Non-invasive quantification of vitamin C, citric acid, and sugar in 'Valência' oranges using infrared spectroscopies.

Near (NIR) and mid (MIR) infrared spectroscopies have been studied as potential methods for non-destructive analyses of the fresh fruits quality. In this study, vitamin C, citric acid, total and reducing sugar content in 'Valência' oranges were evaluated using NIR and MIR spectroscopy with multivariate analysis. The spectral data were used to build up prediction models based on PLS (Partial Least Squares) regression. For vitamin C and citric acid, both NIR (r = 0.72 and 0.77, respectively) and MIR (0.81 and 0.91, respectively) resulted in feasible models. For sugars determination the two techniques presented a strong correlation between the reference values and analytical signals, with low RMSEP and r > 0.70 (NIR: sucrose RMSEP = 12.2 and r = 0.75; glucose RMSEP = 6.77 and r = 0.82; fructose RMSEP = 5.07 and r = 0.81; total sugar RMSEP = 12.1 and r = 0.80; reducing sugar RMSEP = 20.32 and r = 0.82; MIR: sucrose RMSEP = 9.47 and r = 0.80; glucose RMSEP = 6.70 and r = 0.82; fructose RMSEP = 5.20 and r = 0.81; total sugar RMSEP = 11.72 and r = 0.81; reducing sugar RMSEP = 20.42 and r = 0.81). The models developed with MIR presented lower prediction error rates than those made with NIR. Therefore, infrared techniques show applicability to determine of orange quality parameters in a non-destructive way.

Cytotoxic and genotoxic effects of silver nanoparticle/carboxymethyl cellulose on Allium cepa.

Several mutagenic agents may be present in substances released in the environment, which may cause serious environmental impacts. Among these substances, there is a special concern regarding the widespread use of silver nanoparticles (AgNP) in several products due to their widely known bactericidal properties, including in the medical field and the food industry (e.g., active packaging). The assessment of the effects of AgNP released in the environment, having different concentrations, sizes, and being associated or not to other types of materials, including polymers, is therefore essential. In this research, the objective was to evaluate the genotoxic and cytotoxic effects of AgNP (size range between 2 and 8 nm) on root meristematic cells of Allium cepa (A. cepa). Tests were carried out in the presence of colloidal solution of AgNP and AgNP mixed with carboxymethylcellulose (CMC), using distinct concentrations of AgNP. As a result, when compared to control samples, AgNP induced a mitotic index decrease and an increase of chromosomal aberration number for two studied concentrations. When AgNP was in the presence of CMC, no cytotoxic potential was verified, but only the genotoxic potential for AgNP dispersion having concentration of 12.4 ppm.

Antimicrobial potential of linear low-density polyethylene food packaging with Ag nanoparticles in different carriers (Silica and Hydroxyapatite).

Silver nanoparticles incorporation into polymeric packaging aims to prevent microbiological contamination in food products, thus ensuring superior food safety and preservation. In this context, this study aimed to verify the antimicrobial efficacy of linear low-density polyethylene (LLDPE) films incorporated with silver nanoparticles (AgNPs) dispersed in silica (SiO2) and hydroxyapatite (HAP) carriers at different concentrations. AgNPs + carriers polymer films were characterized at 0.2, 0.4, and 0.6% concentrations using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission gun-scanning electron microscope (FEG-SEM), thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), and migration in acidic and non-acidic simulants. Antimicrobial action was investigated on Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and the Penicillium expansum and Fusarium solani fungi with antimicrobial activity by direct contact test and bacterial imaging by scanning electron microscopy. AgNPs addition to the LLDPE matrix did not interfere with the films' chemical and thermal properties and presented no significant migration to the external medium. For antimicrobial action, silver nanoparticles showed, in most concentrations, an inhibition percentage higher than 90% on all microorganisms studied, regardless of the carrier. However, a greater inhibitory action on S. aureus and between carriers was found, making hydroxyapatite more effective. The results indicated that nanostructured films with AgNPs + hydroxyapatite showed more promising antimicrobial action on microorganisms than AgNPs + silica, making hydroxyapatite with silver nanoparticle potentially useful in food packaging, improving safety and maintaining quality.

Recent advances in the development of smart, active, and bioactive biodegradable biopolymer-based films containing betalains.

Betalains are natural nitrogenous water-soluble pigments found in species belonging to the Caryophyllales order and in mushrooms. Betalains can be considered multifunctional molecules due to their diverse bioactivities such as antioxidant, antimicrobial, anticancer, and anti-inflammatory. Furthermore, they can detect pH variations in foods and are considered promising colorimetric bioindicators. The bioactivities of betalains have improved their use as active and bioactive agents, and colorimetric indicators in the development of edible and biodegradable films for foods, which are trends in the food packaging market. Thus, this review presents the state-of-art information on the use of betalains as a multifunctional molecule in the development of smart, active, and bioactive edible and biodegradable packaging for foods. Studies have revealed that betalains can be successfully used to develop: smart films to indicate the freshness and spoilage of foods such as shrimp, fish, and chicken; active films with antimicrobial and antioxidant potentials to increase the shelf life of sausage and shrimp; and bioactive films with health benefits.

Bio-nanocomposite edible coatings based on arrowroot starch/cellulose nanocrystals/carnauba wax nanoemulsion containing essential oils to preserve quality and improve shelf life of strawberry.

This study investigated the effects of bio-nanocomposite coatings developed using arrowroot starch (AA), cellulose nanocrystals (CNC), carnauba wax nanoemulsion (CWN), and Cymbopogon martinii and Mentha spicata essential oils (CEO and MEO, respectively) on the physicochemical, microbiological, bioactive, antioxidant, and aromatic characteristics of strawberries cv. 'Oso Grande' in refrigerated storage for 12 days. The coatings improved the shelf life and stability of strawberries, minimizing their weight loss (2.6-3.9 %), as well as changes in color and texture (except for those coated with CEO), titratable acidity, pH, soluble solids, anthocyanins, phenolic compounds, ascorbic acid content, and antioxidant activity compared with uncoated control strawberries. The bio-nanocomposite coatings containing MEO and CEO also exhibited antimicrobial activity, reduced visible fungal deterioration (40-60 %), and reduced microbial load (3.59-4.03 log CFU g-1 for mesophilic aerobic bacteria and 4.45-5.22 log CFU g-1 for fungi and yeast) during storage. They also significantly reduced the severity of decay caused by inoculation with Botrytis cinerea or Rhizopus stolonifer. The coatings altered the volatile profile of the fruits during storage, decreasing aldehyde and alcohol concentrations and increasing ester concentrations. Thus, these bio-nanocomposite coatings, especially those containing MEO, can be used as antimicrobial coating materials to preserve the post-harvest quality of fresh strawberries.

Nanoemulsions as Edible Coatings: A Potential Strategy for Fresh Fruits and Vegetables Preservation.

Fresh fruits and vegetables are perishable commodities requiring technologies to extend their postharvest shelf life. Edible coatings have been used as a strategy to preserve fresh fruits and vegetables in addition to cold storage and/or controlled atmosphere. In recent years, nanotechnology has emerged as a new strategy for improving coating properties. Coatings based on plant-source nanoemulsions in general have a better water barrier, and better mechanical, optical, and microstructural properties in comparison with coatings based on conventional emulsions. When antimicrobial and antioxidant compounds are incorporated into the coatings, nanocoatings enable the gradual and controlled release of those compounds over the food storage period better than conventional emulsions, hence increasing their bioactivity, extending shelf life, and improving nutritional produce quality. The main goal of this review is to update the available information on the use of nanoemulsions as coatings for preserving fresh fruits and vegetables, pointing to a prospective view and future applications.

Effects of silver nanoparticles prenatal exposure on rat offspring development.

Many types of nanocomposites employed in food packaging are based on silver nanoparticles (AgNP) because of their antibacterial properties, which can increase food shelf-life. As the commercialization of AgNP products has been expanding, the released of such nanoparticles in the environment has caused enormous concern, once they can pose potential risks to the environment and human beings. For instance, exposure of the maternal environment to nanomaterials during pregnancy may impact the health of the dam, fetus and offspring. In this context, here we investigated the effects of prenatal exposure of AgNP on the pregnancy outcomes of dams and postnatal development of their offspring. Pregnant Wistar rats were exposed to distinct AgNP concentrations (0, 1, 3 and 5 µg/kg/day) from beginning to the end of pregnancy. At parturition, newborns were observed regarding clinical signs of toxicity and survival rate. The offspring was examined by evaluating developmental endpoints. A delay in time for vaginal opening and testes descent were detected in the offspring exposed to AgNP during embryonic development. Our results indicate that prenatal exposure to AgNP can compromise neonatal rats' postnatal development, especially the reproductive features.

Real time measurement system based on wireless instrumented sphere.

In this work, we developed a new measurement system which includes a Wireless Instrumented Sphere (WIS) and a Graphical User Interface (GUI) software, called Real Time Analysis (RTA). This system is able to acquire, process and visualize the three axis acceleration of the WIS allowing the identification and measurements of rotations, vibrations and impacts in real time. The aim of this instrument is to help the fruit producers to reduce food wasting and improve quality, especially in Brazil, one of the major agricultural countries in the world, whose losses could surpass 20% along the post-harvesting handling chain. Additionally, a data Post Processing Analysis software (PPA) provided of a video synchronization option was developed to determine the impact magnitude, position and even the cause of the impact itself (drop, fruit-to-sphere impact, etc.). Both GUIs presented graphics of the three axis acceleration vectors, acceleration magnitude and velocity, as well as the calculations of the number of impacts (peak detection), maximum, minimum and average impact magnitude. The WIS board was encapsulated in the middle of a spherical transparent polyurethane elastomer. It was also intended to be a small, simple, robust and low cost instrument. Its final diameter of approximately 63 mm, 160 g weight and 1.1 relative density. The RTA reduces the time for testing and is suitable for a fast feedback and allows the user to make adjustments in the experiment setup, packing system or even monitor any process along the post-harvesting handling chain, with an immediate response. The PPA with video synchronization option, proved to be a unique tool, relating the acceleration information with the video position.

Turgescência de crisântemos após a colheita utilizando o equipamento Wiltmeter® / Postharvest turgidity of chrysanthemums using the equipment Wiltmeter®

O objetivo deste trabalho foi determinar a qualidade e mensurar a turgescência em hastes florais de crisântemos armazenadas em água potável e água destilada, utilizando o método de teor relativo de água (TRA) e o equipamento Wiltmeter® para determinação da pressão de turgescência. As hastes foram colhidas em um campo comercial de flores e acondicionadas ao acaso unitariamente em recipientes contendo água destilada ou água potável. Para acompanhar a condição hídrica das hastes, foram realizadas avaliações da variação da massa fresca, taxa de absorção de água, taxa de transpiração de água, teor relativo de água e pressão de turgescência. Os dados foram submetidos à análise de variância pelo teste F e as médias comparadas ao longo dos dias de vida de vaso, utilizando-se o teste de Tukey a 5 por cento de significância. Para comparação do TRA e a pressão de turgescência, foi calculado o coeficiente de correlação de Pearson. As hastes mantidas em água potável obtiveram melhor resultado na manutenção da turgescência. Há correlação entre as avaliações de pressão de turgescência e o teor relativo de água, que se mantêm mais altas à medida que os tecidos vegetais estão novos e bem hidratados. A estimativa da pressão de turgescência foi eficiente e sensível na avaliação da condição hídrica dos tecidos das hastes de crisântemos cortados.

The main goal of this research was to determine the quality by measuring turgor in flowers stems of chrysanthemums stored in tap water and on distilled water, using the method of relative water content (RWC) and the equipment Wiltmeter®. The flower stems were harvested in a commercial field and placed randomly into unitary containers containing distilled water or tap water. In order to monitor the water status of the stems the follow analyses were done: variation of fresh mass, water absorption rate, water transpiration rate, relative water content and turgor pressure. Data were subjected to analysis of variance by F test, means were compared through the days of vase life, using Tukey test at 5 percent significance level. For comparison of the RWC and the turgor pressure the Pearson correlation coefficient was calculated. Flower stems kept in tap water maintained turgor significantly better than the ones maintained on distilled water. There is a correlation between turgor pressure and relative water content, which remain higher as the plant tissues are new and well hydrated. The estimate of the turgor pressure was effective and sensitive in evaluating the water status of the tissues of the stems of cut chrysanthemums.

Qualidade pós-colheita de caqui 'fuyu' com utilização de diferentes concentrações de cobertura comestível / Postharvest quality of 'fuyu' persimmon using different concentrations of edible coatings

Ao aplicar cera em frutas, tem-se o objetivo de criar uma película de proteção com a função de reduzir a perda de massa por evaporação e transpiração, e ainda diminuir a possibilidade de contaminação dos frutos por agentes causadores de podridão, melhorando assim o aspecto visual do produto. Dessa forma, é possível aumentar o tempo de conservação, diminuindo consequentemente os prejuízos por perdas na pós-colheita. O caqui é uma fruta muito apreciada, com alto potencial de exportação, porém sensível ao manuseio e armazenamento. Objetivou-se, neste trabalho, avaliar o efeito da aplicação da cera comestível Megh Wax ECF-124 (18 por cento de ativos, composta por emulsão de cera de carnaúba, tensoativo aniônico, preservante e água), produzida por Megh Indústria e Comércio Ltda em três diferentes concentrações (25, 50 e 100 por cento), na qualidade pós-colheita do caqui 'Fuyu' armazenado por 14 dias. Os atributos avaliados para qualidade foram: firmeza, pH, acidez titulável, sólidos solúveis, perda de massa e coloração. Os resultados demonstraram que a aplicação da cera nas diferentes concentrações foi efetiva, principalmente na conservação da massa do caqui cv. Fuyu e manutenção da coloração externa. A aplicação de cera não causou diferenças significativas nas propriedades químicas avaliadas. O tratamento na concentração de 25 por cento apresentou menor índice de descarte durante armazenamento, todavia maiores concentrações demonstraram menores valores de perda de massa. Aplicação de cera de carnaúba em caqui apresenta um grande potencial de uso para melhoria na conservação pós-colheita, podendo ser aplicado juntamente com outras tecnologias, auxiliando na manutenção da qualidade para exportação.

One of the main objectives of applying edible coatings on fruits surface is to create a protective film to reduce weight loss due to evaporation and transpiration and also to decrease the risk of fruit rot caused by environmental contamination, in order to improve the visual aspect. Therefore, it is possible to increase shelf life, and decrease post harvest losses. Persimmon is a much appreciated fruit, with high potential for export, but sensitive to handling and storage. This study aimed to evaluate the effect of applying the edible coating Megh Wax ECF-124 (18 percent of active composts, consisting of emulsion of carnauba wax, anionic surfactant, preservative and water) produced by Megh Industry and Commerce Ltda in three different concentrations (25, 50 and 100 percent) on post harvest quality of 'Fuyu' persimmon stored for 14 days. The attributes evaluated for quality were: firmness, pH, acidity, soluble solids, weight loss and color. The results showed that application of carnauba wax in different concentrations was effective on decreasing weight loss of persimmon cv. Fuyu and maintenance of color aspects. Treatment at lower concentration, 25 percent, showed lower rate of discharge, but high concentrations showed lower values of mass loss. Carnauba wax application showed a high potential for use on postharvest conservation, and can be applied together with other technologies, helping to maintain quality for export.

Eficácia de limpeza durante o beneficiamento do tomate de mesa / Effectiveness of cleaning fresh market tomatoes during post harvest handling

Neste trabalho avaliou-se a limpeza do tomate de mesa 'Débora' em relação à eficácia na qualidade dos frutos. Primeiramente, estudou-se a eficácia, com auxílio de esferas de borracha, variando-se as cerdas (náilon, sisal, PET e fibra de coco) e a rotação (40, 80, 120 e 160rpm) das escovas. Depois, com os melhores resultados, foram avaliadas a eficácia da limpeza em tomates e a qualidade pós-colheita dos frutos mensurada pela perda de massa ( por cento), atividade respiratória (CO2) e evolução da concentração de etileno. No primeiro ensaio, as cerdas de náilon, sisal e fibra de coco combinadas com as altas rotações tornaram a limpeza mais eficaz. A cerda PET e a rotação de 40rpm foram ineficientes, apresentando um índice de limpeza (IL) inferior a 50 por cento. Para os tomates, o tratamento com náilon a 120rpm foi o mais eficaz na limpeza (IL=91 por cento); todavia, o tratamento com náilon 160rpm apresentou um IL inferior (88 por cento), pois, devido à alta velocidade, os frutos pulavam e não eram envoltos pelas cerdas. Menores IL foram obtidos com fibra de coco a 80 e 120rpm, mas não estatisticamente diferentes. De modo geral, frutos limpos com náilon e sisal a 120rpm apresentaram as maiores alterações na qualidade pós-colheita quando comparados aos frutos limpos nessas mesmas cerdas a 160rpm. Maior flexibilidade das cerdas proporciona maior contato fruto/cerdas, com melhoria na eficiência de limpeza, o que pode provocar alterações na qualidade pós-colheita do fruto, porém não significativas.

This research evaluated the cleaning process of fresh market tomatoes Débora in relation to the efficiency cleaning and fruit quality. First, the efficiency cleaning was carried, with rubber spheres, changing the types of bristles (nylon, sisal fiber, PET and coconut fiber) as well as the rotation (40, 80, 120 and 160rpm) of rotary brushes. Afterwards, with the best results, the studies were carried out with fresh market tomatoes to evaluate cleaning efficiency and fruit quality measured by weight loss ( percent), respiratory activity (CO2) and ethylene evolution. In the first case, the nylon and sisal fiber were more efficient at higher rotations. PET bristles at 40rpm rotation were inefficient, presenting a cleaning index (CI) lower than 50 percent. The nylon brush treatment at 120rpm was the most efficient cleaning process (CI=91 percent). However, nylon brushes at 160rpm treatment showed the lowest CI (88 percent). These results were probably associated to the fact that, at higher speeds, fruits tended to jump, causing a poor contact between bristles and fruits. The lowest CI was observed on coconut fiber at 80 and 120rpm treatments. In general, cleaned fruits with nylon and sisal fiber at 120rpm demonstrated higher post-harvest quality alterations when compared to cleaned fruits in these brushes at 160rpm. More bristles flexibility provides better contact fruit/bristles increasing cleaning efficiency, however, it can cause changes on post-harvest fruit quality, but no significant.

Superfícies protetoras na diminuição de danos mecânicos em tomate de mesa / Protective surfaces for reduction of mechanical damages on fresh market tomatoes

A perda de qualidade do tomate está relacionada muitas vezes a danos mecânicos que ocorrem desde a colheita até o consumidor, quando os frutos são submetidos a quedas em superfícies não-protegidas ou colidem com outros frutos. O objetivo deste trabalho foi avaliar diferentes superfícies e três alturas de queda com relação à magnitude de impacto e à influência na qualidade do tomate de mesa. Para mensurar a magnitude de impacto, utilizou-se a esfera instrumentada. Já a qualidade dos frutos foi avaliada por meio da análise dos danos internos. Para isso, utilizaram-se três superfícies que apresentaram níveis diferentes de impacto combinadas às três alturas de queda. Como resultado, observou-se que as superfícies emborrachadas, por apresentarem uma maior elasticidade, combinadas a menores alturas de queda, demonstram uma maior absorção do impacto e conseqüentemente menor incidência de danos mecânicos.

Quality losses of fresh market fruit are often related to mechanical damages that occur from harvest thru final consumer. Those damages normally occur when fruits drop from high heights or collide against not protected surfaces or against other fruits. The main goal of this work was to evaluate in laboratory for impact magnitude and tomato quality different surfaces in three drop heights. For measuring impact magnitude it was used the instrumented sphere and for tomato quality the evaluation was based on internal bruising. Fruit drop tests were done using three protective surfaces that showed different levels of maximum acceleration combined with three different heights. It was concluded that the use of determined protective surfaces rubber plate, under low drop high can decrease internal bruising incidence and impact magnitude on packing lines.