Salvador Castillo

Tools to Maintain Postharvest Fruit and Vegetable Quality through the Inhibition of Ethylene Action: A Review

Ethylene is a plant hormone controlling a wide range of physiological processes in plants. During postharvest storage of fruit and vegetables ethylene can induce negative effects including senescence, over-ripening, accelerated quality loss, increased fruit pathogen susceptibility, and physiological disorders, among others. Apart from the endogenous ethylene production by plant tissues, external sources of ethylene (e.g. engine exhausts, pollutants, plant, and fungi metabolism) occur along the food chain, in packages, storage chambers, during transportation, and in domestic refrigerators. Thus, it is a great goal in postharvest to avoid ethylene action. This review focuses on tools which may be used to inhibit ethylene biosynthesis/action or to remove ethylene surrounding commodities in order to avoid its detrimental effects on fruit and vegetable quality. As inhibitors of ethylene biosynthesis and action, good results have been found with polyamines and 1-methylcyclopropene (1-MCP) in terms of maintenance of fruit and vegetable quality and extension of postharvest shelf-life. As ethylene scavengers, the best results can be achieved by adsorbers combined with catalysts, either chemical or biological (biofilters).

Maturity stage at harvest determines the fruit quality and antioxidant potential after storage of sweet cherry cultivars.

Eleven sweet cherry cultivars were harvested at three maturity stages (S1 to S3) based on skin color and stored at 2 degrees C for 16 days and a further period of 2 days at 20 degrees C (shelf life, SL) to analyze quality (color, total soluble solids, and total acidity) and bioactive compounds (total phenolics and anthocyanins) and their relationship to total antioxidant activity (TAA), determined in hydrophilic (H-TAA) or lipophilic (L-TAA) fraction. For all cultivars and maturity stages, the ripening process advanced during postharvest storage with increases in color intensity and decreases in acidity, as well as enhancements in phenolics, anthocyanins, and TAA in both H-TAA and L-TAA, although important differences existed among cultivars. The results showed that sweet cherry should be harvested at stage S3 (4 days later than the commercial harvest date) since after 16 days of cold storage + SL, the highest antioxidant capacity was achieved for both H-TAA and L-TAA.

THE EFFECTS OF ESSENTIAL OILS CARVACROL AND THYMOL ON GROWTH OF PENICILLIUM DIGITATUM AND P. ITALICUM INVOLVED IN LEMON DECAY

In this work the antifungal efficacy of thymol, carvacrol and the mixture of both pure essential oils has been proved against Penicillium digitatum and Penicillium italicum, by using in vitro (liquid media, PDA plates and disk growth) and in vivo (lemon) tests. Results indicated that both essential oils were effective in inhibiting fungal growth in all in vitro tests, with the highest efficacy displayed by thymol. In addition, the application of wax with thymol and carvacrol to lemons inoculated with P. digitatum demonstrated the reduction of decay (expressed as percentage of infected fruit surface) in a concentration dependent manner, as well as reduced respiration rate, ethylene production and total acidity losses. Thus, the application of these essential oils together with wax in the citrus packing lines could be considered as good alternatives to reduce the use of synthetic fungicides.

Sensory, Nutritive and Functional Properties of Sweet Cherry as Affected by Cultivar and Ripening Stage

In this article 11 commercial sweet cherry cultivars were selected to evaluate sensory, nutritive and functional properties over the maturation process on tree. Fruit quality was significantly different among cultivars and maturity stages at harvest, with the highest quality scores being found in the harvest which was 4 days beyond current commercial harvest maturity for all the cultivars tested. Taking into account all of the measured parameters (weight, firmness, color, acidity and total soluble solids), ‘NY-6479’, ‘Prime Giant’ and ‘Sunburst’ could be classified as having the highest quality in terms of sensory attributes. However, ‘Cristalina’ and ‘Sonata’ had the highest functional quality, as determined by the measurement of bioactive compound content and antioxidant capacity. We conclude that a delay of a few days in harvesting of sweet cherries would lead to achieve maximal nutritional (highest sugar and organic acid contents), sensory (greatest firmness and color development) and functional (greatest phenolics content, anthocyanins and antioxidant capacity) quality to provide both eating enjoyment and health benefits to the consumer.

Is it possible to increase the aloin content of Aloe vera by the use of ultraviolet light

In this paper, the effects of ultraviolet (UV) treatments on the aloin content of Aloe vera L. gel have been analyzed. UV-A treatment to A. vera plants for 36 days led to an increase in the aloin concentration in gel, rind tissue, and latex, while a decrease in chlorophylls a and b occurred in the photosynthetic tissue as a consequence of UV treatment. The growth of Penicillium digitatum and Botrytis cinerea (artificially inoculated on the leaf surface) was drastically decreased in UV-A-treated leaves, which could be attributed to the increase in the aloin concentration by the UV-A treatment. In addition, UV-C treatment to detached leaves also led to an increase in the gel aloin concentration, at higher levels than occurred with UV-A treatment, although leaves showed severe lesions after 48 h of treatment.

The addition of rosehip oil to Aloe gels improves their properties as postharvest coatings for maintaining quality in plum

The effect of Aloe vera gel (AV) and Aloe arborescens gel (AA) alone or in combination with rosehip oil (RO) at 2% on ethylene production, respiration rate, quality parameters, bioactive compounds and antioxidant activity during plum postharvest storage was studied. Coated plums showed a delay in ethylene production and respiration rate at 20°C and during cold storage and subsequent shelf life, the main effect being observed for those fruits coated with AA+RO. Quality parameters such as softening, colour and maturity index was also delayed during storage by the use of the coatings, which led to a 2-fold increase in plum storability. Accumulation of bioactive compounds was also delayed although at the end of the experiment the content of bioactive compounds was higher than those found for control fruits at the estimated shelf life. The most effective coating for maintaining plum quality and bioactive compounds was AA+RO.

Preharvest Application of Methyl Jasmonate as Elicitor Improves Yield and Phenolic Content of Artichoke

The effects of methyl jasmonate (MeJa) treatment as an elicitor of artichoke plants [Cynara cardunculus var. scolymus (L.) Fiori] on the yield and quality attributes of artichokes, especially those related to individual phenolic content and antioxidant activity, at two harvest dates and along storage were analyzed in this research. Plants treated gave a higher yield of artichokes in comparison to control plants, with 0.55 kg more per plant. MeJa treatment also increased artichoke quality and phenolic content in the edible fraction at harvest and during storage at 2 °C for 28 days as a result of the accumulation of hydroxycinnamic acids and luteolin derivatives. In addition, antioxidant activity was enhanced by MeJa treatment and correlated with the total phenolic content. Results suggest that MeJa foliar application could be a simple and practical tool to improve the yield and phytochemical content on artichokes, with elicitation being a cheap and environmentally friendly procedure to improve the health-beneficial effects of artichoke consumption.

Recent developments of 1-methylcyclopropene (1-MCP) treatments on fruit quality attributes

Abstract The plant hormone ethylene is involved in a wide range of physiological processes in horticultural crops, including mainly abscission, senescence, and ripening. These effects can be positive or negative depending on the desired use of the horticultural product. However, most postharvest handling is focused on controlling ethylene production or its action. Among the available methods, inhibition of ethylene action by 1-methylcyclopropene (1-MCP) has become a useful tool for the horticulture industry. By 2011 more than 40 countries had approved the use of 1-MCP for horticultural produce, registered with different names (EthylBloc ® , SamartFresh™, SmartTabs™, and EthylBloc™ Sachet) to be used on a wide variety of fruits and vegetables. In this chapter we describe the use of 1-MCP technology as a potent ethylene antagonist with satisfactory results on extending shelf life and maintaining fruit and vegetable quality.

Pre-harvest treatments of pepper plants with nitrophenolates increase crop yield and enhance nutritive and bioactive compounds in fruits at harvest and during storage

Pepper plants (Capsicum annuum L. cv Lamuyo) were treated with a mix of nitrophenolates either by foliar spray or in the irrigation system, and its effect on crop yield and the content of nutritive and bioactive compounds in fruit were analysed at harvest and after post-harvest storage. Treatments were applied at 2-week intervals from the development of first floral bunch (1 March) to end of August. Pepper fruits were harvested at commercial ripening stage (red surface colour) along the growth cycle (from May to September). Total yield (cumulative kilogram per plant) was increased (≈4.5% more) by nitrophenolate treatments due to significant increases in fruit mass, although the number of fruits per plant was unaffected. Pepper fruit quality (weight, firmness and pericarp thickness), its content in nutritive (sugars and organic acids) and bioactive compounds (vitamin C and total phenolics) and antioxidant activity were also enhanced by nitrophenolate treatments at the three harvested dates assayed (end May, mid July and end August). In addition, all these parameters were maintained at higher levels in treated peppers during storage, while diminutions in these parameters occurred generally in control fruit. Thus, nitrophenolate treatments were able to improve crop yield as well as the nutritional value and antioxidant properties of peppers at harvest and after fruit storage.

Enhancement of Antioxidant Systems and Storability of Two Plum Cultivars by Preharvest Treatments with Salicylates

In this research the effect of salicylic acid (SA), acetylsalicylic acid (ASA), and methylsalicylate (MeSA) treatments, applied as a foliar spray during on-tree plum development, on fruit quality attributes, bioactive compounds, antioxidant activity, and the activity of the antioxidant enzymes at harvest and after long-term cold storage was evaluated in two plum cultivars (“Black Splendor”, BS, and “Royal Rosa”, RR). At harvest, plum quality parameters, such as weight, total phenolics (including anthocyanins, in BS), total carotenoids, and antioxidant activity, in both hydrophilic and lipophilic compounds were found at higher levels in plums from SA-, ASA-, and MeSA-treated trees than in those from control trees. During storage, fruit firmness, total acidity, and antioxidant compounds were at higher levels in treated, than in control, plums, which show an effect of salicylate treatments on delaying the plum postharvest ripening process. In addition, the activity of the antioxidant enzymes catalase (CAT), peroxidase (POX), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were also enhanced at the time of harvest in salicylate-treated plums as compared with plums from control trees. The activity of these antioxidant enzymes was also found at higher levels in salicylate-treated plums during storage. Thus, preharvest treatment with salicylates could be a safe, eco-friendly, and new tool to improve and maintain plum quality attributes, and especially their content of antioxidant compounds, with an additional effect on delaying the postharvest ripening process through increasing the levels of antioxidant compounds and the activity of the antioxidant enzymes.