Ultrasound (US) washing has been verified to improve the quality of postharvest blueberry fruit. However, its physiological and molecular mechanisms remain largely unknown. In the present study, an US with a frequency of 25 kHz and a power density of 400 W for 2 min was performed to investigate its role in impacting the quality of blueberries. The results showed that US washing improved the quality of blueberries, with a higher firmness and lignin content (p < 0.05) than the control. Moreover, US washing inhibited the levels of superoxide radical (O₂^·−) production rate and hydrogen peroxide (H₂O₂) content while stimulating the superoxide dismutase (SOD) and catalase (CAT) activities of the blueberry fruit. Transcriptomic analysis screened 163 differentially expressed genes (DEGs), and the key DEGs were mainly enriched in phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant–pathogen interaction pathways. Furthermore, the transcription factors and the structural genes associated with lignin biosynthesis were also identified from the DEGs. More importantly, the correlation analysis revealed that firmness and lignin content were positively correlated with the expression of C4H, COMT1, and POD52 in blueberry fruit, indicating that these genes might be involved in the regulation of US-mediated lignin synthesis. The findings provide new insight into the US-enhanced quality of blueberry fruits.

Postharvest loss of fruits and vegetables remains a significant global challenge, while concerns over chemical residues, energy consumption, and storage-induced physiological disorders have accelerated the search for safe and eco-friendly preservation strategies. As key plant metabolites and signaling molecules, amino acids are gaining more attention for their roles in postharvest biology. This article reviews the primary postharvest issues of fruits and vegetables, the functional roles of representative amino acids, including γ-aminobutyric acid (GABA), glutamate (Glu), arginine (Arg), cysteine (Cys), proline (Pro), and phenylalanine (Phe), with emphasis on the postharvest applications and mechanisms of action of amino acids. Increasing evidence suggests that amino acids can improve postharvest performance mainly by mitigating oxidative stress, enhancing ROS scavenging capacity, retaining cellular membrane integrity, regulating osmotic and energy metabolism, activating phenylpropanoid-mediated defense, and modulating respiration–ethylene processes. These responses contribute to reducing chilling injury, decay, browning, softening, and senescence, thereby helping maintain color, texture, nutritional value, and storage quality. However, the effectiveness of amino acid treatments varies depending on the product types and conditions, and is influenced by concentration, application method, storage environment, and combined preservation strategies. The information in this review provides a systematic foundation for understanding amino acid-mediated modulation mechanisms of postharvest horticultural crops and for developing more environmentally friendly postharvest preservation technologies, while highlighting the need for treatment standardization, mechanistic validation, and commercial-scale evaluation.

In Chinese cuisine, seasoning oil enhances the aroma and appearance of dishes. This study examined how processing affects flavor release in multi-ingredient oils. Volatile organic compounds (VOCs), relative odor activity value (ROAV), and variable importance projection (VIP) were used to assess flavor changes. Optimal frying was 160 °C for 15 min with 11% green Sichuan peppercorn, 3% ghost pepper, 6% green onion, 0.1% bay leaf, 0.2% deseeded tsaoko, 0.5% star anise, 0.3% fennel seeds, 1.5% dried Erjingtiao chili, 5% ginger, and 2.5% red Sichuan peppercorn. Gas chromatography–ion mobility spectrometry (GC-IMS) and gas chromatography–mass spectrometry (GC-MS) analyzed heating at 150 °C, 160 °C, and 170 °C. Temperature strongly influenced VOC formation; 160 °C produced the most diverse VOCs, including aldehydes, ketones, terpenes, esters, and alcohols. Multivariate analysis identified 73 key compounds (VIP > 1) between 150 and 160 °C, but only 39 between 160 and 170 °C, indicating that high heat reduces complexity. Compounds such as 2-methylpyrazine and (E)-2-heptenal contributed caramel, nutty, buttery notes, with 2-methoxy-3-(1-methylethyl)-pyrazine as the core aroma. Frying at 160 °C balanced sweet, floral, and roasted aromas, offering guidance for precise seasoning oil flavor control.