Fabian Guillen | Universidad Miguel Hernandez (original) (raw)

Papers by Fabian Guillen

Antioxidants

The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with... more The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with antioxidant activity at harvest and during storage at 10 °C for 60 days was assayed in two consecutive years, 2019 and 2020. In the first year, trees were treated with 0.1, 0.3 and 0.5 mM of melatonin along the developmental fruit growth cycle, and results showed that bioactive compounds (total phenolics and total and individual anthocyanins) and antioxidant activity at harvest were higher in fruits from melatonin-treated trees than in controls. Other fruit quality parameters, such as firmness, total soluble solids and aril red colour, were also increased as a consequence of melatonin treatment. In fruit from control tress, firmness and acidity levels decreased during storage, while increases occurred on total soluble solids, leading to fruit quality reductions. These changes were delayed, and even maintenance of total acidity was observed, in fruit from melatonin-treated trees with res...

Journal of the Science of Food and Agriculture, 2008

Tomato fruit ripening is a genetically programmed complex of events that terminates with senescen... more Tomato fruit ripening is a genetically programmed complex of events that terminates with senescence.1 In tomato, as well as in other climacteric fruits, the plant hormone ethylene is required for normal fruit ripening and is thus considered as trigger of a wide range of physical, ...

Critical Reviews in Food Science and Nutrition, 2007

Journal of Agricultural and Food Chemistry, 2011

The purpose of this work was to study the variation of phenol compounds, as measured by HPLC, dur... more The purpose of this work was to study the variation of phenol compounds, as measured by HPLC, during the chamber drying under controlled temperature conditions of red grapes of the Merlot and Tempranillo varieties in relation to antioxidant activity. Both lipophilic and hydrophilic antioxidant activities in these grapes increased during the drying process; the former was measured via proton transfer in the coupled oxidation reaction between linoleic acid and β-carotene, and the second via electron transfer in the DPPH assay. The hydrophilic component was invariably greater in Tempranillo grapes, and so was the lipophilic component in Merlot grapes. Only the increase in hydrophilic antioxidant activity obtained a significant correlation with the phenolic compounds during the drying process. However, based on the phenolic fraction analysis, this result was primarily due to phenolic polymers and, to a lesser extent, also to phenolic acids, flavans, and some flavonols and anthocyans.

Postharvest Biology and Technology, 2013

Several postharvest treatments were performed on pomegranate arils prior to storage in rigid poly... more Several postharvest treatments were performed on pomegranate arils prior to storage in rigid polypropylene boxes for 12 days at 3 • C: water (control), ascorbic + citric acids (at 0.5 or 1%), Aloe vera gel (at 50 or 100%), 50% A. vera gel + 0.5% ascorbic and 0.5% citric acid, and 100% A. vera gel + 1% ascorbic and 1% citric acid. A. vera (alone or in combination with acids) led to lower CO 2 and higher O 2 concentrations inside the packages compared with arils treated with water (control). With respect to quality attributes, A. vera coatings led to firmness retention and increased levels of total anthocyanins and total phenolics. In addition, A. vera treatments led to significantly lower counts for both mesophilic aerobics and yeast and moulds. Sensory analysis scores for flavour, texture, aroma, colour and purchase decision were higher in arils treated with A. vera, especially in those arils treated with 100% A. vera + 1% ascorbic and citric acids. Finally, no off-flavours in pomegranate arils were perceived by judges as a consequence of A. vera gel treatment.

Journal of Food Science, 2007

Consumers demand new means of preservation with absence of chemicals. In this work a package was ... more Consumers demand new means of preservation with absence of chemicals. In this work a package was developed (thermosealed baskets) with grapes wrapped with 2 distinct films (M and P) with different permeability (medium and high, respectively) without or with the addition of a mixture of eugenol, thymol, and carvacrol. Table grapes stored on air (control) lost their quality attributes very rapidly, manifested by accelerated weight loss, color changes, softening, and increase in soluble solids concentration and titratable acidity ratio (SSC/TA). The use of modified atmosphere packaging (MAP) alone retarded these changes, the effects being significantly greater when essential oils were added (especially for M film), although atmospheric composition was not affected by incorporating essential oils. In addition, microbial counts (molds and yeasts and mesophilic aerobics) were drastically decreased and accompanied by lower occurrence of berry decay. Although slight odor was detected after opening the packages, absence of the typical flavor of these compounds was found by trained panelists after tasting the berries. Thus, with this safe, simple, and innovative technology, the overall quality (sensory and safety) could be improved and considered as a toll alternative to the use of synthetic fungicides.

Journal of Food Science, 2002

Plums were treated with calcium or heat (45 °C) and then stored at 2 °C for 28 d. Fruit firmness,... more Plums were treated with calcium or heat (45 °C) and then stored at 2 °C for 28 d. Fruit firmness, ethylene, and CO 2 production rates were investigated. The concentrations of endogenous polyamines (free, conjugated-soluble, and cell wall-bound) were also studied. Both treatments improved fruit firmness by increases in Magness-Taylor force and force-deformation ratio, and decreases in flesh deformation. No differences were found in either ethylene or respiration rate production among fruits due to the low storage temperature. Calcium-treating plums increased the conjugated forms of putrescine (conjugated-soluble and cell wall-bound), which are related to higher firmness. Heat-treated plums mainly increased cell wall-bound spermidine, inducing a greater cell wall stability and plum firmness.

Journal of Agricultural and Food Chemistry, 2006

Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to... more Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to our developed patent (SP Patent P200302937) and then stored for 35 days at 1 degrees C, and the subsequent shelf life (SL) was monitored at 20 degrees C. Uncoated clusters showed a rapid loss of functional compounds, such as total phenolics and ascorbic acid. These changes were accompanied by reduction of the total antioxidant activity (TAA) and increases in total anthocyanins, showing an accelerated ripening process. On the contrary, table grapes coated with Aloe vera gel significantly delayed the above changes, such as the retention of ascorbic acid during cold storage or SL. Consequently, Aloe vera gel coating, a simple and noncontaminating treatment, maintained the functional properties during postharvest storage of table grapes.

Postharvest Biology and Technology, 2004

Plum (Prunus salicina Lindl. cv. Blackstar) fruit were harvested at the pre-climacteric stage of ... more Plum (Prunus salicina Lindl. cv. Blackstar) fruit were harvested at the pre-climacteric stage of ripeness. After being treated with calcium (calcium chloride at 1 mM) or heat at 45 • C (hot water dip immersion for 10 min), fruit were mechanically damaged at three equatorial zones with a given force of 50 N and then held at 20 • C under controlled conditions. Results revealed that both treatments led to a reduction of the mechanical damage, and in turn alleviated the physiological responses that occurred in mechanically damaged plums. A reduction of "wound-induced" ethylene and respiration rates, which were detected just a few hours following mechanical damage, was observed for treated plums. During storage, mechanical damage advanced the climacteric ethylene and respiration peaks, while a delay in those plums previously treated either with calcium or heat was found. Thereafter, control plums exhibited an accumulation of free spermidine and abscisic acid in mechanically damaged flesh, which could be considered a physiological response to mechanical stress. These changes were minimised in calcium-and heat-treated damaged plums, indicating that these treatments would induce a significant resistance to mechanical damage in plum.

Journal of Agricultural and Food Chemistry, 2003

The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 µL L -1... more The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 µL L -1 ) on the ripening processes of a climacteric, cv. Santa Rosa, and a suppressed climacteric type, cv. Golden Japan, plum was studied. For both cultivars, positive effects were observed in terms of inhibition of ethylene production and delays of the physical, chemical, and biochemical changes associated with ripening. 1-MCP-treated plums were firmer with lower weight loss, reduced°Brix/titratable acidity ratios, and lower color changes during cold storage and subsequent shelf life at 20°C than controls. For most factors, the effectiveness of 1-MCP was dose-dependent in Santa Rosa but doseindependent for Golden Japan.

Postharvest Biology and Technology, 2008

Lettuce (Lactuca sativa L.) is very sensitive to developing decay from microbial attack during th... more Lettuce (Lactuca sativa L.) is very sensitive to developing decay from microbial attack during the growing period, with severity being increased during postharvest storage. For this reason the application of fungicides is necessary. However, consumers are currently demanding produce free of synthetic chemicals. Thus, in this paper the efficacy of Fungastop TM (a nature-based fungicide) as an antimicrobial, as well as its effect on the overall lettuce quality, was evaluated at harvest and after cold storage and subsequent shelf-life at 20 • C. Two independent experiments were carried out during two different growth cycles: winter-spring and autumn-winter. Fungastop TM had the same efficacy as chemical fungicides in terms of reducing microbial spoilage at harvest with respect to control heads, which was also evident after long storage periods. In addition, lower weight loss and reduction in ethylene production and respiration rates were observed in both Fungastop TM and chemical treated lettuces than found in controls. There was a similar increase in lettuce shelf-life for both treatments compared to the controls, and thus the natural fungicide might be a good alternative to the use of synthetic fungicides, and in turn to fulfil consumer requirements for more natural and healthy foods.

Journal of the Science of Food and Agriculture, 2008

RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness an... more RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness and bioactive compounds) started at the early stages of fruit development, with significant differences among cultivars. Colour hue angle was highly correlated with increase in anthocyanins or ...

Journal of Agricultural and Food Chemistry, 2005

Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is ve... more Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is very susceptible to colonization by fungi, especially Botrytis cinerea, which is considered the most important disease of this commodity. To solve this problem, synthetic fungicides have been used, although legal restrictions and consumer's concern demand the search of other safe means. In the present paper, and as an alternative of synthetic fungicides, an active packaging to improve MAP effectiveness on preserving table grape (cv. Crimson Seedless) quality and safety was developed by the addition of 0.5 mL of eugenol, thymol, or menthol inside the packages. Packages were stored at 1 degree C for 35 days. The final gas composition inside the packages was 1.4-2.0 and 10.0-14.5 kPa of CO(2) and O(2), respectively, with no significant slight differences among treatments. Results showed that the addition of eugenol, thymol, or menthol improved the beneficial effect of MAP in terms of delaying weight loss and color changes, retarding degrees Brix/acidity ratio evolution, and maintaining of firmness. Thereafter, these treatments showed additional benefit in terms of delayed rates of rachis deterioration and berry decay. Finally, the total viable counts for both mesophilic aerobics and especially yeast and molds were significantly reduced in the grapes packaged with the natural antimicrobial compounds. All of the above effects led to maintenance of table grape quality and safety for longer storage periods (3 additional weeks as compared to controls under MAP only).

Postharvest Biology and Technology, 2010

Aloe vera gel was added at several concentrations on potato dextrose agar (PDA) to test its effic... more Aloe vera gel was added at several concentrations on potato dextrose agar (PDA) to test its efficacy on inhibiting mycelium growth of two common fungi responsible for fruit decay (Penicillium digitatum and Botrytis cinerea). For both fungi, the inhibition of mycelium growth rate increased with Aloe concentration, although to gain the same inhibition the necessary A. vera gel concentration was 3-fold higher for B. cinerea than P. digitatum. Overall, the dose of 250 mL L −1 led to 4-and 2-log reductions of mycelium growth for P. digitatum and B. cinerea, respectively. Based on these results, A. vera gel at 250 mL L −1 was applied as a preharvest treatment to table grape vineyards 1 or 1 and 7 days before harvesting. Fruit were cold-stored for 35 days and sampled weekly. Respiration rate and weight loss were significantly reduced in treated samples, while ripening parameters such as colour and fruit firmness were significantly delayed. Both mesophilic aerobics and mould and yeasts counts were significantly lower at harvest in treated samples, the effect being persistent during storage. At the end of the experiment, the percentage of rotted berries was significantly lower in treated than in control fruit. From these results it could be inferred that A. vera could be considered as a promising preharvest treatment to maintain table quality during postharvest storage.

Postharvest Biology and Technology, 2002

The role of putrescine was investigated, exogenously applied during postharvest storage of mechan... more The role of putrescine was investigated, exogenously applied during postharvest storage of mechanically damaged (50 N force) plums, (Prunus salicina Lindl., cv. BlackStar) at 10°C, in relation to fruit firmness (force-deformation ratio and fruit flesh deformation) and ethylene and CO 2 production rates. The metabolism of endogenous polyamines (free, conjugated-soluble, and cell wall-bound was also studied. Infiltration of putrescine led to a reduction in mechanical damage, and an increase in firmness of both force-deformation ratio and fruit flesh firmness parameters. Exogenous putrescine inhibited and delayed ethylene and CO 2 production rates. The analysis of polyamine metabolism revealed an activation of the polyamine biosynthesis pathway, showing an accumulation of cell wall putrescine and spermidine, which are possibly responsible for the greater firmness of putrescine-treated plums compared with controls. In these treated fruit, the increase in free spermidine levels could be acting as a physiological marker of mechanical damage.

Postharvest Biology and Technology, 2013

Recently harvested peaches and plums were coated with either Aloe vera or Aloe arborescens gels a... more Recently harvested peaches and plums were coated with either Aloe vera or Aloe arborescens gels and allowed to ripen at 20 • C for six days. Both coatings significantly delayed ethylene production, the effect being higher in plum which had the highest ethylene production rates. Changes in quality parameters related to peach and plum postharvest ripening, such as colour changes, reduction of acidity and increasing in ripening index (total soluble solids/total acidity ratio), were significantly delayed in coated fruit. In addition, both coatings significantly reduced weight loss, especially the A. arborescens gel. Thus, A. arborescens gel could be even more effective than A. vera gel for use as an edible coating for preserving the quality of climacteric fruit.

Postharvest Biology and Technology, 2014

ABSTRACT The effect of oxalic acid (OA) on the overall quality of artichokes (Cynara cardunculus ... more ABSTRACT The effect of oxalic acid (OA) on the overall quality of artichokes (Cynara cardunculus L subsp. scolymus (L) Hayek, formerly Cynara scolymus L. cv. Blanca de Tudela) was investigated for the first time in this vegetable. Artichokes were dipped in OA solution at 1 mM for 10 mm and then stored at 20 degrees C. OA application delayed the deterioration process in artichokes during storage by retarding weight loss, softening, colour changes and chlorophyll degradation. In addition OA significantly reduced mesophilic aerobics and yeast and moulds counts with respect to controls. Finally, the content of total phenolics and antioxidant activity were not affected negatively by OA treatment. Thus, OA treatment might be a promising method for delaying postharvest deterioration and maintaining the overall quality of artichokes.

International Journal of Food Microbiology, 2011

Two nectarine cultivars ('Flavela' and 'Flanoba') were treated with Aloe vera gel alone, or with ... more Two nectarine cultivars ('Flavela' and 'Flanoba') were treated with Aloe vera gel alone, or with the addition of thymol, and then inoculated with Rhizopus stolonifer, Botrytis cinerea and Penicillium digitatum. Both treatments were effective in reducing the decay incidence caused by the 3 fungi species, although the addition of thymol did not generally improve the efficacy of Aloe vera gel on reducing the infection damage. The coatings were clearly effective in reducing the postharvest ripening process of both nectarine cultivars manifested by a delay in ethylene production and respiration rate, weight loss and softening. Interestingly, these coatings showed effectiveness on reducing decay development in inoculated fruits and thus Aloe vera could be considered as natural antifungal compound and might serve as alternative of synthetic fungicides.

Journal of Agricultural and Food Chemistry, 2006

Heat treatments have been used to extend storability of several fruits, although no information i... more Heat treatments have been used to extend storability of several fruits, although no information is available about their effects on nutritive and functional properties in pomegranates, which was the objective of this research. Thus, pomegranate fruits were heat treated (dips at 45°C for 4 min) and stored at 2°C for 90 days. Every 15 days, samples were taken and further stored 2 days at 20°C for shelf life study. Arils from heat-treated pomegranates exhibited higher total antioxidant activity than controls, which was correlated primarily to the high levels of total phenolics and to lesser extent to ascorbic acid and anthocyanin contents. Additionally, the levels of sugars (glucose and fructose) and organic acids (malic, citric, and oxalic acids) remained also at higher concentrations in arils from treated fruits. With this simple and non-contaminant technology, the functional and nutritive properties, after long periods of storage, could then be even greater than in recently harvested fruits, thus providing a high content in health-beneficial compounds to consumers after the intake of these fruits.

Journal of Food Science, 2003

were packed in either nonperforated polypropylene or perforated polypropylene films and stored at... more were packed in either nonperforated polypropylene or perforated polypropylene films and stored at 1 °C for 53 d. Nonperforated polypropylene packages had the highest CO 2 and lowest O 2 contents, with reduced weight losses and increased berry and skin firmness. Soluble solids concentration increased in unwrapped control grapes as a consequence of the higher weight losses, whereas no significant differences were found for titratable acidity. Both films were equally effective in maintaining skin color, whereas control grapes showed a reduction of color. The highest scores in sensory analyses for crunchiness, juiciness, sourness, and quality were given to nonperforated polypropylene packages after 18 d of storage, and good visual aspect and no off-flavor were detected after 53 d of cold storage.

Antioxidants

The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with... more The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with antioxidant activity at harvest and during storage at 10 °C for 60 days was assayed in two consecutive years, 2019 and 2020. In the first year, trees were treated with 0.1, 0.3 and 0.5 mM of melatonin along the developmental fruit growth cycle, and results showed that bioactive compounds (total phenolics and total and individual anthocyanins) and antioxidant activity at harvest were higher in fruits from melatonin-treated trees than in controls. Other fruit quality parameters, such as firmness, total soluble solids and aril red colour, were also increased as a consequence of melatonin treatment. In fruit from control tress, firmness and acidity levels decreased during storage, while increases occurred on total soluble solids, leading to fruit quality reductions. These changes were delayed, and even maintenance of total acidity was observed, in fruit from melatonin-treated trees with res...

Journal of the Science of Food and Agriculture, 2008

Tomato fruit ripening is a genetically programmed complex of events that terminates with senescen... more Tomato fruit ripening is a genetically programmed complex of events that terminates with senescence.1 In tomato, as well as in other climacteric fruits, the plant hormone ethylene is required for normal fruit ripening and is thus considered as trigger of a wide range of physical, ...

Critical Reviews in Food Science and Nutrition, 2007

Journal of Agricultural and Food Chemistry, 2011

The purpose of this work was to study the variation of phenol compounds, as measured by HPLC, dur... more The purpose of this work was to study the variation of phenol compounds, as measured by HPLC, during the chamber drying under controlled temperature conditions of red grapes of the Merlot and Tempranillo varieties in relation to antioxidant activity. Both lipophilic and hydrophilic antioxidant activities in these grapes increased during the drying process; the former was measured via proton transfer in the coupled oxidation reaction between linoleic acid and β-carotene, and the second via electron transfer in the DPPH assay. The hydrophilic component was invariably greater in Tempranillo grapes, and so was the lipophilic component in Merlot grapes. Only the increase in hydrophilic antioxidant activity obtained a significant correlation with the phenolic compounds during the drying process. However, based on the phenolic fraction analysis, this result was primarily due to phenolic polymers and, to a lesser extent, also to phenolic acids, flavans, and some flavonols and anthocyans.

Postharvest Biology and Technology, 2013

Several postharvest treatments were performed on pomegranate arils prior to storage in rigid poly... more Several postharvest treatments were performed on pomegranate arils prior to storage in rigid polypropylene boxes for 12 days at 3 • C: water (control), ascorbic + citric acids (at 0.5 or 1%), Aloe vera gel (at 50 or 100%), 50% A. vera gel + 0.5% ascorbic and 0.5% citric acid, and 100% A. vera gel + 1% ascorbic and 1% citric acid. A. vera (alone or in combination with acids) led to lower CO 2 and higher O 2 concentrations inside the packages compared with arils treated with water (control). With respect to quality attributes, A. vera coatings led to firmness retention and increased levels of total anthocyanins and total phenolics. In addition, A. vera treatments led to significantly lower counts for both mesophilic aerobics and yeast and moulds. Sensory analysis scores for flavour, texture, aroma, colour and purchase decision were higher in arils treated with A. vera, especially in those arils treated with 100% A. vera + 1% ascorbic and citric acids. Finally, no off-flavours in pomegranate arils were perceived by judges as a consequence of A. vera gel treatment.

Journal of Food Science, 2007

Consumers demand new means of preservation with absence of chemicals. In this work a package was ... more Consumers demand new means of preservation with absence of chemicals. In this work a package was developed (thermosealed baskets) with grapes wrapped with 2 distinct films (M and P) with different permeability (medium and high, respectively) without or with the addition of a mixture of eugenol, thymol, and carvacrol. Table grapes stored on air (control) lost their quality attributes very rapidly, manifested by accelerated weight loss, color changes, softening, and increase in soluble solids concentration and titratable acidity ratio (SSC/TA). The use of modified atmosphere packaging (MAP) alone retarded these changes, the effects being significantly greater when essential oils were added (especially for M film), although atmospheric composition was not affected by incorporating essential oils. In addition, microbial counts (molds and yeasts and mesophilic aerobics) were drastically decreased and accompanied by lower occurrence of berry decay. Although slight odor was detected after opening the packages, absence of the typical flavor of these compounds was found by trained panelists after tasting the berries. Thus, with this safe, simple, and innovative technology, the overall quality (sensory and safety) could be improved and considered as a toll alternative to the use of synthetic fungicides.

Journal of Food Science, 2002

Plums were treated with calcium or heat (45 °C) and then stored at 2 °C for 28 d. Fruit firmness,... more Plums were treated with calcium or heat (45 °C) and then stored at 2 °C for 28 d. Fruit firmness, ethylene, and CO 2 production rates were investigated. The concentrations of endogenous polyamines (free, conjugated-soluble, and cell wall-bound) were also studied. Both treatments improved fruit firmness by increases in Magness-Taylor force and force-deformation ratio, and decreases in flesh deformation. No differences were found in either ethylene or respiration rate production among fruits due to the low storage temperature. Calcium-treating plums increased the conjugated forms of putrescine (conjugated-soluble and cell wall-bound), which are related to higher firmness. Heat-treated plums mainly increased cell wall-bound spermidine, inducing a greater cell wall stability and plum firmness.

Journal of Agricultural and Food Chemistry, 2006

Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to... more Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to our developed patent (SP Patent P200302937) and then stored for 35 days at 1 degrees C, and the subsequent shelf life (SL) was monitored at 20 degrees C. Uncoated clusters showed a rapid loss of functional compounds, such as total phenolics and ascorbic acid. These changes were accompanied by reduction of the total antioxidant activity (TAA) and increases in total anthocyanins, showing an accelerated ripening process. On the contrary, table grapes coated with Aloe vera gel significantly delayed the above changes, such as the retention of ascorbic acid during cold storage or SL. Consequently, Aloe vera gel coating, a simple and noncontaminating treatment, maintained the functional properties during postharvest storage of table grapes.

Postharvest Biology and Technology, 2004

Plum (Prunus salicina Lindl. cv. Blackstar) fruit were harvested at the pre-climacteric stage of ... more Plum (Prunus salicina Lindl. cv. Blackstar) fruit were harvested at the pre-climacteric stage of ripeness. After being treated with calcium (calcium chloride at 1 mM) or heat at 45 • C (hot water dip immersion for 10 min), fruit were mechanically damaged at three equatorial zones with a given force of 50 N and then held at 20 • C under controlled conditions. Results revealed that both treatments led to a reduction of the mechanical damage, and in turn alleviated the physiological responses that occurred in mechanically damaged plums. A reduction of "wound-induced" ethylene and respiration rates, which were detected just a few hours following mechanical damage, was observed for treated plums. During storage, mechanical damage advanced the climacteric ethylene and respiration peaks, while a delay in those plums previously treated either with calcium or heat was found. Thereafter, control plums exhibited an accumulation of free spermidine and abscisic acid in mechanically damaged flesh, which could be considered a physiological response to mechanical stress. These changes were minimised in calcium-and heat-treated damaged plums, indicating that these treatments would induce a significant resistance to mechanical damage in plum.

Journal of Agricultural and Food Chemistry, 2003

The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 µL L -1... more The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 µL L -1 ) on the ripening processes of a climacteric, cv. Santa Rosa, and a suppressed climacteric type, cv. Golden Japan, plum was studied. For both cultivars, positive effects were observed in terms of inhibition of ethylene production and delays of the physical, chemical, and biochemical changes associated with ripening. 1-MCP-treated plums were firmer with lower weight loss, reduced°Brix/titratable acidity ratios, and lower color changes during cold storage and subsequent shelf life at 20°C than controls. For most factors, the effectiveness of 1-MCP was dose-dependent in Santa Rosa but doseindependent for Golden Japan.

Postharvest Biology and Technology, 2008

Lettuce (Lactuca sativa L.) is very sensitive to developing decay from microbial attack during th... more Lettuce (Lactuca sativa L.) is very sensitive to developing decay from microbial attack during the growing period, with severity being increased during postharvest storage. For this reason the application of fungicides is necessary. However, consumers are currently demanding produce free of synthetic chemicals. Thus, in this paper the efficacy of Fungastop TM (a nature-based fungicide) as an antimicrobial, as well as its effect on the overall lettuce quality, was evaluated at harvest and after cold storage and subsequent shelf-life at 20 • C. Two independent experiments were carried out during two different growth cycles: winter-spring and autumn-winter. Fungastop TM had the same efficacy as chemical fungicides in terms of reducing microbial spoilage at harvest with respect to control heads, which was also evident after long storage periods. In addition, lower weight loss and reduction in ethylene production and respiration rates were observed in both Fungastop TM and chemical treated lettuces than found in controls. There was a similar increase in lettuce shelf-life for both treatments compared to the controls, and thus the natural fungicide might be a good alternative to the use of synthetic fungicides, and in turn to fulfil consumer requirements for more natural and healthy foods.

Journal of the Science of Food and Agriculture, 2008

RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness an... more RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness and bioactive compounds) started at the early stages of fruit development, with significant differences among cultivars. Colour hue angle was highly correlated with increase in anthocyanins or ...

Journal of Agricultural and Food Chemistry, 2005

Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is ve... more Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is very susceptible to colonization by fungi, especially Botrytis cinerea, which is considered the most important disease of this commodity. To solve this problem, synthetic fungicides have been used, although legal restrictions and consumer's concern demand the search of other safe means. In the present paper, and as an alternative of synthetic fungicides, an active packaging to improve MAP effectiveness on preserving table grape (cv. Crimson Seedless) quality and safety was developed by the addition of 0.5 mL of eugenol, thymol, or menthol inside the packages. Packages were stored at 1 degree C for 35 days. The final gas composition inside the packages was 1.4-2.0 and 10.0-14.5 kPa of CO(2) and O(2), respectively, with no significant slight differences among treatments. Results showed that the addition of eugenol, thymol, or menthol improved the beneficial effect of MAP in terms of delaying weight loss and color changes, retarding degrees Brix/acidity ratio evolution, and maintaining of firmness. Thereafter, these treatments showed additional benefit in terms of delayed rates of rachis deterioration and berry decay. Finally, the total viable counts for both mesophilic aerobics and especially yeast and molds were significantly reduced in the grapes packaged with the natural antimicrobial compounds. All of the above effects led to maintenance of table grape quality and safety for longer storage periods (3 additional weeks as compared to controls under MAP only).

Postharvest Biology and Technology, 2010

Aloe vera gel was added at several concentrations on potato dextrose agar (PDA) to test its effic... more Aloe vera gel was added at several concentrations on potato dextrose agar (PDA) to test its efficacy on inhibiting mycelium growth of two common fungi responsible for fruit decay (Penicillium digitatum and Botrytis cinerea). For both fungi, the inhibition of mycelium growth rate increased with Aloe concentration, although to gain the same inhibition the necessary A. vera gel concentration was 3-fold higher for B. cinerea than P. digitatum. Overall, the dose of 250 mL L −1 led to 4-and 2-log reductions of mycelium growth for P. digitatum and B. cinerea, respectively. Based on these results, A. vera gel at 250 mL L −1 was applied as a preharvest treatment to table grape vineyards 1 or 1 and 7 days before harvesting. Fruit were cold-stored for 35 days and sampled weekly. Respiration rate and weight loss were significantly reduced in treated samples, while ripening parameters such as colour and fruit firmness were significantly delayed. Both mesophilic aerobics and mould and yeasts counts were significantly lower at harvest in treated samples, the effect being persistent during storage. At the end of the experiment, the percentage of rotted berries was significantly lower in treated than in control fruit. From these results it could be inferred that A. vera could be considered as a promising preharvest treatment to maintain table quality during postharvest storage.

Postharvest Biology and Technology, 2002

The role of putrescine was investigated, exogenously applied during postharvest storage of mechan... more The role of putrescine was investigated, exogenously applied during postharvest storage of mechanically damaged (50 N force) plums, (Prunus salicina Lindl., cv. BlackStar) at 10°C, in relation to fruit firmness (force-deformation ratio and fruit flesh deformation) and ethylene and CO 2 production rates. The metabolism of endogenous polyamines (free, conjugated-soluble, and cell wall-bound was also studied. Infiltration of putrescine led to a reduction in mechanical damage, and an increase in firmness of both force-deformation ratio and fruit flesh firmness parameters. Exogenous putrescine inhibited and delayed ethylene and CO 2 production rates. The analysis of polyamine metabolism revealed an activation of the polyamine biosynthesis pathway, showing an accumulation of cell wall putrescine and spermidine, which are possibly responsible for the greater firmness of putrescine-treated plums compared with controls. In these treated fruit, the increase in free spermidine levels could be acting as a physiological marker of mechanical damage.

Postharvest Biology and Technology, 2013

Recently harvested peaches and plums were coated with either Aloe vera or Aloe arborescens gels a... more Recently harvested peaches and plums were coated with either Aloe vera or Aloe arborescens gels and allowed to ripen at 20 • C for six days. Both coatings significantly delayed ethylene production, the effect being higher in plum which had the highest ethylene production rates. Changes in quality parameters related to peach and plum postharvest ripening, such as colour changes, reduction of acidity and increasing in ripening index (total soluble solids/total acidity ratio), were significantly delayed in coated fruit. In addition, both coatings significantly reduced weight loss, especially the A. arborescens gel. Thus, A. arborescens gel could be even more effective than A. vera gel for use as an edible coating for preserving the quality of climacteric fruit.

Postharvest Biology and Technology, 2014

ABSTRACT The effect of oxalic acid (OA) on the overall quality of artichokes (Cynara cardunculus ... more ABSTRACT The effect of oxalic acid (OA) on the overall quality of artichokes (Cynara cardunculus L subsp. scolymus (L) Hayek, formerly Cynara scolymus L. cv. Blanca de Tudela) was investigated for the first time in this vegetable. Artichokes were dipped in OA solution at 1 mM for 10 mm and then stored at 20 degrees C. OA application delayed the deterioration process in artichokes during storage by retarding weight loss, softening, colour changes and chlorophyll degradation. In addition OA significantly reduced mesophilic aerobics and yeast and moulds counts with respect to controls. Finally, the content of total phenolics and antioxidant activity were not affected negatively by OA treatment. Thus, OA treatment might be a promising method for delaying postharvest deterioration and maintaining the overall quality of artichokes.

International Journal of Food Microbiology, 2011

Two nectarine cultivars ('Flavela' and 'Flanoba') were treated with Aloe vera gel alone, or with ... more Two nectarine cultivars ('Flavela' and 'Flanoba') were treated with Aloe vera gel alone, or with the addition of thymol, and then inoculated with Rhizopus stolonifer, Botrytis cinerea and Penicillium digitatum. Both treatments were effective in reducing the decay incidence caused by the 3 fungi species, although the addition of thymol did not generally improve the efficacy of Aloe vera gel on reducing the infection damage. The coatings were clearly effective in reducing the postharvest ripening process of both nectarine cultivars manifested by a delay in ethylene production and respiration rate, weight loss and softening. Interestingly, these coatings showed effectiveness on reducing decay development in inoculated fruits and thus Aloe vera could be considered as natural antifungal compound and might serve as alternative of synthetic fungicides.

Journal of Agricultural and Food Chemistry, 2006

Heat treatments have been used to extend storability of several fruits, although no information i... more Heat treatments have been used to extend storability of several fruits, although no information is available about their effects on nutritive and functional properties in pomegranates, which was the objective of this research. Thus, pomegranate fruits were heat treated (dips at 45°C for 4 min) and stored at 2°C for 90 days. Every 15 days, samples were taken and further stored 2 days at 20°C for shelf life study. Arils from heat-treated pomegranates exhibited higher total antioxidant activity than controls, which was correlated primarily to the high levels of total phenolics and to lesser extent to ascorbic acid and anthocyanin contents. Additionally, the levels of sugars (glucose and fructose) and organic acids (malic, citric, and oxalic acids) remained also at higher concentrations in arils from treated fruits. With this simple and non-contaminant technology, the functional and nutritive properties, after long periods of storage, could then be even greater than in recently harvested fruits, thus providing a high content in health-beneficial compounds to consumers after the intake of these fruits.

Journal of Food Science, 2003

were packed in either nonperforated polypropylene or perforated polypropylene films and stored at... more were packed in either nonperforated polypropylene or perforated polypropylene films and stored at 1 °C for 53 d. Nonperforated polypropylene packages had the highest CO 2 and lowest O 2 contents, with reduced weight losses and increased berry and skin firmness. Soluble solids concentration increased in unwrapped control grapes as a consequence of the higher weight losses, whereas no significant differences were found for titratable acidity. Both films were equally effective in maintaining skin color, whereas control grapes showed a reduction of color. The highest scores in sensory analyses for crunchiness, juiciness, sourness, and quality were given to nonperforated polypropylene packages after 18 d of storage, and good visual aspect and no off-flavor were detected after 53 d of cold storage.