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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 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 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.

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.

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.

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 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.

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.

Globulins and albumins from mature cowpea seeds had inhibitory activity levels of 9.5 and 67.1 units trypsin inhibited per mg protein and globulins and albumins from immature seeds had trypsin inhibitory activity levels of 6.3 and 26.6 units trypsin inhibited per mg protein, respectively. Albumins from immature seeds had inhibitory activity level of 4 units salivary amylase inhibited per mg albumin. The globulins (native and heated) from both seeds were submitted to hydrolysis by trypsin and analyzed by SDS-PAGE. Native globulins from mature and immature seeds showed digestion products of ∼30 and ∼20 kDa, respectively. Trypsin strongly digested heated globulins from both kinds cowpeas.

Globulins were purified from mature and immature cowpea and algaroba seeds by gel filtration (S-200), anion exchange (DEAE-Sepharose) and other chromatographic methods. These globulins (native and heated) were submitted to hydrolysis by pepsin, chymotrypsin and trypsin and their digestion products were analysed by SDS-PAGE. Results showed that native globulins of both legumes were weakly digested by pepsin and were not digested by serine proteases. Heated proteins from cowpea were digested more rapidly by pepsin and chymotrypsin than was algaroba globulin. Trypsin rapidly digested proteins from both cowpea and algaroba. Comparing the hydrolysis of bean globulins to the algaroba globulins by mammalian enzymes, the globulins from immature cowpea showed better digestibility than mature cowpea; globulins from algaroba pod, which is used as an alternative food, were difficult to digest.

Cashew apple is a tropical pseudofruit consumed as juice due to its excellent nutritional and sensory properties. In spite of being well known for its important antioxidant properties, the cashew apple has not been thoroughly investigated for its therapeutic potential. Thereby, this study evaluated the antioxidant capacity, anti-inflammatory, and wound-healing activities of cashew apple juice. Juices from ripe and immature cashew apples were analyzed for antioxidant, anti-inflammatory, and wound-healing properties. Those were evaluated in murine models of xylene-induced ear edema and wound excision. Swiss mice were treated with cashew juice by gavage. Edema thickness was measured and skin lesions were analyzed by planimetry and histology. Both antioxidant content and total antioxidant activity were higher in ripe cashew apple juice (RCAJ) than in unripe cashew apple juice (UNCAJ). The UNCAJ presented the main anti-inflammatory activity by a significant inhibition of ear edema (66.5%) when compared to RCAJ (10%). Moreover, UNCAJ also showed the best result for wound contraction (86.31%) compared to RCAJ (67.54%). Despite of higher antioxidant capacity, RCAJ did not promote better anti-inflammatory, and healing responses, which may be explained by the fact that treatment increased antioxidants level leading to a redox “imbalance” turning down the inflammatory response modulation exerted by reactive oxygen species (ROS). The results suggest that UNCAJ presents a greater therapeutic activity due to a synergistic effect of its phytochemical components, which improve the immunological mechanisms as well as an optimal balance between ROS and antioxidants leading to a better wound healing process.

Aim and Background Acerola (Malpighia emarginata DC.) is a tropical fruit known for its nutritional and functional properties due to its great contents vitamin C, carotenoids and anthocyanins. The antioxidant potential from plants extracts associated to hepatoprotective activity has been widely studied. However, the effect of antioxidants in natural fruit juice has not been fully searched. The aim of this work was to investigate the antioxidant properties of acerola juice and its hepatoprotective potential against acute ethanol-induced stress. Materials and methods Ripe acerola were collected, processed into juice and initially analyzed to antioxidant properties in vitro. Afterwards, in vivo hepatoprotective activity was evaluated in mice. The animals received the juice by gavage as pretreatment for 15 consecutive days and then, were submitted to ethanol-induced stress in single dose (5 g/kg). The activities of serum enzymes as well as lipid peroxidation degree were evaluated. The activities of serum marker enzymes for liver damage as well as lipid peroxidation degree were evaluated. Results Acerola juice presents great vitamin C (1799.5 mg/100 g FW) and total phenolic (188.4 mg GAE/100 g FW), anthocyanins (9.2 mg/100 g FW), flavonols (7.8 mg/100 g FW) contents and high activity of superoxide dismutase (1053.6 UA/g DM) with a total antioxidant activity of 137.5 μmol Trolox/g FW. The juice treatment inhibited lipid peroxidation and reduced the activities of aminotransferases (p ≤0.05), in mice liver. Conclusion These results indicate that acerola juice is able to prevent the hepatic damage induced by ethanol, probably as a result of an enhancement of the antioxidant status in the animals.

The present research work describes the major changes in the antioxidant properties during development of acerola from five different clones. Ripening improved fruit physicochemical quality parameters; however, total vitamin C and total soluble phenols (TSP) contents declined during development, which resulted in a lower total antioxidant activity (TAA). Despite the decline in TSP, at ripening, the anthocyanin and yellow flavonoid content increased and was mainly constituted of cyanidin 3-rhamnoside and quercetin 3-rhamnoside, respectively. The activities of oxygen-scavenging enzymes also decreased with ripening; furthermore, the reduction in vitamin C was inversely correlated to membrane lipid peroxidation, indicating that acerola ripening is characterized by a progressive oxidative stress. Among the studied clones, II47/1, BRS 237, and BRS 236 presented outstanding results for vitamin C, phenols, and antioxidant enzyme activity. If antioxidants were to be used in the food supplement industry, immature green would be the most suitable harvest stage; for the consumer's market, fruit should be eaten ripe.

Introduction . Films act as semi-permeable gaseous barriers capable of maintaining fruit postharvest quality; thus coatings consisting of non-traditional sources may represent an alternative tool for producers. The objective of our work was to investigate the effect of a galactomannan coating on postharvest quality and physiology of ‘Tommy Atkins’ mangoes. Materials and methods . Physiologically mature mangoes were divided into four lots and stored for 16 d. Control uncoated fruits (lot 1) were stored at ambient temperature (25 °C), the second lot was uncoated and refrigerated (14 °C), the third lot was coated and stored at ambient temperature, and the fourth lot was coated and refrigerated. Fruit were analyzed for physicochemical quality parameters, antioxidant enzymatic activity and lipid peroxidation. Results and discussion . Control fruit (lot 1) lost almost twice the weight of uncoated refrigerated (lot 2) and coated mangoes at both temperatures (lots 3 and 4); the fruit of lot 1 softened faster. Regarding the antioxidant enzymes, the activity of superoxide dismutase decreased throughout storage without statistical differences between treatments and catalasic activity was significantly inhibited under refrigeration. At ambient temperature, coating delayed the catalasic activity peak to day 12, which was coincident with the lowest lipid peroxidation degree, evidencing the association of free radical production and scavenging mechanisms. The galactomannan coating was efficient in reducing weight loss and delaying softening; thus, it maintained quality of ‘Tommy Atkins’ mangoes for a longer period of time than the control treatment during storage at ambient temperature. Refrigeration (14 °C) enhanced the performance of the galactomannan coating; it was effective in slowing down the metabolism and delaying softening to day 12.