Lotus Receptaculum Nelumbinis has been sparking wide research interests due to its rich phenolic compounds. In the present work, ultrasonic-assisted extraction coupled with glycerol was employed to extract phenolic compounds from Receptaculum Nelumbinis and the process was optimized using a response surface methodology with Box-Behnken design (BBD). The optimal conditions for the total phenolic content (TPC) extract were obtained: glycerol concentration of 40%, an extraction temperature of 66 °C, ultrasonic time of 44 min, and the solvent-to-solid ratio of 55 mL/g. Under these optimum extraction conditions, the extraction yield of TPC was 92.84 ± 2.13 mg gallic acid equivalents (GAE) /g. Besides, the antioxidant activities demonstrated the ability of free radical scavenging by four different methods that included 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing activity (RA) were 459.73 ± 7.07, 529.97 ± 7.30, 907.61 ± 20.28, and 983.66 ± 11.80 μmol TE/g, respectively. Six phenolic compounds were identified by ultra-high pressure liquid chromatography combined with triple-time-of-flight mass spectrophotometry (UPLC-Triple-TOF/MS) from the extracts. Meanwhile, Fourier transform infrared (FTIR) was conducted to identify the characteristic functional groups of the extracts and thus reflected the presence of polyphenols and flavonoids. Scanning electron microscopy (SEM) illustrated the microstructure difference of four treatments, which might explain the relationships between antioxidant activities and the structures of phenolic compounds.

Curcumin exhibits antioxidant, antibacterial, antitumor, and anti-inflammatory biological properties. Its dual functionality as both a food additive and a pH-sensitive colorant has led to extensive applications in meat products and other food systems, thereby garnering significant research interest. In recent years, curcumin-loaded active-intelligent food packaging films have emerged as a promising innovation due to their multifunctional capabilities: not only do they prevent microbial contamination and extend food shelf life, but they also enable real-time freshness monitoring through visual colorimetric responses. This paper first delineates the molecular structure and fundamental biological mechanisms of curcumin. Subsequently, it systematically reviews the strategies for curcumin incorporation (including encapsulation techniques and composite formulations) and advanced fabrication methodologies for developing active-intelligent biodegradable films. Finally, the current applications of curcumin in polymer-based smart packaging systems are critically analyzed, with prospective research directions proposed to address existing technological limitations.

The purpose of this study is to explore the effect of 10% carbon dioxide (CO₂) on the fruit quality and sugar metabolism of fresh-cut pear during storage. The results indicated that carbon dioxide treatment maintained fruit quality by delaying the decline of firmness and promoting the accumulation of total soluble solids (TSS). Moreover, carbon dioxide enhanced activities of sucrose synthase (SS), and sucrose phosphate synthase (SPS). The activities of amylase, acid invertase (AI), neutral invertase (NI), SS-cleavage, fructokinase (FK), hexokinase (HK), sorbitol oxidase (SOX), NAD-dependent sorbitol dehydrogenase (NAD-SDH), and NADP-SDH in CO₂-treated fruit were inhibited. Expression levels of key genes were found to correspond with the related enzyme activities. As a result, the accumulation of glucose, fructose, sorbitol, and sucrose were accelerated by CO₂, which were 12.58%, 13.86%, 24.7%, and 13.9% higher than those of the control at the end of storage, respectively. The results showed that CO₂ could maintain the quality of fresh-cut pears by regulating the conversion of various sugar components to enhance soluble sugars content.

Black spot caused by Alternaria alternata is one of the most common postharvest diseases in fruit and vegetables. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of nitric oxide (NO) on the pathogenicity of A. alternata and its underlying mechanism was studied. The results showed that treatment with 0.5 mM L⁻¹ of sodium nitroprusside (SNP) (NO donor) increased the lesion diameter of A. alternata in vivo and in vitro, which was 22.8% and 13.2% higher than that of the control, respectively. Exogenous NO treatment also induced endogenous NO accumulation by activating nitric oxide synthase (NOS). In addition, NO triggered an increase in reactive oxygen species (ROS) levels. NO enhanced activities and gene expression levels of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). Moreover, NO stimulated cell wall degrading enzymes by activating the corresponding gene expression in vivo and in vitro. These results suggested that exogenous NO promoted the pathogenicity of A. alternata by inducing ROS accumulation and activating antioxidants and cell wall degrading enzymes. The present results could establish a theoretical foundation for the targeted control of the black spot disease in pear fruit.

Black spot, one of the major diseases of kiwifruit, is caused by Alternaria alternata. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of L-arginine on the pathogenicity of A. alternata and the underlying mechanisms were investigated. The results showed that treatment with 5 mM L⁻¹ of L-arginine promoted spore germination and increased the colony diameter and lesion diameter of A. alternata in vivo and in vitro, which were 23.1% and 9.3% higher than that of the control, respectively. Exogenous L-arginine treatment also induced endogenous L-arginine and nitric oxide (NO) accumulation by activating nitric oxide synthase (NOS), arginine decarboxylase (ADC) and ornithine decarboxylase (ODC). In addition, exogenous L-arginine triggered an increase in reactive oxygen species (ROS) levels by activating the activity and inducing gene expression upregulation of NADPH oxidase. The hydrogen peroxide (H₂O₂) and superoxide anion (O₂^.−) levels were 15.9% and 2.2 times higher, respectively, than in the control group on the second day of L-arginine treatment. Meanwhile, antioxidant enzyme activities and gene expression levels were enhanced, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). In addition, exogenous L-arginine stimulated cell wall-degrading enzymes in vivo and in vitro by activating gene expression. These results suggested that exogenous L-arginine promoted the pathogenicity of A. alternata by inducing the accumulation of polyamines, NO, and ROS, and by activating systems of antioxidants and cell wall-degrading enzymes. The present study not only revealed the mechanism by which low concentrations of L-arginine increase the pathogenicity of A. alternata, but also provided a theoretical basis for the exclusive and precise targeting of A. alternata in kiwifruit.

The effects of a fungal elicitor from Trichothecium roseum on signal pathways of salicylic acid (SA), jasmonic acid (JA), and Ca²⁺ in potato tubers were investigated. The results showed that fungal elicitor treatment effectively inhibited the lesion diameter of Fusarium sulphureum in vivo, which was 17.5% lower than that of the control. In addition, fungal elicitor treatment triggered an increase in O₂⁻ production and H₂O₂ content. The fungal elicitor enhanced the activities and gene expression levels of isochorismate synthase (ICS), phenylalanine ammonia lyase (PAL), allene oxide cyclase (AOC), allene oxide synthase (AOS), lipoxygenase (LOX), and Ca²⁺-ATPase. Furthermore, the fungal elicitor promoted an increase in calmodulin (CaM) content. Protective enzymes (dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), chitinase (CHI), and β-1,3-glucanase (Glu)) and disease-resistance-related genes (PR1, PR2, and PDF1.2) were induced to be upregulated by elicitor treatment. These results indicated that the fungal elicitor induced disease resistance by accelerating the accumulation of reactive oxygen species (ROS), activating SA, JA, and Ca²⁺ signaling, and upregulating resistance genes. The results of this study revealed the molecular mechanism of fungal elicitor-induced resistance in the potato, which provides a theoretical basis for the mining of new, safe, and efficient elicitor-sourced antifungal agents and is of great importance for the effective control of potato dry rot disease.