthy foods, industrialized foods, and ultra-processed foods, as well as to evaluate the role of socio-demographic characteristics and interest in health in these associations. To this end, 512 Brazilians completed a word association task on these three concepts and then answered a questionnaire about interest in health and socio-demographic issues. In general, participants associated "Healthy food" mainly with "Unprocessed products." Conversely, "Industrialized foods" and "Ultra-processed foods" were associated with "Processed products," "Negative perceptions," "Health harm," and "Industry". Despite this, it was found that "Industrialized foods" were also perceived positively, mainly due to convenience. Consumer associations were influenced (p ≤ 0.05) both by interest in health and by socio-demographic profile. Individuals with a high interest in health mainly associated "Industrialized foods" and "Ultra-processed foods" with the presence of preservatives, additives, and pesticides, and with diseases. As for those with low interest in health, there was a greater lack of knowledge of the concepts. Doubts and lack of knowledge were observed for "Industrialized foods" and "Ultra-processed foods," mainly among consumers with low educational level. The results indicate the need to develop communication strategies that reach consumers to facilitate understanding and, in this way, help them to make more conscious food choices.
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Alimento Processado , Alimentos , População da América do Sul , Humanos , Brasil , ComunicaçãoRESUMO
Monascus ruber is an important fungus that causes spoilage in table olives, resulting in the darkening of the brine, the softening of the fruit, increased pH, and apparent mycelial growth. This study aimed to evaluate this resistance, providing a model to determine the optimal processing conditions for mitigating fungal contamination and prolonging shelf life without antifungal agents while optimizing pasteurization to reduce energy consumption. The resistance in brine (3.5% NaCl; pH 3.5) from Arauco cultivar green olives imported from Argentina was assessed. Four predictive models (log linear, log linear + shoulder, log linear + tail, log linear + shoulder + tail) estimated kinetic parameters for each survival curve. Log linear + shoulder + tail provided the best fit for 70 °C and 75 °C, with low RMSE (0.171 and 0.112) and high R2 values (0.98 and 0.99), respectively, while the log linear model was used for 80 °C. Decimal reduction times at 70, 75, and 80 °C were 24.8, 5.4, and 1.6 min, respectively, with a z-value of 8.2 °C. The current regulatory processes are insufficient to eliminate M. ruber at requisite levels, considering reduced antifungal agents.
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High-pressure homogenization (HPH) is a non-thermal technology widely studied to replace, partially or in total, the conventional thermal preservation processes used in the food industry, thus minimizing undesirable changes in the nutritional and sensory characteristics of liquid products. The main effect of HPH is the size reduction of dispersed particles thus affecting physical stability of the products, despite also inactivating microorganisms, preserving bioactive compounds, and maintaining sensory characteristics. During the process, the fluid is driven under high-pressure through a micrometric gap inside the valve. Phenomena including cavitation, shear and turbulence are responsible for the changes in the fluid. From this perspective, the present paper reviews the effects of HPH on the inactivation of microorganisms and preservation of bioactive compounds of fruit juices treated with this technology. The juice matrices reported were apple, apricot, banana, blackberry, carrot, kiwifruit, mandarin, mango, orange, peach, pomegranate, rosehip, strawberry and tomato. The paper elucidates the potential application of HPH to fruit juice processing aiming at producing safe products with high nutritional and sensory quality.
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Sucos de Frutas e Vegetais , Malus , Viabilidade Microbiana , Frutas/químicaRESUMO
The high hydrostatic pressure (HHP) process has been studied for several applications in food technology and has been commercially implemented in several countries, mainly for non-thermal pasteurization and shelf-life extension of food products. HHP processing has been demonstrated to accelerate proteolytic hydrolysis at a specific combination of pressure and pressure-holding time for a given protein source and enzyme. The enzymatic hydrolysis of proteins is a well-known alternative to producing biologically active peptides, with antioxidant and antihypertensive capacity, from different food protein sources. However, some of these protein sources contain allergenic epitopes which are often not degraded by traditional hydrolysis. Moreover, the peptide profile and related biological activity of a hydrolysate depend on the protein source, the enzymes used, the parameters of the proteolysis process (pH, temperature, time of hydrolysis), and the use of other technologies such as HHP. The present review aims to provide an update on the use of HHP for improving enzymatic hydrolysis, with a particular focus on studies which evaluated hydrolysate antihypertensive and antioxidant capacity, as well as residual allergenicity. Overall, HHP has been shown to improve the biological properties of hydrolysates. While protein allergenicity can be reduced with traditional hydrolysis, HHP can further reduce the allergenicity. Compared with traditional hydrolysis methods, HHP-assisted protein hydrolysis offers a greater opportunity to add value to protein-rich products through conversion into high-end hydrolysate products with enhanced nutritional and functional properties.
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High-pressure processing (HPP) has emerged in the food industry as an alternative to thermal juice preservation treatments, with its appeal being its assurance of safety for products with nutritional and sensory qualities similar to those of fresh food. However, HPP remains to be fully understood, particularly regarding hazards and process validation to mitigate microbiological risks. One of the challenges is understanding the large variation in the sensitivity of pathogenic strains to pressure associated with microbial genotypes, phenotypes, and food composition. This manuscript provides an overview of barotolerance mechanisms and the influence of pH and soluble solids in low- and high-acidity juices in the resistance of pathogenic strains of Escherichia coli, Salmonella spp., and Listeria monocytogenes, as well as their surrogates. The presented information can be used in the selection of challenge microorganisms for validation tests, including the results of a few studies with tropical and blended fruit and vegetable juices and the influence of the food matrix on the high pressure resistance of pathogenic strains.
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Escherichia coli , Listeria monocytogenes , Pressão Hidrostática , Microbiologia de Alimentos , Salmonella , Manipulação de Alimentos/métodos , Contagem de Colônia Microbiana , Sucos de Frutas e VegetaisRESUMO
Post-harvest diseases can be a huge problem for the tropical fruit sector. These fruits are generally consumed in natura; thus, their integrity and appearance directly affect commercialization and consumer desire. Anthracnose is caused by fungi of the genus Colletotrichum and affects tropical fruits, resulting in lesions that impair their appearance and consumption. Antifungals generally used to treat anthracnose can be harmful to human health, as well as to the environment. Therefore, essential oils (EO) have been investigated as natural biofungicides, successfully controlling anthracnose symptoms. The hydrophobicity, high volatility, and oxidative instability of essential oils limit their direct application; hence, these oils must be stabilized before food application. Distinct delivery systems have already been proposed to protect/stabilize EOs, and nanotechnology has recently reshaped the food application limits of EOs. This review presents robust data regarding nanotechnology application and EO antifungal properties, providing new perspectives to further improve the results already achieved in the treatment of anthracnose. Additionally, it evaluates the current scenario involving the application of EO directly or incorporated in films and coatings for anthracnose treatment in tropical fruits, which is of great importance, especially for those fruits intended for exportation that may have a prolonged shelf life.
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Portulaca oleracea Linn. (P. oleracea L.) has recently gained attention as a functional food due to the chemical composition of this plant regarding bioactive compounds. The special attention to the use of P. oleracea as an ingredient in functional food products is also due to the promotion of sustainable food. It is an unconventional food plant, and its consumption may contribute to preserving biodiversity due to its cultivation in a polyculture system. Food sovereignty may be achieved, among other strategies, with the consumption of unconventional food plants that are more resistant in nature and easily cultivated in small places. P. oleracea grows spontaneously and may be found in streets and sidewalks, or it may be cultivated with seeds and cuttings propagation. The culinary versatility of P. oleracea opens up opportunities to explore the development of sustainable, functional food products. This mini-review shows that functional food products developed from P. oleracea are already available at the research level, but it is expected that more scientific literature focusing on the development of P. oleracea functional products with proven anticancer activities may be released in the near future. Polysaccharides, some phenolic compounds, alkaloids, and cerebrosides are associated with the inhibition and prevention of carcinogenesis through in vitro and in vivo investigations. The anticancer activities of P. oleracea, its bioactive compounds, and the involved molecular mechanisms have been reported in the literature. The importance of further elucidating the cancer inhibition mechanisms is in the interest of forthcoming applications in the development of food products with anticancer properties for implementation in the human diet.
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Alcaloides , Portulaca , Cerebrosídeos , Alimento Funcional , Humanos , Extratos Vegetais/farmacologia , Portulaca/químicaRESUMO
This study investigated the use of Novo Pro-D® (NPD) and Ficin (FC) as alternative proteases for the production of bioactive peptides with reduced allergenicity from whey protein concentrate (WPC). In addition, the use of high hydrostatic pressure processing as pre-treatment of WPC and its impact on the final characteristics of hydrolysates were also evaluated. NPD treatments generated hydrolysates with a 98% reduction of soluble proteins, greater in vitro antioxidant capacity, and less immunoreactivity when compared to FC ones. However, pre-treatment was an essential tool to improve WPC hydrolysis when FC was used, resulting in hydrolysates with less soluble proteins, enhanced antioxidant capacity, and less allergenicity compared with conventional hydrolysis. As for NPD, the pre-treatment of WPC improved the in vitro antioxidant capacity and resulted in a 100% reduction in immunoreactivity to ß-lactoglobulin in a shorter processing time. Importantly, bioactive peptides generated by FC displayed an improved ability to induce in vitro arterial relaxation, compared with those obtained from NPD process. Therefore, this study provides innovative evidence regarding how the proteases used for production of whey hydrolysates can improve its biological effects, and discloses the use of high hydrostatic pressure combined with enzymatic hydrolysis as a promising alternative to produce hydrolysates with improved properties.
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Proteínas do Leite , Hidrolisados de Proteína , Antioxidantes/química , Ficina , Hidrólise , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Proteínas do Leite/química , Peptídeo Hidrolases/metabolismo , Peptídeos/química , Soro do Leite , Proteínas do Soro do LeiteRESUMO
The aim of the present study was to develop a mixed tropical fruit juice of cashew apple, acerola and melon with low added-sugar content considering sensory and nutritional aspects. Five formulations were developed varying the concentration of the different fruits. A total of 172 consumers rated their overall liking using a 9-point hedonic scale and described their sensory characteristics using a Check-all-that-apply question. In addition, the functional properties of the juices were evaluated by analyzing vitamin C, total phenolic compounds and antioxidant capacity. Results showed that the addition of sugar and fruit composition affected the sensory characteristics and consumer liking of the formulations. Samples without added sugar and with higher melon concentration showed lower liking scores (p < 0.05). In addition, the highest concentration of acerola had a positive effect on nutritional characteristics. The formulation with 50% of fruit pulp (60% of cashew apple, 30% of acerola and 10% of melon), 47% of water, and 3% of added sugar achieved the best results. The effect of aroma on sweetness perception was investigated by adding identical to natural aromas of melon, apple and pineapple to the selected formulation. However, aroma did not significantly modify sweetness perception, evaluated using a rate-all-that-apply question.
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Anacardium , Malpighiaceae , Ácido Ascórbico , Comportamento do Consumidor , Frutas , Sucos de Frutas e Vegetais , Odorantes , Açúcares , PaladarRESUMO
This study evaluated the effect of different extraction technologies and conditions in order to obtain jaboticaba skin extracts. Firstly, the skins were extracted by conventional extraction, according to a rotatable central composite design, varying ethanol concentration, solid:liquid ratio, and temperature. Next, ultrasound-assisted extraction was performed using different power densities and times. Finally, high-pressure extractions were performed with varying pressures and times. For agitated bed extraction, the highest anthocyanin content was observed for ethanol concentrations varying between 60% and 80%. Thus, the independent variables which more influenced anthocyanin content were ethanol concentration and solid:liquid ratio. Folin-Ciocalteu reducing capacity was linearly affected by the increase in temperature. Ethanol concentration was the variable that most influenced ABTS+. On the other hand, the increase in ethanol concentration decreased the antioxidant capacity by ABTS+. Considering the ultrasound extraction, increasing its power did not affect total monomeric anthocyanins content, while the increase in process time had better yields. The highest antioxidant capacity and total monomeric anthocyanins were found for the highest extraction time. Similarly, with ultrasound, the increase in high hydrostatic-assisted extraction time positively influenced anthocyanin content and antioxidant capacity. As a result, the ultrasound-assisted method was found to be the best extraction technology for anthocyanins recovery.
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Tropical fruits, such as cashew apple, acerola, and melon, can be used to obtain innovative juices with high contents of bioactive compounds. Technological processes are needed to ensure the safety of products during their shelf life. However, these processes can modify the sensory properties of the juice, which have an important role in consumer acceptance. From this perspective, this study aimed to evaluate consumer perception of the sensory characteristics of tropical mixed juice based on cashew apple, acerola, and melon obtained using different processing methods during cold storage at 4° C. Microbiological aspects were monitored during refrigerated storage at 4 °C. Samples were exposed to four technological processes: control (unprocessed), pasteurization (90 °C/1 min), and high-pressure processing: HHP1 (500 MPa/5 min) and HHP2 (520 MPa/2 min). Thirty fruit juice consumers participated in the characterization of mixed juices using rate-all-that-apply (RATA) questions. Samples were analyzed at zero, 14, and 28 days of storage at 4 °C. Data were analyzed by ANOVA, and Fisher's test was used for post-hoc comparison of means and PCA. Results showed that 12 of the 22 RATA terms differed (p ≤ 0.05) regarding the mean perceived intensity, suggesting that consumers perceived differences in the sensory characteristics of the juices. The first dimension of the PCA separated the pasteurized juices from the others. Pasteurized samples were characterized by yellow color, cooked aroma, cooked flavor, off aroma, off flavor, stale aroma, and stale flavor. On the other hand, the unprocessed (control) and pressurized (HPP1 and HPP2) juices were characterized by orange color, fruit aroma, fruit flavor, sweet aroma, fresh juice, and watery consistency. Results confirmed the suitability of the sensory characterization performed by consumers using RATA and the potential of HHP to obtain juices with sensory characteristics similar to the fresh product.
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Manipulação de Alimentos , Sucos de Frutas e Vegetais , Manipulação de Alimentos/métodos , Frutas , Pasteurização , PaladarRESUMO
Active cellulose acetate films incorporated with oregano essential oil (antimicrobial film) were previously subjected to high hydrostatic pressure treatment (300 MPa/5 min (FHP1) or 400 MPa/10 min (FHP2)) and investigated for possible changes in their antimicrobial efficiency. In parallel, the efficiency of the antimicrobial films, high hydrostatic pressure (300 MPa/5 min or 400 MPa/10 min), or a combination of antimicrobial film and high hydrostatic pressure, was tested on coalho cheese, experimentally contaminated with Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus, stored for 21 days under refrigeration. Investigations in culture media (agar, brain-heart infusion broth, and micro-atmosphere) detected antimicrobial efficiency for all films, with or without high hydrostatic pressure, against the three bacteria. However, the data indicated that the treatment with 300 MPa/5 min may have impaired the migration of oregano essential oil from FHP1, justifying its lower efficiency in solid medium and brain-heart infusion broth. In cheese samples, the combination of antimicrobial film and 400 MPa/10 min caused greater reductions in counts for the three microorganisms, at zero time throughout the entire coalho cheese storage. Only antimicrobial film or combination (antimicrobial film and high hydrostatic pressure) were able to control microbial multiplication during the 21 days. Therefore, the results confirm that the individual use of high hydrostatic pressure (300 MPa/5 min or 400 MPa/10 min) at the level evaluated can allow bacterial multiplication during storage and that the combination of antimicrobial packaging and high hydrostatic pressure has greater potential to ensure a safer coalho cheese.
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Anti-Infecciosos , Queijo , Listeria monocytogenes , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Pressão HidrostáticaRESUMO
Effects of high hydrostatic pressure (HHP) processing (200-400 MPa/5 or 10 min) on functional properties of cellulose acetate (CA) films were investigated. As for mechanical properties, HHP caused a reduction in tensile strength (TS), Young's modulus (YM) and an increase in elongation at break (EB). The pressurized films were more luminous, yellowish, reddish and opaque. Less affinity for water was detected for pressurized films through analyses of contact angle and moisture absorption, in addition to reducing the water vapor transmission rate (WVTR). Scanning electron microscopy (SEM) showed the occurrence of delamination for most films, except those treated with 200 MPa/10 min and 300 MPa/10 min. All films showed a predominance of amorphous structure in X-ray diffraction analysis (XRD). That is alignment with the results of differential scanning calorimetry (DSC), which presented values for glass transition temperature (Tg), water adsorption and melting temperature characteristic of materials with low crystallinity. Films treated with HHP had better mechanical resistance during the sealing at 250 °C. In overall the results confirmed the minimal influence of HHP on the functional properties of the CA film and contributed to the scientific and technological knowledge for its potential application in foods processed by HHP.
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Specific treatments combining high temperatures of up to 150⯰C and moderate pressure of up to 0.6â¯MPa have been applied to Bacillus subtilis 168 spores conditioned at different aw levels (between 0.10 and 0.70) corresponding to different residual water contents within the spore core. The spores were treated as a dry powder in a pressurized nitrogen environment or in water/glycerol solutions. These thermodynamic conditions were intended to prevent any water evaporation from the spore core during time/temperature treatments. Our results clearly show that retaining liquid water in the core by applying pressure during the treatment resulted in greater spore destruction (between 2.4 and 4.9 log at 150⯰C, 120â¯s and aw 0.5 in powder) than the destruction observed after the treatment at atmospheric pressure (0.7 log), during which the water rapidly evaporated because its boiling point was reached. Moreover, we found that the water activity level of the spore had a significant impact on spore destruction: the higher the aw level, the greater the spore inactivation. We obtained similar results from spores heat-treated in powder and in water/glycerol solution at the same aw, confirming the strong influence of this parameter. We hypothesized that the increased spore inactivation was related to the well-known thermal sensitivity of vital organic molecules such as proteins, enzymes, and ribosomes in the presence of water.