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

Effects of chitosan‑calcium coating on the physiological characteristics and browning of Stropharia rugosoannulata during postharvest storage

The effects of chitosan‑calcium (CTSCa) coating on the physiological characteristics and browning of fresh Stropharia rugosoannulata were investigated. The 0.5 % CTS-Ca coating reduced the weight loss rate, opening rate, and browning of mushrooms. CTS-Ca could decrease the contents of total phenols and the activities of enzymes associated with enzymatic browning, increase the activities of antioxidant enzymes, and reduce the production of malondialdehyde, a product of membrane lipid metabolism. Based on transcriptomic analysis, CTS-Ca treatment down-regulated the expression of genes on the chorismate/tyrosine pathway to inhibit the synthesis of phenolic substrates and tyrosinase activity, up-regulated the three energy metabolism pathways of glycolysis, TCA cycle, and oxidative phosphorylation to maintain the integrity of the cell membrane, increased the expression of catalase and superoxide dismutase genes to scavenge ROS. Our results would provide a simple and practical preservation solution for S. rugosoannulata during the postharvest storage.

Exploring the possible mechanisms of X-rays treatment for retention aroma volatiles in shiitake mushrooms during low temperature storage

X-rays irradiation has been demonstrated to effectively preserve the freshness of edible fungi and delay the loss of aroma during storage. In this study, shiitake mushrooms were irradiated with X-rays dose of 0.5 kGy and stored at 2 °C for 35 days. Non-irradiated mushrooms were recorded as control group. Results indicated that 0.5 kGy X-rays treatment preserved the flavor quality by exhibiting higher volatile substance content in shiitake mushrooms. X-rays treatment promoted the activities of lipoxygenase (LOX) and alcohol dehydrogenase (ADH) and oxidation of linoleic acid. In addition, the degradation of methionine and cysteine was facilitated by X-rays. Higher enzymes activities for γ-glutamyl transpeptidase (GGT) and cystine sulfoxide lyase (CS lyase) were found in 0.5 kGy X-rays irradiated mushrooms. These findings suggest that the retention of mushroom flavor by X-rays treatment is closely related to fatty acid metabolism, sulfur-containing amino acid metabolism, and lentinic acid metabolism.

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.

Volatile flavor behavior characterization of Hericium erinaceus during postharvest storage using E-nose, HS-GC-IMS, and HS-SPME-GC-MS after treated with electron-beam generated X-ray irradiation

Flavor alteration is a crucial factor affecting the quality of mushrooms during preservation. The dynamic variations of volatile profiles of fresh Hericium erinaceus with electron-beam generated X-ray irradiation were investigated by combining E-nose, headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). E-nose analysis achieved rapid discrimination in all treatments over storage time. 65 and 73 volatile organic compounds (VOCs) were identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. Thereinto, 1-octen-3-ol, 1-octen-3-one, and 2-octanone were screened out as the characteristic VOCs, which contents declined during storage. While the contents of (E)-2-octenal, (E)-2-nonenal, and 1-octanol increased. The flavor profile changes from distinct mushroom and floral odor to an intense alcohol and fatty odor. Notably, one-kGy irradiation remained more volatiles and denser mushroom odor after storage. Multivariate analysis further confirmed that 1.0 kGy irradiation contributed to the overall aroma retention during postharvest storage of H. erinaceus.

Effects of 60Coγ-irradiation combined with sodium dehydrogenate on post-harvest preservation and physiological indices of Volvariella volvacea

Volvariella volvacea is a mushroom known for its high palatability and nutritional value. However, it is susceptible to spoilage thus making it challenging to preserve and keep fresh after harvest, resulting in constraints in long-distance transportation and long-term storage. This study aimed to investigate the feasibility of using irradiation and sodium dehydrogenate (SD) as a preservative in the preservation process of V. volvacea. The effects of three treatments of 0.8 kGy 60Coγ irradiation (B), 0.04% SD (C), combined with 0.04% SD and 0.8 kGy 60Coγ irradiation (A) on the postharvest freshness of V. volvacea were investigated. The assessment indices for V. volvacea, including appearance, browning rate, weight loss, respiration rate, MDA content, antioxidant enzyme activities, vitamin C (Vc), and soluble protein content, were measured and compared. The three treatments were compared to determine the changes in storage time over 7 days post-harvest. The results demonstrated that the hardness of the fruiting body exhibited a significant increase of 81.19%, 97.96% and 168.81% in comparison to the control, B and C, respectively, following the application of the treatment A. Compared to the control group, the soluble protein content was significantly increased by 20.28%. Respiration intensity and browning rate were significantly lower in the control treatment, decreasing by 35.07% and 45.49% respectively. On the 6th day of storage, the activities of SOD and POD increased by 81.06% and 73.71%, respectively, compared to the control, which significantly delayed the senescence of the fruiting bodies. The Vc content was significantly increased by 50.27%, 133.90%, and 101.39% in treatment B, which received 0.8 kGy 60Coγ irradiation alone, compared to the control, treatment A, and treatment C, respectively. The treatment C alone significantly reduced respiratory intensity and MDA variables by 39.55% and 31.01%, respectively, compared to the control. The findings can provide theoretical references and technical support for extending the preservation period of V. volvacea after harvesting by using irradiation and sodium dehydrogenate as a preservative.

Novel strategies for enhancing quality stability of edible flower during processing using efficient physical fields: A review

Edible flowers are an exotic part of the human diet due to their distinct sensorial properties and health benefits. Due to consumers demand edible flowers and their products with natural freshness and high nutritional value, there is increasing research on the application of green and efficient edible flower processing technologies. This paper reviews the application of a number of physical fields including ultrasound, microwave, infrared, ultraviolet, ionizing radiation, pulse electric field, high hydrostatic pressure, and reduced pressure aiming to improve the processing and product quality of edible flowers. The mechanism of action, influencing factors, and status on application of each physical energy field are critically evaluated. In addition, the advantages and disadvantages of each of these energy fields are evaluated, and trends on their future prospects are highlighted. Future research is expected to focus on gaining greater understanding of the mechanism action of physical field-based technologies when applied to processing of edible flowers and to provide the basis for broaden the application of physical field-based technologies in industrial realm.

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.

Insights into the current status of bioactive value, postharvest processing opportunities and value addition of black carrot

Black carrots are a type of carrot that is naturally dark purple or black in color. They are a good source of antioxidants, vitamins, and minerals, and have been shown to have several health benefits, including reducing the risk of cancer, heart disease, and diabetes. This review article discusses the bioactive compounds present in black carrot, including anthocyanins, phenolic acids, carotenoids, and organic acids and sugars. It also compares the bioactive compounds and antioxidant capacity of black carrot with other carrot varieties. Furthermore, it discusses various postharvest processing methods, both conventional and novel, such as encapsulation, drying, and microbial decontamination, highlighting their effects on preserving and stabilizing the bioactive compounds. The review also emphasizes the incorporation of black carrot into different food products, including dairy items, beverages, and baked goods, and their impact on nutritional enhancement. The article provides knowledge on utilizing black carrot for improved nutritional and functional outcomes.