Impact of pre- and post-fermentation fining with polyvinylpolypyrrolidone on the chemical stability and aromatic profile of Viognier wine.

Polyvinylpolypyrrolidone (PVPP) is a synthetic, insoluble polymer that can be added to white wines to improve the chemical stability of the final product by precipitating unstable low molecular weight phenolic compounds responsible for visual defects and undesirable flavor characteristics (e.g., excessive bitterness and/or astringency). The objective of this study was to characterize the effects of PVPP on the quality characteristics of Viognier wine when added pre- or post-fermentation as compared to an untreated control wine. Both PVPP-treated wines contained significantly lower concentrations of monomeric phenolics and browning pigments than the control wine (p ≤ 0.05). The addition of PVPP prior to fermentation conferred protection against oxidation of the wine as measured by acetaldehyde concentration (p ≤ 0.05). Analysis of the volatile aroma profile of each wine by headspace solid phase microextraction gas chromatographymass spectrometry (HS-SPME-GC-MS) revealed that the overarching aroma profiles of the PVPP-treated wines were significantly different from the control wine, but there was no difference between wines treated with PVPP pre-fermentation versus those treated post-fermentation. Specifically, statistically significant differences were observed in 9 of the 22 quantified aroma compounds, including those notably associated with the "stone fruit" aroma of Viognier. A negative correlation was identified between aroma compound concentration removal and the hydrophobicity of each compound, suggesting that the observed differences in aroma may be due to adsorption of aroma compounds by PVPP. The findings from this study present risks and benefits to wine quality upon treatment with PVPP at commercially recommended levels, and provide potentially valuable information for industrial wine producers.

Microscopic assessment of the degradation of millet starch granules by endogenous and exogenous enzymes during mashing.

The high gelatinization temperature (GT) of millet starch prevents the usage of infusion or step mashes as an effective means to generate fermentable sugars (FS) in brewing because the malt amylases lack thermostability at GT. Here, we investigate processing modifications to determine if millet starch can be efficiently degraded below GT. We determined that producing finer grists through milling did not introduce enough granule damage to markedly change gelatinization characteristics, though there was improved liberation of the endogenous enzymes. Alternatively, exogenous enzyme preparations were added to investigate their ability to degrade intact granules. At the recommended dosages (0.625 µL/g malt), significant FS concentrations were observed, although at lower concentrations and with a much-altered profile than possible with a typical wort. When exogenous enzymes were introduced at high (10×) addition rates, significant losses of granule birefringence and granule hollowing were observed well below GT, suggesting these exogenous enzymes can be utilized to digest millet malt starch below GT. The exogenous maltogenic α-amylase appears to drive the loss of birefringence, but more research is needed to understand the observed predominate glucose production.

Partitioning of caffeine and quinine in oil-in-water emulsions and effects on bitterness.

The bulk vegetable oil-water partition coefficient of caffeine and quinine was determined by a shake-flask method as log Kow  = -1.32 and 2.97. These values were consistent with the effect of oil concentration on the distribution of the bitterants in an oil-in-water emulsion (0-2 and 0-20 wt% oil stabilized with 0.125 and 1 wt% whey protein isolate, respectively). For example, in a 20% o/w emulsion, approximately 90% of the total caffeine remained in the aqueous phase, whereas in a 2% o/w emulsion, only ∼20% of the quinine remained in the aqueous phase. The intensity of the bitter taste of caffeine and quinine in emulsions was assessed by a large cohort (n = 100) of untrained participants. An increase in fat in the emulsions (from 0.5 wt% to 2 wt% oil emulsions stabilized with 0.125 wt% whey protein isolate) caused a significant decrease in perceived bitterness that was accompanied by a decrease in the aqueous concentration of the hydrophobic bitterant quinine Specifically, the bitterness of quinine was reduced ∼13% in the o/w emulsion with more fat, and this drop paralleled a drop in the aqueous concentration and was generally consistent with aqueous dose-response functions published elsewhere. For the hydrophilic bitterant caffeine, there was no significant change in the perceived bitterness or aqueous concentration with changing oil concentration. We conclude that the perceived bitterness of a hydrophobic bitterant like quinine in an emulsion depends on the aqueous concentration rather than the overall concentration.

Impact of mashing protocol on the formation of fermentable sugars from millet in gluten-free brewing.

The production of fermentable sugars (FS) in gluten-free (GF) brewing is hindered by the high starch gelatinization temperatures of GF malts and lower diastatic power compared to barley malt. Our previous work has demonstrated that starch gelatinization was the primary hurdle, and when decoupled from a single mash phase, high concentrations of FS could be produced. However, more research was required to improve the applicability of GF brewing. In this study, millet was used as a model GF malt demonstrating that despite the low α-amylase and ß-amylase activities compared to barley malt âˆ¼ 90 % of the FS (∼110 g/L) could be produced within 40 min. Limitations to enzyme extraction and separation due to coarse milling and lautering initially limited FS by âˆ¼ 30 g/L, requiring additional processing or exogenous enzyme supplements that improved fermentable sugar generation by âˆ¼ 20 g/L. Overall, millet is a promising brewing ingredient, provided appropriate mashing procedures are implemented.

Evidence from an fMRI study that dessert-flavored e-cigarettes engage taste-related, but not smoking-related, brain circuitry for female daily smokers.

Regulations limiting the sale of flavored e-cigarette products are controversial for their potential to interfere with e-cigarette use as a cessation aid in addition to curbing youth use. Limited research suggests that flavor might enhance the addictive potential of e-cigarettes; however, the acute effects of flavored aerosols on brain function among humans have not been assessed. The present study aimed to isolate and compare the neural substrates of flavored and unflavored e-cigarette aerosols on brain function among nine female daily smokers. Participants inhaled aerosolized e-liquid with 36 mg/mL of nicotine with and without a strawberry-vanilla flavor while undergoing functional magnetic resonance imaging. We used general linear modeling to compare whole-brain mean neural activation and seed-to-voxel task-based functional connectivity between the flavored and unflavored inhalation runs. Contrary to our hypothesis, the flavored aerosol was associated with weaker activation than the unflavored aerosol in the brain stem and bilateral parietal-temporal-occipital region of the cortex. Instead, the flavor engaged taste-related brain regions while suppressing activation of the neural circuits typically engaged during smoking and nicotine administration. Alternatively, functional connectivity between subcortical dopaminergic brain seeds and cortical brain regions involved in motivation and reward salience were stronger during the flavored compared to unflavored aerosol run. The findings suggest that fruity and dessert-flavored e-cigarettes may dampen the reward experience of aerosol inhalation for smokers who initiate e-cigarette use by inhibiting activation of dopaminergic brain circuits. These preliminary findings may have implications for understanding how regulations on flavored e-cigarettes might impact their use as cessation aids. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Unburned Tobacco Cigarette Smoke Alters Rat Ultrastructural Lung Airways and DNA.

INTRODUCTION: Recently, the Food and Drug Administration authorized the marketing of IQOS Tobacco Heating System as a Modified Risk Tobacco Product based on an electronic heat-not-burn technology that purports to reduce the risk. METHODS: Sprague-Dawley rats were exposed in a whole-body mode to IQOS aerosol for 4 weeks. We performed the chemical characterization of IQOS mainstream and we studied the ultrastructural changes in trachea and lung parenchyma of rats exposed to IQOS stick mainstream and tissue pro-inflammatory markers. We investigated the reactive oxygen species amount along with the markers of tissue and DNA oxidative damage. Moreover, we tested the putative genotoxicity of IQOS mainstream through Ames and alkaline Comet mutagenicity assays. RESULTS: Here, we identified irritating and carcinogenic compounds including aldehydes and polycyclic aromatic hydrocarbons in the IQOS mainstream as sign of incomplete combustion and degradation of tobacco, that lead to severe remodelling of smaller and largest rat airways. We demonstrated that IQOS mainstream induces lung enzymes that activate carcinogens, increases tissue reactive radical concentration; promotes oxidative DNA breaks and gene level DNA damage; and stimulates mitogen activated protein kinase pathway which is involved in the conventional tobacco smoke-induced cancer progression. CONCLUSIONS: Collectively, our findings reveal that IQOS causes grave lung damage and promotes factors that increase cancer risk. IMPLICATIONS: IQOS has been proposed as a safer alternative to conventional cigarettes, due to depressed concentration of various harmful constituents typical of traditional tobacco smoke. However, its lower health risks to consumers have yet to be determined. Our findings confirm that IQOS mainstream contains pyrolysis and thermogenic degradation by-products, the same harmful constituents of traditional cigarette smoke, and, for the first time, we show that it causes grave lung damage and promotes factors that increase cancer risk in the animal model.

Impact of copper-based fungicides on the antioxidant quality of ethanolic hop extracts.

Hops contain a variety of compounds possessing antioxidant capacity including phenolic and polyphenolic compounds as well as α- and ß- acids. These compounds may contribute to the oxidative stability of beer during brewing and storage. Hop plants may be treated with copper-based fungicides (CBFs) which have been shown to increase the total copper content of harvested hop cones; however, copper ions are well known to catalyze the generation of reactive oxygen species production in beer and may negatively impact its oxidative stability. Increased copper content in CBF-treated hops has been previously shown to have deleterious effects on the aroma quality of hops and beer. The impact of CBFs on the antioxidant content and quality of hops has not been previously investigated. In this study, ethanolic extracts of CBF-treated hops are evaluated for their metal content and antioxidant quality in order to determine whether excess copper from CBF treatment negatively impacts their antioxidant capacity.

Influence of Region on Sensory and Chemical Profiles of Pennsylvania Grüner Veltliner Wines.

The influence of cultural and environmental factors on the sensory and chemical profiles of wines has been the subject of research investigation for many years, and an examination of these relationships can help determine whether wine regional trends exist. The present study investigated the chemical and sensory factors that drive regional differences in Pennsylvania Grüner Veltliner wines through a controlled winemaking study across two vintages in 2018 and 2019. Descriptive analysis was used to identify key sensory attributes of Pennsylvania Grüner Veltliner. Intensities of these attributes were evaluated in wines vinified under identical conditions from grapes harvested across nine Pennsylvania vineyards. Chemical profiles of finished wines were examined through volatile, phenolic, and color analyses. Significant sensory differences were found between wine regions, with some trends consistent across both vintages; however, regionality based on compositional analyses was less clear. As the first study to examine Pennsylvania Grüner Veltliner wines sensorially, results revealed sensory characteristics that can be useful for wineries and their tasting room staff in marketing these lesser-known white wines to wine consumers as the variety grows in popularity in the state.

Effect of alkyl chain length on the antioxidant activity of alkylresorcinol homologues in bulk oils and oil-in-water emulsions.

The antioxidant cut-off theory details the importance of fine-tuning antioxidant hydrophobicity to optimize antioxidant effectiveness for a given food system; however, previous research has utilized synthetic antioxidant homologues which fail to align with the food industry's demand for natural ingredients. Alkylresorcinols represent a natural homologous series of phenolipid antioxidants. The antioxidant activities of individual alkylresorcinol homologues were investigated in bulk oils and oil-in-water emulsions. In oils, antioxidant activity decreased as alkyl chain length increased and there was no effect on rate of loss. In emulsions, optimum antioxidant activity was observed at intermediate alkyl chain length (C21:0) and longer homologues were lost more rapidly. Radical scavenging capacity decreased as alkyl chain length increased but alkylresorcinols were unable to chelate iron. This suggests that intrinsic properties (e.g. radical scavenging capacity) are responsible for the antioxidant activity of alkylresorcinols in oils while physicochemical phenomena (e.g. partitioning) drive antioxidant activity of alkylresorcinols in emulsions.

Gliadin Sequestration as a Novel Therapy for Celiac Disease: A Prospective Application for Polyphenols.

Celiac disease is an autoimmune disorder characterized by a heightened immune response to gluten proteins in the diet, leading to gastrointestinal symptoms and mucosal damage localized to the small intestine. Despite its prevalence, the only treatment currently available for celiac disease is complete avoidance of gluten proteins in the diet. Ongoing clinical trials have focused on targeting the immune response or gluten proteins through methods such as immunosuppression, enhanced protein degradation and protein sequestration. Recent studies suggest that polyphenols may elicit protective effects within the celiac disease milieu by disrupting the enzymatic hydrolysis of gluten proteins, sequestering gluten proteins from recognition by critical receptors in pathogenesis and exerting anti-inflammatory effects on the system as a whole. This review highlights mechanisms by which polyphenols can protect against celiac disease, takes a critical look at recent works and outlines future applications for this potential treatment method.

Impact of Atomizer Age and Flavor on In Vitro Toxicity of Aerosols from a Third-Generation Electronic Cigarette against Human Oral Cells.

Electronic cigarettes (ECs) are categorized into generations which differ in terms of design, aerosol production, and customizability. Current and former smokers prefer third-generation devices that satisfy tobacco cravings more effectively than older generations. Recent studies indicate that EC aerosols from first- and second-generation devices contain reactive carbonyls and free radicals and can cause in vitro cytotoxicity. Third-generation ECs have not been adequately studied. Further, previous studies have focused on cells from the respiratory tract, whereas those of the oral cavity, which is exposed to high levels of EC aerosols, have been understudied. We quantified the production of reactive carbonyls and free radicals by a third-generation EC and investigated the induction of cytotoxicity and oxidative stress in normal and cancerous human oral cell lines using a panel of eight commercial EC liquids. We found that EC aerosols produced using a new atomizer contained formaldehyde, acetaldehyde, and acrolein, but did not contain detectable levels of free radicals. We found that EC aerosols generated from only one of the eight liquids tested using a new atomizer induced cytotoxicity against two human oral cells in vitro. Treatment of oral cells with the cytotoxic EC aerosol caused a concomitant increase in intracellular oxidative stress. As atomizer age increased with repeated use of the same atomizer, carbonyl production, radical emissions, and cytotoxicity increased. Overall, our results suggest that third-generation ECs may cause adverse effects in the oral cavity and normal EC use, which involves repeated use of the same atomizer to generate aerosol, may enhance the potential toxic effects of third-generation ECs.

An Electronic Aerosol Delivery System for Functional Magnetic Resonance Imaging.

BACKGROUND: Public health concerns over the addictive potential of electronic cigarettes (e-cigs) have heightened in recent years. Brain function during e-cig use could provide an objective measure of the addictive potential of new vaping products to facilitate research; however, there are limited methods for delivering e-cig aerosols during functional magnetic resonance imaging (fMRI). The current study describes the development and feasibility testing of a prototype to deliver up to four different e-cig aerosols during fMRI. METHODS: Standardized methods were used to test the devices' air flow variability, nicotine yield, and free radical production. MRI scans were run with and without the device present to assess its safety and effects on MRI data quality. Five daily smokers were recruited to assess plasma nicotine absorption from e-liquids containing nicotine concentrations of 8, 11, 16, 24, and 36 mg/ml. Feedback was collected from participants through a semi-structured interview and computerized questionnaire to assess comfort and subjective experiences of inhaling aerosol from the device. RESULTS: Nicotine yield captured from the aerosol produced by the device was highly correlated with the nicotine concentration of the e-liquids used (R2 = 0.965). Nicotine yield was reduced by a mean of 48% and free radical production by 17% after traveling through the device. The e-liquid containing the highest nicotine concentration tested (36 mg/ml) resulted in the highest plasma nicotine boost (6.6 ng/ml). Overall, participants reported that the device was comfortable to use and inhaling the e-cig aerosols was tolerable. The device was determined to be safe for use during fMRI and had insignificant effects on scan quality. CONCLUSIONS: With the current project, we were able to design a working prototype that safely and effectively delivers e-cig aerosols during fMRI. The device has the potential to be used to assess brain activation during e-cig use and to compare brain reactivity to varying flavors, nicotine concentrations, and other e-cig characteristics.

Microbial synergy between Pichia kudriazevii YS201 and Bacillus subtilis BS38 improves pulp degradation and aroma production in cocoa pulp simulation medium.

Interactions between two major microorganisms from Ivorian cocoa fermentation, namely Bacillus subtilis BS38 and Pichia kudriazevii YS201, were investigated during fermentation in cocoa pulp simulation medium. The strains were mutually inhibitory, with Bacillus being more susceptible to this antagonistic effect than Pichia. However, both strains yielded different pulp-degrading enzymes, namely polygalacturonase (PG) from Pichia and pectate lyase (Pel) from Bacillus, that cooperate to efficiently breakdown pectin and vegetable pulp. The quantification of aromas from microbial cultures using Gas Chromatography-Mass Spectroscopy (GC-MS) coupled with headspace microextration (SPME) method, showed that P. kudriazevii produce mainly alcohols such as ethanol (63.165 g/L), phenylethanol (1.005 g/L), methylbutanol (0.138 g/L) and esters, notably ethyl acetate (0.037 g/L) and isoamyl acetate (0.032 g/L). The volatile fraction produced by Bacillus was dominated by butanediol (5.707 g/L), acetoin (1.933 g/L), phenylethanol (0.035 g/L) and acetic acid (0.034 g/L). In co-culture, Bacillus produced low levels of aroma compounds whereas a moderate decrease in the production of these compounds was observed in the yeasts strain. Thus, the dominant aromas present in the co-culture were mainly those from the yeasts strain; however, a 1.37 fold increase of ethanol production was observed in co-culture indicating a synergy between the strains. This study showed that cooperation between B. subtilis BS38 and P. kudriazevii YS201 leads principally to increasing pulp degradation and ethanol production, known as desirable properties for a well processing of cocoa fermentation.

Modeling the Impacts of Weather and Cultural Factors on Rotundone Concentration in Cool-Climate Noiret Wine Grapes.

The sesquiterpenoid rotundone is the compound responsible for the "black pepper" aroma of many plant species, including several economically important wine grape varieties. Since its identification in wine in 2008, there has been an increased interest in understanding how individual climatic or cultural factors affect the accumulation of rotundone in grapes and subsequently the level of wine "pepperiness." However, no study has assessed climatic and viticultural factors together to identify which variables have the strongest influence on rotundone accumulation. Our study aimed to fill this knowledge gap by developing a predictive model that identified factors that explain rotundone concentrations in Noiret (Vitis sp.) grapes at harvest. Over the 2016 and 2017 seasons, we measured 21 viticultural, meso- and microclimatic variables and concentrations of rotundone in Noiret wine grapes at seven vineyards in the northeastern U.S. Vineyard growing degree days (GDD v ) and the amount of solar radiation (cumulative solar exposure; CSEv) accumulated from the beginning of fruit ripening to harvest were the variables best correlated (r = 0.70 and r = 0.74, respectively) with rotundone concentrations. Linear correlations between microclimatic parameters and rotundone concentrations were weaker, but overall rotundone was negatively correlated with low (<15°C) and high (>30°C) berry temperatures. Using the 2-year data set we were able to develop a four-variable model which explained more than 80% of the variation in rotundone concentration at harvest. The model included weather [growing degree days during fruit ripening (GDD v )] and plant-related variables (concentrations of phosphorus and calcium in the leaf petiole, and crop load). The model we developed could be used by wine producers to identify sites or cultural practices that favor rotundone accumulation in Noiret grapes after performing a model validation with an additional, external data set. More broadly, the statistical approach used here could be applied to other studies that also seek to assess the effects of multiple factors on a variable of interest under varying environmental conditions.

Impact of electronic cigarette heating coil resistance on the production of reactive carbonyls, reactive oxygen species and induction of cytotoxicity in human lung cancer cells in vitro.

Electronic cigarette (e-cigarette; e-cig) use has grown exponentially in recent years despite their unknown health effects. E-cig aerosols are now known to contain hazardous chemical compounds, including carbonyls and reactive oxygen species (ROS), and these compounds are directly inhaled by consumers during e-cig use. Both carbonyls and ROS are formed when the liquid comes into contact with a heating element that is housed within an e-cig's atomizer. In the present study, the effect of coil resistance (1.5â€¯Ω and 0.25â€¯Ω coils, to obtain a total wattage of 8 ±â€¯2 W and 40 ±â€¯5 W, respectively) on the generation of carbonyls (formaldehyde, acetaldehyde, acrolein) and ROS was investigated. The effect of the aerosols generated by different coils on the viability of H1299 human lung carcinoma cells was also evaluated. Our results show a significant (p < 0.05) correlation between the low resistance coils and the generation of higher concentrations of the selected carbonyls and ROS in e-cig aerosols. Moreover, exposure to e-cig vapor reduced the viability of H1299 cells by up to 45.8%, and this effect was inversely related to coil resistance. Although further studies are needed to better elucidate the potential toxicity of e-cig emissions, our results suggest that these devices may expose users to hazardous compounds which, in turn, may promote chronic respiratory diseases.

In Vitro Antioxidant and Cancer Inhibitory Activity of a Colored Avocado Seed Extract.

Avocado (Persea americana) seeds have been used traditionally for a number of health-related indications. Because of its high polyphenol content, we investigated the potential antioxidant and anticancer effects of a colored avocado seed extract (CASE). CASE exhibited an oxygen radical acceptance capacity value of 2012 ± 300 trolox equivalents/mg. CASE reduced lipid hydroperoxide formation in an oil-in-water emulsion (33% reduction at 500 µg/mL). CASE dose-dependently reduced the viability of human breast (MCF7), lung (H1299), colon (HT29), and prostate (LNCaP) cancer cells in vitro. The half maximal inhibitory concentrations ranged from 19 to 132 µg/mL after treatment for 48 h. CASE treatment downregulated the expression of cyclin D1 and E2 in LNCaP cells. This was associated with cell G0/G1 phase cycle arrest. CASE also dose-dependently induced apoptosis in LNCaP cells. CASE reduced nuclear translocation of nuclear factor κB, a prosurvival signal. Further studies are needed to examine these effects in in vivo models.

Physicochemical interactions with (-)-epigallocatechin-3-gallate drive structural modification of celiac-associated peptide α2-gliadin (57-89) at physiological conditions.

(-)-Epigallocatechin-3-gallate (EGCG), a major phenolic constituent of tea, has been shown to have biological activity within inflammatory pathways involved with food allergies and intolerances. Proposed mechanisms for this effect include sequestration and structural modification of immunostimulatory proteins as a result of interactions with EGCG. The present study employs biophysical techniques including dynamic light scattering, circular dichroism and nuclear magnetic resonance to elucidate the likely mechanism(s) by which EGCG interacts with α2-gliadin (57-89) (α2g), an immunodominant peptide in celiac disease pathogenesis. We demonstrate that EGCG interacts with α2g in a multi-phase reaction driven by non-specific binding, resulting in the formation of polydisperse EGCG/α2g complexes which induce changes in peptide structure. We also show that these interactions occur at a range of pH levels associated with digestion, including pH 2.0, 6.8 and 7.5. Based on previous reports of binding specificity of enzymes and antigen presenting cells in celiac disease pathogenesis, our results provide foundational support for EGCG to prevent recognition of immunostimulatory gliadin epitopes by the body and thus prevent the inflammatory and autoimmune response associated with celiac disease.

UV-C irradiated gallic acid exhibits enhanced antimicrobial activity via generation of reactive oxidative species and quinone.

A novel light-enhanced antimicrobial treatment was developed by exposing gallic acid (GA) to UV-C light. GA (15 mM) solution was exposed to UV-C for 30 min and subsequently incubated with E. coli O157:H7 for 30 min to achieve a 3.2 ±â€¯0.2 log CFU/mL reduction. The antimicrobial activity is affected by the irradiation duration, wavelength, and pH of solution. The addition of benzenesulfinic acid (BSA) to UV-C irradiated GA lowered (P < 0.05) its antimicrobial activity, indicating that quinones contributed to its overall antimicrobial effect. In addition, the attenuated (P < 0.05) antimicrobial activity of UV-C exposed GA in the presence of reactive oxidative species (ROS) quenchers, the generation of hydrogen peroxide, and increased levels of intracellular oxidative stress detected in E. coli O157:H7 illustrated that ROS also played a role in the antimicrobial effect of UV-C irradiated GA. UV-C irradiated GA could be applied as a novel antimicrobial in food systems.

Loss and formation of malodorous volatile sulfhydryl compounds during wine storage.

Volatile sulfur compounds (VSCs), particularly low molecular weight sulfhydryls like hydrogen sulfide (H2S) and methanethiol (MeSH), are often observed in wines with sulfurous off-aromas. Recent work has shown both H2S and MeSH can increase up to a few µM (> 40 µg/L) during anoxic storage, but the identity of the latent sources of these sulfhydryls is still disputed. This review critically evaluates the latent precursors and pathways likely to be responsible for the loss and formation of these sulfhydryls during wine storage based on the existing enology literature as well as studies from food chemistry, geochemistry, biochemistry, and synthetic chemistry. We propose that three precursor classes have sufficient concentration and metastability to serve as latent sulfhydryl precursors in wine: 1) transition metal-sulfhydryl complexes, particularly those formed following Cu(II) addition, which are released under anoxic conditions through an unknown mechanism; 2) asymmetric disulfides, polysulfanes, and (di)organopolysulfanes formed through transition-metal mediated oxidation (e.g., Cu(II)) of sulfhydryls or pesticide degradation, and released through sulfitolysis, metal-catalyzed thiol-disulfide exchange or related reactions; 3) S-alkylthioacetates, primarily formed during fermentation, and releasable hydrolytically. Some evidence also exists for S-amino acids serving as precursors. Based on these findings, we propose a "decision tree" approach to choosing appropriate strategies for managing wines with sulfurous off-aromas.

Antioxidant activity of a winterized, acetonic rye bran extract containing alkylresorcinols in oil-in-water emulsions.

Naturally derived antioxidants are in high demand as the food industry strives to meet consumer preferences for non-synthetic additives. Alkylresorcinols (ARs) represent a novel class of natural antioxidants that can be derived from a natural waste stream (bran) and have the potential to inhibit lipid peroxidation given their phenolic structure. The antioxidant activity of rye bran extract containing ARs was investigated in an oil-in-water emulsion and was found to inhibit lipid oxidation reactions. The concentration of ARs in the continuous phase of emulsions was measured to understand partitioning behavior, as this is known to impact antioxidant activity. It was found that a majority of the ARs were associated with the lipid phase and those in the continuous phase were associated with surfactant micelles, perhaps inhibiting their interaction with water-soluble pro-oxidants. These results show that a rye bran extract containing ARs can function as a radical scavenging antioxidant in lipid dispersions.