Postharvest Spoilage Research Articles

On-demand removable hydrogel film derived from gallic acid-phycocyanin and polyvinyl alcohol for fruit preservation

Postharvest spoilage of fruits accounts for significant losses ranging between 20 %–30 %, leading to considerable resource wastage and economic downturns. The development of an effective fresh-keeping packaging material is of paramount importance. This study introduces an innovative on-demand removable active fruit fresh-keeping film (GPP), created by embedding a GP (gallic acid-phycocyanin) fiber mesh hydrogel with functional properties into a polyvinyl alcohol (PVA) matrix. The resultant GPP hydrogel-based film demonstrates outstanding UV and water vapor barrier capabilities, mechanical stability, resistance to external mechanical stress, universal surface adhesion, antibacterial efficacy, and on-demand removal attributes, while being devoid of potential toxicity hazards. Utilizing grapes and blueberries as representative fruits, it is shown that the GPP hydrogel film significantly preserves the fruits' hardness, pH, total soluble solids content (TSS), and minimizes the rate of weight loss, thereby prolonging the shelf life to 13 days for grapes and 20 days for blueberries at ambient temperature. These results underscore the potential of this hydrogel-based film as an invaluable material for fruit preservation within the food industry.

Transcriptomic and functional analyses on a Botrytis cinerea multidrug-resistant (MDR) strain provides new insights into the potential molecular mechanisms of MDR and fitness.

Botrytis cinerea is a notorious pathogen causing pre- and post-harvest spoilage in many economically important crops. Excessive application of site-specific fungicides to control the pathogen has led to the selection of strains possessing target site alterations associated with resistance to these fungicides and/or strains overexpressing efflux transporters associated with multidrug resistance (MDR). MDR in B. cinerea has been correlated with the overexpression of atrB and mfsM2, encoding an ATP-binding cassette (ABC) and a major facilitator superfamily (MFS) transporter, respectively. However, it remains unknown whether other transporters may also contribute to the MDR phenotype. In the current study, the transcriptome of a B. cinerea multidrug-resistant (MDR) field strain was analysed upon exposure to the fungicide fludioxonil, and compared to the B05.10 reference strain. The transcriptome of this field strain displayed significant differences as compared to B05.10, including genes involved in sugar membrane transport, toxin production and virulence. Among the induced genes in the field strain, even before exposure to fludioxonil, were several putatively encoding ABC and MFS transmembrane transporters. Overexpression of a highly induced MFS transporter gene in the B05.10 strain led to an increased tolerance to the fungicides fluopyram and boscalid, indicating an involvement in efflux transport of these compounds. Overall, the data from this study give insights towards better understanding the molecular mechanisms involved in MDR and fitness cost, contributing to the development of more efficient control strategies against this pathogen.

Isolation, Identification and Cross-Infection of Pathogens Responsible for Postharvest Spoilage in Yam And Cocoyam Across Markets in Awka, Anambra State Nigeria

Isolation, Identification and Cross-Infection of Pathogens Responsible for Postharvest Spoilage in Yam And Cocoyam Across Markets in Awka, Anambra State Nigeria

Antifungal potentials of ten selected plants against fungi associated with postharvest spoilage of fruits

Antifungal potentials of ten selected plants against fungi associated with postharvest spoilage of fruits

Development and Characterization of Modified Gelatin-Based Cling Films with Antimicrobial and Antioxidant Activities and Their Application in the Preservation of Cherry Tomatoes.

The utilization of functional cling films presents a promising approach to alleviate post-harvest spoilage caused by microbial activity, oxidative metabolism, and moisture loss in agricultural products. To overcome the environmental problems of conventional packaging materials, in this study, we developed functional fruit and vegetable cling films based on glycidyltrimethylammonium chloride and rosemarinic acid cross-linked gelatin (RQ-GEL). The results indicate that the prepared RQ-GEL film possesses excellent UV light barrier properties and mechanical performance. RQ-GEL inhibited S. aureus and E. coli by 93.79% and 92.04%, respectively. DPPH and ABTS free radical scavenging activities were as high as 87.69% and 84.6%. In the cherry tomato preservation experiment, when compared to uncovered samples, the RQ-GEL group had a 29.77% reduction in weight loss and a significant 26.92% reduction in hardness. Meanwhile, the RQ-GEL group delays the decline of fruit total soluble solids and titratable acidity content, and prolongs the preservation period of cherry tomatoes. Hence, RQ-GEL cling film is poised to emerge as a promising packaging material for the post-harvest preservation of agricultural products.

Predicting infection of strawberry fruit by Mucor and Rhizopus spp. under protected conditions

Postharvest spoilage of strawberry grown under protection, caused by Mucor spp. and Rhizopus spp., has recently become more common in the UK, but there is insufficient knowledge to develop and implement integrated management against Mucor and Rhizopus. Field sampling was conducted to obtain field data for developing models to predict the infection of Mucor and Rhizopus on strawberry fruit. Fruits were exposed to naturally occurring inoculum for a period of 24 hours before surface-sterilisation and incubation to estimate the level of infection by Mucor and Rhizopus. The observed incidence data, together with climatic conditions and inoculum trap counts, were used analysed firstly within the framework of (1) generalised linear model (GLM), and (2) classification tree. Field sampling confirmed previous research that ripening/ripe strawberry fruits are more susceptible to infection by Mucor and Rhizopus. Climatic variability, particularly in vapour pressure deficit, appears to be more important in influencing the rotting incidence of both Mucor and Rhizopus. However, the predictability of both Mucor and Rhizopus, whether as a continuous variable (incidence) in the GLM analysis or as a categorical risk in classification tree analysis, is too low to be of practical value based on those predictors used in the present study. Thus, current management may have to be based on scheduled preharvest application of alternative products to reduce infection and local pathogen inoculum as well as adopting management practice to minimise pathogen inoculum in the planting. Future research is needed to develop methods for rapid yet accurate in situ quantification of pathogen inoculum to improve disease risk predictions.

Efficacy of ginger (Zingiber officinale) in controlling fungi causing postharvest deterioration in yam tuber

Yam (Dioscorea sp.) is a popular tuber in Cameroon, where it is grown for both food and income. One of the most challenging aspects of the long-term storage of yam tubers is post-harvest spoilage, often caused by fungi. The use of post-harvest chemicals on yam tubers is not a matter of course. The present study evaluated the efficacy of aqueous extract and powder of Zingiber officinale against fungi associated with the storage rot of yam. The fungi were isolated from two yam cultivars, “Calabar” and “Ghana”, from three localities in Cameroon. The antifungal activity of the aqueous extract and ginger powder was studied in vivo on slices of yam tubers. The results obtained showed that eight fungi were associated with yam tubers and exhibited typical rotting symptoms. The most prevalent and virulent fungus was Penicillium sp., which caused decay volumes of 12.76 cm3 and 8.74 cm3 for “Calabar” and “Ghana” cultivars, respectively. Fungal spoilage was greatly reduced by the application of aqueous extract and ginger powder. The aqueous extract tested at the 30% dose was more effective with up to 80% inhibition. However, the ginger powder was more effective against Penicillium sp., Aspergillus niger, and Colletotrichum sp. associated with rot in the variety “Ghana” with total inhibition (100%). Therefore, the aqueous extracts and powder of Zingiber officinale can be used as a bio fungicide to improve the shelf life of yam tubers.

Evaluation of microbiome and physico-chemical profiles of fresh fruits of Musa paradisiaca, Citrus sinensis and Carica papaya at different ripening stages: Implication to quality and safety management.

The ripening of fleshy fruits is a developmental process that involves changes in color, texture, aroma, nutrients, and diversity of microbiomes. Some microorganisms, specially, bacteria and molds are responsible for postharvest spoilage of fruits. Thus, this study is aimed at evaluating the alterations in microbiome and physico-chemical properties of selected fruits at different ripening stages. Totally, 108 fresh fruit samples of Musa paradisiaca, Citrus sinensis and Carica papaya at three ripening stages were collected and processed in this study. The biochemical methods and MALD-TOF MS were used in identification. The physico-chemical properties of all samples were analyzed using standard methods. The minimum counts (6.74± 0.48-6.76± 0.42 log CFU/mL) and the maximum count (7.51± 0.43-7.96± 0.34 log CFU/mL) of AMB in all fruit samples was observed at mature green and overripe stages of the fruits, respectively. The ripening stage has significantly affected the microbial counts (P < 0.05) in all fruits, except counts of Enterobacteriaceae in banana and orange, and fungal counts in orange. The bacterial community of all fruits was predominated by B. cereus (33.7%), A. faecalis (17.3%), P. putida (15.2%), M. morganii (11.1%), S. sciuri (6.6%) and S. epidermidis (4.9%); while the fungal microbiome was constituted by Candida spp. (33.9%) followed by Saccharomyces spp. (18.1%) and Aspergillus spp. (16.3%). The ripening stages have also significantly affected the physico-chemical property in all samples. Accordingly, the lowest pH (3.53) and highest content of ascorbic acid (69.87 mg/100g) were observed in mature green oranges and overripe papaya, respectively, while the maximum concentration of total sugar (17.87%) and reducing sugar (14.20%) were recorded in overripe bananas. The presence of some potential human pathogens and spoilage microorganisms in fruit samples could contribute to post-harvest product losses besides the potential health risk associated with consumption of the tainted fruits. Hence, proper safety management practices and preservation mechanisms should be developed and put in place to ensure consumers safety against pathogens besides minimizing product losses through microbial spoilage.

Isolation and Identification of Fungi Associated with Post-Harvest Spoilage of Apple (Pyrus Malus) Traded in Kano Metropolis, Nigeria

Storage of fruits at suboptimal condition provides fungi to grow and some produce mycotoxins, which can be dangerous/harmful for human consumption. This study was conducted to isolate and identify fungi associated with spoilage of apples sourced from Kano markets, Nigeria. A total of nine (9) fresh apple samples were collected randomly from different supermarkets on September of 2023 in Kano, Nigeria. Each apple was placed in a sterile plastic bag at room temperature (25–30°C) for fifteen days or until fungal growth was evident all over the samples. Growth of fungal colonies on Potato Dextrose Agar (PDA) was observed and molecular confirmation by Polymerase Chain Reaction (PCR) was conducted along with sequencing (sanger sequencing). Four fruit spoilage fungi were isolated, namely: Aspergillus fumigatus, Aspergillus niger, Curvularia spp, and Yeast spp. Out of the 9 samples that were analyzed, A. fumigatus and Curvularia spp were the most frequent isolates, A. fumigatus was seen in a total of 3 isolates (33.33%), Curvularia spp in 3 isolates (33.33%), A.niger in 2 isolates, and the least was Yeast spp seen in 1 isolate (11.11%). Sequence analysis of the Internal Transcribed Spacer regions of the nuclear encoded rDNA of the A.fumigatus isolate showed significant alignments for Penicillium griseofulvum. This is a potential refinement of the initial morphological characterization. The unexpected identification underscores the significance of incorporating molecular methods in fungal identification processes. The variation between initial morphological identification and molecular results emphasizes the need for precise and accurate identification techniques, particularly when dealing with closely related species. Most of these fungal isolates are pathogenic and can still produce severe illness in immune-compromised individuals, and sometimes otherwise healthy people may also become infected. The study highlights the limitations of traditional fungal identification techniques, as molecular analysis revealed Penicillium griseofulvum instead of the initially identified Aspergillus fumigatus in fungi from damaged apples. This underscores the importance of integrating molecular methods with conventional approaches for accurate fungal identification, vital for managing postharvest losses and ensuring food safety.

Coordination of elicitors and ascorbate-glutathione cycle: A vital nexus for mitigating post-harvest injury and losses of cultivated fruits

Fruit losses and waste are predominantly caused by postharvest diseases, with their management traditionally reliant on pesticides. The extensive utilisation of synthetic fungicides can cause harmful impacts on both human health and the environment, necessitating a reduction in their use. Recent advancements have led to the development of novel, benign strategies using natural or biologically derived compounds. These compounds, known as 'elicitors,' have the strength to instigate the plant's defence mechanism, enhancing the fruit’s resilience counter to future stress and reducing postharvest spoilage. In recent years, the impact of the plant defence system concerning elicitor compounds has been measurable through physiological parameters or the enzymatic activity of molecular markers. Antioxidant activity, a crucial parameter to determine fruit quality and tolerance to biotic and abiotic stresses, significantly functions in stress response and maintaining postharvest quality. Elicitors can prompt endurance in fruits instead of diverse environmental stresses by promoting the biosynthesis of antioxidant components and enhancing antioxidant capability through the ascorbate-glutathione (AsA-GSH) cycle. Recent findings have exhibited that applying chemical elicitors can enhance antioxidant activity by augmenting the content of AsA and GSH and by regulating the redox stability, thereby maintaining quality in harvested fruits. This review summarises recent findings demonstrating how elicitor sprays enrich antioxidant activity in harvested fruits by accelerating the synthesis of antioxidants and defence components. This provides insight into fruit defence mechanisms induced under various elicitors and their prospects in postharvest biology.

Antifungal Activity of Citrus Limon Leaf Extracts against Fungal Pathogens Isolated from Decaying Potato Tubers in Supermarkets of the Eastern Cape Province, South Africa

Globally, fungal pathogens pose severe threats to stored cereal and tuber crops, resulting in substantial losses in economic crops. This study investigated the inhibitory activities of aqueous, ethanol, and acetone leaf extracts of Citrus limon L. Osbeck against the mycelial growth of Curvularia mebaldsii, Fusarium oxysporum, and Penicillium species isolated from spoilt potato tubers retailed within supermarkets in Eastern Cape Province, South Africa. Various concentrations (100 g/L, 50 g/L, and 25 g/L) of the C. limon leaf extracts (aqueous, acetone and ethanol) were prepared and (5 mL) amended with potato dextrose agar (oxoid, UK) previously inoculated with the 7-day old culture of each fungal isolates before incubation at 28 oC. The percentage growth inhibition was determined to evaluate the antifungal efficacy of each extract. Aqueous, ethanol and acetone extracts at 50g/L and 100 g/L displayed 100 % inhibition against all three pathogens except Penicillium sp. with 91.0 - 90.97 % inhibition. The ethanol and acetone extracts had the most inhibitory effects against F. oxysporum C. mebaldsii. In contrast, the aqueous extracts displayed the least effects, though not significantly different (p0.05) across the concentrations. The notable antifungal effects against F. oxysporum, a prominent pathogen of post-harvest spoilage of potatoes, suggest the potential use of C. limon extracts to enhance the shelf-life of potatoes in supermarkets, specifically, and for post-harvest storage in general.

Application of UV-B Light and Low-Toxicity Compounds to Prevent Postharvest Spoilage on Lemons

Application of UV-B Light and Low-Toxicity Compounds to Prevent Postharvest Spoilage on Lemons

Reproducible Method for 1-Methylcylopropene (1−MCP) Application and Quantitation for Post-Harvest Research

Actively combating post-harvest food spoilage and waste can dramatically increase the efficiency of food utilization worldwide. In climacteric fruits, chemical treatments such as 1−MCP are an effective way of reducing post-harvest spoilage and waste by inhibiting the fruit’s ability to perceive ethylene. 1−MCP treatment is increasingly being used to explore the complex nature of ripening physiology at a fundamental level; however, differences in application and quantitation methods create difficulties in comparing conclusions across studies. Here, we report an effective and reproducible method for 1−MCP application and quantitation for small–medium-sized research applications. By use of surrogate alkene standards 1-butene and cis-2-butene, the highly volatile and elusive 1−MCP molecule can be identified and quantified by gas chromatography and subsequent standard curves may be developed. It is hoped that the methodology outlined here can help standardize consistent 1−MCP application for post-harvest research without excessive investment in specialized equipment.

Exploring the antifungal potential of Allium sativum and Ocimum gratissimum against post-harvest fungal pathogens in mango fruits

&lt;p&gt;Post-harvest spoilage of fruits and vegetables caused by fungal pathogens is a serious challenge to fruit production in many parts of the world. The study was conducted to evaluate the sensitivity of fungal pathogens associated with post-harvest rot of mango fruits to crude extracts from two edible plants, &lt;em&gt;Allium sativum&lt;/em&gt; and &lt;em&gt;Ocimum gratissimum&lt;/em&gt;, in the study area. Five different fungal isolates were isolated from diseased mango fruits collected from fruit stores in the study area and identified as &lt;em&gt;Aspergillus&lt;/em&gt; spp. (M&lt;sub&gt;1&lt;/sub&gt;), &lt;em&gt;Rhizopus&lt;/em&gt; spp. (M&lt;sub&gt;2&lt;/sub&gt;), &lt;em&gt;Fusarium&lt;/em&gt; spp. (M&lt;sub&gt;3&lt;/sub&gt;), &lt;em&gt;Penicillium&lt;/em&gt; spp. (M&lt;sub&gt;4&lt;/sub&gt;), &lt;em&gt;Fusarium&lt;/em&gt; spp. (M&lt;sub&gt;5&lt;/sub&gt;), &lt;em&gt;Penicillium&lt;/em&gt;&lt;em&gt; spp.&lt;/em&gt; (M&lt;sub&gt;6&lt;/sub&gt;), &lt;em&gt;Aspergillus&lt;/em&gt; spp. (M&lt;sub&gt;7&lt;/sub&gt;), and Colletotrichum spp. (M&lt;sub&gt;8&lt;/sub&gt;) using radial growth rate and morphological features of the mycelia. A constant concentration of each of the crude extracts was applied to the growth media containing the growing cultures of the fungal isolates. The radial extension of the colonies for each isolate was measured along pre-marked perpendicular axes on the base of the petri dish after 24 h, and this continued for 10–14 days. It was observed that &lt;em&gt;Rhizopus&lt;/em&gt; spp., &lt;em&gt;Fusarium&lt;/em&gt; spp., &lt;em&gt;Penicillium&lt;/em&gt;&lt;em&gt; spp&lt;/em&gt;., and Colletotrichum spp. had the least growth rate when treated with the extracts.&lt;/p&gt;

Antifungal edible coatings for fruits based on zein and chitosan nanowhiskers.

Fresh produce have a more limited shelf life than processed ones. Their sensory attributes such as appearance and surface texture are important features in consumer perception and liking. The decomposition of fresh produce, which is caused by enzymes, chemical reactions, and microbial infections, often caused by Colletotrichum species, is inevitable. However, it can be slowed down. Several materials have been developed for this purpose, with an emphasis on active coatings using nanomaterials. In this study, the protective effects of a zein coating containing chitosan nanowhiskers (CSW) for the maintenance of fruit quality were investigated using guava (Psidium guajava L.) as a model fruit. CSW were previously characterized, and their antifungal effects against distinct Colletotrichum species (Colletotrichum asianum, Colletotrichum tropicale, Colletotrichum gloeosporioides, and Colletotrichum brevisporum) were proven. Coatings were characterized by thermogravimetric analysis, optical profilometry, and mechanical properties. Total soluble solids, pH, mass loss, and visual inspection of uncoated and coated guava fruits were also verified during 9 days. Results show that CSW length and aspect ratio decreased for longer extraction times. A similar behavior was found for x-ray diffraction in which peak intensity decreases under the same conditions. CSW degradation (ca. 250-400°C) also depends on extraction time in which more crystalline whiskers are the most thermally stable ones. The addition of CSW did not significantly (p<0.05) modify the homogeneity and continuity of coating but prevented microbial growth assuring fruit quality during storage. In summary, coatings protected guava fruits from post-harvest spoilage while preserving quality and extending shelf life. PRACTICAL APPLICATION: Fresh foods such as fruits and vegetables have a more limited shelf life than processed ones.

Advances in Postharvest Diseases Management of Fruits and Vegetables: A Review

Sustainable agriculture requires factors to directly stimulate plant growth and induce the plant’s innate immune system to protect against stresses. Protection of plants is one of the main approaches to the supply of food resource. Furthermore, improved techniques for plant disease management must be environmentally sustainable, reliable, acceptable by society, and chemical-free to ensure sustainable food security. Although it is not possible to accurately determine postharvest losses due to diseases and physiological disorders, the use of proper harvesting and transportation methods that minimize damage to the product, along with optimal storage conditions that prevent the development of diseases, will be effective in reducing these postharvest losses. Since handling and storage conditions are potential threats for postharvest spoilage, it is necessary to identify environmentally friendly approaches and their precision mechanisms for postharvest disease management. Recently, biological control, non-chemical, and eco-friendly techniques have been investigated for this purpose.

Transcriptome combined with long non-coding RNA analysis reveals the potential molecular mechanism of high-CO2 treatment in delaying postharvest strawberry fruit ripening and senescence

Strawberry fruit is susceptible to postharvest spoilage with a short shelf-life, and high-CO2 treatment is an effective method to maintain the postharvest storage quality of fruit and vegetables. The aim of this study is to investigate the molecular mechanisms of high-CO2 treatment delaying the ripening and senescence of strawberry fruit after harvest. The results of this study showed that high-CO2 treatment delayed the softening and anthocyanin accumulation of strawberry fruit during storage. Transcriptome combined with long non-coding RNA (lncRNA) analysis revealed that ripening and senescence-related genes involved in abscisic acid (ABA) metabolism, cell wall degradation and anthocyanin accumulation could be regulated as potential targets by lncRNAs. Under high-CO2 treatment conditions, the expression levels of a large number of lncRNAs were altered, thereby affecting the expression patterns of downstream ripening and senescence-related target genes and resulting in the delay of fruit ripening and senescence. This study provides new insights into the molecular mechanisms of strawberry fruit ripening and senescence and high-CO2 treatment applied to postharvest preservation of strawberry fruit from the lncRNA-mRNA perspective.

Postharvest spoilage pathogen associated with turmeric (Curcuma longa L.) product in Southwestern Ethiopia

Postharvest spoilage pathogen associated with turmeric (Curcuma longa L.) product in Southwestern Ethiopia

Multispectral Sorting Based on Visibly High-Risk Kernels Sourced from Another Country Reduces Fumonisin and Toxigenic Fusarium on Maize Kernels

Fusarium species infect maize crops leading to the production of fumonisin by their toxigenic members. Elimination of microbes is critical in mitigating further postharvest spoilage and toxin accumulation. The current study investigates the efficacy of a previously described multispectral sorting technique to analyze the reduction of fumonisin and toxigenic Fusarium species found contaminating maize kernels in Kenya. Maize samples (n = 99) were collected from six mycotoxin hotspot counties in Kenya (Embu, Meru, Tharaka Nithi, Machakos, Makueni, and Kitui County) and analyzed for aflatoxin and fumonisin using commercial ELISA kits. Aflatoxin levels in majority (91%) of the samples were below the 10 ng/g threshold set by the Kenya Bureau of Standards and therefore not studied further. The 23/99 samples that had >2,000 ng/g of fumonisin were selected for sorting. The sorter was calibrated using kernels sourced from Ghana to reject visibly high-risk kernels for fumonisin contamination using reflectance at nine distinct wavelengths (470–1,550 nm). Accepted and rejected streams were tested for fumonisin using ELISA, and the presence of toxigenic Fusarium using qPCR. After sorting, there was a significant (p < 0.001) reduction of fumonisin, by an average of 1.8 log ng/g (98%) and ranging between 0.14 and 2.7 log ng/g reduction (28–99.8%) with a median mass rejection rate of 1.9% (ranged 0% to 48%). The fumonisin rejection rate ranged between 0 and 99.8% with a median of 77%. There was also a significant reduction (p = 0.005) in the proportion of DNA represented by toxigenic Fusarium, from a mean of 30–1.4%. This study demonstrates the use of multispectral sorting as a potential postharvest intervention tool for the reduction of Fusarium species and preformed fumonisin. The spectral sorting approach of this study suggests that classification algorithms based on high-risk visual features associated with mycotoxin can be applied across different sources of maize to reduce fumonisin.

New fungi causing postharvest spoilage of cucumber fruits and their molecular characterization in Egypt

New fungi causing postharvest spoilage of cucumber fruits and their molecular characterization in Egypt