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This paper discusses the design, development and construction of a low cost system to measure plant-based bioactive compounds. The proposed system uses a light emitting diode (LED), an optical filter, a cuvette holder, a photodiode, an electronic board and a mechanical structure. The results are based on transmittance and reflectance absorptiometric measurements. In order to evaluate the sensitivity of the prototype sensor it was tested against a commercial spectrophotometer. The two systems measured the bioactive compounds of a variety of different fruits (acerola, pineapple, plum, atemoya, banana, cashew apple, kiwi, pitomba, sapodilla, yellow mombin and grape). The coefficient r of the two systems were similar (r = 0.99 for total polyphenols, r = 0.95 for total flavonoids, r = 0.99 for ascorbic acid). Nevertheless, further research is required to improve the precision of this optical sensor, which has significant potential for industrial applications.

Vicilins are related to cowpea seed resistance toward Callosobruchus maculatus due to their ability to bind to chitinous structures lining larval midgut. However, this binding mechanism is not fully understood. Here, we identified chitin binding sites and investigated how in vitro and in silico chemical modifications interfere with vicilin chitin binding and insect toxicity. In vitro assays showed that unmodified vicilin strongly binds to chitin matrices, mainly with acetylated chitin. Chemical modifications of specific amino acids (tryptophan, lysine, tyrosine), as well as glutaraldehyde cross-linking, decreased the evaluated parameters. In silico analyses identified at least one chitin binding site in vicilin monomer, the region between Arg208 and Lys216, which bears the sequence REGIRELMK and forms an α helix, exposed in the 3D structure. In silico modifications of Lys223 (acetylated at its terminal nitrogen) and Trp316 (iodinated to 7-iodine-L-tryptophan or oxidized to β-oxy-indolylalanine) decreased vicilin chitin binding affinity. Glucose, sucrose, and N-acetylglucosamine also interfered with vicilin chitin binding affinity.

Physiologically mature ‘Paluma’ guava were treated with galactomannan (0.75%) and carnauba wax (0.9%) coating, stored at ambient (25 °C) and refrigerated (11 °C), and evaluated every 3rd day for postharvest quality and physiology. Ambient uncoated fruit were apt for consumption for only nine days; meanwhile, coated guavas were acceptable for 15 d with climacteric respiratory peak of 168.6 mg kg−1 h-1 at day 12, and firmness of 14.3 N attributed to lower lipid peroxidation and cell wall hydrolysis. Coating increased antioxidant enzymes SOD and CAT activities that led to 35% lower hydrogen peroxide content, when compared to uncoated control. Coating prevented guava degreening by inhibiting chlorophyll degradation with content of 45.05 mg kg-1, lower carotenoid content with 27.8 mg kg-1 and PPO activity, under refrigeration for 15 d. Refrigerated uncoated fruit exhibited as symptoms of chilling injury inhibition of softening and respiratory peak. Principal component analysis showed that coating and refrigeration treatment maintains guava quality for 15 d of storage similar to observed for control, at day zero. In conclusion, galactomannan-carnauba wax coating improved guava postharvest quality through maintenance of firmness and color, besides preventing chilling symptoms under refrigeration.

The aim of this study was use the pulsed light (PL) as tool to booster the postharvest resistance in melons. Cantaloupe melons at mature stage were submitted to the treatments as follows: control, pulsed light (PL; 9 J cm−2), 1-methylcyclopropene (1-MCP; 600 nL L-1) and 1-MCP + PL (600 nL L-1 + 9 J cm−2). Postharvest resistance measurements according survival analysis developed at 4 °C, included: ethylene production, 1-aminocyclopropane- l -carboxylic acid (ACC) oxidase activity, ACC synthase activity, firmness, pH, soluble solids, titratable acidity, SS/AT ratio, soluble sugars, vitamin C, total polyphenols, phenylalanine ammonia lyase (PAL) activity, colour epicarp, free polyamines (putrescine-Put, spermine-Spe and spermidine-Spd) and total polyamines (TPo). Combined effect of the PL+1-MCP promoted an additional of 12 days in the shelf life of melons. PL limited the ethylene biosynthesis leading to an immediate upregulation of polyamines (Put + Spe + Spd), hence, associated with high amounts of TPo (56%). PL treatment promoted an increase of PAL activity (67%) that synthesized high content of phenolic compounds (55%). The results suggest that PL with a fluence of 9 J cm−2 stimulate the postharvest defense mechanisms in melon, due to the ethylene production limitation, which was influenced by the increased polyamines, maintaining the quality attributes.

The objective of this work was to determine quality, bioactive content and metabolism of vitamin C and phenolic compounds during the development of acerola BRS 238 (Frutacor). Fruits were harvested at five different stages of maturation and evaluated for physical-chemical and chemical quality characteristics, as well as for the metabolism of vitamin C and polyphenols variables. During development, there was an increase in SS/AT ratio, a decrease in chlorophyll content, increase in carotenoids content, and a decline in vitamin C and polyphenols content, alhhtough of yellow flavonoids and anthocyanins content increased. The enzyme activity of vitamin C metabolism, ascorbate oxide (AO) and ascorbate peroxidase (APX) decreased with ripening, while for phenolic metabolism, the activity of phenylalanine ammonia lyase (PAL) increased and polyphenoloxidase (PPO) decreased. It can be concluded that the fruits of aceroleira BRS 238 had a high content of bioactive compounds. For industrial extraction of bioactive compounds, fruits must be harvested at the initial stages, while for fresh consumption, they must be harvested in the final stages of development. El objetivo de este trabajo fue determinar las características de calidad, contenido de bioactivos y metabolismo de la vitamina C y compuestos fenólicos durante el desarrollo de la acerola BRS 238 (Frutacor). Las frutas se cosecharon en cinco etapas diferentes de maduración y se evaluaron las características de calidad físico-químicas y químicas, así como el metabolismo de la vitamina C y los polifenoles. Durante el desarrollo de estos frutos hubo un aumento en la relación SS / AT, una disminución en el contenido de clorofila, un aumento en el contenido de carotenoides, una disminución en el contenido de vitamina C y polifenoles, mientras el contenido de flavonoides amarillos y las antocianinas aumentaron. La actividad enzimática del metabolismo de la vitamina C, oxidasa de ascorbato (AO) y la peroxidasa de ascorbato (APX) disminuyaran con la maduración, mientras que para el metabolismo fenólico, la actividad de la fenilalanina amoniaco liasa (PAL) aumentó y la polifenoloxidasa (PPO) disminuyó. Se puede concluir que los frutos de aceroleira BRS 238 tuvieron un alto contenido de compuestos bioactivos. Para la extracción industrial y bioactiva, estos frutos deben cosecharse en la etapa inicial, mientras que para el consumo fresco, deben cosecharse en las etapas finales de desarrollo. O objetivo deste trabalho foi determinar caracteristicas de qualidade, o conteúdo de bioativos e a atividade de enzimas do metabolismo da vitamina C e dos compostos fenólicos durante o desenvolvimento da acerola BRS 238 (Frutacor). Frutos foram colhidos em cinco diferentes estádios de maturação e avaliados quanto as características físico-químicas e químicas de qualidade, assim como para o metabolismo de vitamina C e de polifenóis. Durante o desenvolvimento desses frutos houve um aumento na relação SS/AT, uma queda no conteúdo de clorofila, aumento no conteúdo de carotenoides, um declínio no conteúdo de vitamina C e polifenóis, todavia o conteúdo de flavonoides amarelos e antocianinas aumentaram. A atividade das enzimas do metabolismo da vitamina C, ascorbato oxidade (AO) e peroxidase do ascorbato (APX) diminuíram com o amadurecimento, enquanto para o metabolismo fenólicos, a atividade da fenilalanina amônia liase (PAL) aumentou e da polifenoloxidase (PPO) reduziu. Pode-se concluir que os frutos da aceroleira BRS 238 apresentaram alto conteúdo de compostos bioativos. Para extracção industrial e bioativos, esses frutos devem ser colhidos no estádio inicial, enquanto para consumo in natura, devem ser colhidos nos estádios finais do desenvolvimento.

Devido ao seu elevado conteudo de vitamina C, a acerola e utilizada como fonte dessa vitamina e utilizada no enriquecimento de produtos industriais. Esse trabalho teve como objetivo desenvolver um metodo de monitoramento do conteudo de vitamina C durante a producao do seu extrato a partir de acerola, quando foram estudadas diferentes etapas de processamento. Os modelos de calibracao e validacao foram obtidos por regressao dos quadrados minimos parciais com a correlacao dos valores do metodo de referencia por espectrofotometria a 525 nm e dos dados de absorcao por espectroscopia no infravermelho proximo de 800 nm a 2.500 nm. O modelo de quantificacao mais robusto foi determinado utilizando o coeficiente de determinacao, o erro de validacao interna e erro de previsao. O conteudo de vitamina C variou de 1.188,39 a 9.959,74 mg. 100 g -1 , durante todo processamento. O erro de previsao RMSEP 166,27 mg 100 g -1 obtido corrobora com o uso de espectroscopia NIR como uma metodologia promissora para o processamento de acerola com vistas a extracao de vitamina C, com a possibilidade de verificar o conteudo em etapas intermediarias da propria linha de producao e permitindo que ajustes sejam feitos para correcao.

The objective of this work was to identify and evaluate the bioactive compounds, as well as the antioxidant potential, present in mature fruits of cambuizeiro (Myrcia multiflora) from the Chapada do Araripe, Brazil. In the fruits were evaluated: vitamin C, total anthocyanins, yellow flavonoids, total polyphenols, total antioxidant activity by the FRAP, DPPH and ABTS methods, and the antioxidant superoxide dismutase (SOD) and catalase (CAT) activity. Cambui had an average vitamin C content of 56.40 mg/100 g, 2869.44 mg/100 g total anthocyanins 2858.50 mg/100 g yellow flavonoids and 1007.64 mg EAG/100 g of total polyphenols. While the total antioxidant activity according to FRAP method was 123.94 μM ferrous sulphate/g, DPPH was 1805.66 g/g EC50, and ABTS was 32.62 μM trolox/g. The enzymatic activity of SOD was 846,203 AU/g, while CAT did not read. These results indicate that the mature fruits of cambuizeiro present high antioxidant potential, corroborating to the idea that their consumption may result in benefits to human health. Resumen El objetivo de este trabajo fue identificar y evaluar los compuestos bioactivos, así como el potencial antioxidante, presentes en frutos maduros de cambuizeiro (Myrcia multiflora) procedente de la Chapada del Araripe, Brasil. En los frutos fueron evaluados: vitamina C, antocianinas totales, flavonoides amarillos, polifenoles totales, actividad antioxidante total por los métodos de FRAP, DPPH y ABTS y actividad de la enzima antioxidante superóxido de la dismutasa (SOD) y catalasa (CAT). En los frutos de cambuí se encontró un contenido medio de vitamina C de 56,40 mg/100 g; 2869,44 mg/100g de antocianinas totales 2858,50 mg/100g de flavonoides amarillos y 1007,64 mg EAG/100 g de polifenoles totales. Mientras que la actividad antioxidante total según método FRAP fue de 123,94 μM de sulfato ferroso/ g, el DPPH fue 1805,66 g/g EC50, y el ABTS fue 32,62 μM trolox/g. La actividad enzimática de la SOD fue 846,203 UA/g, mientras que no se registró presencia de CAT. Estos resultados indican que los frutos maduros del cambuizeiro presentan elevado potencial antioxidante lo que sugiere que su consumo puede resultar en beneficios a la salud humana.

The Phyllanthus genus is widely distributed in tropical and subtropical areas of the world and present several pharmacological applications. Drought is a restrictive factor for crop development and production, and is becoming a severe problem in many regions of the world. The species Phyllanthus amarus and Phyllanthus niruri were subjected to drought stress for varying periods of time (0, 3, 5, 7, and 10 days), and afterwards, leaves were collected and evaluated for physiological and biochemical responses, such as oxidative stress markers and drought-associated defense mechanisms. Results show that P. amarus has an endogenously higher level of variables of the oxidative/antioxidant metabolism, and P. niruri presents the most significant changes in those variables when compared to control and stressed plants. For both Phyllanthus species, drought stress induces higher levels of organic acids such as malic, succinic, and citric acids, and amino acids such as proline, GABA, alanine, and valine. Moreover, P. niruri plants respond with greater glucose and corilagin contents. Therefore, considering the evaluated metabolic changes, P. amarus is better adapted to drought-stress, while P. niruri presents an acclimation strategy that increases the corilagin levels induced by short-term drought stress.

The quality of zein (Z)- and zein-tannic acid (ZTA)-coated guavas was monitored throughout 12 days of storage. Coated fruit showed lower changes in terms of visual appearance, chlorophyll contents and color. Weight loss, softening, and changes in soluble solids were also decreased by the coatings. The respiration peak as well as H2O2 and superoxide dismutase activity peaks were delayed by the coatings, and the ethylene production was reduced. So, the results were consistent with a slowed down ripening of guavas by the coatings, which was probably related to lowered oxygen permeability of guava skin. ZTA coating was more effective than Z to reduce weight loss, softening, color changes, ethylene production, and oxidative stress. The higher efficiency of ZTA coating was ascribed to zein crosslinking, which probably resulted in decreased gas permeability, promoting lower respiration rates and lower ROS production, slowing down the ripening process, and extending guava stability.

The objective of this work was to evaluate the effects of the preharvest treatment with gibberellic acid (GA3) and aminoethoxyvinylglycine (AVG) on the quality and physiological attributes of ripe 'CCP 76' cashew (Anacardium occidentale) peduncles at different developmental stages. Sprays of 180 mg L-1 GA3 and 180 mg L-1 AVG were applied, combined and isolated, at 34, 40, and 44 days after anthesis (DAA), and peduncles were harvested ripe at 46 DAA and evaluated for physical and physiological variables. The treatment with GA3 resulted in firmer peduncles with a greater apical diameter, but did not affect the physiological variables activity of the pectin methylesterase and polygalacturonase cell wall enzymes and degree of lipid peroxidation of the biological membranes, nor the physical attributes total mass (peduncles and nut) and nut size. At early developmental stages (34 DAA), GA3 increased the activity of the antioxidant enzymes superoxide dismutase and catalase, and, at later stages (40 DAA), promoted polyphenol and carotenoid accumulation. The application of AVG at the final stages (44 DAA) provided greater total antioxidant activity, despite the lower ascorbate peroxidase activity. The application of GA3 pre-harvest increases the firmness and diameter of the cashew peduncles, and the treatment with AVG increases the total antioxidant activity of the peduncles. Resumo: O objetivo deste trabalho foi avaliar o efeito do tratamento pré-colheita com ácido giberélico (GA3) e 1-aminoetoxivinilglicina (AVG) nos atributos de qualidade e fisiológicos de pedúnculos maduros de cajueiro (Anacardium occidentale) 'CCP 76', em diferentes estádios de desenvolvimento. Foram realizadas pulverizações com 180 mg L-1 GA3 e 180 mg L-1 AVG, combinadas e isoladas, aos 34, 40 e 44 dias após a antese (DAA), e os pedúnculos foram colhidos maduros aos 46 DAA para avaliações de variáveis físicas e fisiológicas. O tratamento com GA3 proporcionou pedúnculos mais firmes e com maior diâmetro apical, mas não influenciou as variáveis fisiológicas atividades das enzimas pectinametilesterase e poligalacturonase da parede celular e grau de peroxidação lipídica das membranas biológicas, nem os atributos físicos massa total (pedúnculo e castanha) e comprimento e largura da castanha. Em estádios iniciais (34 DAA), GA3 aumentou a atividade das enzimas antioxidantes superóxido dismutase e catalase, e, nos finais (40 DAA), promoveu o acúmulo de polifenóis e carotenoides. A aplicação de AVG, ao final do desenvolvimento (44 DAA), proporcionou maior atividade antioxidante, apesar da menor atividade da ascorbato peroxidase. A aplicação de GA3 em pré-colheita promove aumento da firmeza e do diâmetro dos pedúnculos de cajueiro, e o tratamento com AVG aumenta a atividade antioxidante dos pedúnculos.

The objective of this study was to evaluate the changes in quality and antioxidant metabolism during ripening of passion fruits from organic and conventional production systems. Postharvest quality, variables of antioxidant metabolism (enzyme and non-enzymes), total antioxidant activity (TAA), lipid peroxidation degree as indicator of oxidative stress and the activity of phenolic-associated enzyme, phenylalanine ammonia lyase (PAL) were evaluated in fruits harvested at developmental stages: breaker/turning yellow (physiologically mature) and completely yellow color (ripe). Results show that organic fruits were smaller, although with higher soluble solids content and a lower acidity. At breaker stage, PAL activity was 24% than higher in organic fruits than in conventional fruits, although, total phenolic content was higher in conventional fruits harvested at both breaker (36.14 mg GAE 100 g−1) and ripe (36.47 mg GAE 100 g−1) stages. Organic fruit showed a significantly greater lipid peroxidation degree of biological membranes, despite their also higher APX activity and vitamin C contents. Results suggest that organic cropping system induced an oxidative stress in passion fruit, negatively influencing fruit size, although inducing the antioxidant defense mechanism, through increments of vitamin C and antioxidant enzymes activity.

This study investigated the effect of pulsed light (PL) on the respiratory rate, quality (firmness, color and soluble solid content), bioactive compounds (ascorbate and carotenoid) and total antioxidant activity of fresh-cut “Tommy Atkins” mangoes. Fresh-cut mangoes were subjected to PL treatments: control (0P), 1 pulse (1P; 0.7 J cm−2), 4 successive pulses (4P; 2.80 J cm−2) and 1 pulse per day for 4 days (1P4D; 2.80 J cm−2) before storage for 7 days at 6 °C. The 1P and the 4P treatments reduced fresh mass loss during storage, while 4P-treated samples also showed a slower decline of yellow color, as shown by parameter b and overall better visual appearance. After 7 days of storage, total ascorbate content was 40% higher in the 1P4D treatment than in control, whereas total carotenoid content (0.894 mg g−1 FM) and total antioxidant activity (144 μmol trolox 100 g−1 FM) were the highest in the 4P-treated samples. Results suggest that PL mode of application is more important than the fluence or final dose received by fresh-cut mangoes; moreover, 4P is an effective method to preserve, or even improve quality of fresh-cut mangoes.

Phytochemicals from tropical fruits and their by-products have shown the potential to use as antimicrobial natural. This study aimed to optimize the recovery of phenolic compounds (total polyphenols and flavonoids) from cashew apple using ultrasound-assisted extraction to promote the functional attributes to its coproducts and to evaluate their antioxidant and antimicrobial potential. An experimental design applying a response surface methodology was used for the extraction process. The ethanol concentration (13.76 % to 56.21 %) and the ultrasonic bath time (21.71 to 78.28 min.) were considered as independent variables, and the polyphenols content, total flavonoids as dependent variables. The phenolic profile of optimized hydroalcoholic extracts (UPLC-QToF-MSE) and their antimicrobial potential against foodborne pathogenic bacteria was assessed. The optimized conditions for a total phenolic extract of 750 mg GAE 100 g-1 were 42.16 % ethanol and 37.34 min in an ultrasonic bath, and for total flavonoids of 479.07 mg of quercetin per 100 g-1 were 37.15 % ethanol and 25.13 min. A total of 15 compounds including quercetin and myricetin derivatives, gallic acid, and anacardic acid were identified. The extracts displayed effective action against Staphylococcus aureus and Listeria monocytogenes. The extracts were effective against foodborne pathogenic bacteria thus demonstrating their potential to be a good natural alternative to synthetic additives in the food industry.

Growth regulators may influence fruit development and thus, their postharvest quality. This study aimed to evaluate the effects of preharvest treatment with aminoethoxyvinylglycine (AVG) or gibberellic acid (GA3) on postharvest quality and life of apples of two cashew cultivars, CCP 76 e BRS 189, during cold storage. Growth regulators (180 mg L −1 ) were applied at maturation stage 1 and apples were harvested at stage 7, ripe. Ripe, treated and control, apples were stored at 3 ± 2 °C for CCP 76 and at 5 ± 2 °C, for BRS 189 and evaluated at harvest (0 day) and every 5 days up to 20 days of storage. The influence of growth regulators preharvest treatment on cashew apples differed among cultivars. For BRS 189 apples, GA3 treatment slowed down mass loss, as treated samples lost 0.72% while control lost 0.81%; and avoided the development of undesirable characteristics during storage. GA3-treated samples were statistically firmer, 13.61 N than control, 9.93 N; and together with AVG-treated samples showed a significantly reduced pectin methyl esterase (PME) activity to 1492.88 UA mg −1 P when compared to control 2129.87 UA mg −1 P. For cv. CCP 76, GA3 treatment also slowed down mass loss, as treated samples lost 0.85% and control, 0.99%, however apples were inapt for consumption after 15 days of storage. GA3-treated samples were statistically firmer, 15.40 N than control, 11.38 N. The constituents of the antioxidant metabolism of both cashew apples varieties were mainly affected by storage period, but not by growth regulators. Therefore, results of preharvest AVG treatment on cashew apple physiology and quality were inconsistent. However, GA3 treatment improved postharvest quality of CCP 76 e BRS 189 cashew apples through reduction of mass loss and firmness loss, without any negative impact on physicochemical variables. GA3 exerted a greater influence on BRS 189 apples which showed, besides lower mass and firmness loss, a better visual appearance and lower cell wall hydrolase PME activity, during storage.

Thermally-processed coconut water often develop a commercially-undesirable pink color, thus, NMR, UPLC-HRMS, GC-MS analyses combined with chemometrics approach were applied to evaluate chemical variations in comparison to tender water (control) that could explain such color change. Chemometrics on negative ionization mode dataset showed trimeric and A-type dimeric procyanidins, and caffeoylshikimic acid as main identified secondary metabolites induced by processing, while, control water presented mainly cytokinin trans-zeatin riboside, procyanidin dimer, caffeoylshikimic acid and trihydroxy-octadecenoic acid. Processing increased long-chain saturated palmitic and stearic fatty acids contents, meanwhile NMR analysis showed a decline in primary metabolites content as sugars fructose and glucose, and short-chain organic acids. Among the results observed for thermally processed coconut water, the increase in oligomeric procyanidins as A-type dimer and trimer may be associated with pink color development as these are precursors of anthocyanin pigment and/or by enhancing color stability of anthocyanin solutions.

Ultrasound (US) was applied as a post-processing treatment on fresh-cut mangoes as a means to preserve quality and to further understand its possible physiological effects. Processed fruits were sonicated at 25 kHz for 30 min and stored for 7 days under refrigeration at 4 °C. Fruits were analyzed on treatment day (day 0) and after storage (day 7) for quality through physicochemical and chemical variables, while color and firmness were evaluated in association to physiological variables, at last, variables of oxidative/antioxidant were also analyzed. Initially (day 0), US significantly reduced soluble solids and sugar content in 15 %, although after storage (day 7), there was no difference between treatments. After storage (day 7), US-treated mango was softer, 139.34 N, than control, 241.15 N, and firmness loss was not associated to cell membrane integrity, as determined by lipid peroxidation degree, but to cell wall integrity as hydrolases pectin methylesterase and polygalacturonase were stimulated. The color attribute °Hue was affected by US and declined significantly after the storage (day 7) to 80.79, indicating darkening of tissue. Results indicate that guaiacol peroxidase was the primary cause of darkening while polyphenol oxidase activity, carotenoids, and total flavonoids could not be associated to changes in color. Constant levels of hydrogen peroxide indicate that sonication did not induce an oxidative imbalance in mangoes, and thereby, the non-enzymatic antioxidants, total antioxidant activity, and activity of antioxidant enzymes superoxide dismutase and catalase were not influenced by the US. Therefore, US affected negatively fresh-cut mangoes’ quality through deteriorating changes, and further work should be carried on to explore ultrasound under different conditions as to ensure this technology could be appropriately used at mango postharvest.

It is not precisely determined, but the acerola tree is probably native to islands of the Caribbean and Antilles, although it may be found in the wild and cultivated in northern South America, Central America, and Southern Mexico. The fruit is a drupe and when ripe, has a thin epicarp, a mesocarp (pulp) that represents 70%–80% of total fruit weight, and a trilobed endocarp enveloping an average of one seed that is 3–5 mm in diameter, an oval shape and two cotyledons. The mature or ripe acerola is a very delicate and highly perishable product with a storage life of 2–4 days at temperatures higher than 20°C. Considering its chemical composition (100 g fruit), acerola has a water content ranging from 92% to 95%, 332 kcal of calories which are assigned to carbohydrates (57.24 g), lipids (3.2 g) and protein (16.94 g) contents. Regarding the lipid fraction, the following fatty acids were identified: oleic (31.9%), linoleic (29.2%), palmitic (21.8%), stearic (13.9%) and linolenic (1.3%). The main sugars are fructose and glucose, and to a lesser extent, sucrose. Among the phytochemical constituents of acerola, there are vitamins such as thiamine (B1), riboflavin (B2), niacin (B3) and provitamin A and minerals as calcium, iron, potassium, magnesium and phosphorus. However, its greatest nutritional appeal is a very high content vitamin C ranging from 862.86 to 1465.22 mg/100 g pulp in ripe fruit that can reach up to 3756.06 mg/100 g pulp in immature fruit.

The goal of this study was study the postharvest quality of acerola clone BRS 236 (Malpighia emarginata D.C.) which was harvested at physiological maturity and submitted to four treatments under immersion during 5 minutes at 25 °C, which are: control (water), 60 mg L-1; 120 mg L-1 and 180 mg L-1. After treatment the fruits were packed in polystyrene trays and placed with polyethylene film and then stored at 10 ± 2 °C and 85 ± 5% RH for 12 days. Were analyzed in three days intervals (0, 3, 6, 9 and 12 days): skin color, firmness, pH, titratable acidity, soluble solids, SS/TA ratio, vitamin C and yellow flavonoids. Vitamin C, anthocyanins and yellow flavonoids were not influenced by treatments with GA3 at the end of 12-day of cold storage at 10 ºC. The exogenous application of 120 mg L-1 of GA3 resulted in retention of red color and content of anthocyanins of acerola fruits BRS 236 clone 12-day storage at 10 °C. RESUMO Objetivou-se com este trabalho estudar a qualidade pós-colheita de acerolas do clone BRS 236 (Malpighia emarginata D.C.), colhidas na maturidade fisiológica e submetidas a quatro tratamentos com ácido giberélico (GA3) por imersão durante 5 minutos a 25 °C, sendo eles: controle (água), 60 mg L-1; 120 mg L-1 e 180 mg L-1. Após o tratamento os frutos foram colocados em bandejas de isopor e cobertos com filme de polietileno, e em seguida armazenados à temperatura de 10±2 ºC, com umidade relativa de 85±5%, durante 12 dias. Foram analisadas em intervalo de três dias (0, 3, 6, 9 e 12 dias): coloração da casca, firmeza, pH, acidez total titulável, sólidos solúveis, relação SS/AT, vitamina C e flavonóides amarelos. Compostos bioativos como a vitamina C e flavonóides não foram influenciados pelos tratamentos com GA3 ao final de 12 dias de armazenamento a 10 ºC. A aplicação exógena de 120 mg L-1 de GA3 resultou em maior retenção da cor e conteúdo de antocianinas em acerolas do clone BRS 236 durante 12 dias de armazenamento a 10 ºC.

Information on antioxidant properties at different ontological stages may help producers and food technologists to identify which cultivar and/or maturity stage are most adequate for their need, therefore this work aimed to study the changes in the antioxidant metabolism during acerola development. Fruit from cv. Flor Branca, BRS366 and Florida Sweet were harvested at different stages: immature green colored (I), physiologically mature with green color and maximum size (II), breaker (III) and full red ripe (IV). After harvest, fruits were selected, divided into four replications with 500 g each and evaluated regarding their titratable acidity, pH, soluble solids, total soluble sugar, vitamin C, polyphenol, anthocyanin, yellow flavonoid, total antioxidant activity and antioxidant enzyme activity. Anthocyanin and flavonoid were determined through LC-DAD-ESI/MS and all analysis followed a completely randomized factorial 3 x 4 design. Fruits of 'Florida Sweet' presented significantly higher soluble solids (9.46ºBrix). Vitamin C content decreased during ripening, but ripe 'BRS 366' fruits showed the greatest values (1363 mg.100 g-1) and highest TAA with 42.36 µM TEAC.g-1FW. Cyanidin 3-rhamnoside (520.76 mg.100 g-1 DM) and quercetin 3-rhamnoside (33.72 mg.100 g-1 DM) were the most abundant anthocyanin and yellow flavonoids found mainly in 'Flor Branca' fruit of acerola, whose antioxidant enzymes activities were also higher. Ripe 'Florida Sweet' fruit presents a great potential for fresh consumption, meanwhile physiologically mature 'BRS 366' fruit seems the best option for the bioactive compounds processing industry. As 'Flor Branca' fruit of acerola kept the highest activity levels, it could be an indicative of greater potential for postharvest conservation. Informações sobre propriedades antioxidantes em diferentes estádios ontológicos podem ajudar os produtores e tecnólogos de alimentos a identificar quais cultivares e/ou estádio de maturidade são os mais adequados para a sua necessidade; portanto, o objetivo deste trabalho foi estudar as alterações no metabolismo antioxidante durante o desenvolvimento de frutos da aceroleira. Frutos das cv. Flor-Branca, BRS 366 e Florida Sweet foram colhidos em diferentes estádios: imaturos com cor verde (I), fisiologicamente maduros com cor verde e tamanho máximo (II), com cor predominantemente vermelha (III) e totalmente vermelha, maduro (IV). Após a colheita, os frutos foram selecionados, divididos em quatro repetições com 500 g cada e avaliados quanto à acidez titulável, pH, sólidos solúveis, açúcares solúveis totais, vitamina C, polifenóis, antocianinas, flavonoides amarelo, atividade antioxidante total e atividade de enzimas antioxidantes. Antocianina e flavonoides foram determinados por meio LC-DAD-ESI/MS, e todas as análises seguiram um delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 4. Frutos de aceroleira 'Florida Sweet' apresentaram níveis significativamente mais elevados de sólidos solúveis (9,46ºBrix). O conteúdo de vitamina C diminuiu durante o amadurecimento, porém frutos de aceroleira 'BRS 366' maduras apresentaram os maiores valores (1.363 mg.100 g-1) e maior TAA com 42,36 mM TEAC.g- 1. Cianidina 3-ramnosideo (520,76 mg.100 g-1 MS) e quercetina 3-ramnosideo (33,72 mg.100 g-1 MS) foram as antocianinas e flavonoides amarelos mais abundantes encontrados nos frutosda variedade 'Flor-Branca', cujas atividades das enzimas antioxidantes também foram superiores. Frutos de aceroleira 'Florida Sweet' maduros apresentam grande potencial para o consumo in natura, enquanto frutos da 'BRS 366'fisiologicamente maduros parecem ser a melhor opção para a indústria de processamento de compostos bioativos. Como frutos de acerola 'Flor-Branca' mantiveram os mais altos níveis de atividade antioxidante, este pode ser um indicativo de maior potencial para a conservação pós-colheita.

The study investigated the effects of individual and combined preharvest applications of gibberellic acid (GA3, 180 mg L−1) and aminoethoxyvinylglycine (AVG, 180 mg L−1) at 34, 40 and 45 days after anthesis (DAA) on preharvest fruit drop, postharvest quality and antioxidant metabolism of ‘BRS 189’ cashew. AVG treatment at 45 DAA reduced significantly preharvest cashew drop to 26% while control presented 90% of fruit drop, moreover, without detrimental effects on peduncle and nut physical and physicochemical quality, except for 60% reduction in total antioxidant activity due to 50% reduction in total vitamin C content. GA3 treatments did not reduce cashew drop significantly when compared to control, although they incremented significantly total cashew weight (27%) due to increases in peduncle weight (29%) and length (14%), especially GA3 treatment at 40 DAA that also promoted significant increases in peduncle SS/TA ratio (23%) and firmness (33%) due to inhibition of PME cell wall hydrolytic activity. Peduncles treated with GA3 at 40 DAA also presented statically higher total carotenoid (16%) and polyphenol (59%) contents, despite the reduction in total vitamin C (25%) and total antioxidant activity (70%). Thus, AVG at 45 DAA was effective in reducing fruit drop, while GA3 treatment at 40 DAA promoted cashew quality with increases in peduncle weight and size, in SS/TA ratio, in firmness and in total carotenoid and polyphenol contents.

Table grapes have high market value in international markets due to their attractive taste and high antioxidant content. However, their market potential is limited by losses due to Botrytis cinerea Pers. Fr. Cinnamon leaf oil (CLO) is a natural fungicidal and antioxidant agent that can be used to avoid postharvest losses due to B. cinerea Pers. Fr. and to increase the antioxidant levels of this produce. CLO was applied to grapes as water emulsions (0, 0.5, 2.5, and 5 g L−1), as vapors (0, 0.196, 0.392, and 0.588 g L−1), or as a chemical incorporated into pectin coatings (0 and 36.1 g L−1). Afterwards, berries were stored at 10 °C for 15 d and were evaluated periodically for the fungal decay index, the total phenolic and flavonoid contents and the antioxidant activity using the Trolox equivalent antioxidant capacity and DPPH radical inhibition methods. The odor acceptability of the treated berries was evaluated after 10 d of storage. The CLO emulsion (5 g L−1) significantly reduced the fungal decay without affecting the antioxidant properties of the berries. The application of CLO as a vapor was more effective according to the evaluated parameters than the emulsions; all tested concentrations inhibited fungal decay and increased the flavonoid content and antioxidant activity. When CLO was incorporated into the pectin, no fungal decay appeared, and the highest antioxidant activity was observed after 15 d of storage. Additionally, all treatments, except the emulsion treatment, increased the odor acceptability of the treated berries compared to the control berries. From this study, it can be concluded that CLO as vapors or coatings can be used to control decay and increase the antioxidant health benefits of grapes due to CLO's antifungal and antioxidant properties.

Cashew immature and ripe peduncles ( Anacardium occidentale L.) from orange- and red-colored clones CCP 76 and BRS 189, respectively, were prepared as juice or fibrous fraction and submitted to UPLC–MS analyses, while the soluble fraction was also submitted to enzymatic evaluation. Cinnamoyl glucoside was present in ripe juice samples from both cashew clones, while monogalloyl diglucoside and digalloyl glucoside were present in immature juice samples from both cashew clones. Four compounds were found at immature fiber of both clones, anacardic acids (1, 2, 3) and GA 19 . The phenolic biosynthetic pathway was evaluated in juice samples and phenylalanine ammonia-lyase activity decreased significantly during the development, although it was much higher in ripe CCP 76. UDP-glycosyltransferases activity differed between clones, however its product cinnamoyl glucoside was a possible chemical marker of ripe juice samples from both clones. Flavonol synthase showed the highest specific activity in both cashew clones and its product, flavonols were identified in cashew apple at immature and ripe stages.

There is renewed interest in the antibacterial and antioxidant properties of essential oils as food additives. Among essential oils, cinnamon leaf oil is a potent antibacterial and antioxidant agent; however, the application in food systems can be affected by its volatility. The use of edible films is a good alternative for incorporating antibacterial agents and antioxidants into foods. This study aimed to develop an edible pectin film enriched with the essential oil from cinnamon leaves and prove that this application can increase the antioxidant status and reduce bacterial growth of fresh-cut peach. Films with different oil concentrations (0.0, 7.3, 15.7 and 36.1 oil g/l) were evaluated regarding eugenol content, thickness, moisture content, water vapour transmission, in vitro antioxidant activity and antibacterial properties of the films. No significant differences were found for the water vapour transmission among the films with different oil concentrations. The higher the added oil concentration the higher the eugenol content and antioxidant capacity; the films with 36.1 g/l were the only materials showing inhibition zones against Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes. Peaches were positively affected by the coating treatment, increasing its antioxidant status, odour acceptability and decreasing bacterial growth. These results demonstrate that the development of an edible film formulated with cinnamon leaf oil can be useful to preserve fresh-cut peach quality. Copyright © 2012 John Wiley & Sons, Ltd.

The effects of a clarifying process using pectinases and chitosan on the physicochemical characteristics, antioxidant capacity and quality attributes of açaí fruit (Euterpe oleracea Mart.) juice were evaluated. Clarification of acaí pulp resulted (P ≤ 0.05) in a 50 % loss of total anthocyanin (4.2730 mg/100 mL) and 29 % reduction in antioxidant capacity (33.60 μM FeSO4/g). A high association (P ≤ 0.05) was found between the decrease of antioxidant capacity and total anthocyanin loss. The use of pectinases associated with chitosan as an aid for clarification of açaí juice proved to be highly effective and resulted in a clear juice with a brighter purple to red color that was free of lipids, insoluble solids, and others substances that cause hazes. The obtained clarified açaí juice is a genuinely high-value anthocyanin-rich product that could be used as colorant and functional ingredient to fruit juices and soft drinks.

The effects of ultrasound process on quality parameters and on peroxidase (POD), polyphenol oxidase (PPO) and ascorbate peroxidase (APx) activities of cantaloupe melon juice were investigated. A factorial central composite design was carried out changing processing time and ultrasound intensity. POD, PPO and APx residual activities, color and phenolic compounds were the responses analyzed. Applying ultrasound power intensity of 376 W/cm 2 for 10 min resulted in significant reduction of POD and PPO activities and the total inactivation of APx. No color degradation was observed. However, ultrasound (US) processing also caused the reduction on phenolic compounds (30%). The technology showed to be suitable for cantaloupe melon stabilization as alternative to thermal and other treatments that results in quality loss. US processing was also able to improve and keep the juice homogeneity (cloud stability) during 6 weeks of cold storage (4 °C). This is a very interesting advantage for juice processing because cantaloupe pulp settles very fast resulting in a two phase product.

The influence of ultrasound processing on the physicochemical characteristics of pineapple juice was investigated through an experimental design changing ultrasound time and intensity. After processing, the polyphenoloxidase (PPO) activity in the pineapple juice was reduced by 20% as result of the treatment with longer exposure and higher intensity (376 W/cm2 and 10 min). The effect on phenolic compounds compared to the fresh pineapple juice (non-sonicated) was not statistically significant. Ultrasound processing reduced juice viscosity by 75% of the initial value (non-sonicated juice). The higher the ultrasound intensity and the juice exposure (processing time), the higher the final temperature of the juice, reaching a maximum of 54 °C. Ultrasound processing enhanced the juice color and its stabilization along 42 days of storage compared to the non-sonicated juice. Thermal treatment at the highest temperature reached due to juice sonication (54 °C) showed no effect on PPO inactivation.

The effects of supplemental Ca2+ on membrane integrity and lipid composition of cowpea plants submitted to salt stress (75 mM NaCl) were evaluated. The experimental design was factorial (2 × 6 + 1) corresponding to six saline treatments supplemented with CaCl2 and six saline treatments supplemented with CaSO4, both at 0.5, 1.25, 2.5, 5.0, 7.5 and 10.0 mM, plus control treatment (plants grown in half-strength Hoagland’s nutrient solution without supplemental calcium addition). Samples of leaves and root tips were analyzed for total lipid, glycolipid and fatty acid contents and membrane damage symptoms. Salt stress greatly reduced total lipid content in leaves and roots and caused great damage to membrane structures. In leaves, the glycolipid content was differently influenced by calcium treatments. Moreover, salinity increased the saturated/unsaturated fatty acid ratio in leaves and an increase in the concentration of calcium intensified this response. In roots, only saturated fatty acids were detected and their content was strongly influenced by salinity and very little by calcium treatments. Supplemental Ca2+ was unable to ameliorate the negative effects of salinity on the structural integrity and fluidity of plant membranes in cowpea.

This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and non-enzymatic antioxidants. In acerola purée, anthocyanin and polyphenols are strongly correlated to soluble solids content and vitamin C seems a major contributor to total antioxidant activity. Clone II47/1 had an outstanding performance regarding the antioxidant potential of its purée and the best storage period at -18ºC would be 150 days, for all clones studied.

Studies have shown that vicilins (7S storage proteins) from seeds were able to bind to the surface of the Callosobruchus maculatus larval midgut and to the peritrophic matrices of the midguts of Diatraea saccharalis and Tenebrio molitor , inhibiting larval development. Vicilins were also shown to inhibit yeast growth and bind to yeast cells through the association with chitin-containing structures. The present work studies the association of peptides from vicilins of genotypes of Vigna unguiculata (susceptible and resistant to bruchid) with acetylated chitin and the toxicity of vicilin fragments and chitin-binding vicilin fragments to C. maculatus and phytopathogenic fungi. Hydrolysis of vicilins with alpha-chymotrypsin results in a complex mixture of fragments that were separated by chitin-affinity chromatography. Chitin-binding peptides from both genotypes were toxic to C. maculatus larvae, and alpha-chymotrypsin-hydrolyzed vicilins were deleterious to the above insect and to Fusarium oxysporum , Colletotrichum musae , and Saccharomyces cerevisiae fungi.

Sapoti (Manilkara zapota) e um fruto climaterico que amadurece rapidamente apos a colheita e os estudos acerca da extensao de sua vida util pos-colheita sao principalmente restritos ao uso de baixa temperatura e atmosfera modificada. Este trabalho avaliou a influencia do 1-metilciclopropeno (1-MCP) sobre o amolecimento e bioquimica da parede celular durante o amadurecimento de sapoti, assim como o seu potencial de conservacao pos-colheita. Sapotis foram tratados com 1-MCP, um antagonista do etileno, a 300 nL L-1 por 12 h e, em seguida, armazenados sob atmosfera modificada a 25oC por 23 d. O 1-MCP retardou significativamente o amadurecimento de sapoti por 11 d, via diminuicao da atividade das enzimas hidroliticas da parede celular e, portanto, os frutos tratados com 1-MCP exibiram menor solubilizacao dos poliuronideos, hemicelulose e acucares neutros livres quando comparados com os frutos-controle. O 1-MCP retardou o amaciamento do sapoti, indicando que esse processo e dependente da producao e percepcao de etileno.

This work aimed to evaluate the thermostability of antioxidant (superoxide dismutase - SOD, catalase - CAT and ascorbate peroxidase - APX) and deteriorative (guaiacol peroxidase - G-POD, polyphenoloxidase - PPO, pectin-methylesterase - PME and polygalacturonase - PG) enzymes from soursop and cashew apple juices. Juices were prepared homogenizing ripe fruit pulps and submitting to different thermal treatments (55, 65, 75, 85 and 95°C) for different time period (1, 3, 5, 10, 15, 20 and 30 min) then enzymatic activities were evaluated. The treatments at 55°C for soursop juice and at 75°C for cashew apple juice presented the best results, considering the low residual activities for deteriorative enzymes and the retained activity of SOD. Our results suggest appropriate technological condition to thermal processing from soursop and cashew apple juice whereby ensuring quality beyond their functionality. RESUMO Este trabalho objetivou avaliar a estabilidade térmica de enzimas antioxidantes (superóxido dismutase - SOD, catalase - CAT e ascorbato peroxidase - APX) e deteriorantes (guaiacol peroxidase - G-POD, polifenol oxidase - PPO, pectinametilesterase - PME e poligalacturonase - PG) em sucos de graviola e de caju. Os sucos foram preparados homogeneizando a polpa das frutas maduras e submetendo-os a diferentes tratamentos térmicos (55, 65, 75, 85 e 95°C) em diferentes períodos de tempo (1, 3, 5, 10, 15, 20 e 30 minutos) e, posteriormente, as atividades enzimáticas foram avaliadas. Os tratamentos a 55°C para o suco de graviola e a 75°C para o suco de caju apresentaram os melhores resultados, considerando as baixas atividades residuais para as enzimas deteriorantes e manutenção da SOD. Nossos resultados sugerem condições tecnológicas adequadas para o processamento térmico do suco de graviola e de caju, pelo qual é assegurada a sua qualidade, além de sua funcionalidade.

This study evaluated a 2% chitosan-based coating with 500 mg L 1 trans-cinnamaldehyde on quality attributes, pro- and anti-oxidative metabolism, and structural integrity of biological membranes and cell wall of fresh-cut melon (Cucumis melo var. Cantalupensis Naud.) stored for 20 days at 4 C. Coating improved (P < 0.05) samples’ firmness, colour, soluble solids, total vitamin C and carotenoid content for up to 15 days of storage, thereafter samples showed signs of decay with softening of processed melon resulting from structural changes in both biological membranes and cell walls. Coating also reduced hydrogen peroxide radical levels leading to lower antioxidant enzymatic activity and lipid peroxidation degree and electrolyte leakage levels compared with control. Coating improved produce visual quality due to reduction in the activity of browning-associated enzymes, G-POD and PPO. Results indicate that coating improved quality of fresh cut Cantaloupe melons by acting as a physical barrier to gas exchange decreasing respiration rate and consequently, O2-dependent processes, while trans-cinnamaldehyde acted as free radical scavenger and enzyme inhibitor. The lower respiration rate inhibited the establishment of an oxidative stress induced by fruit processing and senescence with less damage to biological membranes, lower cell wall hydrolase activities and loss of bioactive compounds.

The laticifer fluid of Calotropis procera is rich in proteins and there is evidence that they are involved in the pharmacological properties of the latex. However, not much is known about how the latex-containing proteins are produced or their functions. In this study, laticifer proteins of C. procera were pooled and examined by 1D and 2D electrophoresis, masses spectrometry (MALDI-TOF) and characterized in respect of proteolytic activity and oxidative enzymes. Soluble laticifer proteins were predominantly composed of basic proteins (PI>6.0) with molecular masses varying between 5 and 95 kDa. Proteins with a molecular mass of approximately 26,000 Da were more evident. Strong anti-oxidative activity of superoxide dismutase (EC 1.15.1.1) (1007.74+/-91.89 Ug(-1)DM) and, to a lesser extent ascorbate peroxidase (EC 1.11.1.1) (0.117(d)+/-0.013 microMol H(2)O(2)g(-1)min(-1)), were detected. However, catalase (EC 1.11.1.6) was absent. The strong proteolytic activities of laticifer proteins from C. procera were shown to be shared by at least four distinct cysteine proteinases (EC 3.4.22.16) that were isolated by gel filtration chromatography. Serine and metaloproteinases were not detected and aspartic proteinase activities were barely visible. Chitinases (EC 3.2.1.14) were also isolated in a chitin column and their activities quantified. The presence of these enzymatic activities in latex from C. procera may confirm their involvement in resistance to phytopathogens and insects, mainly in its leaves where the latex circulates abundantly.

There is an abundant literature about the biological and physiological effects of UV-B light and the signaling and metabolic pathways it triggers and influences. Much less is known about UV-C light even though it seems to have a lot of potential for being effective in less time than UV-B light. UV-C light is known since long to exert direct and indirect inhibitory and damaging effects on living cells and is therefore commonly used for disinfection purposes. More recent observations suggest that UV-C light can also be exploited to stimulate the production of health-promoting phytochemicals, to extent shelf life of fruits and vegetables and to stimulate mechanisms of adaptation to biotic and abiotic stresses. Clearly some of these effects may be related to the stimulating effect of UV-C light on the production of reactive oxygen species (ROS) and to the stimulation of antioxidant molecules and mechanisms, although UV-C light could also trigger and regulate signaling pathways independently from its effect on the production of ROS. Our review clearly underlines the high potential of UV-C light in agriculture and therefore advocates for more work to be done to improve its efficiency and also to increase our understanding of the way UV-C light is perceived and influences the physiology of plants.