Postharvest cherry tomatoes are prone to senescence, decay and nutrient loss during the storage period owing to microbial invasion and their own metabolism. In this work, postharvest cherry tomatoes were treated with a composite coating of 1% chitosan and 1% curdlan, and the characteristics of postharvest cherry tomatoes during storage were investigated. Compared to control samples, after 21 d of storage under ambient conditions, the cherry tomatoes treated with the chitosan and curdlan coatings showed less rottenness, less weight loss, a lower respiration rate, reduced ethylene production, lower malonaldehyde (MDA) content and reduced membrane permeability. After the samples were treated with the composite coating, the activities of free radical scavenging enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were maintained at higher levels; the activities of related disease-resistant enzymes such as chitinase (CHI) and glucanase (GLU) were also maintained at higher levels. The soluble solids, titratable acidity, firmness, vitamin C content, lycopene content and antioxidant activities of postharvest cherry tomatoes treated with the composite coating exhibited higher levels as well. The composite coating of chitosan and curdlan might be a potentially promising method for preserving postharvest cherry tomatoes and other fruits.

Brown rice (BR) has gradually become a new choice for consumers due to its exceptionally nutritional value. Whereas starch retrogradation profoundly reduces its edibility, shelf-life and consumer acceptance, limiting the development of BR and even other starch-based food products. So, it is crucial for controlling the retrogradation properties of brown rice starch (BRS), and which has received significant attention in the food industry. Enzymatic modification is considered as an effective manner to retard starch retrogradation by degrading starch to an appropriate extent. Ganoderma lucidum can secrete various hydrolytic enzymes related to starch hydrolysis, providing a theoretical basis and feasibility for improving the starch retrogradation. Our study delves into characteristic changes of brown rice (BR) and its starch (BRS) when modified by the intracellular enzyme of Ganoderma lucidum, which contains several inhibiting retrogradation enzymes (GlIRE), mainly including α-amylase, β-amylase, and cellulase. GlIRE treatments significantly decreased the setback viscosity to 1544.33 ± 24.01 cP (2 h), diffraction intensities and relative crystallinity to 21.90 ± 0.06% (2 h) and 19.22 ± 0.19% (3 h) as per RVA and XRD analysis, accompanied with more pits and pores in surface morphology. The DSC analysis showed that GlIRE treatments significantly depressed the gelatinization enthalpy to 5.86 ± 0.46 J/g (2 h) and retrogradation enthalpy. FT-IR analysis also indicated the contribution of GlIRE treatments to retard starch retrogradation, including shifting the peaks of 3500 cm⁻¹-3200 cm⁻¹ to lower wave numbers and decreasing the transmittance, as well as R₁₀₄₇/R₁₀₂₂ values reducing from 0.87 to 0.73, mainly due to the shortening of starch chain length and the weakening of hydrogen bonding strength between or within the molecular chains. Simultaneously, it aslo found that GlIRE treatments effectively improved the textural properties of BR, with reducing of hardness, chewiness and gumminess, and increasing of adhesiveness. Interestingly, GC-MS analysis showed that GlIRE treatments could also significantly affect the types and contents of volatile compounds in BR. Our study highlights the efficacy of GlIRE in starch retrogradation and rice quality-improvement, showcasing a new expansion of the research and application of G. lucidum and a science-based strategy for developing the edible quality of starch-based food.

Ganoderic triterpenoids (GTs) are the primary bioactive constituents of the Basidiomycotina fungus, Ganoderma lucidum. These compounds exhibit antitumor, a

摘要

Ganoderma triterpenoids (GTs), the major bioactive metabolites of Ganoderma lucidum, are widely known for their pharmaceutical versatility. However, their natural biosynthesis ability is insufficient to meet industrial demands, so it is urgently required to clarify the metabolic network of GTs and develop new strategies to increase the total GTs production. Recently, the complex multi-tiered regulatory framework, which includes the sequential integration of environmental perception, signal transduction, and transcriptional reprogramming, has been fully dissected. This review synthesizes recent breakthroughs that illustrate how environmental stimuli are transduced through independent or intricate spatiotemporal interactions involving reactive oxygen species (ROS), calcium ions (Ca²⁺), and nitric oxide (NO). Such interplays give rise to oscillatory or feedback loops that precisely modulate metabolic production. Moreover, we systematically examine various transcription factors that control metabolic fluxes by either directly targeting the rate-limiting enzymatic steps of the mevalonate (MVA) pathway and downstream CYP450-modification networks, or via epigenetic and complex-mediated pathways. Importantly, we consider the application of gene editing, AI/ML-guided enzyme engineering, and subcellular compartmentalization as innovative ways to overcome their yield bottlenecks. Successful heterologous construction of biosynthetic pathways highlights the continuing trend towards predictability in biomanufacturing. In summary, this review presents a holistic translational approach from foundational regulatory mechanisms to synthetic assembly, establishing G. lucidum as a viable and intelligent bio-manufacturer for producing high valuable GTs.