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Light-Emitting Diodes (LEDs) and Ultraviolet Light-Emitting Diodes (UV LEDs) consist in a semiconductor of light, that are emerging in the market, due to their singular characteristics, as being a solid-state cold source of light, which has potential application in food preservation. For this reason, this study lens to provide a review of the effects of LED and UV LED application in fresh fruits and vegetables, under refrigeration storage. Analyzing the LED role, in extending the shelf-life of postharvest food, these present the capability of improving the quality physicochemical and microbiological of fruits and vegetables, such as: color (chlorophyll), weight loss, total phenolic and flavonoid content, phenylalanine ammonia-lyase activity and total soluble solids. In addition, it’s able to stop chemical reactions and increasing the activity of fruits and vegetable defenses. UV LED light, on the other hand, operates in an effective and straightway in the inactivation the food pathogens, such as Escherichia coli, Pseudomonas fluorescens and Salmonella spp, for example. Therefore, UV LED light can be applied to delay the senescence of foods, however, the wavelength must match the target organism, depending on the food.

A mathematical model for a co-current moving bed heat exchanger (MBHE) is presented. The bed is diluted and composed of spheres of uniform radius which are transported by a dragging fluid in plug f...

In this study, a mathematical method was applied to establish modelling selection criteria for lumped parameter analysis (LPA), in the solid phase, of a diluted co-current moving bed heat exchanger (MBHE), with isothermal walls. Simplified expressions for particle temperature errors are obtained, showing, for certain parametric ranges, excellent agreement with the exact solution results. Another remarkable result is that for a MBHE with isothermal walls and very low particle Biot numbers, the possibility of steep intraparticle temperature gradients is demonstrated. Through a scale analysis, this behavior is explained, along with the physical foundations guiding the LPA selection criteria. The differences between two basic forms of approximation in MBHE modelling, that is, the uniform particle temperature assumption (UPTA) and LPA, are characterized. Also, new contributions are provided by the determination of parametric condition for the equality between the temperatures of the fluid and the particle surface and by limiting solutions.

Due to the large amount of toxic effluents generated by the textile industry using most of synthetic dyes, natural dyes are increasingly gaining prominence, in keeping with the global trend toward prioritizing the use of cleaner technologies. However, the application of natural dyes is still restricted, mainly due to their instability in solution and poor fixation onto textile substrates. Thus, research is required to improve the performance of these dyes in order to obtain products with the characteristics desired by the industry. In this study, the potential of natural annatto dye in the dyeing of polyester (PES) fiber was analyzed and the color and stability parameters in solution were evaluated through two experiments. Initially, the stability of the natural annatto dye in solution was determined under different conditions of temperature, pH, and dye concentration and the application of this dye in conventional PES fiber dyeing was investigated. Subsequently, the influence of the use of a carrier in the dyeing of PES fiber was evaluated. The results indicated that the variables with the greatest effect on the degradation of the dye are temperature and pH. The natural annatto dye showed good interaction with the PES fiber in the conventional dyeing process, presenting good results of color yield and levels of fastness. In the dyeing processes conducted with and without a carrier, the dyeing performed in the latter provided better results, with the advantage of allowing the application of lower temperatures.

Oils are subject to several reactions that lead to physical–chemical, sensory and nutritional deterioration. This deterioration process is called rancidity or lipid oxidation, a spontaneous and irreversible phenomenon that can be delayed by the addition of antioxidants. Usually, vegetable oil producers choose to add antioxidants to the upper limit permitted by applicable law as it is not entirely clear the ideal dosages of pure or combined antioxidants designated for this purpose. In order to determine the optimum dosage of antioxidants that minimizes the impact of lipid oxidation of soybean oil bottled in PET (ethylene terephthalate) and replace the traditional antioxidant tert-Butylhydroquinone (TBHQ), an accelerated oven shelf-life test was performed. The antioxidants ascorbyl palmitate (AP), mix of tocopherols and rosemary extract (RE) were evaluated, pure and in combination, at different dosages. Most of the evaluated antioxidants delayed lipid oxidation of soybean oil, but a mixture containing AP and RE presented results of TOTOX statistically lower (higher oxidative stability) than that with TBHQ. One the other hand, regarding OSI at 120 °C, the result obtained by that mixture was statistically lower (less oxidative stability) than that obtained with TBHQ, in both evaluated dosages.

Spirulina is an excellent source of proteins, vitamins, minerals, and essential fatty acids. Due to its nutritional composition, this microalga has been commercially produced and used in a...

Food spoilage is associated with pH change. Thus, the aim of this study was to develop a pH-sensing film based on the addition of anthocyanin extracted from jaboticaba peel to a biopolymeric matrix. UV–Vis spectroscopy analysis of the anthocyanin extract was performed to detect the color change in a broad pH range (1–11). Also, the thermal properties, morphology, moisture content (MC), water solubility (WS), water vapor permeability (WVP) and release test results were examined. The applicability of the pH-sensing film as intelligent packaging was tested by monitoring milk spoilage. Results showed that the film developed has satisfactory thermal stability up to 200 °C. Also, the MC and WVP properties of the film were reduced when the anthocyanin extract was present, 11.5% and 6.5 × 10–10 g H2O Pa− 1 s−1 m−1, respectively, while the WS showed an increase (54.33%). Release tests showed remarkable performance in simulated alcoholic and fatty aqueous foods. The food application test demonstrated the potential use of the anthocyanin-based film as a food quality indicator due to film visual color change ( $$\Delta E$$ >10, after 8 days of milk spoilage monitoring).

Rice stands out as the most consumed cereal in the world because it is a source of vitamins, minerals, fiber, bioactive compounds, and unsaturated fatty acids. Based on this assumption, the objective of this work was to qualify and quantify fatty acids, in samples consisting of raw, integral, parboiled, and white rice marketed in southern Brazil (Vale do Itajaí) and the Vale do Pó region in northern Italy. The results of this work demonstrate that 95% of the total lipid content, in the respective rice typologies of both countries, is represented by palmitic, oleic, and linoleic acid. These results indicate that the technological processes influence the nutritional and functional quality of the rice grain in these countries. Regarding the content of total polyphenols, the maximum average value obtained was 477 g Eq g-1 for rice from both countries and the best results for antioxidant activity, using the Photoquem® method with methanolic extract, was 3.43 µM Eq Trolox g-1 for the Italian rice samples. These results indicate that the technological processes influence the nutritional and functional quality of rice grain from these countries.

Although the skin effect has been widely studied over the years, many of its topics remain unclear for most electrical engineers, including undergraduate students and fresh graduates. Yet, in the cases of application of power frequency current, the knowledge gap to be bridged is more significant. Thus, for contributing to the widening in the knowledge of this effect, this work presents an analysis of the behavior of the current density distribution over the cross-section of differently combined rectangular conductors subject to power frequency current. In this case, since an analytical approach is not feasible, the numerical method of matrix solution of integral equations was adopted due to its simplicity, fast convergence, and its application is presented through some providentially chosen theoretical examples before a practical case may be analyzed. As the main results, the influence of a correlated effect that is the proximity effect shows itself as being predominant and the method presents itself as being very convenient for studying the current density distribution in conductors with a cross-section other than the circular, which allow bridging the knowledge gap in this theme. Moreover, the comparison of theoretical cases quite significant. Moreover, the method is adequate to planar configurations, by typical configurations, as in the case of bus bars of electrical panels.

This study aimed to evaluate the physical-chemical characteristics and the viability of lactic acid bacteria during the fermentation process of the yogurt and after the freeze-dried process, in addition to testing three thickener formulations for the rehydration of the yogurt powder. During the fermentation process, the production of lactic acid and the growth of lactic acid bacteria were accompanied. Before and after freeze-dried process, yogurt was analyzed for pH, titratable acidity, carbohydrates, proteins, lipids and viable lactic acid bacteria. After lyophilization, three thickener formulations were tested to evaluate the rehydration of powdered yogurt. At the end of the fermentation process, it was verified that the lactic acid bacteria grew to reach 7.8.107 UFC.g-1 and the acidity obtained was 9.27 g.L-1. The viable lactic acid bacteria count of freeze-dried and non-freeze-dried yogurt was 5.6.107 CFU.g-1 and 7.8.107 CFU.g-1, respectively. Non-freeze-dried and freeze-dried yogurts showed a content of 20.8% and 21.0% carbohydrates, 4.0% and 3.6% protein and 3.7% and 2.7% lipids, respectively. The combination of thickeners that provided viscosity similar to commercial yogurts was the guar gum, pectin and maltodextrin mix. Thus, it was possible to verify that the freeze-drying process maintains the physical-chemical characteristics and viability of lactic acid bacteria. In addition, the developed yogurt presented easy reconstitution at the time of consumption. Este trabajo tuvo como objetivo evaluar las características físico-químicas y la viabilidad de las bacterias del ácido láctico durante el proceso de fermentación del yogur y después de su liofilización, así como probar tres formulaciones de espesantes para la rehidratación del yogurt en polvo. A lo largo del proceso de fermentación, se monitoreó la producción de ácido láctico y el crecimiento de las bacterias. Después de la liofilización, se probaron tres formulaciones de espesante para evaluar la rehidratación del yogur en polvo. Antes y después de la liofilización, se analizó el pH del yogur, la acidez titulable, carbohidratos, proteínas, lípidos y bacterias viables del ácido láctico. También se evaluaron, después de la liofilización, tres formulaciones espesantes para rehidratar yogur en polvo. Al final del proceso de fermentación se verificó que las bacterias lácticas crecieron hasta alcanzar 7,8,107 UFC.g-1 y la acidez obtenida fue de 9,27 g.L-1. El recuento de las bacterias del ácido láctico viables del yogur liofilizado y no liofilizado fue de 5,6,107 UFC.g-1 y 7,8,107 UFC.g-1, respectivamente. Los yogures no liofilizados y liofilizados tenían un contenido de 20.8% y 21.0% de carbohidratos, 4.0% y 3.6% de proteínas y 3.7% y 2.7% de lípidos, respectivamente. La combinación de espesante que proporcionó una viscosidad similar la yogur comercial fue la mezcla de goma guar, pectina y maltodextrina. Por lo tanto, fue posible verificar que el proceso de liofilización mantiene las características fisico-químicas y las bacterias lácticas viables. Además, el yogur desarrollado presentó una fácil reconstitución en el momento del consumo. Este trabalho teve por objetivo avaliar as características físico-químicas e a viabilidade de bactérias lácticas durante o processo fermentativo de iogurte e após a sua liofilização, bem como testar três formulações de espessantes para a reidratação do iogurte em pó. Ao longo do processo fermentativo, foi acompanhada a produção de ácido láctico e o crescimento de bactérias lácticas. Antes e após a liofilização o iogurte foi analisado em relação ao pH, acidez titulável, teor de carboidratos, proteínas, lipídios e bactérias lácticas viáveis. Após liofilização, foram testadas três formulações de espessantes para avaliar a reidratação do iogurte em pó. Ao término do processo fermentativo foi verificado que as bactérias lácticas cresceram até atingir 7,8.107 UFC.g-1 e a acidez obtida foi de 9,27 g.L-1. A contagem de bactérias lácticas viáveis de iogurte liofilizado e não-liofilizado foi de 5,6.107 UFC.g-1 e 7,8.107 UFC.g-1, respectivamente. Os iogurtes não liofilizados e liofilizados apresentaram um teor de 20,8% e 21,0% de carboidratos, 4,0% e 3,6% de proteínas e 3,7% e 2,7% de lipídios, respectivamente. A combinação de espessantes que proporcionou viscosidade semelhante ao iogurte comercial foi o mix de goma guar, pectina e maltodextrina. Assim, foi possível verificar que o processo de liofilização manteve as características físico-químicas e a viabilidade de bactérias ácido lácticas. Além disso, o iogurte desenvolvido apresentou fácil reconstituição no momento do consumo.

Refrigeration and coating of active biopolymers are two potential approaches to extending the shelf life of fresh fruits. Thus, the aim of this study was to test the influence of storage temperature (5 and 10 °C ± 1 °C) and whey concentration (edible coating), on functional, physical-chemical, and microbiological characteristics of acerola stored for 12 days. Edible coatings were produced using whey (30% and 60%) and glycerol. Samples were compared to a control (no coating), during storage at both temperatures. Storage at 10 °C improved the maintenance of the acerola color, while storage at 5 °C increased the stability of vitamin C and decreased microbial growth (p ≤0.05). The application of edible coating reduced the total color variation and degradation (a*) at both temperatures. The concentration of whey influenced significantly (p≤0.05) on the vitamin C content (A10-60), and on the mesophilic (A5-60 and A10-60) and psychrotrophic bacteria (A10-60) counts.

Since the 19th century, when European immigrants colonised the Itajai Valley region (Santa Catarina/Brazil), Kochkase (cooked cheese) has been one of the traditional products of the area. The process standardised quality and reproducibility of this cheese follow artisanal practices and, despite having a specific Technical Regulation, stimulus is needed for its production within an organised sector. Scientific interventions have been taking place at the Regional University of Blumenau to guide assurance of quality, defining process parameters and good practices at all stages of the productive chain of Kochkase. As support for the appreciation, consolidation and recognition of this product, this review focuses on the establishment of a scientific knowledge base that could be used for further application. Issues related to chemistry, biochemistry, microbiology, quality attributes, legislation, preparation method and storage were considered, to identify challenges associated with achieving improvements proposals in production and marketing, as well as future opportunities.

Oxidative stability and fatty acid composition of the pumpkin seed oil (PSO) were studied, during roasting process from 80 to 150 °C and oil heat treatment (220 ˚C), by FTIR (Fourier - transform infrared) – Spectroscopy and GC/MS (Gas chromatography - mass spectrometry). The physicochemical parameters (density and iodine value) showed a significant increase (p < 0.05) during roasting, with a maximum value observed in the oil roasted at temperatures from 90 to 110 ˚C. The relative contents of polyunsaturated fatty acids (PUFAs) decreased to 87.7%, and saturated fatty acids (SFAs) increased to 112.5% at unroasted sample, after thermal treatment of oil samples. Especially at temperature 90 and 110 ˚C, oil samples have demonstrated that relative contents of PUFAs decreased to 95 % and SFAs increased to 101.6%. FTIR Spectroscopy provide to understand mechanism of chemical changes of seed during roasting process and, as result, which of obtained compounds are responsible for increasing thermal stability of oil lipids. In this study, it was observed that the best temperature for roasting pumpkin seeds is 110 ˚C, since at this point, both oxidation and Maillard reactions give rise to compounds with maximum antioxidant effect (lipid stability).

Strawberry (Fragaria spp.) is a non-climacteric fruit, widely consumed in several countries, but is extremely sensitive and susceptible to mechanical damage during harvest, transport, and storage, reducing the shelf life. In order to prolong the shelf life of this product, edible starch-based coatings were developed, with propolis extract (MSP) and without the addition of ethanolic propolis extract (MS) and uncoated samples, used as control (MC). All samples were stored under isothermal conditions (4 °C ± 0.5 °C), for 10 days. Physicochemical analyzes (pH, mass variation, vitamin C, color, and phenolic compounds) were carried out to characterize and identify the coating efficiency in the conservation of strawberries. The formulations of the coatings with and without the addition of propolis had a significant (p ≤ 0.05) effect on the variation of fruit weight. The propolis coating showed greater stability in the vitamin C content and pH levels, up to the 10th day of cold storage, in comparison to the samples with starch coating and the control. The treatments (MS, MSP, and MC) did not significantly influence (p > 0.05) the color and the content of total polyphenols.

There has been an increasing debate about the use of synthetic chemical compounds and the consequences of their use in food preservation. In this context, the utilization of some natural compounds produced by bacteria, showing an inhibitory effect against microorganisms associated with food contamination, have gained attention as preservation technology. In order to improve the production and yield costs of bacteriocins, detailed studies are necessary to determine the conditions that allow an optimized production and extraction of bacteriocins from lactic acid bacteria (LAB). In this context, this article aims to discuss the information regarding the main factors that influence bacteriocin production by LAB. The biosynthesis of bacteriocins can be influenced by various culture conditions, such as the composition of the medium, pH, temperature and growth kinetics of the microorganisms. One of the limiting factors for the use of bacteriocins on a large scale in food preservation is the economic factor. In order for the production costs of bacteriocins to be reduced, making them attractive, it is necessary to know the optimum parameters of production, thus maximizing productivity and making costs more attractive.

Considering the increasing of shelf life of leafy vegetables, the most important factor to keep the quality is the rapid cooling. The lettuce packaging under refrigeration and specific relative humidity just after harvest provides decreased breathing by water loss, which affects addition to weight, appearance, flavor and texture. This study aimed to investigate the effect of temperature and relative humidity in the appearance global of refrigerated curly lettuce and stored in PET crystal surrounded by PVC packaging for 14days. The samples were stored in incubator chamber (B.O.D.), simulating domestic refrigeration conditions at 4°C and a relative humidity of 74%. The package acted as a barrier, slowing food degradation caused by microorganisms and physicochemical changes resulting from the metabolism and external factors. For the sensory analysis we used a hedonic scale unstructured nine points.

The main phenomena involved in the food refrigeration process are heat and mass transfer. In this context, the aim of this study was to evaluate the influence of refrigeration system parameters on food quality during postharvest storage. Experiments were conducted where the mean air temperature, air temperature fluctuation, air velocity, thermal oscillation period and humidity ratio were controlled, to quantify the food mass transfer, cooling rates and sensorial acceptance. The food sample under evaluation was lettuce packed in perforated polyethylene bags. A standardized test (IEC 63169:2020) was performed under the same experimental conditions for comparison. Food cooling rate was influenced by air velocity and a gradual increase (0.1–1.1 °C) in food temperature was observed during storage. A temperature increase from 3.0 to 7.0 °C, raised the mass loss of the food by 8.8%, which was directly influenced by the driving force provided by the humidity. Higher temperature fluctuations led to negative results in the sensorial analysis, with less freshness and higher consumption rejection.

Desenvolvimento e características nutricionais do biscoito com bagaço de malte Weizen e canela Um dos resíduos gerados na produção de cerveja é o bagaço de malte de cevada. Quando descartado incorretamente, causa danos ao meio ambiente. No entanto, bagaço de malte tem uma grande quantidade de fibras e proteínas em sua composição, tornando este resíduo grande potencial para uso em assados, como pães e biscoitos. O uso de bagaço no preparação de biscoitos, considerando sua composição físico-química, contribui para seu valor nutricional e funcional. Este estudo teve como objetivo analisar os aspectos nutricionais e características funcionais do biscoito com adição de bagaço de malte Weizen. A tabela nutricional prova que o biscoito é rico em fibras e proteínas e recomendado. O biscoito apresentou 7,75% de proteína por 100g e tem 0,28mg/kg de polifenóis, realizando ação antioxidante.

In this study, a mathematical method was developed and applied to an existing analytical solution of a model for heat transfer in a co-current diluted moving bed, making it possible to determine criteria for selecting the lumped parameter analysis. This procedure differs from those previously reported, which generally follow an empirical approach or are based on very simplified models of the physics associated with moving beds. In developing the criteria, conditions for the lumped parameter analysis are obtained and error expressions are determined. A comparison between criteria described in the literature and those proposed herein is presented and the results enable a rational understanding of the existing criteria. The mathematical method is very general and could be applied to other problems in the fields of engineering and physics.

This article presents a review of the scientific literature on the nutritional value of topinambur (Jerusalem artichoke) and its potential use in the formulation of food products. The scientific review covers the chemical, amino-acid, vitamin, mineral composition of topinambur, its pharmacological and therapeutic and prophylactic effect on the human organism. The distinctive features of topinambur are the content of more than 20% of dry substances, among which up to 80% contains a polymeric homologue of fructose - inulin. The content of pectin substances varies up to 11% of dry weight. Consumption of topinambur as a part of foodstuffs has a beneficial effect on absolutely all the chains and causes of diseases of the digestive system, cardiovascular system and liver. A number of findings about the use of topinambur roots in the process of preparation of meat, milk, confectionary and bread products are presented, its positive effect on the nutritional value and consumer properties of the final product is characterized. Utilization of Jerusalem artichoke in formulation of various food products is a good way to increase the alternative usage area of them.

Kochkase is a cheese traditionally produced from raw milk. The use of raw milk is preferred by consumers, but presents some safety concerns. This study investigated the microbial growth during the ripening stage of kochkase, made from raw and pasteurised milk, at different temperatures (15, 25 and 35 °C). The growth of lactic acid bacteria, aerobic mesophilic bacteria and yeasts and moulds was analysed and predicted according to the Baranyi and Roberts model. Ripening at 15 °C maximised the ratio between the growth of desirable (lactic acid bacteria) and undesirable groups of microorganisms. Finally, the cooking step reduced the microbial count for both cheeses made, improving safety. The results represent an important step toward better understanding properties and safety aspects of kochkase, and they indicate that the effect of the cooking process can be similar to that of pasteurisation, ensuring product safety when good manufacturing practices are adopted.

Strawberry is a non-climacteric pseudofruit that has a short shelf life after harvest. Among the factors responsible for the strawberries quality loss are the high metabolic activity and high susceptibility to microbial attack, mainly by fungi. The objective of this work is to study physicochemical parameters of strawberries (Fragaria vesca L.) submitted to different cooling system conditions. Strawberries were stored at temperatures of 2 °C and 6 °C with a range of ±1 °C and packed in polyethylene terephthalate (PET) trays wrapped by polyvinyl chloride (PVC) film. Samples were evaluated for their physicochemical aspects, such as: mass variation, vitamin C content and total polyphenols. The assays were done in triplicate. The results show that storage at 6 °C ±1 °C is better to maintain the strawberries quality stored during 6 days, because under these conditions a lower mass variation was obtained. These parameters are associated with low moisture loss, which also assists in the preservation of polyphenols. And storage at 2 °C ±1 °C favored the maintenance of total polyphenols and Vitamin C. With this information it is possible to optimize technologies for this type of food with focus on reducing the environmental impact and waste of food and drinking water, supporting research developed in multinational refrigeration area.

Lipid oxidation is responsible for physicochemical and organoleptic changes which reduce not only the food shelf life but also its acceptability. However, this deterioration process can be delayed or prevented by the addition of antioxidants. The aim of this study was to evaluate the effect of different antioxidants, pure and in combination (ascorbyl palmitate, rosemary extract and mix of tocopherols) compared to TBHQ (tert-butylhydroquinone) on oxidative stability index (OSI) of soybean oil stored in PET bottles by Rancimat at 120°C. The rancimat method is included in the AOCS Cd 12b-92 standard, due to the ease of use and reproducibility that allows the OSI evaluation in a relatively short period. Therefore, an accelerated shelf life study was performed at 60°C for 30 days. The results showed that all evaluated antioxidants and their combinations delayed the lipid oxidation of soybean oil. However, a mix containing ascorbyl palmitate and rosemary extract presented OSI (Oxidative Stability Index) similar to TBHQ. At the end of the 30th day, this referred blend of antioxidants had OSI of 4.83 hours at 120 °C, while treatment with TBHQ showed 5.90 hours at the same temperature. Thus, it was concluded that the evaluated concentration of the ascorbyl palmitate and rosemary extract blend may be an excellent alternative to TBHQ during the maintenance of the soybean oil shelf life in PET bottles.