Study of Chemical Profiles of Volatile and Non-Volatile Bioactive Compounds of Muscadine Grapes (Vitis rotundifolia) During Ripening Stages and Evaluation of Their In Vitro Biological Properties

Muscadine grapes (Vitis rotundifolia) have attracted consumers because of their unique flavors and high concentrations of bioactive phytochemicals. The aim of this study was to investigate the effects of ripening stages (i.e., stage I, II, and III) of muscadine on physiochemical properties, volatile organic compounds (VOCs), and phenolic compounds in the grapes, and explore the enzymatic inhibitory effects of the muscadine extracts and some of its inherent phenolics on some important enzymes, such as angiotensin-I-converting enzyme (ACE), pancreatic lipase (PL), tyrosinase, collagenase and elastase, relevant to human chronic diseases. Physiochemical properties of the muscadine grapes were evaluated in order to understand the biological changes of the grapes during the ripening progress. Significance differences (p ≤ 0.05) were observed in regards of the size, weight, pH, total soluble solid, sugar content and titrable acidity of the muscadine grapes during their 3 ripening stages. The berry size, berry weight, and titrable acidity decreased after the stage II, whereas °Brix, pH, sugar content continuously increased through the whole ripening stages up to the stage III. Twenty eight VOCs were detected by headspace solid phase microextraction (HS-SPME) coupled to a gas chromatography-mass spectrometry (GC-MS). The grapes in the stages I and II had relatively similar flavor patterns, which were different from that in stage III. The principal component analysis (PCA) indicated that butyl-2-buetenoate, hexyl acetate, propyl acetate, ethyl trans-2-butenoate, hexyl-2-butenoate, ethyl acetate, butyl acetate, 1-octanol, ethyl hexanoate, and β-citral were present as distinct volatile chemicals in the stage III, which usually result in the fruity, floral, and pleasant aromas. Phenolic compounds (e.g., epicatechin, epicatechin gallate, resveratrol, and myricetin, etc) at three ripening stages were determined using a high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). In addition, antioxidant activities of the muscadine extracts and identified major phenolics were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2\u27-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid (ABTS). Total phenolic content (TPC) and total flavonoid content (TFC) decreased along with the ripening stages, while the antioxidant activities were enhanced through the ripening stages. With regard to the phenolic compounds, the concentrations of phenolic compounds were significantly different in three ripening stages. Most bioactive phenolic compounds, except myricetin and quercetin, consistently increased along with the ripening stages. The study of enzymatic inhibitory activities of ACE, pancreatic lipase, tyrosinase, collagenase and elastase demonstrated that the muscadine extracts, regardless of their ripening stages, and the selected phenolics (i.e., epicatechin, epicatechin gallate, resveratrol, and myricetin, etc) exerted their enzymatic inhibitions in a competitive inhibition model against all the aforementioned enzymes. The results indicated that the muscadine grapes possessed the strong anti-hypertension, anti-obesity and anti-skin disease activities. Furthermore, it was found that the extraction of anthocyanin was the most efficient at pH 3.0, which accompanied with a greater antioxidant activity. To quantify anthocyanidins in the muscadine grapes, the extracted anthocyanins were hydrolyzed under acidic conditions that were optimized at 100 °C for 60 minutes. The samples extracted from muscadine grapes at pH 3 and pH 5 showed similar anthocyanidin profiles with high concentrations of delphinidin and cyanidin, which are relatively unstable chemicals that are unfavorable for making muscadine juice or wine

Estimating the Acute Health Effects of Smoke Exposure from an Urban Factory Fire Accident: A Case Study of a Tire Factory Fire in Korea

International audienceackground: A major industrial fire accident occurred in a tire manufacturing factory in Daejeon, Korea, on 12 March 2023 and lasted for 3 d, generating air pollutant emissions. Although evidence regarding the health effects of urban fires is limited, residents near tire factory may have experienced health hazards due to smoke exposure from fire plumes.Objectives: Capitalizing on the timing of this fire incident as a natural experiment, we estimated the attributable excess air pollution exposure and associated disease development among residents living near the tire factory.Methods: We used the generalized synthetic control method to estimate air pollution exposure and health burden attributable to the accident among residents living in smoke-exposed districts. Based on satellite images and air pollution monitoring results, three administrative districts (within 1.2kmfrom the factory) were defined as smoke-exposed, and the other 79 districts of Daejeon were defined as controls. Among the 11 monitoring stations in Daejeon, the station located 500m from the factory was used to estimate excess air pollution exposure (PM10, PM2.5, NO2, O3, SO2, and CO) for residents in the exposed districts. The number of daily district-level disease-specific incidence cases were acquired from the National Health Insurance Database and used to estimate excess health burden resulting from the fire.Results: During the first week following the factory fire, residents of exposed districts had an estimated excess exposure to 125.2 [95% confidence interval (CI): 44.9, 156.7] μg/m3of PM10, 50.4 (95% CI: 12.7, 99.8) ppb of NO2, and 32.0 (95% CI: 21.0, 35.9) ppb of SO2. We also found an average increase in the incidence cases of other diseases of upper respiratory tract [20.6 persons (95% CI: 6.2, 37.4)], lung disease due to external agents [2.5 persons (95% CI: 2.1, 3.3)], urticaria and erythema [5.9 persons (95% CI: −0.6, 11.2)], and episodic and paroxysmal disorders [8.5 persons (95% CI: 3.7, 13.4)] in exposed districts.Discussion: Excessive air pollution exposure and disease incidence were identified among residents living close to the tire factory. Preventive measures, such as a warning system, to avoid health impacts to people breathing fire-related pollution may be beneficial for communities impacted by such events. https://doi.org/10.1289/EHP14115

Antioxidant Capacities of Fractions of Bamboo Shaving Extract and Their Antioxidant Components

This research was conducted for evaluation of antioxidant activities of four fractions from bamboo shavings extract (BSE) and their antioxidant components. The antioxidant capacities of BSE and four fractions on ABTS, DPPH, FRAP and total antioxidant capacity assays exhibited the following descending order: DF > n-butanol fraction (BF) > BSE ≈ ethyl acetate fraction (AF) > water fraction (WF). Among the identified phenolic compounds, caffeic acid exhibited the highest antioxidant capacities on DPPH, FRAP and total antioxidant capacity assays. An extremely significant positive correlation between the antioxidant activities with the contents of total flavonoids, total phenolic acids, or total phenolics was observed in this study. The result indicated that the bamboo shaving extract and its solvent fractions could act as natural antioxidants in light of their potent antioxidant activities

Environmentally Stable and Reconfigurable Ultralow-Power Two-Dimensional Tellurene Synaptic Transistor for Neuromorphic Edge Computing

While neuromorphic computing can define a new era for next-generation computing architecture, the introduction of an efficient synaptic transistor for neuromorphic edge computing still remains a challenge. Here, we envision an atomically thin 2D Te synaptic device capable of achieving a desirable neuromorphic edge computing design. The hydrothermally grown 2D Te nanosheet synaptic transistor apparently mimicked the biological synaptic nature, exhibiting 100 effective multilevel states, a low power consumption of ∼110 fJ, excellent linearity, and short-/long-term plasticity. Furthermore, the 2D Te synaptic device achieved reconfigurable MNIST recognition accuracy characteristics of 88.2%, even after harmful detergent environment infection. We believe that this work serves as a guide for developing futuristic neuromorphic edge computing