Onion (Allium cepa L.) is a common vegetable, widely consumed all over the world. Onion contains diverse phytochemicals, including organosulfur compounds, phenolic compounds, polysaccharides, and saponins. The phenolic and sulfur-containing compounds, including onionin A, cysteine sulfoxides, quercetin, and quercetin glucosides, are the major bioactive constituents of onion. Accumulated studies have revealed that onion and its bioactive compounds possess various health functions, such as antioxidant, antimicrobial, anti-inflammatory, anti-obesity, anti-diabetic, anticancer, cardiovascular protective, neuroprotective, hepatorenal protective, respiratory protective, digestive system protective, reproductive protective, and immunomodulatory properties. Herein, the main bioactive compounds in onion are summarized, followed by intensively discussing its major health functions as well as relevant molecular mechanisms. Moreover, the potential safety concerns about onion contamination and the ways to mitigate these issues are also discussed. We hope that this paper can attract broader attention to onion and its bioactive compounds, which are promising ingredients in the development of functional foods and nutraceuticals for preventing and managing certain chronic diseases.

The study compared and analyzed the quality of loquat jam with different cooking times through physicochemical parameters, headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) and intelligent senses. The results showed that with the prolongation of the cooking time, the color of loquat jam slowly deepened, the energy significantly increased, the adhesiveness, gumminess, hardness and chewiness enhanced, the free amino acid content increased from 22.40 to 65.18 mg/g. The organic acid content increased from 1.64 to 9.82 mg/g. Forty-seven volatile flavor compounds were identified in five types of loquat jam using HS-GC-IMS, among which the relative content of aldehydes was sharply higher than that of other chemical substances, playing an important role in the flavor formation of loquat jam. LJ0, LJ1 and LJ2 had higher aldehyde content, followed by LJ3 and LJ4 had the lowest aldehyde content. The orthogonal partial least squares-discriminant analysis (OPLS-DA) screened 15 marker compounds that could distinguish five types of loquat jam. The E-nose results showed a significant difference in olfactory sense between loquat jam cooked for 100 and 120 min. The E-tongue results corroborated the results of free amino acids (FAAs) and organic acids, indicating that the gustatory sense of loquat jam changed significantly when the cooking time reached 120 min. The results provided a basis for further research on the relationship between the cooking process and quality characteristics of loquat jam.

To explore the effects of different preservation methods on the quality of loquat after fresh-keeping treatment, various preservation techniques were employed. These included natural preservation (NP), vacuum freezing preservation (VFP), vacuum at room temperature preservation (VP) and freezing preservation (FP). The quality assessment involved analyzing the effects of these preservation methods using physicochemical indexes, a colorimeter, an electronic nose (E-nose), an electronic tongue (E-tongue) and gas chromatography–mass spectrometry (GC–MS). The results showed minor differences in loquat quality under different preservation methods, with sensory scores ranging from 55 to 78 and ΔE values ranging from 11.92 to 18.59. Significant variations were observed in moisture content (ranging from 53.20 g/100 g to 87.20 g/100 g), calorie content (ranging from 42.55 Kcal/100 g to 87.30 Kcal/100 g), adhesion (ranging from 0.92 to 1.84 mJ) and hardness (ranging from 2.97 to 4.19 N) (p < 0.05). Additionally, the free amino acid content varied from 22.47 mg/g to 65.42 mg/g. GC–MS analysis identified a total of 47 volatile flavor substances in varieties of loquats, including 13 aldehydes, 9 esters, 6 ketones, 2 acids, 3 alcohols, 2 phenols, 3 pyrazines, 1 furan and 8 other substances. The relative content of aldehydes was significantly higher than that of other chemicals. The VFP and FP samples exhibited higher aldehyde content compared to the NP and VP samples. Moreover, Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) revealed 18 marked compounds that could differentiate between 5 loquat species. Analysis using E-nose and E-tongue indicated significant changes in the olfactory and gustatory senses of loquats following preservation. The VFP samples demonstrated the most effective preservation of loquat quality with minimal impact. This study provides some theoretical guidance for the home preservation of loquats.

To investigate the impact of microencapsulation on the volatile organic compounds (VOCs) in Zanthoxylum oil, this study compared unencapsulated Zanthoxylum oil (ZO) with microencapsulated Zanthoxylum oil (MZO) using physicochemical analysis, sensory evaluation, and molecular sensory analysis. Sensory evaluation revealed significant differences in aroma attributes between ZO and MZO, whereas no notable differences were observed in numbing intensity or overall acceptability. Colorimetric analysis indicated significant distinctions between the two samples. Electronic nose (E-nose) analysis demonstrated a reduction in overall aroma intensity for MZO compared to ZO. Gas chromatography–mass spectrometry (GC–MS) identified 43 VOCs, including 22 compounds present in both samples, accounting for 46.8% of the total. Terpenes represented the predominant class in both ZO (69.7%) and MZO (68.2%). Comprehensive analysis based on odor activity value (OAV) and variable importance in projection (VIP) identified nine volatile compounds as key aroma contributors. Gas chromatography–ion mobility spectrometry (GC–IMS) detected 90 the volatile organic compounds (VOCs), with esters (30.38%) and heterocyclic compounds (10.42%) predominating in ZO, while esters (29.08%) and alcohols (26.12%) were predominant in MZO. Compared to ZO, MZO exhibited increased levels of alcohols (from 12.04% to 26.12%) and terpenes (from 1.39% to 3.53%), but decreased levels of acids (from 5.77% to 2.72%) and aldehydes (from 10.29% to 4.62%). This approach provides a comprehensive assessment of flavor quality before and after microencapsulation, offers a scientific basis for quality control, and facilitates the development and utilization of Zanthoxylum oil resources.

Salt stress is a major abiotic constraint that limits plant growth by inducing oxidative stress, disrupting photosynthetic processes, and damaging cellular membranes. Although Rosa rugosa is considered relatively tolerant to adverse environments, differences in antioxidant defense and physiological responses among its cultivars under sustained salt stress remain insufficiently understood. Comparative evaluation of these responses is important for identifying salt-tolerant germplasm and understanding stress-adaptation mechanisms. In this study, two R. rugosa cultivars, Siji and Fenghua, were subjected to irrigation treatments with solutions containing 0, 50, 100, or 150 mM NaCl for 28 days under controlled conditions. Morphological traits, salt injury, photosynthetic pigments, osmolytes, ROS accumulation, antioxidant enzyme activities, and lipid peroxidation were measured to assess cultivar-specific differences in salt-stress responses. Salt stress caused concentration-dependent growth inhibition, increased salt injury, and reduced chlorophyll content, while oxidative-stress responses differed between the two cultivars, with stronger adverse effects observed in Fenghua. Siji maintained better growth performance, higher fresh and dry mass of sampled leaves, greater chlorophyll retention, better maintenance of several osmolytes, and stronger antioxidant enzyme activities under the higher NaCl treatments. In contrast, Fenghua showed greater ROS accumulation and higher MDA under the higher NaCl treatments, which are consistent with greater oxidative stress and membrane lipid peroxidation. Exploratory correlation and principal component analyses further showed that antioxidant defense, osmotic adjustment, chlorophyll retention, and reduced oxidative damage were closely associated with salt tolerance in Siji. These results indicate that greater antioxidant capacity, osmotic adjustment, and membrane protection were associated with the superior salt-stress performance of ‘Siji’ compared with ‘Fenghua’. The study identifies Siji as a promising R. rugosa candidate for further salt-tolerance evaluation and provides useful physiological and biochemical indicators for salt-tolerance screening in ornamental rose breeding.

To assess the impact of developmental stages on the postharvest quality of loquat, fruits at five distinct maturity phases (T1–T5) were systematically analyzed. This study employed a range of analytical techniques to conduct a comprehensive examination of the variations in quality, nutritional content, and volatile compounds of loquat across different developmental stages. Sensory evaluation indicated that the T4 stage achieved the highest score (93.21 ± 1.13), with significant differences observed in a* (6.56–13.08) and b* values (16.91–22.16). Both moisture content (45.45–86.94 g/100 g) and fruit firmness (8.65–3.31 N) exhibited a decline with delayed harvest (p < 0.05). Scanning electron microscopy (SEM) analysis revealed that, as the developmental period progressed, the pores in the loquat cell walls enlarged, and the cellular structure became increasingly relaxed. GC–MS and GC–IMS detected 48 and 47 volatile compounds, respectively. Using orthogonal partial least squares discriminant analysis (OPLS–DA), we identified 14 key compounds that distinguish the five developmental stages. E-nose and E-tongue analyses showed significant changes in the smell and taste profiles of loquats over time, with the T1 stage notably different from later stages. This study offers important insights and guidance on the postharvest quality of loquats at various developmental stages.