A simple and sensitive vortex assisted liquid–liquid microextraction method for the simultaneous determination of haloanisoles and halophenols in wines

Dissipation and residue of triadimefon in Rosa roxburghii

Rosa roxburghii (R. roxburghii) is a unique, edible, medicinal fruit rich in vitamin C found in Southwest China. Triadimefon (TDF) is a triazole fungicide that is widely used to control powdery mildew in R. roxburghii. To assess the safety of TDF in R. roxburghii, an LC-MS/MS method was developed for the simultaneous quantification of TDF and its major metabolite, triadimenol (TDN) in R. roxburghii. Both TDF and TDN showed high correlation coefficients (>0.999) for the solvent- and matrix-matched calibrations. The recovery rates of TDF and TDN in R. roxburghii ranged from 90.18% to 100.42%, with a relative standard deviation (RSD) of 1.25%-9.22%. The limit of quantification (LOQ) was 0.01 mg·kg-1. The half-life of TDF in R. roxburghii was between 2.74 and 3.07 days, with terminal residues ranging from < LOQ to 1.84 mg·kg-1. Recommended maximum residue limits (MRLs) and safe pre-harvest intervals (PHIs) for TDF in R. roxburghii were 0.5 mg·kg-1 and 21 days, respectively. This study provides essential data for TDF's safe and judicious use in R. roxburghii production.

Uncorking Haloanisoles in Wine

Haloanisoles in wine have devastating effects on the aroma and quality of the wine. 2,4,6-trichloroanisole (TCA) was discovered and coined as “cork taint” in 1982. However, we now understand that there are many more haloanisoles that contribute to these musty odors, including 2,4,6-Tribromoanisiole (TBA), 2,3,4,6-tetrachloroanisole (TeCA), and pentachloroanisole (PCA). While TCA, TeCA, and PCA can all be traced back to the cork, TBA’s phenol precursor is ubiquitous in building material as a fire retardant, making it a much larger vector. All haloanisoles have the ability to aerosolize and resettle onto surfaces in the winery, making this a very difficult problem to eliminate. This literature review will cover the multiple haloanisoles found in wine, their sensory impacts, their effect on wine quality, and current methodologies with regard to their analysis.

Hydrophobic deep eutectic solvent-based ultrasonic-assisted liquid-liquid microextraction combined with GC for eugenol, isoeugenol, and methyl isoeugenol determination in aquatic products

The use of deep eutectic solvents (DESs) has great prospects because of the green and efficient characteristics, which can be used for developing analytical methods for foods. In this research, assisted by ultrasonic waves, a liquid-liquid microextraction detection method combined with gas chromatography was established for three anaesthetics (eugenol, isoeugenol, and methyl isoeugenol) in aquatic food. The processing conditions including the components, ratio of hydrogen bond acceptor and hydrogen bond donor, DES volume, ultrasonic time, and pH were evaluated and optimised to improve the extraction efficiency, which was based on the DES structures and properties. In-house method validation was carried out by applying to real samples. A Thymol: levulinic acid DES (with a molar ratio of 1:2) was used as the extractant and the recoveries were as high as 93-101% for eugenol, 90-100% for methyl isoeugenol, and 86-94% for isoeugenol with RSDs <5% under optimum conditions. The limit of detection and quantification of the eugenol compounds were 0.08-0.10 μg/mL and 0.26-0.33 μg/mL, respectively. The method has green credentials and comparable LOD to homologous apparatus, which can be used for the determination of eugenol components in aquatic food.

Chloroanisoles occurrence in wine from grapes subjected to electrolyzed water treatments in the vineyard

Recently the use of electrolyzed water (EW) attracted much attention as a high-performance, new technology for its potential use in the food industry. The aim of this work was to investigate the impact of grape EW treatments, applied at different time intervals prior to harvest, on the indigenous yeast populations of grape surface (Chenin blanc and Cabernet franc) and the occurrence of 2,4,6-trichloroanisole (TCA) in Cabernet franc wine. In addition, the evolution of inoculated and spontaneous fermentations on treated and non-treated grapes was also considered. The yeast population present on grape berries surface was influenced in a grape variety and EW treatment time-dependent way, since only Chenin blanc grapes treated with EW 7 days prior to harvest had significantly lower yeast population levels, compared to the respective control. Concerning the yeast diversity in the grape samples, a dominance of Aureobasidium pullulans was observed in treated grapes, independently of the grape variety. At the end of alcoholic fermentation, 2,4,6-trichloroanisole was detected in wine when the EW solution was applied at one or two weeks before harvest time. After wine storage, 2,4,6-trichloroanisole and chlorophenols contents generally exhibited a loss relative to initial values. The results showed that EW treatments tended to slightly increase the TCA concentration in final wine and did not affect the fermentation performances and chromatic properties of resulting wine. On the other hand, absorption or desorption phenomena by wine lees could be involved in the change of 2,4,6-trichloroanisole concentration in wine during storage time.

The occurrence of haloanisoles as an emerging odorant in municipal tap water of typical cities in China

In this study, occurrence of the haloanisoles odorous compounds in tap water of Chinese cities, were investigated by solid-phase microextraction (SPME)-GC/MS analysis. This study revealed the occurrence of four kinds of haloanisoles in 22 cities of China in both summer and winter. Except 2,4,6-tribromoanisole (2,4,6-TBA), all studied haloanisoles showed higher frequency of detection. 2,3,6-Trichloroanisole (2,3,6-TCA) and 2,3,4-trichloroanisole (2,3,4-TCA) showed higher occurrence concentration; however, the relative odor values of them was lower. These values of 2,4,6-TBA and 2,4,6-trichloroanisole (2,4,6-TCA) in all samples were greater than zero in both summer and winter, indicating the odor from haloanisoles could be felt by human noise. This study further showed that Beijing exhibited most serious occurrence of haloanisoles that were depended on the season and drinking water distribution system (country and city). From this study, it was confirmed that haloanisoles was important taste and odor compounds in tap water of China. Based on the survey of occurrence of halophenol and residual chlorine, the possible source for the formation of haloanisoles in tap water was discussed. Furthermore, several suggestions on control the haloanisoles odor in drinking water treatment plant and water distribution system were provided.