Fresh Mushroom Preservation Techniques

Impact of pulsed light treatment on enzyme inactivation and quality attributes of whole white button mushroom (Agaricus bisporus) and its storage study

Whole white button mushrooms (WWBM) exhibit a limited shelf-life owing to the oxidative enzymatic browning. Inactivation of polyphenol oxidase-PPO and peroxidase-POD in WWBM and its kinetic behavior were studied using pulsed light(PL) treatment (0.13-1.11 J/cm2). The first-order kinetics explained PL-induced enzyme inactivation. Rate constants(k) for PPO and POD were 3.84 and 2.55 cm2/J. FTIR-analysis revealed secondary-structural changes in partially-purified enzyme. PL-treatment retarded browning, retained phenolics and enhanced vitamin D2. PL-treatment at 1.11 J/cm2 rendered WWBM both microbially and enzymatically stable. The PL-treated WWBM's shelf-life at 4, 20, and 37 °C were 5, 3, and 1 day. At 4 °C, browning increased by 6.1 %; firmness decreased by 55.2 %, while PL-treated mushrooms retained 90.6 % phenolics, 78.9 % antioxidant capacity, and 64.2 % D2 after 5 days. Higher activation energy value confirmed phenolics were most sensitive during storage. PL-technology supports UN Sustainable Development Goals by reducing chemical use, lowering carbon-footprints, minimizing pollution, and enhancing shelf-life, promoting sustainable global trade.

Bondarzewia dickinsii Against Colitis-Associated Cancer Through the Suppression of the PI3K/AKT/COX-2 Pathway and Inhibition of PGE2 Production in Mice

BACKGROUND

Bondarzewia dickinsii (BD) is a newly discovered edible mushroom with rich nutritional components. This study presents a thorough analysis of the components of BD, examining its inhibitory effects and the underlying mechanisms by which BD influences colitis-associated cancer (CAC).

METHODS

AOM/DSS-induced CAC mice (male C57BL/6) were used, and a histopathological analysis, intestinal microbiota assessment, and metabolomics profiling were carried out, as well as an evaluation of relevant proteins and factors, to investigate the CAC-inhibitory effects of BD.

RESULTS

BD is rich in nutritional components, including a total sugar content of 37.29% and total protein content of 24.9%. BD significantly diminished colon inflammation, as well as the size and quantity of tumors. In addition, BD modified the diversity of intestinal microbiota and changed the levels of 19 serum metabolites, including arachidonic acid. BD significantly reduced prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) in colon tissue. Furthermore, it was found to inhibit the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/COX-2 signaling pathway.

CONCLUSIONS

In general, BD inhibited the onset and progression of CAC by modulating the composition of intestinal microbiota and metabolite levels, suppressing the PI3K/AKT/COX-2 pathway, and decreasing PGE2 expression. This study provides a significant reference for the development of BD as a dietary supplement and pharmaceutical agent in the treatment of CAC.

Carvacrol Effectively Inhibits Pseudomonas tolaasii In Vitro and Induces Resistance to Brown Blotch Disease in Postharvest Agaricus bisporus

Carvacrol (CAR), a naturally occurring phenolic monoterpene compound, has recently received attention for its potential use in food preservation. However, whether it is effective in controlling brown blotch disease caused by Pseudomonas tolaasii in edible mushrooms is unknown. The results of this study showed that CAR effectively inhibits and kills P. tolaasii in vitro by disrupting cell membrane integrity and causing the leakage of cellular components. Intracellular proteins and the DNA of P. tolaasii may not be the targets of CAR. CAR fumigation at a concentration as low as 20 μmol L-1 CAR effectively inhibited P. tolaasii-caused brown blotch disease in Agaricus bisporus, accompanied by a decrease in polyphenol oxidase activation, melanin production, and malondialdehyde accumulation. CAR treatment also significantly increased the activities of β-1,4-N-acetyl-glucosaminnidase, three antioxidant enzymes, and phenylpropanoid pathway-related enzymes, as well as promoting the accumulation of phenolic, flavonoid, and lignin substances in mushrooms, thereby inducing the resistance of mushrooms to the disease. These results demonstrate the potential application of carvacrol to control bacterial disease in A. bisporus mushrooms.

Inhibition of polyphenol oxidase for preventing browning in edible mushrooms: A review

Edible mushrooms are rich in nutrients and bioactive compounds, but their browning affects their quality and commercial value. This article reviews various methods to inhibit polyphenol oxidase (PPO)-induced browning in mushrooms. Physical methods such as heat treatment, low temperatures, irradiation, and ultrasound effectively reduce PPO activity but may affect mushroom texture and flavor. Chemical inhibitors, including synthetic chemicals and natural plant extracts, provide effective PPO inhibition but require careful monitoring of their content. Biological methods, including gene editing and microbial fermentation, show promise in targeting PPO genes and enhancing antioxidant production. Combining these methods offers a comprehensive strategy for preserving mushroom quality, extending shelf life, and maintaining nutritional value. PRACTICAL APPLICATION: These approaches can be applied in the food industry to improve post-harvest mushroom preservation, enhance product quality, and reduce waste, benefiting both producers and consumers. Further research and innovation are needed to optimize the practical application of these methods in large-scale processing and storage conditions.

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

The Agaricus bisporus (Button mushroom) stands out as one of the most prolific edible fungi which offers robust flavor and nutrition. Nonetheless, this mushroom contains high moisture levels and intense respiration. Without appropriate postharvest preservation techniques, the button mushroom readily experiences browning and senescence. To ensure optimum quality, prompt cooling and appropriate storage conditions are essential. This present research investigated the postharvest quality of button mushrooms stored in a controlled atmosphere (CA) with different initial gas compositions. The findings revealed that button mushrooms in the CA group demonstrated considerable enhancements in appearance and overall quality, effectively delaying browning and senescence compared to those in the control group. The optimal gas composition is 1-3% O2 and 15-17% CO2 (CAII), which effectively inhibited the expression of polyphenol oxidase (PPO)- and lactase (LAC)-related genes in the button mushroom, maintaining a high L* value. Furthermore, the application of 1-3% O2 and 15-17% CO2 (CAII) not only preserved visual quality but also extended the postharvest shelf life of the button mushroom by minimizing metabolic activities that contribute to senescence. Moreover, 1-3% O2 and 15-17% CO2 (CAII) storage also reduced the expression levels of genes associated with ethylene synthesis, which is reflected in the gradual decrease in cell membrane permeability. Consequently, this research underscores the critical importance of controlled atmosphere storage in improving the marketability and sustainability of this widely consumed mushroom.

Revolutionizing Mushroom processing: Innovative techniques and technologies

In recent years, the global mushroom industry has seen remarkable growth due to its nutritional benefits, increasing market value, and rising consumer demand. Mushrooms are valued for their unique flavor, low sugar and salt, and rich Vitamin D content. In India as well as across the globe, mushroom cultivation is becoming increasingly popular among new entrepreneurs, leveraging the diverse agro-climatic conditions and substantial agricultural waste. Various government policies are also fostering research and development in this sector. To extend shelf life and preserve quality, various preservation techniques are employed, including drying, freezing, canning, high-pressure processing and modified atmosphere packaging. Furthermore, cutting-edge technologies such as nuclear magnetic resonance and spectroscopy are improving post-harvest processing, helping to maintain sensory properties and nutritional content. Automation is also transforming mushroom processing by enhancing efficiency and scalability. This review examines the innovative methods and technologies driving advancements in mushroom production and quality worldwide.

Sensory Characteristics and Volatile Organic Compound Profile of Wild Edible Mushrooms from Patagonia, Argentina

The Andean-Patagonian forests of South America offer a great variety of wild edible mushrooms, many with ancestral use and others linked to new mycogastronomic offers. However, their sensory properties and detailed characterizations have not yet been deeply explored and described, nor have their alterations due to cold storage. The aims of this work were to perform a sensory characterization through a trained panel evaluation, perform target volatile compounds analysis and evaluate post-harvest preservation methods effects on nine species of wild edible mushrooms with different trophic habits (Cortinarius magellanicus, Panus dusenii, Fistulina antarctica, F. endoxantha, Gloeosoma vitellinum, Grifola gargal, Lepista nuda, Ramaria patagonica, and Cyttaria hariotii). The sensory description of dehydrated specimens through quantitative descriptive analysis showed that panelists were a significant source of variation; F. antarctica and R. patagonica registered distinct sweet flavor/spice odor and wood/sweet flavor, respectively, and different textures. Refrigeration produced a rapid loss of sensory characteristics, whereas freezer conservation satisfactorily maintained the characteristics in F. anctartica, R. patagonica, G. vitellinum, and C. hariotti for at least four months. A total of 60 target volatile organic compounds were detected, corresponding to grass, mushroom, alkane, and pungent odors in F. anctartica, R. patagonica, and G. vitellinum. The detailed sensory characterization and post-harvest conservation options of these novel products constitute crucial information to promote their sustainable use and local development through innovative activities linked to tourism, such as mushroom gastronomy and mycotourism.

Pulsed light treatment of whole white button mushroom (Agaricus bisporus): Kinetics and mechanism of microbial inactivation and storage study

The whole white button mushrooms (WWBMs) are highly perishable due to susceptibility to microbial spoilage. This study explored the potential of pulsed light (PL) treatment for decontamination and shelf-life extension of WWBM. WWBM surface was inoculated with Escherichia coli, Listeria monocytogenes, and Aspergillus niger spores (8.1, 8.0, and 8.05 log10 CFU/g, respectively) and tested for inactivation against various PL intensities (fluence 0.13-0.75 J/cm2). The kinetics and mechanism of microbial inactivation were explored, and shelf life was determined at 4, 20, and 37°C. Microbial inactivation increased with increasing PL intensity. PL-induced microbial inactivation was well explained by Weibull model with shape parameters (β-value) for E. coli, L. monocytogenes, A. niger, aerobic mesophiles, and yeast and mold as 0.87, 0.92, 0.91, 0.89, and 0.94, respectively. PL-treatment at 0.75 J/cm2 resulted in >5-log cycle reduction in all inoculated and natural microorganisms. Exposure to PL led to collapse of cellular structure, ruptured cell wall, and leakage of cellular material in all microorganisms and spores along with alterations in nucleic acid and lipid bands. At 4°C, maximum shelf life of 5 days was achieved when WWBM was exposed at 0.75 J/cm2. The WWBM retained 83.3% phenolics, 83.9% antioxidant capacity, and 77.4% vitamin D2 at 4°C while reducing the polyphenol oxidase and peroxidase activity by 89% and 79%. The degradation rate for quality parameters increased with storage temperature. The activation energy of the browning index affirmed it as the most sensitive quality attribute during storage. The study concluded the potential of PL treatment to prolong the shelf life of WWBM.

Edible colorimetric label based on immobilized purple sweet potato anthocyanins onto edible film for packaged mushrooms freshness monitoring

An edible colorimetric label has been developed to determine the freshness level of mushrooms, i.e. white oyster mushrooms (Pleurotus ostreatus). The edible indicator label has been fabricated based on purple sweet potato (Ipomoea batatas L.) anthocyanins (PSPA) immobilized onto an edible film made of chitosan and cornstarch with added PVA. The freshness parameters of the mushrooms were pH, weight loss, texture, and sensory evaluation. The results showed that the colorimetric label was dark purple when the mushroom was fresh, and turn to light purple when the mushroom was still fresh, and finally green when the mushroom was no longer fresh. The color value (mean Red) of the label was measured using the ImageJ program, where its color value (mean Red) increased with decreasing freshness level of the mushrooms. The edible label can distinguish fresh mushrooms from spoilage, making it suitable to be used in a packaged mushroom as a freshness indicator.

Sausage Quality during Storage under the Partial Substitution of Meat with Fermented Oyster Mushrooms

The increasing global demand for meat production, driven by a rapidly expanding population and changing dietary preferences has prompted the search for protein-rich, sustainable, and healthier meat alternatives. In this context, edible mushrooms are viewed as advantageous substitutes for meat, offering a viable solution. This study aimed to investigate the effects of partially replacing (25% and 50%) pork meat in sausage samples with fermented oyster mushrooms (Pleurotus ostreatus), which were subjected to various pretreatments. Six different pretreatments were applied to fresh oyster mushrooms as follows: blanching in water, steaming, oven-cooking, microwave treatment, high hydrostatic pressure treatment, and ultraviolet light treatment. The effects of mushroom replacement on the moisture, pH, lipid oxidation, color, and textural properties of sausages during the 4-week refrigerated storage period were evaluated. The results revealed that replacing pork meat with fermented oyster mushrooms resulted in an increase in moisture content and b* values and a decrease in pH, L*, a*, and shear force values, proportional to the mushroom percentage. The lipid oxidation findings suggest that the antioxidant capabilities of fermented oyster mushrooms were influenced by the pretreatment methods applied to the mushrooms, exhibiting varying levels of effectiveness.

Valorization of agro-forest wastes (oak acorns, vineyard pruning, and olive pruning) through the cultivation of shiitake (Lentinula edodes) mushrooms

Experimental research has been focusing on developing new substrates for growing shiitake mushrooms as alternatives to the standard oak sawdust substrate. The selection of appropriate lignocellulosic materials is based on their availability in the production area and their compatibility with the requirements of the mushroom species being cultivated. In comparison to oak sawdust substrate (OS) as the control, this study evaluated the potential of oak acorns (OA), olive pruning (OLPR), and vineyard pruning (VIP), and various combinations: OA-OLPR:1-1, OA-VIP:1-1, OS-OLPR:1-1, and OS-VIP:1-1, prepared on a dry weight basis. In comparison to OS, complete mycelial development was hastened in OA, OA-VIP: 1-1, and OS-VIP:1-1 by 9.5, 7.9, and 4.2 days and delayed in OLPR and OS-OLPR:1-1 by 11.3 and 7.0 days, respectively. Also, harvest was earlier in OA, OA-VIP:1-1, and OS-VIP:1-1 by 9.3, 6.7, and 3.3 days, respectively, while it was significantly delayed in OLPR, VIP, and OS-OLPR:1-1 by 12.3, 3.7, and 8.0 days, respectively. While the total biological yield was significantly reduced in OLPR, OS-OLPR:1-1, VIP, and OS-VIP:1-1, it was comparable to OS in OA, OA-OLPR:1-1, and OA-VIP:1-1 (597.0, 552.0, 532.2, and 556.2 g/kg, respectively). Production was consistently high over two consecutive flushes in OS, OA, and OA-VIP: 1-1. Total biological yields were higher in OA-OLPR: 1-1 than OS-OLPR:1-1 and in OA-VIP:1-1 than OS-VIP:1-1. OA increased mushroom number and firmness, VIP and OLPR increased mushroom weight, and OA-VIP:1-1 increased pileus thickness. Mushrooms' protein and fiber contents were higher than OS in all substrates and the highest in OA-OLPR:1-1 (8.7 %) and OLPR (2.8 %), respectively. Conclusively, the substrates OA, OA-VIP: 1-1, and OA-OLPR:1-1 may alternate oak sawdust; however, the first two substrates have an advantage over the third due to earlier harvests. Also, it is more favorable to use VIP and OLPR in combination with OA than to use them alone.

Novel Post-Harvest Preservation Techniques for Edible Fungi: A Review

Edible fungi are well known for their rich nutrition and unique flavor. However, their post-harvest shelf-life is relatively short, and effective post-harvest preservation techniques are crucial for maintaining their quality. In recent years, many new technologies have been used for the preservation of edible fungi. These technologies include cold plasma treatment, electrostatic field treatment, active packaging, edible coatings, antimicrobial photodynamic therapy, and genetic editing, among others. This paper reviews the new methods for post-harvest preservation of mainstream edible fungi. By comprehensively evaluating the relative advantages and limitations of these new technologies, their potential and challenges in practical applications are inferred. The paper also proposes directions and suggestions for the future development of edible fungi preservation, aiming to provide reference and guidance for improving the quality of edible fungi products and extending their shelf-life.

Pre- and Postharvest Strategies for Pleurotus ostreatus Mushroom in a Circular Economy Approach

Mushroom cultivation presents a viable solution for utilizing agro-industrial byproducts as substrates for growth. This process enables the transformation of low-economic-value waste into nutritional foods. Enhancing the yield and quality of preharvest edible mushrooms, along with effectively preserving postharvest mushrooms, stands as a significant challenge in advancing the industry. Implementing pre- and postharvest strategies for Pleurotus ostreatus (Jacq.) P. Kumm (oyster mushroom) within a circular economy framework involves optimizing resource use, minimizing waste, and creating a sustainable and environmentally friendly production system. This review aimed to analyze the development and innovation of the different themes and trends by bibliometric analysis with a critical literature review. Furthermore, this review outlines the cultivation techniques for Pleurotus ostreatus, encompassing preharvest steps such as spawn production, substrate preparation, and the entire mushroom growth process, which includes substrate colonization, fruiting, harvesting, and, finally, the postharvest. While novel methodologies are being explored for maintaining quality and extending shelf-life, the evaluation of the environmental impact of the entire mushroom production to identify areas for improvement is needed. By integrating this knowledge, strategies can be developed for a more sustainable and circular approach to Pleurotus ostreatus mushroom cultivation, promoting environmental stewardship and long-term viability in this industry.

Comparative studies on the cultivation, yield, and nutritive value of an edible mushroom, Pleurotus tuber-regium (Rumph. ex Fr.) Singer, grown under different agro waste substrates

In the present study, Pleurotus tuber-regium (Rumph. ex Fr.) Singer collected from Keeriparai forest of Kanyakumari district, South India was cultivated using environmentally benign, low-cost agricultural waste residues (paddy straw, sugarcane bagasse, rice husk, and sawdust) as growth substrates. The main goal of this study was to assess the cultivation, yield, and nutritional value of P. tuber-regium fruiting bodies grown under different growth substrates. Spawn running time and time for primordia formation were found to be shorter in mushroom growing with paddy straw substrate compared to sawdust and sugarcane bagasse. A quick spawn run time was observed in paddy straw substrate (12 ± 1 day) followed by sugarcane bagasse (15 ± 1 day) and sawdust (23 ± 1 day). The primordia was well developed in the macrofungus grown with paddy straw substrate on 18 ± 1 day followed by sugarcane bagasse (22 ± 1 day) and sawdust (32 ± 1 day). Significantly higher yield of fruiting bodies with increased contents of protein and carbohydrate and low level of fat was obtained when P. tuber-regium was cultivated with paddy straw substrate. While, cultivation of P. tuber-regium in sawdust and sugarcane bagasse resulted in increased contents of K, Na, Ca, and Mg along with highest energy value. On the other hand, rice husk did not support the cultivation of this macrofungus. Therefore, it is of significant interest to initiate the commercial production of this macrofungus so as to fight against the problems of malnutrition found in few African and south Asian countries.

Recent advances and role of melatonin in post-harvest quality preservation of shiitake (Lentinula edodes)

Shiitake mushrooms are renowned for their popularity and robust nutritional value, are susceptible to spoilage due to their inherent biodegradability. Nevertheless, because of their lack of protection, these mushrooms have a short shelf life. Throughout the post-harvest phase, mushrooms experience a persistent decline in quality. This is evidenced by changes such as discoloration, reduced moisture content, texture changes, an increase in microbial count, and the depletion of nutrients and flavor. Ensuring postharvest quality preservation and prolonging mushroom shelf life necessitates the utilization of post-harvest preservation techniques, including physical, chemical, and thermal processes. This review provides a comprehensive overview of the deterioration processes affecting mushroom quality, covering elements such as moisture loss, discoloration, texture alterations, increased microbial count, and the depletion of nutrients and flavor. It also explores the key factors influencing these processes, such as temperature, relative humidity, water activity, and respiration rate. Furthermore, the review delves into recent progress in preserving mushrooms through techniques such as drying, cooling, packaging, irradiation, washing, and coating.

Postharvest of fresh white shimeji mushroom subjected to UV-C radiation

This study aimed to evaluate the postharvest characteristics of edible fresh white shimeji mushrooms under different UV-C radiation doses. The experimental design used was fully randomized, in a 5 × 8 factorial scheme (UV-C radiation dose: 0 (control), 1, 2, 3, and 4 kJ m-2 x day of analysis), with 3 replications of 70 ± 1 g mushrooms each. After exposure to different doses, they were stored at 2 ± 0.5 °C and 60 ± 3.8 % RH. Data were subjected to permutational multivariate analysis (PERMANOVA) (p ≤ 0.05). There was no significance for interaction, nor the factor day, only for the UV-C radiation doses factor. Regarding PCA, among the doses applied, the dose of 2 kJ m-2 was effective in maintaining the quality of mushrooms with greater lightness, greater whiteness index, a greater amount of total extractable polyphenols, and total antioxidant activity. In conclusion, the dose of 2 kJ m-2 was effective in maintaining the postharvest quality of white shimeji mushrooms.

Effect of Pleurotus eryngii on the Characteristics of Pork Patties during Freezing and Thawing Cycles

Temperature fluctuations severely damage the quality, oxidation stability, and structure of pork patties. This study investigated the potential reasons for Pleurotus eryngii (Pe) to protect frozen pork patties from quality degradation caused by temperature fluctuations and promoted the application of a natural ingredient. In this experiment, the pH, the water holding capacity (WHC), the properties of color and texture, the appearance, the degree of protein and lipid oxidation, and the microstructure of patties with different additions of Pe (0%, 0.25%, 0.50%, 1.00%, and 2.00%) were intensified during freezing and thawing (F-T) cycles. The results showed that patties with 0.50% Pe exhibited a distinguishable improvement in the changes of pH, WHC, color, and texture during F-T cycles (p < 0.05). With the times of F-T cycles increasing, 0.50% Pe was able to inhibit lipid oxidation of patties by decreasing the peroxide value (POV) and the thiobarbituric acid reactive substances (TBARS) value to 0.87 and 0.66-fold, respectively, compared to those in the control group. It was also able to suppress the protein oxidation of the patties with a protein sulfhydryl content increasing to 1.13-fold and a carbonyl content decreasing to 0.49-fold compared to the patties in the control group (p < 0.05) after 5 F-T cycles. In addition, the figures of appearance and microstructure of samples indicated that 0.50% Pe effectively restrained the deterioration of structure features from patties after 5 F-T cycles. Thus, the addition of Pe effectively maintained the characteristics of pork patties under F-T cycles.

Epsilon-poly-l-lysine alleviates brown blotch disease of postharvest Agaricus bisporus mushrooms by directly inhibiting Pseudomonas tolaasii and inducing mushroom disease resistance

The natural antimicrobial peptide, epsilon-poly-l-lysine (ε-PL), is widely acknowledged as a food preservative. However, its potential in managing bacterial brown blotch disease in postharvest edible mushrooms and the associated mechanism remain unexplored. In this study, concentrations of ε-PL ≥ 150 mg L-1 demonstrated significant inhibition effects, restraining over 80% of growth and killed over 99% of Pseudomonas tolaasii (P. tolaasii). This inhibition effect occurred in a concentration-dependent manner. The in vivo findings revealed that treatment with 150 mg L-1 ε-PL effectively inhibited P. tolaasii-caused brown blotch disease in Agaricus bisporus (A. bisporus) mushrooms. Plausible mechanisms underlying ε-PL's action against P. tolaasii in A. bisporus involve: (i) damaging the cell morphology and membrane integrity, and increasing uptake of propidium iodide and leakage of cellular components of P. tolaasii; (ii) interaction with intracellular proteins and DNA of P. tolaasii; (iii) inhibition of P. tolaasii-induced activation of polyphenol oxidase, elevation of antioxidative enzyme activities, stimulation of phenylpropanoid biosynthetic enzyme activities and metabolite production, and augmentation of pathogenesis-related protein contents in A. bisporus mushrooms. These findings suggest promising prospects for the application of ε-PL in controlling bacterial brown blotch disease in A. bisporus.

A comprehensive review of the application of ultrasonication in the production and processing of edible mushrooms: Drying, extraction of bioactive compounds, and post-harvest preservation

Edible mushrooms are high in nutrients, low in calories, and contain bioactive substances; thus, they are a valuable food source. However, the high moisture content of edible mushrooms not only restricts their storage and transportation after harvesting, but also leads to a shorter processable cycle, production and processing limitations, and a high risk of deterioration. In recent years, ultrasonic technology has been widely applied to various food production operations, including product cleaning, post-harvest preservation, freezing and thawing, emulsifying, and drying. This paper reviews applications of ultrasonic technology in the production and processing of edible mushrooms in recent years. The effects of ultrasonic technology on the drying, extraction of bioactive substances, post-harvest preservation, shelf life/preservation, freezing and thawing, and frying of edible mushrooms are discussed. In summary, the application of ultrasonic technology in the edible mushroom industry has a positive effect and promotes the development of this industry.

Review of postharvest processing of edible wild-grown mushrooms

Edible wild-grown mushrooms, plentiful in resources, have excellent organoleptic properties, flavor, nutrition, and bioactive substances. However, fresh mushrooms, which have high water and enzymatic activity, are not protected by cuticles and are easily attacked by microorganisms. And wild-grown mushroom harvesting is seasonal the harvest of edible wild-grown mushrooms is subject to seasonality, so their market availability is challenging. Many processing methods have been used for postharvest mushroom processing, including sun drying, freezing, packaging, electron beam radiation, edible coating, ozone, and cooking, whose effects on the parameters and composition of the mushrooms are not entirely positive. This paper reviews the effect of processing methods on the quality of wild and some cultivated edible mushrooms. Drying and cooking, as thermal processes, reduce hardness, texture, and color browning, with the parallel that drying reduces the content of proteins, polysaccharides, and phenolics while cooking increases the chemical composition. Freezing, which allows mushrooms to retain better hardness, color, and higher chemical content, is a better processing method. Water washing and ozone help maintain color by inhibiting enzymatic browning. Edible coating facilitates the maintenance of hardness and total sugar content. Electrolytic water (EW) maintains total phenol levels and soluble protein content. Pulsed electric field and ultrasound (US) inhibit microbial growth. Frying maintains carbohydrates, lipids, phenolics, and proteins. And the mushrooms processed by these methods are safe. They are the focus of future research that combines different methods or develops new processing methods, molecular mechanisms of chemical composition changes, and exploring the application areas of wild mushrooms.

New preservation and detection technologies for edible mushrooms: A review

Edible mushrooms are nutritious, tasty, and have medicinal value, which makes them very popular. Fresh mushrooms have a high water content and a crisp texture. They demonstrate strong metabolic activity after harvesting. However, they are prone to textural changes, microbial infestation, and nutritional and flavor loss, and they therefore require appropriate post-harvest processing and preservation. Important factors affecting safety and quality during their processing and storage include their quality, source, microbial contamination, physical damage, and chemical residues. Thus, these aspects should be tested carefully to ensure safety. In recent years, many new techniques have been used to preserve mushrooms, including electrofluidic drying and cold plasma treatment, as well as new packaging and coating technologies. In terms of detection, many new detection techniques, such as nuclear magnetic resonance (NMR), imaging technology, and spectroscopy can be used as rapid and effective means of detection. This paper reviews the new technological methods for processing and detecting the quality of mainstream edible mushrooms. It mainly introduces their working principles and application, and highlights the future direction of preservation, processing, and quality detection technologies for edible mushrooms. Adopting appropriate post-harvest processing and preservation techniques can maintain the organoleptic properties, nutrition, and flavor of mushrooms effectively. The use of rapid, accurate, and non-destructive testing methods can provide a strong assurance of food safety. At present, these new processing, preservation and testing methods have achieved good results but at the same time there are certain shortcomings. So it is recommended that they also be continuously researched and improved, for example through the use of new technologies and combinations of different technologies. © 2023 Society of Chemical Industry.

Effect of Controlled Atmosphere Packaging on the Physiology and Quality of Fresh-Cut Dictyophora rubrovolvata

Dictyophora rubrovolvata is a typical edible fungus of Guizhou Province and is very popular due to its unique taste and texture. In this study, the effect of a controlled atmosphere (CA) on fresh-cut D. rubrovolvata shelf life was investigated. Firstly, this study addresses the influence of different O₂ concentrations (5%, 20%, 35%, 50%, 65%, 80%, or 95%) with N₂ balance on fresh-cut D. rubrovolvata quality while stored at 4 ± 1 °C for 7 d. Then, on the basis of the determined O₂ concentration (5%), CO₂ (0%, 5%, 10%, 15%, or 20%) was involved and stored for 8 d at 4 ± 1 °C. Evaluations of physiology parameters, texture, browning degree, nutritional, umami, volatile components, and total colony numbers were determined in fresh-cut D. rubrovolvata. From the results of water migration, the sample of 5% O₂/5% CO₂/90% N₂ was closer to 0 d than other groups at 8 days. Meanwhile, the polyphenol oxidase (2.26 ± 0.07 U/(g·min)), and catalase activity (4.66 ± 0.08 U/(g·min·FW)) were superior to the samples of other treatment groups on the eighth day (3.04 ± 0.06 to 3.84 ± 0.10 U/(g·min), 4.02 ± 0.07 to 4.07 ± 0.07 U/(g·min·FW)). Therefore, we found that a gas environment with 5% O₂/5% CO₂/90% N₂ could ensure the membrane integrity, oxidation, and prevent the browning of fresh-cut D. rubrovolvata, thus better maintaining the physiological parameters. Meanwhile, it also maintained the samples' texture, color, nutritional value, and umami taste. Furthermore, it inhibited the increase in total colony numbers. The volatile components were closer to the initial level compared with other groups. The results indicate that fresh-cut D. rubrovolvata could maintain its shelf life and quality when stored in 5% O₂/5% CO₂/90% N₂ at 4 ± 1 °C.

Recent advance in quality preservation of non-thermal preservation technology of fresh mushroom: a review

Fresh mushrooms have a long history of cultivation and consumption, but high postharvest losses are a concern in the commercial production of mushrooms worldwide. Thermal dehydration is widely used in the preservation of commercial mushrooms, but the flavor and taste of mushrooms are significantly altered after dehydration. Non-thermal preservation technology, which effectively maintains the characteristics of mushrooms, is a viable alternative to thermal dehydration. The objective of this review was to critically assess the factors affecting fresh mushroom quality after preservation is remarkable, with the ultimate goal of developing and promoting non-thermal preservation technology for preserving fresh mushroom quality, effectively extending the shelf life of fresh mushrooms. The factors influencing the quality degradation process of fresh mushrooms discussed herein include the internal factors associated with the mushroom itself and the external factors associated with the storage environment. We present a comprehensive discussion of the effects of different non-thermal preservation technologies on the quality and shelf life of fresh mushrooms. To prevent quality loss and extend the shelf life after postharvest, hybrid methods, such as physical or chemical techniques combined with chemical techniques, and novel nonthermal technologies are highly recommended.

Advances in the Role and Mechanisms of Essential Oils and Plant Extracts as Natural Preservatives to Extend the Postharvest Shelf Life of Edible Mushrooms

China has a large variety of edible mushrooms and ranks first in the world in terms of production and variety. Nevertheless, due to their high moisture content and rapid respiration rate, they experience constant quality deterioration, browning of color, loss of moisture, changes in texture, increases in microbial populations, and loss of nutrition and flavor during postharvest storage. Therefore, this paper reviews the effects of essential oils and plant extracts on the preservation of edible mushrooms and summarizes their mechanisms of action to better understand their effects during the storage of mushrooms. The quality degradation process of edible mushrooms is complex and influenced by internal and external factors. Essential oils and plant extracts are considered environmentally friendly preservation methods for better postharvest quality. This review aims to provide a reference for the development of new green and safe preservation and provides research directions for the postharvest processing and product development of edible mushrooms.

Improving the nutritional quality and bio-ingredients of stored white mushrooms using gamma irradiation and essential oils fumigation

Mushrooms are highly perishable in nature and deteriorate within a few days after harvesting due to their high respiration rate and delicate epidermal structure. Consequently, the shelf-life of freshly harvested mushroom is limited to 1–3 days at ambient condition. Hence, the current investigation was carried out to study γ-irradiation effects (1.5 and 2.0 kGy) and essential oils (EOs) fumigation including geranium (60 and 80 μL/L) and lemongrass (40 and 60 μL/L) on nutritional quality (Vitamins C and D2) as well as bio-ingredients such as total soluble proteins, phenolic and flavonoids contents, antioxidant activity were determined as an origin of potential natural antioxidant plus the profile of phenols and flavonoids identified by HPLC. As well as activities of some enzymes (PPO, SOD, PAL, and APX) of Agaricus bisporus mushroom at 4 °C during storage time for twelve days. The findings showed that there was a reduction in the contents of Vit. C and vitamin D2 in all mushroom samples during storage, where the essential oil treatment especially 60 μL/L of geranium and 40 μL/L of lemongrass gave the least decrease (3.42 and 3.28 mg/100 g FW, respectively) of ascorbic acid content compared to the other treatments while the irradiated samples (1.5, and 2.0 kGy) gave the lowest decrease of vitamin D2 (106.30 and 114.40 mg/kg DW, respectively) at the end of storage time. The content of the bio-ingredients content was affected by the storage periods, and the samples treated with oil fumigation gave the best content and the same trend happened with the antioxidant activity. The enzymes activity increased by the storage period, especially after 4 days of storage, and then the activity decreased after that. Quantification of phenolic and flavonoid compounds affected by storage periods in all treatments and the EO-treated mushrooms gave the best amount of them. Thus, samples of mushrooms treated with oil fumigation especially 60 μL/L of geranium and 40 μL/L of lemongrass can successfully increase the nutritional value plus maintain the value of the mushrooms during storage time.

Pleurotus ostreatus Grown on Agro-Industrial Residues: Studies on Microbial Contamination and Shelf-Life Prediction under Different Packaging Types and Storage Temperatures

The short shelf-life of mushrooms, due to water loss and microbial spoilage, is the main constraint for commercialization and consumption. The effect of substrate type combined with different temperatures and packaging conditions on the shelf-life of fresh Pleurotus ostreatus is scantily researched. The current study investigated the shelf-life of fresh oyster mushrooms grown on low (0.3, 0.3, 0.17) and high (0.7, 0.7, 0.33) rates of olive pruning residues (OLPR), spent coffee grounds (SCG), and both combined residues (OLPR/SCG) with wheat straw (WS), respectively, at ambient (20 °C) and 4 °C temperatures under no packaging, polyethylene plastic bag packaging (PBP), and polypropylene vacuum bag packaging (VBP). Results showed that at ambient temperature OLPR/SCG mushrooms PBP-bagged had an increased shelf-life by 0.5-1.2 days in comparison with WS ones. The predictive models adopted to optimize mushroom shelf-life at ambient temperature set rates of 0.289 and 0.303 of OLPR and OLPR/SCG, respectively, and PBP as the most suitable conditions (9.18 and 9.14 days, respectively). At 4 °C, OLPR/SCG mushrooms VBP-bagged had a longer shelf-life of 2.6-4.4 days compared to WS ones. Predictive models noted a maximized shelf-life of VBP-bagged mushrooms (26.26 days) when a rate of 0.22 OLPR/SCG is incorporated into the initial substrate. The combination of OLPR and SCG increased the shelf-life of fresh Pleurotus ostreatus by decreasing the total microbial count (TMC) while delaying weight loss and veil opening, and maintaining carbohydrate content, good firmness, and considerable protein, in comparison with WS regardless the storage temperature and packaging type.

Recent Advances in Postharvest Irradiation Preservation Technology of Edible Fungi: A Review

Edible fungi have high edible, medicinal and economic value. Rapid development of the edible fungi industry can meet people's consumption demands. However, due to lack of suitable preservation technology after harvest, edible fungi are susceptible to mechanical damage, microbial infection, and discoloration, which could affect the quality and shelf life of fresh edible fungi. Many techniques have been developed to extend the postharvest storage time of fresh edible fungi and irradiation technology has been proven to be one of the potential technologies. This review summarizes the internal and external factors affecting the postharvest quality deterioration of edible fungi, introduces the types of irradiation preservation technology and describes comprehensive advances in the effects of irradiation on shelf life, microbiology, organoleptic qualities, nutritional qualities (proteins, fats, sugars and vitamins) and enzymatic activities of edible fungi from different regions and of different species worldwide. This review uncovers that the postharvest quality decay of edible fungi is a complex process. The irradiation preservation of edible fungi is affected not only by the edible fungus itself and the storage environment but also by the radiation type, radiation dose and radiation source conditions. Future studies need to consider the combined application of irradiation and other novel technologies to further improve the preservation effect of edible fungi, in particular in the area of irradiation's influence on the flavor of edible fungus.

Influence of Convective and Vacuum-Type Drying on Quality, Microstructural, Antioxidant and Thermal Properties of Pretreated Boletus edulis Mushrooms

Freshly harvested Boletus edulis mushrooms are subjected to rapid loss of quality due to the high moisture content and enzymatic activity. Drying time, quality characteristics, microstructural and thermal properties were studied in mushrooms ground to puree subjected to hot air drying (HAD), freeze drying (FD) and centrifugal vacuum drying (CVD). The influence of hot water blanching and UV-C pretreatments was additionally investigated. The rehydration ability of mushroom powders was improved by FD, especially without pretreatment or combined to UV-C exposure. The HAD and CVD, with no pretreatment or combined to UV-C, ensured good preservation of phenolics and antioxidant activity of dried mushrooms. The total difference in color of mushroom pigments extracted in acetone was lower in samples dried by CVD and higher in ones by FD. Blanching before HAD produced whiter product probably due to the reduced polyphenoloxidase activity. Scanning Electron Microscopy (SEM) analysis showed fewer physical changes in FD-samples. Heat-induced structural changes were noticed by Differential Scanning Calorimetry (DSC), Thermogravimetry (TG) and Derivative Thermogravimetry (DTG) analysis, in particular of biopolymers, confirmed by ATR-FTIR analysis. Based on our complex approach, the UV pretreatment of mushrooms could be a better alternative to water blanching. Centrifugal vacuum emerged as a new efficient drying method in terms of bioactive compounds, color and thermal stability, while FD led to better rehydration ability and microstructure.

Biopreservation of Wild Edible Mushrooms (Boletus edulis, Cantharellus, and Rozites caperata) with Lactic Acid Bacteria Possessing Antimicrobial Properties

There is scarce data on the influence of fermentation with lactic acid bacteria (LAB) on the quality and safety of edible mushrooms. The aim of this study was to ferment Suillus luteus, Boletus edulis, Cantharellus cibarius, and Rozites caperata with LAB strains (Lacticaseibacillus casei LUHS210 and Liquorilactobacillus uvarum LUHS245) and to evaluate the influence of this technology on colour characteristics, pH, mould/yeast count, liking, emotional response, volatile compound (VC) profile, and the formation of biogenic amines (BA). Additionally, ultrasonication or prolonged thermal treatment were applied before fermentation. The LUHS245 strain showed better preservation properties in the case of fungal inhibition; however, prolonged thermal treatment and/or ultrasound pre-treatment ensure safer fermentation. Mushroom species and type of pre-treatment had a significant effect on colour coordinates and pH (p ≤ 0.0001). A greater variety of VC was identified in pre-treated and fermented samples. Significant differences were found between the emotions induced in consumers. The lowest sum of BA was found in thermally pre-treated and fermented R. caperata, while the highest was in ultrasonicated and fermented B. edulis. Finally, despite good overall acceptability, it is important to select appropriate LAB strains for the fermentation of edible mushrooms to ensure their safety in the case of BA formation.