Alginate Coatings Preserve Fruit Quality and Bioactive Compounds during Storage of Sweet Cherry Fruit

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

Off-odor compounds responsible for quality loss of minimally processed baby spinach stored under MA of low O2 and high CO2 using GC–MS and olfactometry techniques

Strong off-odor development is still one of the major problems associated with quality loss of baby spinach stored in MA with low O2 and high CO2. Freshness has been generally evaluated by sensory techniques that allow the description of aromatic profiles but it does not identify the responsible compound(s). An approach including sensory analysis and Gas Chromatography-Mass Spectrometry (GC–MS)/Gas Chromatography-Olfactometric (GC-O) techniques were applied to elucidate the complex combination of volatile organic compounds (VOCs) responsible for the off-odor perception of intact baby spinach without generation of new volatiles due to tissue manipulation. After 14 days, levels of low O2 and high CO2 (0.3 and 9.3 kPa, respectively) were achieved and off-odors development was detected. After GC–MS/GC-O analysis, there were 39 main compounds with olfactory activity, identified as alcohols associated with lipid peroxidation or LOX pathway; sulfur compounds from amino acid degradation; and alkanes from lipid autoxidation processes or carotenoid degradation. Odor-active compounds were grouped into the six odor categories as described by the sensory panel, with rotten and fishy being the strongest odors perceived after storage. The isolated VOCs grouped in the rotten descriptor were the alcohols 1-pentanol, (Z)-3-hexen-1-ol and 1-octen-3-ol, and the sulfur compounds methanethiol and dimethyl disulfide. A compound responsible for fishy notes was dimethyl sulfide but some evidence indicated that amine compounds with low odor thresholds could be also implicated. Since sulfur compounds were perceived by all sniffers and easily detected by mass spectrometry, they may be good candidates as biomarkers of off-odors in baby spinach

Polyamines as an ecofriendly postharvest tool to maintain fruit quality

Polyamines (PAs) are natural compounds involved in a wide range of plant growth and developmental process, such as cell division, dormancy breaking, germination, development of flower buds, fruit set, growth and ripening, as well as in plant responses to environmental stresses including chilling injury. This chapter will focus on the role of PAs in fruit growth and ripening, with special emphasis on the effects of pre- and postharvest PA treatment on fruit quality attributes, bioactive constituents with antioxidant activity, and tolerance of fruit to chilling injury damage. The results of this chapter provide evidence for the numerous beneficial effects of the exogenous PA treatments, both at pre- and postharvest time in fruit quality attributes including their concentration in antioxidant compounds. Taking into account that PAs are naturally occurring molecules their application as pre- or postharvest treatment could be considered as an environmentally compatible tool as they can be metabolized by fruit cells. In addition, it should be pointed out that although exogenous application of PAs enhances their endogenous levels, the concentrations remain far lower than the toxic ones. Since modern agriculture is searching for effective biological molecules with well-known metabolic effects but without toxicological effects, a possible answer may be related to PA treatments

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 consume

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 °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 (HTAA) 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

Effects of alginate edible coating on preserving fruit quality in four plum cultivars during postharvest storage

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 arborescens and Aloe vera gels as coatings in delaying postharvest ripening in peach and plum fruit

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 frui

Aloe arborescens and Aloe vera gels as coatings in delaying postharvest ripening in peach and plum fruit

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 frui

Changes in hydrophilic and lipophilic antioxidant activity and related bioactive compounds during postharvest storage of yellow and purple plum cultivars

Eight plum cultivars (four dark-purple and four yellow) were harvested at the commercial ripening stage, and changes of fruit quality properties were evaluated during cold storage and subsequent shelf-life, with special emphasis on bioactive compounds (phenolics, anthocyanins and carotenoids) and antioxidant activity (TAA). From the eight plum cultivars, four showed the typical climacteric ripening pattern (‘Blackamber’, ‘Larry Ann’, ‘Golden Globe’ and ‘Songold’) while four behaved as suppressed-climacteric types (‘Golden Japan’ ‘Angeleno’, Black Diamond’ and ‘TC Sun’), the latter being described for the first time. At harvest, large variations in phytochemicals and antioxidant activity were found among cultivars in peel and pulp tissues, although phytochemical concentration and antioxidant activity were higher in the peel than in the flesh (2–40-fold depending on the bioactive compound). During storage, increases in total phenolics for all cultivars (peel and pulp), in total anthocyanin content in the peel of the dark-purple plums, and total carotenoids in the peel and pulp of the yellow cultivars were observed. This behaviour of the bioactive compounds was reflected in TAA changes, since hydrophilic-TAA (H-TAA) was correlated with both phenolics and anthocyanins, while lipophilic-TAA (L-TAA) was correlated with carotenoids. LTAA comprised about 30–50% of the TAA in plum tissues. Carotenoids and phenolics (and among them the anthocyanins) could be the main lipophilic and hydrophilic compounds contributing to L-TAA and H-TAA, respectively.No significant loss of bioactive compounds and TAA occurred during prolonged plum storage. Moreover, for a better evaluation of the antioxidant potential of plums, the contribution to carotenoids should not be overlooked