Eleven sweet cherry cultivars were harvested at three maturity stages (S1 to S3) based on skin color and stored at 2 °C for 16 days and a further period of 2 days at 20 °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.
Proanthocyanidins (PAs) were characterized in husk, membranes, arils, and seeds of ‘Mollar de Elche’ pomegranate cultivar using liquid chromatography–electrospray ionization–ion-trap tandem mass ...spectrometry after acid catalysis in the presence of phloroglucinol (phloroglucinolysis). PAs were also evaluated in commercial juice and in the juice made in the laboratory by pressing fresh arils. Pomegranate PAs were composed of a very rich mixture of flavan-3-ols: catechin, epicatechin, gallocatechin, epigallocatechin, epigallocatechin gallate, and epicatechin gallate. Catechins and gallocatechins were the most abundant units, while galloylated flavanols were detected at lower concentrations. The highest PA content was found in husk (1840.5 μg/g), followed by seeds (316.2 μg/g) and membranes (51.4 μg/g). With regard to the pomegranate edible parts, arils showed concentrations of 34.4 μg/g and pressed aril juice of 21.3 mg/L, lower than those found in other traditional PA-containing food and beverages, such as apple, grapes, chocolate, red wine, or tea. Higher concentrations similar to those found in red wine were observed in commercial whole fruit pressed pomegranate juice (146.9 mg/L). These PA concentrations represented between 0.1 and 7% of the total polyphenol content in the different pomegranate samples, which were richer in ellagitannins and anthocyanins. The mean degree of polymerization (1.2–2.1) revealed that PAs in Mollar pomegranate samples are constituted mainly of monomers and dimers, which may influence in better absorption and bioavailability of these compounds.
Sweet cherry cultivars (‘Cristalina’ and ‘Prime Giant’) harvested at commercial ripening stage were treated with salicylic acid (SA), acetylsalicylic acid (ASA) or oxalic acid (OA) at 1 mM and then ...stored for 20 days under cold temperature. Results showed that all treatments delayed the postharvest ripening process, manifested by lower acidity, color changes and firmness losses, and maintained quality attributes for longer periods than controls. In addition, total phenolics, anthocyanins and antioxidant activity increased in untreated fruit during the first 10 days of storage and then decreased, while in fruits of all treatments, these parameters increased continuously during storage without significant differences among treatments. Thus, postharvest treatments with natural compounds, such as SA, ASA or OA, could be innovative tools to extend the storability of sweet cherry with higher content of bioactive compounds and antioxidant activity as compared with control fruits.
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► Alginate as edible coating maintains plum quality during postharvest storage. ► Ethylene production was inhibited by alginate coating in 4 climacteric plum cultivars. ► Softening, ...weight and acidity losses were delayed by alginate treatment. ► Colour changes, due to anthocyanin and carotenoid accumulation, were retarded in alginate-coated plums.
Four plum (Prunus salicina Lindl.) cultivars (“Blackamber”, “Larry Ann”, “Golden Globe” and “Songold”), were treated with 1 or 3% alginate as an edible coating before storage. Analytical determinations were made after 7, 14, 21, 28 and 35 days at 2°C and after a 3 day period at 20°C (shelf-life). Both treatments were effective in inhibiting ethylene production for all cultivars, especially when 3% alginate was used. The changes in fruit quality parameters related to plum postharvest ripening, such as weight and acidity losses, softening and colour changes, were significantly delayed by the use of both edible coatings. The delay of the ripening process was also related to lower anthocyanin and carotenoid accumulation. Overall results suggest that these treatments could increase the plum storage period with optimum quality, 2 weeks for “Larry Ann” and “Songold” and 3 weeks for “Blackamber” and “Golden Globe” more than controls.
•Aloe vera gel maintains quality of ready-to-eat pomegranate arils.•Microbial spoilage was reduced in Aloe vera-coated arils.•Shelf life of pomegranate arils was extended with enhanced bioactive ...compounds.•Panellists preferred arils treated with Aloe vera alone or in combination with acids.
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 CO2 and higher O2 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.
γ-Aminobutyric acid (GABA) plays important roles in plant development, including the maintenance of fruit quality when applied as postharvest treatment. However, little information is available about ...the effects of preharvest GABA treatments. Thus, GABA (10, 50 and 100 mM) was applied as foliar spray at key points of fruit development in three sweet cherry cultivars and over two years. The results show that quality parameters, such as total soluble solid content, titratable acidity and firmness were higher in the fruit from GABA-treated trees than in the controls, either at harvest or during four weeks of cold storage. In addition, the total phenolic and total and individual anthocyanin concentrations were also enhanced by GABA treatments and the fruit color was improved. The activities of the antioxidant enzymes catalase, ascorbate peroxidase and peroxidase were also enhanced by the GABA treatments. The most effective concentration was 50 mM, which led to extending the storage period of sweet cherries with high quality traits to up to four weeks, while for the controls this was two weeks. Thus, GABA treatment had a clear effect on delaying the postharvest ripening and senescence processes in sweet cherries, with an additional effect on enhancing the content of bioactive compounds, such as phenolics and anthocyanins, with antioxidant properties and health benefits.
Sweet cherry fruits harvested at commercial maturity stage were treated with an edible coating based on sodium alginate at several concentrations (1%, 3% or 5%
w/v
). The coatings were effective on ...delaying the evolution of the parameters related to postharvest ripening, such as colour, softening and loss of acidity, and reducing respiration rate. In addition, the edible coatings showed a positive effect on maintaining higher concentration of total phenolics and total antioxidant activity, which decreased in control fruits associated with the over-ripening and senescence processes. Results from quality parameters and antioxidant activity suggested that the maximum storability period for control fruits was 8 days at 2 °C plus 2 days at 20 °C, while alginate-coated cherries could be stored with optimal quality and enhanced antioxidant activity up to 16 days at 2 °C plus 2 days at 20 °C.
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.
► Aloe vera reduces the fungal growth of
Rhizopus stlonifer,
Botrytis cinerea and
Penicillium digitatum.
► Aloe vera plus thymol does not improve the efficacy of
Aloe vera gel alone.
► Aloe vera as a treatment maintains fruits quality and reduces ripening by a delay in ethylene and respiration rate.
► Aloe vera could be considered as a natural antifungal product.
•Aloe arborescens gel as edible coating has been used for the first time in fruit.•Aloe vera and Aloe arborescens gels were effective on delaying ethylene climacteric production in both stone ...fruit.•Both coatings delayed ripening index, weight loss and colour evolution during storage at ambient temperature.•Aloe arborescens gel could be alternative to Aloe vera for commercial purposes.
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.
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