Postharvest Quality Parameters Research Articles

Evaluating the application feasibility of thyme oil nanoemulsion coating for extending the shelf life of papaya (Carica papaya cv. Tainung No. 2) with postharvest physiology and quality parameters

Papaya (Carica papaya L.) is a typical climacteric fruit with a brief shelf life due to the rapid degradation of quality during post-ripening, necessitating appropriate postharvest management to address this challenge. This study aimed to investigate the characteristics of thyme oil nanoemulsion (TO-NE) coating and utilize its benefits for preserving papaya. This study also investigated the physiological properties and quality changes of papaya storage at 20 ℃ and, in parallel, examined the effects of TO-NE coating to mitigate microbial infection of papaya during storage. The postharvest papaya was soaked in different concentrations (0.1, 0.25, and 0.5 mg/g) of TO-NE for coating. At the same time, the decay loss rate and effective shelf life were also evaluated. This study revealed that polygalacturonase (PG) and pectinesterase (PME) activities were inhibited during the storage of papaya treated with 0.25 mg/g TO-NE coated compared to the control group. This resulted in the preservation of the firmness of papaya fruits, in addition to a higher ascorbic acid content, delayed total soluble solids (TSS) accumulation, and total chlorophyll content (TCC) degradation, with a lagging color change for two days. The respiration rate and ethylene production were suppressed, while the 0.25 mg/g TO-NE coated group at day 14 (ethylene peak) were 63.2 mg CO2 kg−1 h−1 and 7.3 µL kg−1 h−1, lower than control. The 0.25 mg/g TO-NE coating treatment significantly reduced the decay rate for 10 days of storage, preserving their appearance and facilitating ripening. This is a viable option for extending Tainung No.2 papaya shelf life.Graphical

Postharvest Quality of Citrus medica L. (cv Liscia-Diamante) Fruit Stored at Different Temperatures: Volatile Profile and Antimicrobial Activity of Essential Oils.

Citron (Citrus medica L. cv. Liscia-diamante), cultivated in the "Riviera dei Cedri" (southern Italy), is mainly utilized in the production of candied fruit and essential oils (EOs). Up to now, no information regarding the effect of storage temperatures on citron has been reported. Here, citron samples, after harvesting, were stored at different temperatures (5, 10 and 20 °C at 70% relative humidity) for two weeks, and the main postharvest quality parameters were evaluated. Moreover, EOs extracted from the stored samples were chemically characterized to reveal changes in the volatiles profile and antimicrobial activity. The EOs presented monoterpene hydrocarbons (87.1 to 96.3% of the total oil profile) as the most abundant compounds, followed by oxygenated metabolites ranging from 9.7 to 3.1% of the total pattern. Postharvest quality traits showed a good retention of green peel color during storage at 5 °C, while EOs from samples stored for 7 and 14 days at 10 and 20 °C, respectively, showed the highest antimicrobial activity against most assayed strains. The results indicated storage at 10 °C for 7 days as the most suitable for the preservation of the postharvest quality of the fruit and the antimicrobial activity of the extracted EOs.

Antifungal activity of essential oils rich in ketones against Botrytis cinerea: New strategy for biocontrol

Plant secondary metabolites, including essential oils (EOs), are becoming an alternative to traditional methods of controlling phytopathogens. In the present work we evaluated the antifungal activity of EOs from two populations of Aloysia polystachya on the causal agent of gray mold, Botrytis cinerea. The chemical composition of EOs showed carvone and α-thujone as the main components of each EO, determining that they were two different chemotypes. The antifungal effect of both chemotypes against B. cinerea was evaluated in their vapor phase, at different concentrations. The MIC for the carvone-rich chemotype was 71 μL L−1, while the α-thujone-rich chemotype completely inhibited growth at a concentration of 189 μL L−1. Both chemotypes significantly inhibited the germination of fungal conidia. The normal morphology of the hyphae of B. cinerea was compromised in the presence of both chemotypes, showing flattening and emptying of the content, compared to the untreated mycelium. The effect of the chemotypes on the disease caused by the fungus was also evaluated in artificially inoculated tomatoes, with the carvone-rich chemotype being more effective in reducing the characteristic symptoms. None of the chemotypes produced alterations in postharvest quality parameters. Our data allow us to propose the EO of A. polystachya with abundant content of the terpene carvone, as a natural strategy for the control of the pathogen B. cinerea. This research is important to show how the existence of variants within the same botanical species implies differences in their effectiveness as fungicides.

Volatile Metabolites to Assess the Onset of Chilling Injury in Fresh-Cut Nectarines.

Fresh-cut processing is a good strategy to enhance the commercialization of peaches and nectarines, which easily deteriorate during low-temperature storage mostly due to the occurrence of chilling injury. Although several studies have been performed to improve the shelf-life of fresh-cut stone fruit, the achievement of high-quality fresh-cut peaches and nectarines still constitutes a challenge. The present study aimed to gain insights into the evolution of the postharvest quality of fresh-cut nectarines (Prunus persica L. Batsch) Big Bang, cold-stored at two different storage temperatures (4 and 8 °C) for up to 10 days. Several aspects influencing the quality traits (sensory and postharvest quality parameters; the profile of phenolic and volatile organic compounds (VOCs)) were explored to predict the marketable life of the fresh-cut nectarines. The respiration rate was higher in samples stored at 4 °C, while the browning process was more evident in fruit stored at 8 °C. Partial Least Squares Regression performed on VOCs showed that samples stored at 4 °C and 8 °C presented a different time evolution during the experiment and the trajectories depended on the interaction between time and temperature. Moreover, Multiple Linear Regression analysis discovered that the 17 VOCs affected by the storage conditions seemed to suggest that no chilling injury was detected for nectarines Big Bang. In conclusion, this approach could also be used with other nectarine cultivars and/or different stone fruits.

The Impact of Rootstock on "Big Top" Nectarine Postharvest Concerning Chilling Injury, Biochemical and Molecular Parameters.

Peaches and nectarines have a short shelf life even when harvested at appropriate physiological maturity. Market life is increased by storage at low temperatures. However, chilling injury symptoms can appear, causing physiological disorders and limiting shipping potential. The rootstock effect on the post-harvest quality has hardly been explored. Thus, the principal aim of this work was to study the influence of seven different Prunus rootstocks on the "Big Top" nectarine cv, considering harvest and post-harvest quality parameters and their correlation with chilling injury disorders. Basic fruit quality traits, individual sugars and organic acids analyzed by HPLC and other biochemical compounds such as relative antioxidant capacity, total phenolics content, flavonoids, anthocyanins, vitamin C and related enzyme activities (PAL, POD, PPO) were considered. In addition, correlations with possible candidate genes for chilling injury (CI) tolerance were searched by qPCR. Although a low susceptibility to CI symptoms has been found in "Big Top", rootstocks "PADAC 9902-01", "PADAC 99-05" and "ReplantPAC" exhibited lower CI symptoms. A statistically significant influence of the evaluated rootstocks was found concerning the parameters of this study. Phenols and anthocyanins seem to be important parameters to be considered in the prevention of chilling injury disorders. Moreover, PAL1, PPO4, PG2 and LDOX genes relative expressions were positively associated with chilling injury susceptibility. This study opens new perspectives for understanding peach fruit adaptation and response to cold storage temperatures during the post-harvest period.

Chitosan Coating Incorporated with Carvacrol Improves Postharvest Guava (Psidium guajava) Quality

Guava (Psidium guajava L.) is an important economic crop grown widely in tropical and subtropical regions. Guava exhibits fast ripening and senescence as a climacteric fruit, causing a short shelf life and quality deterioration. Chitosan–essential oil nanoemulsions can be an edible coating used to improve postharvest quality attributes. In this study, chitosan was mixed with carvacrol to generate a nano-emulsoid solution containing 0.1 and 0.2% (v/v) carvacrol, using a sonic dismembrator. Guava fruit were coated with the above emulsion and postharvest quality parameters were measured during storage at 20 ± 1 °C and RH = 80 ± 5% for 8 days. The result illustrated that the particle size of the chitosan–carvacrol emulsions was nanoscale, and their high stability was demonstrated by the zeta potential and polydispersity index. Chitosan coating (2%, w/v, 310–375 kDa) containing 0.2% (v/v) carvacrol maintained postharvest quality compared to chitosan alone, with higher firmness, soluble solid content, total acid, and total phenol content, and lower weight loss and pericarp browning. The collective data were further verified by principal component analysis. A chitosan coating containing carvacrol can reduce postharvest losses. It can be applied as an effective strategy to improve postharvest fruit quality.

Bio-based nanomaterial suspensions as sprayable coatings for maintaining blueberry postharvest quality

The growing concerns about postharvest fruit spoilage demand sustainable active coating materials with high performance. In this work, bioactive spray coating suspensions were developed for the postharvest preservation of blueberries using chitosan, cellulose, and lignocellulose nanofibers (ChNFs, CNFs, and LCNFs), sodium alginate (SA), and tea tree essential oil (TTO). Characteristics, including the rheological properties of coatings and the effect on physicochemical postharvest quality parameters of blueberry fruit were investigated. The nanomaterials and SA were shown to make stable and sprayable coating suspensions with high surface charge (zeta potential value of −61.3 mV), shear thinning behavior, steady viscosity, and outstanding viscoelastic behavior from their ability to restore fibrous network structure and ion strength of SA to inhibit nanofibers aggregation. The coatings with LCNFs and SA were more effective in retarding moisture loss of postharvest blueberries during storage compared with coatings without LCNFs and SA. Blueberries coated with ChNF/LCNF/SA/TTO had a soluble solids content (SSC) increase of 16.2% after 15 storage days, while uncoated and other coated blueberries had more than a 21.7% SSC increase. In addition, the ChNF/LCNF/SA/TTO coating had an entangled matrix structure and enhanced hydrophobicity, improving gas barrier performance on the blueberry surface. As a result, the coating was able to preserve the moisture, stiffness, firmness, and individual sugar contents of blueberries during storage. Utilizing nanomaterials and other natural polysaccharides in coatings can offer an economically feasible and sustainable approach for functionalizing biomass materials to preserve fruits.

Increasing the Vase Life of Chrysanthemum Cut Flowers by Using Silver and Zinc Nanoparticles.

Cut flowers are horticultural products that have great potential to be developed. Efforts to maintain quality and extend the shelf life of cut flowers are very important to obtain a product that is accepted in the market. The main problems of chrysanthemum cut flowers are the leaves easily turning yellow, wilting, and failure to fully open flowers. This study aimed to obtain the best pulsing solution formulation that increases vase life and maintains the freshness of chrysanthemum cut flowers. Pulsing solution treatment was carried out on chrysanthemum cut flowers during the evaluation period. Pulsing solution treatment consisted of control, AgNO3, nano-Ag (NAg), ZnO, and nano-Zn (NZn). The results showed that NAg20 treatment increased the vase life of chrysanthemum cut flowers up to 23 days, which was 19 days longer than the control. Nano-Ag inhibits bacterial growth, flower wilting, color degradation, and carotenoids. In addition, nano-Ag increased the size of the bloom-flower diameter. Considering the results of all postharvest quality parameters mentioned above, NAg20 extends the vase life of chrysanthemum cut flowers.

Harnessing the metabolic modulatory and antioxidant power of 1-(3-Phenyl-Propyl) cyclopropane and melatonin in maintaining mango fruit quality and prolongation storage life

BackgroundThe aim of this study was to compare and investigate the effects of 1-(3-phenyl-propyl) cyclopropene (PPCP) and melatonin (MT) as anti-ethylene agents on postharvest senescence, quality, chilling tolerance, and antioxidant metabolism in the mango fruit cv. “Keitt”. The study involved exposing the fruit to 20 μL L− 1 PPCP or 200 μM MT, in addition to a control group of untreated fruit, before storing them at 5 ± 1 °C for 28 d. The findings revealed that the treatments with PPCP and MT were effective in reducing chilling injury and preserving fruit quality when compared to the control group.ResultsThe use of 20 μL L− 1 PPCP was an effective treatment in terms of mitigating chilling injury and preserving fruit quality for 28 d. This was attributed to the decrease in metabolic activity, specifically the respiration rate and the production of ethylene, which led to the maintenance of fruit firmness and bioactive compounds, energy metabolism, and antioxidant activity, such as ascorbic acid, total flavonoids, trolox equivalent antioxidant capacity, dehydroascorbate reductase, glutathione reductase activity, ATP, and ATPase activity. The study also found that the MT treatment at 200 μM was effective in reducing chilling injury and weight loss and improving membrane stability. Additionally, it led to a decrease in malondialdehyde content and electrolyte leakage, and the maintenance of fruit quality in terms of firmness, peel and pulp colour values for mango peel and pulp total carotenoid content, as well as phenylalanine ammonia lyase and tyrosine ammonia lyase activity. These findings indicate that PPCP and MT have the potential to be efficient treatments in maintaining mango quality and minimizing post-harvest losses.ConclusionThe utilisation of treatments with 20 μL L− 1 of PPCP or 200 μM MT was found to effectively preserve the postharvest quality parameters, in terms of bioactive compounds, energy metabolism, and antioxidant activity, of mangoes cv. “Keitt” that were stored at 5 ± 1 °C for 28 d.

MODIFIED ATMOSPHERE PACKAGING OF CAULIFLOWER FOR ENHANCING THE EFFECTIVENESS OF COOL BOT COLD STORAGE TO PRESERVE THE POSTHARVEST QUALITY IN NEPAL

In recent years, cool bot storage was introduced to smallholder farmers in Nepal as a low-cost alternative to cold storage. The present study was carried out to evaluate the efficacy of different poly films in perforated modified atmosphere packaging on the postharvest life of cauliflower in cool bot-equipped cold rooms and ambient room conditions in the years 2019 and 2020 in the month of December. The cauliflower curds (hybrid variety White Top) were harvested from commercial vegetable growers at a fully mature stage. The compact and mature curds were harvested in the morning and brought to the National Horticulture Research Centre in Khumaltar. The curds were kept overnight for pre-cooling. Four different poly films (25 μ, 50 μ, 75 μ, and 100 low-density polyethylene with 16 perforations were used during storage in two different storage conditions. The study was conducted in a completely randomized block design. Curds were kept at ambient room conditions (15.5°C, 58% RH) for 10 days and at cool, bot devised, cold storage (11.25°C, 96% RH) for 15 days and analyzed for various postharvest quality parameters every 5 days of storage. The results modified atmosphere packaging i.e.50μ LDPE was found effective in cauliflower stored in ambient room conditions with quality perspective but the packaging didn’t provide additive effects in shelf life and quality of cauliflower in cool bot storage conditions.

Development and evaluation of earth air heat exchanger cum evaporative cool system as an energy-efficient method for storage of tomatoes.

The lack of adequate on-farm storage facilities is one of the leading causes of enormous postharvest losses of fresh commodities, negatively affecting farmers' livelihoods and the sector's economic contribution. The aim of the current study was to develop and evaluate a solar-powered earth air heat exchanger cum evaporative cooling (EAHE-EC) system as an energy-efficient method for the storage of fresh produce for smallholders. The postharvest quality parameters of tomatoes stored under ambient storage (AS) and in an EAHE-EC system were assessed at regular time intervals during storage. These include weight loss, total soluble solids, titratable acidity, fruit firmness, color, pH, ascorbic acid, lycopene content, total phenolic acid, and antioxidant activity. The average temperature and relative humidity inside the EAHE-EC system varied from 20.59 to 22.61 °C and 82.60% to 89.43%, respectively, in comparison with AS (26.39-39.21 °C and 22.09-43.58%). Storage methods and time had a significant (P < 0.05) effect on tomato quality. Based on the retention of the overall quality until the end of the storage period, the shelf life of tomatoes was recorded as 21 days in the EAHE-EC system, which was 1.5 times more than AS (14 days). The extra shelf-life gained by tomatoes in the EAHE-EC system may provide a sufficient buffer period for smallholders for retailing and marketing. This suggests that the developed system can maintain postharvest quality and increase the shelf life of tomatoes. It therefore has potential as an energy-efficient system for the storage of fruits and vegetables, including tomatoes. © 2023 Society of Chemical Industry.

Produção e qualidade de frutos de goiaba ‘Paluma’ com porta-enxerto tolerante a nematoides irrigados no semiárido

ABSTRACT Using nematode-resistant and/or -tolerant rootstock is a strategy that has maintained guava cultivation feasible in the irrigated perimeters of the Brazilian semi-arid region. The objective was to evaluate the production, gas exchange, and fruit quality of ‘Paluma’ guava with and without nematode-tolerant rootstock under different irrigation depths and production periods. The experimental design was randomized blocks, in the mixed 2 × 4 × 2 factorial scheme, corresponding to two forms of cultivation of ‘Paluma’ guava (without and with nematode-tolerant rootstock), four irrigation depths (60, 80, 100, and 120% of crop evapotranspiration - ETc), and two production periods, with four replicates. Guava plants were evaluated for physiological, production and post-harvest quality parameters. Gas exchange in ‘Paluma’ guava leaves was higher in the second production cycle, under irrigation depths above 100% ETc, not differing with the use of the rootstock. The use of the rootstock ‘BRS Guaraçá’ promotes a greater number of fruits and production with the increase of the irrigation depth, mainly in the second half of the year, with the increase of soluble solids and titratable acidity in the fruits.

Efficacy of stingless bee (Heterotrigona itama) propolis aqueous extract in controlling anthracnose and maintaining postharvest quality of chilli (Capsicum annuum) during storage

Anthracnose, mainly caused by Colletotrichum spp., is one of the fungal diseases resulting in major economic losses affecting chilli production worldwide. Propolis extract from honeybee has been discovered for its antifungal properties, which can potentially reduce postharvest decay. Therefore, the present work investigated the efficiency of aqueous extract of stingless bee (Heterotrigona itama) propolis in controlling postharvest anthracnose and maintaining quality of chilli. Colletotrichum capsici was isolated and characterised from infected chilli. Stingless bee propolis extract at different concentrations of 1, 2, 5, and 10% were assessed in vitro to inhibit the mycelial growth of C. capsici. The best concentration in inhibiting C. capsici growth was thereafter selected for in vivo experiments. All tested concentrations of stingless bee propolis extract inhibited the mycelial growth of C. capsici the highest being 35% inhibition from the treatment of 10% propolis extract. The extract at this concentration was therefore tested in vivo, and showed effectiveness in reducing the percentage of disease severity in chilli. The propolis extract was also efficient in reducing weight loss, retaining firmness, pH, total soluble solid, and colour (a* value) throughout 21-day storage at 10°C. The present work demonstrated that aqueous extract of stingless bee propolis could have the potential to control anthracnose disease and delay deterioration, thus maintaining the postharvest quality parameters of chilli. This natural product from stingless bee has the prospect to be an alternative to synthetic fungicide.

Novel Approach for Improving Papaya Fruit Storage with Carnauba Wax Nanoemulsion in Combination with Syzigium aromaticum and Mentha spicata Essential Oils

Application of hydrophobic coatings, such as carnauba wax nanoemulsions, combined with natural antimicrobials, has been demonstrated to be an effective solution in extending the shelf life of fruits. The present study evaluated the effectiveness of carnauba wax nanoemulsion (CWN) coatings containing free or encapsulated with β-cyclodextrin (β-CD) essential oils of Syzigium aromaticum (CEO) and Mentha spicata (MEO) for the post-harvest conservation of papaya fruit. The chemical composition of the essential oils (EOs) was analyzed using GC-MS. Subsequently, coatings incorporating free and encapsulated EOs were prepared and applied to papaya fruit. Fruit was evaluated for post-harvest quality parameters during 15 days of storage. Clove essential oil presented as main compounds eugenol (89.73%), spearmint and carvone (68.88%), and limonene (20.34%). The observed reduction in weight loss in coated fruit can be attributed to the formation of a physical barrier provided by the coating. Compared to the control group, which experienced the highest weight loss of 24.85%, fruit coated with CWN and CWN-MEO:β-CD exhibited significantly lower weight loss percentages of only 5.78% and 7.5%, respectively. Compared to the control group, which exhibited a release of ethylene at a rate of 1.3 µg kg−1 h−1, fruit coated with CWN, CWN-MEO:β-CD, and CWN-MEO coatings demonstrated a lower ethylene release rate at 0.7 µg kg−1 h−1. Although the physical-chemical properties of papayas, including pH, Brix, titratable acidity, color, and texture, remained largely unchanged during storage with the coatings, analysis of incidence and severity of papaya post-harvest deterioration revealed that coatings containing essential oils effectively acted as antifungals in the fruit. Microscopy images showed that CWN and CWN-MEO:β-CD coatings are more uniform compared to the others. The edible coatings, especially CWN and CWN-MEO: β-CD, can act as antimicrobial coatings on papaya fruit, increasing their conservation during post-harvest storage.

Effect of chitosan with different molecular weights on the antifungal activity against Colletotrichum gloeosporioides and activation of the non‐enzymatic antioxidant system on infected papaya

Chitosan (Ch) is a biopolymer with excellent antimicrobial and antioxidant properties, capable of maintaining the organoleptic quality of fruits. These properties have been related to its molecular weight. However, the effect of different molecular weights on the non-enzymatic antioxidant system and postharvest quality of anthracnose-infected papaya is still unknown. Therefore, this study evaluated the effect of different Ch molecular weights (13, 25, and 55kDa) on anthracnose development, antioxidant capacity, and postharvest quality of papaya. The Ch-55, Ch-25, and 13kDa inhibited the development of Colletotrichum gloeosporioides. In comparison with thiabendazole, Ch with different molecular weights showed fungicidal effects. Ch-55kDa reduced anthracnose incidence and severity and maintained postharvest quality parameters of papaya. In addition, Ch-55 and Ch-13kDa favored synthesis of ascorbic acid, total phenolics, and antioxidant capacity. Therefore, Ch-55kDa is an alternative to the protection against C. gloeosporioides and a stimulant of the non-enzymatic antioxidant system in papaya fruits during its postharvest storage. PRACTICAL APPLICATION: Ch with different molecular weights have different effects over anthracnose control and postharvest quality in papaya. In addition, they have different stimulation levels on the non-enzymatic antioxidant system of papaya fruits, in a higher level than the chemical fungicide TBZ, by regulating the growth of the fungus and the degradative processes that are generated in fungal infection. In this sense, we believe that our findings could be of interest for producers and farmers to take advantage of this biopolymer to control anthracnose, preserve the postharvest quality, and stimulate the non-enzymatic antioxidant system of papaya fruit.

Plant growth regulators preserved the longevity of cut stems of Chrysanthemum morifolium by orchestrating physio-biochemical and anatomical responses

The marketability of cut flowers is determined by their postharvest quality parameters. Among these parameters, vase life is most crucial and different plant growth regulators (PGRs) play a significant role in regulating vase life. With the objective, to regulate vase life and other quality parameters of commercially important cut stems of chrysanthemum cv. White Star, a study was planned to have an insight into the role of different PGRs in orchestrating underlying physio-biochemical and anatomical responses. Three PGRs viz., Benzyl adenine (50, 100, 150 and 200 μM BA), Thidiazuron (5, 10, 15 and 20 μM TDZ) and Salicylic acid (50, 100, 150 and 200 μM SA) were used as pulsing solution. The results revealed that PGR especially 10 μM TDZ delayed leaf and floret senescence as compared to control. The visual observations (retention of green colour of leaves and white of florets) were correlated to enhanced water absorption, relative water content, membrane stability index, total soluble sugars and total soluble proteins ; higher content of chlorophyll in leaves and lower content of carotenoids and anthocyanins in florets. Further, the antioxidant enzymes (peroxidase and catalase) activities were also higher in PGR-treated stems than in control. These results were further supported by anatomical studies that indicated minimum blockage in xylem and maintenance in turgidity of cells as revealed through the size of tissues (radius of pith) of treated stems (control-118.48 mm and 10 μM TDZ-177.94 mm). Although all PGR concentrations significantly maintained relative water content, membrane stability index, respiratory substrates and antioxidant activity for a longer time, the low concentrations of TDZ had the most relevant impact on longevity. The longevity of stems treated with10 μM TDZ was up to 23 days as compared to 13 days in control. So 10 μM TDZ could be used as a chemical tool to improve chrysanthemum longevity and increase its commercial potential.

Improving Runner Production, Total yield and Postharvest Quality of Strawberry Fruits using Plant Growth Regulators

In this study, different plant growth regulators were tested to improve runner production, total yield and postharvestquality of strawberry fruits. For this, different concentrations of gibberellic acid (GA3) (50 ppm, 100 ppm), naphthaleneacetic acid (NAA) (40 ppm, 80 ppm) and benzyl adenine (BA) (150 ppm, 300 ppm) were used as foliar sprays along withonly water as control. Experiment was arranged in Randomized Complete Block Design (RCBD) with three replicationsand data collected was analysed and means were compared. Results showed that maximum survival percentage (100.00),number of runners per plant (18.77), number of plantlet on each runner (6.88), leaf area (58.45 cm2), chlorophyll contentof leaves (67.87 g/ml), , average number of flowers per plant (28.98), average number of fruits per plant (26.78), fruityield per plant (309.78 g), weight of fruit (11.57 g) and size of fruit (15.34 mm) were found in strawberry plants whichwere sprayed with GA3 @ 100 ppm. However, maximum number of days to flowering (55.89) and number of days toharvest (85.76) were observed in strawberry plants which were treated with only water (control). Postharvest qualityparameters like total soluble solids (TSS) (13.21 °Brix), titratable acidity (1.24%), vitamin C (39.12 mg/100 g), ashcontent (0.78), total carotenoids (4.92 mg/100 g FW), total anthocyanins (4.05 mg/100 g FW), total flavonoids (9.09mg/100 g FW), total phenolics (9.12 mg gallic acid/100 g) and antioxidant activity (102.91 μg/100 mg FW) were alsorecorded maximum in plants, sprayed with GA3 @ 100 ppm. Based on current findings it can be concluded that GA3 @100 ppm was found the best plants growth regulator for vegetative growth and postharvest quality attributes of strawberryas compared to all the other growth regulators tested.

Effects of chitosan and nano-SiO2 concentrations on the quality of postharvest guavas (Psidium guajava L.)

Guava (Psidium guajava L.) is a perishable fruit susceptible to postharvest losses at tropical ambient temperature. Therefore, the development of green storage solution such as biodegradable film could be an alternative to increase guavas’ shelf life. The primary objective of the present work was to explore the effects of combining chitosan and nano-SiO2 coating at different concentrations on the external and internal quality parameters of guavas during 12-d storage at 15°C, and 8-d storage at 30°C. Weight loss, skin colour, firmness, ascorbic acid content, total soluble solids (TSS), decay incidence, and sensory taste score during storage were also analysed. Guavas coated with 2% chitosan and 0.02% nano-SiO2 film were economically optimum to maintain the tested postharvest quality parameters, including better skin colour, higher TSS, fruit firmness, ascorbic acid content, and good taste scores, while keeping lower weight loss and decay incidence when compared with those of other treatments at both tested temperatures. Therefore, chitosan and nano-SiO2 as a coating is a promising strategy for improving the postharvest quality of guavas.

Edible Coating Based on Carnauba Wax Nanoemulsion and Cymbopogon martinii Essential Oil on Papaya Postharvest Preservation

Papaya is a fruit of great importance worldwide. However, significant losses during postharvest have been reported, which can be minimized by applying lipid nanoemulsions as edible coatings associated with natural antimicrobial compounds. These coatings provide a barrier to gases and water vapor, in addition to improving mechanical properties, thereby delaying natural senescence and minimizing deterioration by phytopathogens during storage. The aim of this study was to investigate the preservation potential of papaya fruits treated with an edible coating based on an association between carnauba wax nanoemulsion (CWN) and Cymbopogon martinii essential oil (CEO). Coatings formulated with CWN and/or CEO were applied to papaya fruits, and resulted in late ripening during the 12-day storage period, without negatively affecting postharvest fruit quality parameters. The coatings reduced weight loss and maintained firmness, in addition to delaying changes in fruit color during storage. Coatings formulated with CWN + CEO were the most efficient formulations in reducing the incidence and severity of fruit rots during storage. CWN coatings incorporating CEO present additional functionalities in maintaining postharvest quality parameters of papaya fruits.

Chitosan-Based Edible Coatings Containing Essential Oils to Preserve the Shelf Life and Postharvest Quality Parameters of Organic Strawberries and Apples during Cold Storage.

Edible coatings and films have been researched for more than three decades due to their ability to be incorporated with different functional ingredients or compounds as an option to maintain the postharvest quality of fruits and vegetables. The aim of this study was to evaluate the effect of three types of chitosan-based (CH) edible coatings obtained from medium and high molecular weight chitosan, containing ascorbic or acetic acid and sea buckthorn or grape seed essential oils on the physical-chemical and microbiological properties of organic strawberries and apple slices during cold storage at 4 °C and 8 °C. Scanning electron microscope images showed both a smooth structure and a fracture and pore structure on strawberry coatings and a dense and smooth structure on the apple slices coatings. Further, the edible coatings managed to reduce the microbial load of yeasts and molds of the coated strawberries during the storage period. Overall, the treatments preserved the ascorbic acid, total polyphenol content, and antioxidant activity for all the tested samples compared to the control sample, throughout the storage period. In addition, the water activity (aw) of the coated samples presented lower values (0.96-0.98) than the control samples. The obtained results indicate that the developed chitosan-based edible coatings could maintain the postharvest parameters of the tested samples, also leading to their shelf-life prolongation.