Postharvest Fruit Quality Research Articles

Effect of lignite substrate and supplementary lighting and packaging type on post-harvest storage quality of cucumber fruit

Cucumber is an economically important vegetable grown all over the world. Consumers demand that high-quality cucumber fruit is available throughout the year. The aim of this study was to evaluate the effects of growing conditions such as lignite substrates and assimilation lighting in hydroponic cultivation and storage methods on the quality and post-harvest shelf life of greenhouse cucumber fruit. Cucumber fruit quality was analysed from harvest through cold storage and simulated trading conditions.Plants were grown in lignite and mineral wool growing mats. Sunlight supplementation was carried out using sodium and LED lamps. Post-harvest fruit were packed in plastic crates, cardboard boxes or plastic bags and stored in a cold store (5 days) and under simulated trading conditions (10 days - 5 days in a cold store and another 5 days at 22 ᵒC). The weight loss of cucumber fruit during storage was determined depending on the combination. After fruit harvest, after fruit storage in the cold store and after 10 days of storage under simulated trading conditions, fruit hardness, dry matter content, TSS, nitrate content of cucumber fruit were studied and sensory evaluation of fruit quality was carried out.Fruit from plants grown in lignite substrate had lower weight loss during storage and significantly higher TSS (total soluble solids) and dry matter content. They also had a lower nitrate content compared to fruit harvested from plants grown in mineral wool substrate. Furthermore, the best sensory parameters were found in fruit from plants grown in lignite substrate under LED lighting. It was also found that PE film packaging reduced the weight loss of fruit during transport and storage, and that fruit removed from the film and placed in a cardboard box lost weight more slowly compared to the other packaging tested.

L-Arginine treatment maintains postharvest quality in blueberry fruit by enhancing antioxidant capacity during storage.

The postharvest quality of blueberry fruit is largely limited by deterioration. l-arginine (Arg) is a functional nontoxic amino acid with high biological activities. This study investigated the positive effects and the underlying mechanism of Arg treatment on the quality of postharvest blueberries. Arg effectively mitigated fruit decay and improved the quality of blueberries, including weight loss, firmness, and soluble solid content. Mechanistically, Arg-mediated activation of the anti-oxidative defense system reduced reactive oxygen species-mediated oxidative damage. Moreover, Arg treatment decreased the activities and gene expression of phospholipase D, lipoxygenase, and lipase-inhibiting membrane lipid peroxidation during the prolonged storage of blueberries. Meanwhile, Arg treatment increased nitric oxide (NO) content and NO synthase activity. Furthermore, correlation and principal component analyses revealed the enhancement of Arg treatment on antioxidant capacity. This study suggests that Arg treatment can maintain the postharvest quality of blueberries by improving antioxidant capacity.

Biostimulants Improve Yield and Quality in Preharvest without Impinging on the Postharvest Quality of Hass Avocado and Mango Fruit: Evaluation under Organic and Traditional Systems

The fruit agribusiness sector is one of the most dynamic in Colombia. Within this sector, avocado and mango are of great importance, both in terms of area planted and volume exported. Increasing the productivity, quality, and postharvest life of these fruits is a priority, due to the high losses that occur in the preharvest and postharvest stages. One current alternative to achieve this are biostimulants, which have the potential to improve the productivity and quality of fruit. The objective of this work was to evaluate the effect of the preharvest application of two biostimulants on the yield and quality of avocados and mangos. The study was carried out in production systems for cv. Hass avocado (traditional and organic) and cv. Keitt mango (traditional). In each system, two treatments were evaluated: conventional and conventional + biostimulant. Under field conditions, yield and quality variables such as weight, number of fruits, visual appearance, and size were determined. In postharvest, the fruits obtained from preharvest treatments were subjected to two storage conditions (6 and 20 °C) during the ripening process. Postharvest quality variables such as respiration, ethylene rates, weight loss, color index, firmness, total soluble solids, and titratable acidity were evaluated. The results indicated that the use of biostimulants caused a significant increase (p ≤ 0.05) in the yield, number of fruits, and preharvest quality parameters of size and weight, without negatively affecting the postharvest quality of the fruits. The biostimulant increases the total weight of fruits in organic and conventional avocado by ~55 and 25%, respectively, while in mango, this figure increased by ~23%. Hence, biostimulants can be utilized to increase the productivity of fruit trees.

Evaluating Food Additives Based on Organic and Inorganic Salts as Antifungal Agents against Monilinia fructigena and Maintaining Postharvest Quality of Apple Fruit.

A set of commonly used food additives was evaluated for their antifungal activity against the brown rot disease of fruits caused by the fungal pathogen Monilinia fructigena, which is one of the most economically important agents, causing important damage to pome fruits, such as pears and apples. The radial mycelial growth of the fungal pathogen was assessed in PDA amended with different concentrations (0.5, 2, 2.5, and 5%) of each additive. The results underlined that most of the additives displayed a significant inhibition of mycelial growth, with the extent of inhibition varying depending on the specific additive and concentration used. Five food additives showed high inhibition rates (above 88%), of which sodium bicarbonate, sodium carbonate, copper sulphate, and sodium hydroxide were the most effective, whereas ammonium carbonate, magnesium chlorite, and citric acid were the least effective. Interestingly, the coatings containing sodium bicarbonate, copper sulphate, and ammonium bicarbonate significantly reduced the incidence of brown rot disease in apples, but other additives were not effective, such as ammonium carbonate and magnesium sulphate. The anhydrous sodium sulphate used at a concentration of 2%, was found to be one of the least effective additives, with a reduction rate of 20%. Subsequently, food additives showing good growth inhibition rates and reduction in disease severity were then tested in semi-commercial trials at temperatures of 4 °C and 22 °C. The results indicated that these additives demonstrate effectiveness in controlling M. fructigena at specific concentrations, and lower temperatures (4 °C) can improve the efficiency of the control measures. In addition, the selected food additives exhibited significant antimicrobial activity against M. fructigena, suggesting their application as a promising alternative for managing brown rot disease in apple fruits.

Phenylalanine maintains the postharvest quality of ‘Jinfeng’ pear fruit by modulating the tricarboxylic acid cycle and chlorophyll catabolism

Quality breakdown caused by high respiration, evaporation, and pigment degradation affects the storage ability and shelf life of pear fruit. Phenylalanine is an aromatic amino acid that can enhance the nutritional quality and disease resistance of vegetables and fruit. This study was conducted to assess the effects of exogenous phenylalanine on quality indicators, tricarboxylic acid (TCA) cycle, and chlorophyll catabolism of ‘Jinfeng’ pear fruit. Results showed that phenylalanine treatment declined a* value, b* value, ΔE, and malondialdehyde content, enhanced L* value, soluble solids and ascorbic acid contents, and titratable acidity, but delayed the decrease of flesh firmness. Phenylalanine also reduced pyruvate dehydrogenase, isocitrate dehydrogenase, aconitase, citrate synthase, fumarase, succinate dehydrogenase, and malate dehydrogenase activities and gene expressions as well as PcNADP-ME expression and α-keto glutaric dehydrogenase (α-KGDH) activity in the TCA cycle of pears. Moreover, phenylalanine suppressed the expression levels of PcNCY1, PcHCAR, PcCHL1, PcPAO, PcRCCR, PcPPH, and PcSGR1/2 in chlorophyll degradation. Meanwhile, phenylalanine treatment enhanced malic acid, citric acid, succinic acid, total chlorophyll, chlorophyll a, and chlorophyll b contents in pears. These results indicate that exogenous phenylalanine could keep the quality of pears after harvest by inhibiting the key gene expression and enzyme activity in the TCA cycle and chlorophyll degradation. These findings also suggest that phenylalanine can be used as a potential inducer to delay yellowing and maintain the postharvest quality of fruit.

PpMYB105 inhibits chilling injury by regulating PpMsrA1 in peach fruit.

MeJA supplementation enhanced the chilling tolerance and gene expression of PpMsrA1. PpMYB105 protein positively regulated the PpMsrA1 promoter. PpMYB105 mediated the MeJA-boosted chilling tolerance by regulating PpMsrA1. Cold storage can maintain the quality of postharvest fruit. However, peaches easily suffer from chilling injury (CI) during cold storage, leading to economic loss. Results showed that methyl jasmonate (MeJA) supplementation reduced the CI severity, and enhanced the gene expression of methionine sulfoxide reductase A1 (PpMsrA1). It was found that MeJA application elevated the MsrA activity and methionine (Met) content, and reduced the methionine-S-sulfoxide (Met-S-SO) content and reactive oxygen species (ROS) production afterwards. Moreover, PpMYB105 could activate the transcription of PpMsrA1 by binding to the MYB binding element in its promoter. The gene expression of PpMYB105 was up-regulated by MeJA application. Overexpression of PpMYB105 in tomatoes enhanced the chilling tolerance and gene expression of SlMsrA1. Virus-induced gene silencing of PpMYB105 in peaches resulted in the increase in CI severity and the decrease in gene expression of PpMsrA1. Thus, PpMYB105 was involved in the MeJA-boosted chilling tolerance by regulating PpMsrA1.

Frequency of application of 24-epibrassinolide on plant growth, physiology and postharvest fruit quality of Cantaloupe grown at elevated temperature

ABSTRACT Reduction of yield in tropical greenhouses is an issue with Cucumis melo L. var. cantaloupensis. A natural occurring hormone, 24-epibrassinolide (EBR), regulates cellular activities and physiological processes of plants and signaling. To determine effects of EBR application, cantaloupe cvs. Himalai-99 and Glamour (factor 1) were treated with 0.1 mg∙L−1 EBR applied over four frequencies (factor 2) as; F1: no EBR (control), F2: at 15 DAT (days after transplant), F3: at 15 + 30 DAT, and F4: at 15 + 30 + 45 DAT at 47 ± 3°C (5°C higher than the ambient greenhouse) in a factorial Randomized Complete Block Design (RCBD) with four replicates. Postharvest fruit quality was monitored at room temperature (26°C) in a completely randomized design with four replicates. Data were analyzed using Analysis of Variance, mean separation with least significant difference and associations between parameters with Pearson correlation. Application of EBR at 15 + 30 DAT (F3) increased plant dry weight, leaf area, specific leaf area, root length, root surface area, photosynthesis rate, stomatal conductance, transpiration rate and chlorophyll content. It increased the quantum efficiency of photosystem II, peroxidase and catalase activities by 50%, stomatal length and width by 75% and decreased malondialdehyde and proline content by 56%. Pre-harvest foliar application of EBR at 15 + 30 DAT reduced postharvest weight loss and ethylene emission rate by two fold and reduced ascorbic acid and antioxidant depletion rates during storage. The EBR application at 15 + 30 DAT produced the best plant and fruit quality performances, while the application of EBR at fruit development stage (45 DAT) caused reduced fruit quality.

Effect of Calcium Chloride (CaCl2) and Carbon Dioxide (CO2) on Post Harvest Quality of Apple Fruit (Malus domestica) cv. Gala

The study investigated the effects of calcium chloride (CaCl2) and carbon dioxide (CO2) on the post-harvest quality of Gala apple fruit (Malus domestica). The apples were stored under controlled refrigerated conditions for 90 days, and eight different treatment combinations were tested: 0.5% CaCl2, 1.0% CaCl2, 900ppm CO2, 1000ppm CO2, 0.5% CaCl2 + 900ppm CO2, 0.5% CaCl2 + 1000ppm CO2, 1.0% CaCl2 + 900ppm CO2, and 1.0% CaCl2 + 1000ppm CO2. Various quantitative and quality parameters were evaluated throughout the experiment, including fruit weight loss, firmness, total soluble solids (TSS), pH, titratable acidity (TA), ascorbic acid, and sensory evaluation at 30, 60, and 90 days of post-harvest storage. The results demonstrated that fruit weight loss was significantly in the treatments with calcium and carbon dioxide compared to the control group. Furthermore, the calcium and carbon dioxide treatments led to an increase in pH and total soluble solids, and causing a decrease in firmness, titratable acidity, and ascorbic acid during the 90-day cold storage at 0 to 2°C. The findings also indicated that the calcium and carbon dioxide treatments influenced the production of ethylene to the control group. Overall, the experiment revealed that post-harvest calcium treatments prevented fruit softening and minimized weight losses. The application of 1.0% CaCl2 + 1000ppm CO2 showed superior results compared to other treatments, effectively controlling weight loss, maintaining firmness, and minimizing fruit decay. In conclusion, storing Gala apples under controlled atmosphere conditions with the application of calcium chloride and carbon dioxide successfully inhibited fungal growth, maintained firmness, minimized weight loss, and extended the shelf life compared to the control group. These findings have significant implications for the apple industry, as they provide a means to improve fruit quality and increase the shelf life of apples. Future research may build upon these results to refine treatment conditions, gain a deeper understanding of the underlying mechanisms, and explore the application of these techniques to other apple varieties and different fruits. Ultimately, these experimental findings have the potential to contribute to the development of practical strategies for enhancing the shelf life of apple fruits, ensuring better quality and reduced post-harvest losses.

Chilling-related browning of ‘Wonhwang’ pear cortex is associated with the alteration of minerals and metabolism

‘Wonhwang’ pear (Pyrus pyrifolia Nakai) is affected by a wide range of physiological disorders, especially internal browning (cortex browning) during long-term cold storage and subsequent shelf life. Postharvest fruit quality and metabolic changes of many Asian pears (P. pyrifolia) are well characterized, but little is known about the minerals and metabolites associated with internal browning induction and development in ‘Wonhwang’ pear during cold storage. The present study compares minerals and metabolites in cortex tissue of healthy fruit as well as symptomatic (browned) and sound tissues from fruit with internal browning that developed during long-term cold storage. P, K, Ca, sorbitol, shikimic acid, palmitic acid (C16:0), linoleic acid (C18:2), α-linolenic acid (C18:3), methionine, 1-hexenol, and (Z)-3-hexenal were lower in browned tissue than in healthy and sound tissues. In contrast, levels of glucose, fructose, fumaric acid, valine, leucine, isoleucine, lysine, phenolic compounds, lignoceric acid (C24:0), ethyl esters, and some volatile aldehydes were highest in browned tissue, compared with the other tissues. Many ethyl esters, aromatic amino acids, branched-chain amino acids, phenolic compounds, soluble solids content, fructose, and glucose were associated with internal browning. Furthermore, “tryptophan metabolism”, “arginine biosynthesis”, “alanine, aspartate, and glutamate metabolism”, “α-linolenic acid metabolism”, and “glycine, serine, and threonine metabolism” were the processes most impacted by internal browning. Overall, the largest metabolic differences appeared between damaged and asymptomatic cortex as several metabolic processes were influenced by internal browning.

Cinnamon essential oil vapor alleviates the reduction of aroma-related volatiles in cold-stored "Feicheng" peach using HS-GC-IMS.

"Feicheng" peach is popular for its unique aroma, but its defect of being highly sensitive to chilling injury (CI) often leads to aroma loss and internal browning. Essential oils (EOs) are often used to enhance the antioxidant capacity of plants and fruits, as well as to trigger their defense against biotic/abiotic stresses. This study aimed to examine the effect of cinnamon essential oil (CEO) vapor treatment on the aroma quality of peach fruit during cold storage using HS-GC-IMS. The results showed that 50 μL/L CEO vapor reduced the severity of internal browning (IB) in peaches at the stage of 7 ~ 21 d during refrigeration (Significantly, the L* value was higher and the IB index was lower than that of control, p < 0.05). Meanwhile, the evident reduction or loss of aroma content caused by CI was restored to a higher level than the control (p < 0.05). Furthermore, CEO treatment promoted the release of aroma-related volatiles as evidenced by more propyl acetate, and the dimer of amyl acetate, isoamyl acetate, butyl acetate detected than that on harvest day and no-treated group after 21 d of cold storage plus 2 d of shelf life. Genes of PpLOX1, PpLOX2, PpHPL1 and PpADH1 associated with aroma-related volatile biosynthesis revealed higher transcript abundance in peach fruits treated with CEO than the control (p < 0.05). Overall, our study demonstrated that CEO in vapor phase may be beneficial to alleviate the quality deterioration in aroma and flesh color of "Feicheng" peaches caused by CI, which lays a theoretical reference for maintaining postharvest quality of peach fruits.

A Study Investigating the Effects of Postharvest Treatments of Sodium Nitroprusside and Potato Starch on the Quality and Storage Life of Two Advertised Guava Cultivars

The availability of fresh guava fruit in the domestic, as well as the international market, is limited due to its short postharvest life. Hence, the present research was performed to evaluate the effect of postharvest application of potato starch and sodium nitroprusside on the storage life and quality of guava fruit. Data was examined statistically using ANOVA with Fishers' least significant difference LSD test using statistics software 8.1 with 5% levels of significance difference. Treated fruits remained in storage for 15 days while the untreated fruit started decaying within 10 days of storage. The physical parameters of guava like fruit firmness, visual quality, marketability index, disease incidence, and fruit decay showed highly significant results when treated with different concentrations of potato starch and sodium nitroprusside. The sensory traits such as texture, taste, flavor, aroma, and overall acceptance were also decreased with the progress of storage days. Biochemical fruit quality traits of guava like TSS, TA, TSS/TA ratio, ascorbic acid, and Ion leakage were significantly influenced when treated with different coatings of potato starch and sodium nitroprusside and subjected to ambient storage. The phytochemical traits of guava like total phenolic contents, total antioxidant contents, and total carotenoid content showed highly significant variations among storage periods and treatments. Activities of various antioxidative enzymes such as superoxide dismutase activity, peroxidase activity POD, and catalase activity CAT exhibited highly significant differences at the end of the storage period. The potato starch and sodium nitroprusside treatments managed the postharvest quality of guava fruit by delaying fruit senescence reduction because of enhanced antioxidant enzymes. Hence, the investigation revealed that the different concentrations of potato starch and sodium nitroprusside coating improved the storage life of guava with retaining better fruit quality attributes.

Konjac glucomannan/low-acyl gellan gum edible coating containing thymol microcapsule regulates cell wall polysaccharides disassembly and delays postharvest softening of blueberries

Softening is one of the crucial factors causing the deterioration of postharvest fruit quality. In this study, the effects of konjac glucomannan/low-acyl gellan gum/microcapsule of thymol (TKL) coating on the storage characteristics, the ultrastructure of cell wall and transcription expression of pectin-related metabolism of blueberries fruits during low-temperature storage were investigated. TKL coating suppressed the expression of pectin-related enzymes disassembly (VaPE2, VaPE3, VaPG3, VaPL2 and Vaβ-Gal2), reduced the activity of cell wall polysaccharide degrading enzymes (PG, PE, PL, β-Gal, α-Man, α-Af, Xth, β-Xyl, Cx, β-Glu), maintained the normal morphological structure and stability of cell wall, and prolonged the shelf life of blueberries fruits. Overall, TKL is a promising coating that can effectively maintain the firmness, inhibit the postharvest softening and prolong the shelf life of the blueberries during storage period.

Postharvest Calcium Chloride Treatment Strengthens Cell Wall Structure to Maintain Litchi Fruit Quality.

Litchi (Litchi chinensis Sonn.) fruit deterioration occurs rapidly after harvest and is characterized by pericarp browning, pulp softening, and decay. In this study, we found that calcium chloride (CaCl2) treatment (5 g L-1 CaCl2 solution vacuum infiltration for 5 min) affected the cell wall component contents and cell wall-degrading enzyme activities of litchi fruit during storage at room temperature. CaCl2 treatment significantly increased the contents of Ca2+ and cellulose, while it decreased the water-soluble pectin content, and the activities of polygalacturonase, β-galactosidase, and cellulase in the litchi pericarp. Meanwhile, the treatment resulted in significantly increased contents of Ca2+, water-soluble pectin, ionic-soluble pectin, covalent-soluble pectin and hemicellulose, and upregulated activities of pectinesterase and β-galactosidase, while significantly decreasing the activities of polygalacturonase and cellulase in litchi pulp. The above results indicate that CaCl2 treatment strengthened the cell wall structure of litchi fruit. More importantly, the enzymatic browning of the pericarp, softening of the pulp, and disease incidence were delayed. The treatment had a more pronounced effect on the pericarp than on the pulp. We consider CaCl2 treatment to be a safe and effective treatment for maintaining the postharvest quality of litchi fruit.

Postharvest Application of Sodium Selenite Maintains Fruit Quality and Improves the Gray Mold Resistance of Strawberry

Strawberry is a worldwide demanded edible fruit with high economic and nutritional value; however, a very short storage life largely limits its supply and marketing. In this study, strawberries were treated using sodium selenite with different concentrations (6, 12, 18, and 24 mg/L), and the postharvest fruit quality and resistance to Botrytis cinerea were substantially assessed. Among all concentrations, 12 mg/L Se was the most effective treatment, which maintained fruit skin brightness, reduced natural decay incidence, severity, and weight loss, increased the Se content in fruit, and thus maintained the postharvest fruit quality of the strawberry. Furthermore, strawberries treated with 12 mg/L Se had lower flavonoid, phenolic, anthocyanins, proanthocyanidins, H2O2, and O2− contents compared to the control and, correspondingly, lower antioxidant capacity; moreover, 12 mg/L Se treatment decreased the decay incidence and severity caused by the infection of B. cinerea. Collectively, our findings may provide a reference for developing safe and environmentally friendly alternative methods to sustain quality and manage gray mold in postharvest strawberries as well as other horticultural crops.

1 H-cyclopropa[b]naphthalene: a novel ethylene antagonist for extending storage life and maintaining quality of climacteric and suppressed climacteric plums

Ethylene is a key trigger that governs the rate of fruit ripening, storability, and postharvest quality of fresh fruit. Efficient inhibition of ethylene action is essential to slow down the postharvest ripening processes, extend storage life and maintain optimum fruit quality during storage. Ethylene antagonist compounds with the likelihood of application as liquid formulation would facilitate managing ethylene broadly as both preharvest and/or postharvest treatments. This study examined the effects of different aqueous formulations of 1 H-cyclopropa[b]naphthalene (NC) as an ethylene antagonist in the cold stored (1 °C) Japanese plums ‘Angeleno’ (suppressed-climacteric) and ‘Tegan Blue’, which exhibit climacteric peaks, respectively. NC was applied as a 2 µM spray solution prepared using only distilled water (NCA), 5% ethanol (NCE), 0.02% Tween® 20 (NCT), 5% β-cyclodextrin (NCD) or a 1 µM fumigant for 18 h at ambient conditions (20 ± 1 °C). Regardless of formulation, NC retarded ethylene production in both the suppressed-climacteric and climactic cultivars. The capacity of NC to suppress ethylene production was relatively higher in ‘Angeleno’ than in ‘Tegan Blue’. Levels of bioactive compounds such as total phenols, total anthocyanins and total antioxidant capacity in fruit treated with NC were at par with the control. NC fumigation was the most effective treatment in suppressing ethylene production and maintaining fruit quality followed by NCE, NCT, NCD and NCA in both plum cultivars. Amongst the NC spray solutions, the ones with ethanol or Tween® 20 as adjuvants outperformed other solutions. Ethylene production positively correlated with weight loss, SSC, SSC: TA and concentrations of individual sugars, but was negatively correlated with firmness, titratable acidity (TA) and individual organic acids in both cultivars. The results also support the notion that ethylene has a role in the synthesis of phenolic compounds and anthocyanin depending on the sugar substrates present in the phenylpropanoid and flavonoid pathways.

Effects of L-Cysteine and γ-Aminobutyric Acid Treatment on Postharvest Quality and Antioxidant Activity of Loquat Fruit during Storage.

Sichuan is the China's leading producer of loquat, with the largest cultivation area and yield ranked first in China. Loquat is a seasonal fruit highly appreciated by consumers; however, the fruit is prone to browning and lignification after harvest, affecting its storage quality. The effects of L-Cysteine (L-Cys, 0.01, 0.05, 0.1, 0.2%) and γ-aminobutyric acid (GABA, 0.025, 0.05, 0.075, 0.1%) on the sensory quality and antioxidant activity of loquat fruit during cold storage at 4 °C for 35 days and simulated shelf life for 5 days were investigated. The results showed that after 40 days of storage, compared with the control, 0.05% L-Cys and 0.05% GABA treatment of 'Zaozhong No. 6' loquat fruit effectively reduced the weight loss rate, browning index, decay index, respiratory rate, firmness, and lignin content and slowed the decreases in total soluble solids, soluble sugar, titratable acidityand vitamin C contents. The application of 0.05% L-Cys and 0.05% GABA significantly increased the contents of total phenols, total flavonoids, flavanols, and carotenoids; delayed the increase of relative electric conductivity, MDA, POD, and PPO activities; and significantly enhanced the activities of SOD and CAT, DPPH free radical scavenging ability, and FRAP, thereby improving antioxidant capacity. In summary, 0.05% L-Cys and 0.05% GABA treatment promotes the quality of loquat fruit after 40 days of storage, and significantly enhances antioxidant capacity, thus delaying senescence after harvest.

Enhanced shelf-life of peach fruit in alginate based edible coating loaded with TiO2 nanoparticles

This study was conducted to determine the effects of nanoparticle based edible coatings on post-harvest quality of peach fruits during 7 days storage at ambient temperature. The edible coatings consisted of sodium alginate (SA) supplemented with green synthesized titanium dioxide (TiO2) nanoparticles and mousami peel extract (MPE). TiO2 nanoparticles with diameters ranging from 5 nm to 20 nm were synthesized with Citrus limetta (mousami) peel extract. The structural analysis of TiO2 nanoparticles were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM). The optical properties were studied by UV-VIS spectroscopy which confirmed the anatase phase of TiO2 nanoparticles. Different nanoemulsion coatings of SA, SA-TiO2 nanoparticles (SA-NT) and SA-NT-MPE were developed to study various post-harvest quality attributes of peaches. Coating treatment significantly reduced percent weight loss, retained antioxidant activity and ascorbic acid content than control samples. The coating had a significant (p<0.05) impact on polyphenol oxidase activity, titratable acidity and firmness of peach samples during storage. Similarly, coated peach samples retained color index and slowed down the yeast and mold count during the storage period. At the end of the storage period, coated samples with coating solutions containing TiO2 nanoparticles and MPE exhibited the lowest yeast and mold counts (4.17 ± 0.12 log10 cfu g−1) whereas uncoated peach samples showed the highest yeast and mold counts (7.15 ± 0.09 log10 cfu g−1). Therefore, this study demonstrated the ability of nanoemulsion as coating agent in maintaining the quality and extending the self-life of peach fruit for up to 7 days at ambient temperature.

Effects of methionine treatment on storage quality and antioxidant activity of postharvest jujube fruit

Jujube fruits usually suffer from physiological disorders or infectious diseases during storage, leading to quality deterioration, softening, or rotting. Therefore, this study aims to investigate the effect of methionine soaking treatment on the postharvest jujube fruit decay rate and storage quality. Methionine treatment significantly reduced the decay rate of postharvest jujube fruit and effectively maintained fruit color and titratable acid. Methionine treatment effectively delayed the decrease of firmness, soluble solids, ascorbic acid, and lignin contents in jujube fruit. Methionine treatment reduced the content of alanine and phenylalanine, and increased the content of glycine in jujube fruit, but displayed no significant effect on total amino acid content. In addition, jujube fruits in the methionine treatment group had a higher total phenolic and flavonoid content and antioxidant capacity, both in free and bound forms. Compared with the control, methionine treatment also significantly increased the content of individual phenolic acid fractions (gallic acid, vanillic acid, and syringic acid) and flavonoid fractions (catechin, epicatechin, rutin) in free form as well as individual phenolic acid fractions in bound form (gallic acid and ferulic acid) in jujube fruits. Overall, this study suggested that the methionine treatment could be used as a prospective preservative to reduce the postharvest decay of jujube fruit and alleviate its nutritional quality deterioration during cold storage at 4°C.

Atividade repelente de óleos essenciais contra mosca do mediterrâneo e suas influências na qualidade pós colheita em goiaba paluma

ABSTRACT Brazil is one of the world's largest guava (Psidium guajava) producing countries, but the economic performance of this crop can be negatively affected by the damage caused by Ceratitis capitata (Diptera: Tephritidae). The main methods for controlling C. capitata are based on broad-spectrum insecticide applications. However, the negative effects of using this control method stimulate the development of sustainable alternatives, such as the use of essential oils (EO). In this sense, the objective of the present study was to evaluate the repellent activity of EO of citronella (Cymbopogon nardus), clove (Syzygium aromaticum), and copaiba (Copaifera officinalis) for repellency of C. capitata in Paluma guava fruits and determine their effects on postharvest fruit quality, under laboratory-controlled conditions. The fruits were treated with citronella, clove, and copaiba EO and placed in covered plastic containers attached to the ends of arenas of 20 cm diameter and 15 cm height. The fruit physical and chemical analysis was carried out based on the same oils applied in the repellent test. The C. nardus essential oil presented a greater repellency of C. capitata females. The EO applications proved to be a good strategy for maintaining the fruit post-harvest quality.

Improvement of Postharvest Fruit Quality of Two Popular Chinese Cherry (Prunus pseudocerasus) Cultivars by Biological and Chemical Preservatives

Improvement of Postharvest Fruit Quality of Two Popular Chinese Cherry (Prunus pseudocerasus) Cultivars by Biological and Chemical Preservatives