Use Of Sulfur Dioxide Research Articles

Potential Use of Silica Nanoparticles for the Microbial Stabilisation of Wine: An In Vitro Study Using Oenococcus oeni as a Model.

The emerging trend towards the reduction of SO2 in winemaking has created a need to look for alternative methods to ensure the protection of wine against the growth of undesired species of microorganisms and to safely remove wine microorganisms. This study describes the possible application of silica nanospheres as a wine stabilisation agent, with Oenococcus oeni (DSM7008) as a model strain. The experiment was conducted firstly on model solutions of phosphate-buffered saline and 1% glucose. Their neutralising effect was tested under stirring with the addition of SiO2 (0.1, 0.25, and 0.5 mg/mL). Overall, the highest concentration of nanospheres under continuous stirring resulted in the greatest decrease in cell counts. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses showed extensive damage to the bacterial cells after stirring with silica nanomaterials. Then, the neutralising effect of 0.5 mg/mL SiO2 was tested in young red wine under stirring, where cell counts were reduced by over 50%. The obtained results suggest that silica nanospheres can serve as an alternative way to reduce or substitute the use of sulphur dioxide in the microbial stabilisation of wine. In addition, further aspects of following investigations should focus on the protection against enzymatic and chemical oxidation of wine.

Survival of common foodborne pathogens on dried apricots made with and without sulfur dioxide treatment

To fill the current knowledge gap in the survival of foodborne pathogens on dried fruits, this study monitored the survival of three common pathogens on dried apricots. Sun-dried apricots made with (DAS) and without sulfur dioxide (DANS) treatments were used and were inoculated using a dry (sand) or a wet (phosphate-buffered saline, PBS) carrier. The survival of Shiga-toxin-producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes (LM) on inoculated dried apricots was monitored for three months during ambient temperature storage. When dried apricots were inoculated with the wet carrier, all three pathogens survived the 48- hour drying period. After drying and during ambient temperature storage, the number of culturable pathogen cells decreased as the storage time increased. Among all three pathogens, STEC survived with higher culturable numbers for a longer period of time than the other two pathogens on DANS over the 90-day storage period. When pathogens were inoculated via the dry carrier, Salmonella survived with higher culturable numbers among three pathogens on DANS, indicating its enhanced survivability after being dried on sand and exposed to stress conditions before inoculation. In addition, regardless of the inoculation carriers, pathogens survived for longer periods of time or with higher levels on DANS, indicating the antimicrobial properties of free SO2 contained in DAS. In summary, based on the results of this study, pathogens can survive on dried fruits; factors affecting pathogen survival include the types of test pathogens, inoculation methods, and the use of sulfur dioxide.

Biotechnological Approach Based on Selected Saccharomyces cerevisiae Starters for Reducing the Use of Sulfur Dioxide in Wine.

Sulfites are considered the main additives in winemaking for their antimicrobial, antioxidant and anti-oxidasic activities. The current concern about the potential negative effects of sulfur dioxide (SO2) on consumer health has focused the interest on replacing or reducing SO2 use. Our work aims to develop a strategy based on the use of selected starter culture, able to perform wine fermentation without SO2 addition. Four selected Saccharomyces cerevisiae indigenous strains were tested as mixed starter cultures in laboratory scale fermentations. The starter culture, characterized by a similar percentage of dominance of both strains composing the mixed starter and able to produce a wine characterized by the best combination of chemical and aromatic characteristics, was chosen. This mixed culture was tested as a starter at pilot scale with and without SO2 addition, by using a higher inoculum level in the vinification without SO2. The selected starter confirmed higher dominance ability in vinification without SO2 addition than in SO2-added fermentation, demonstrating that sulfite addition is not a guarantee to reach an absolute dominance of starter culture on indigenous microflora. The proposed biotechnological tool allowed to produce good quality wines possessing also “functional properties”, as NO-SO2 added wines were characterized by high polyphenol content and antioxidant activity.

Sanitization of Oak Barrels for Wine—A Review

Oak barrels form an integral part of wine production, especially that of high-quality wines where they are implemented as fermentation and aging vessels. Insufficient cleaning and sanitization of barrels can result in microbial spoilage which may have a detrimental impact on wine quality. To date, no review has been published on the various sanitization methods for wine barrels. The objective of this review is to provide an overview of the sanitization methods used in wineries from conventional techniques like the use of sulfur dioxide and steam to alternative and new approaches using ozone and high-power ultrasound. The methods' efficacies are outlined in terms of their ability to eradicate spoilage microorganisms such as Brettanomyces and acetic or lactic acid bacteria. Furthermore, their advantages and drawbacks are described together with their influence on physicochemical properties of the wood. Finally, limitations in existing knowledge are discussed and areas that merit further research are identified.

The Oxygen Consumption Kinetics of Commercial Oenological Tannins in Model Wine Solution and Chianti Red Wine.

One property of oenological tannins, oxygen reactivity, is commonly exploited in winemaking. The reactivity is mediated by the presence of catalysts (i.e., transition metals and sulfur dioxide) and protects wine against oxidation. This work compares the oxygen consumption rate (OCR) of four commercial oenological tannins (two procyanidins from grape skin and seed, an ellagitannin from oak wood and a gallotannin from gallnut) in a model wine solution and Chianti red wine. All samples were subjected to consecutive cycles of air saturation at 20 °C to increase the total level of oxygen provided. After each cycle, the oxygen level was measured by means of a non-invasive luminescent sensor glued to a transparent surface (sensor dots) until there was no further change in substrate reactivity. The OCR followed first-order kinetics, regardless of the tannin. As expected, the ellagitannin showed the fastest OCR, followed by the two from grape seeds and skins and finally the gallotannin. The total O2 consumption in the red wine was almost double that of the model solution, due to the oxidation of wine substrates. The measurement of OCR is helpful for setting up an advanced winemaking protocol that makes use of tannins to reduce the use of sulfur dioxide.

Bacteriophages as an Up-and-Coming Alternative to the Use of Sulfur Dioxide in Winemaking.

Certain acetic and lactic acid bacteria are major causes of quality defects in musts and wines, giving rise to defects such as a “vinegary,” “sharp, like nail polish-remover” taste or preventing alcoholic and/or malolactic fermentation. Sulfur dioxide is the major tool currently used in the control of these bacteria in wine. The aim of this work was to isolate bacteriophages from musts and wine of different grape varieties that were able to eliminate lactic and acetic acid bacteria spoilages at the laboratory scale. Musts obtained from grape-berries of Vitis vinifera cv. Chardonnay and Moscatel and a red wine made with V. vinifera cv. Tintilla de Rota were used to isolate bacteriophages. Bacteriophages were obtained from each of the musts and the wine and belonged to the order Caudovirals and the family Tectivirals. They were isolated by classical virology methods and identified by electron microscopy. The host bacteria used in the study were lactic acid bacteria of the species Lactobacillus hilgardii, Lactobacillus plantarum, and Oenococcus oeni and the acetic bacteria Acetobacter aceti. A comparative study was performed by adding phage titrations and SO2 to musts and wines, which had been previously inoculated with bacteria, to study the effectiveness of bacteriophages against bacteria. The comparative study showed that some bacteriophages were as effective as sulfur dioxide at low concentrations.

Light-induced reactions of methionine and riboflavin in model wine: Effects of hydrolysable tannins and sulfur dioxide

The riboflavin-mediated photo-degradation of methionine in white wine has been related to onset of undesired light-struck taste. This research investigated the effects of different concentrations of riboflavin and methionine, hydrolysable tannins from various sources (nut galls, chestnut and oak woods) and sulfur dioxide on methionine degradation in a model wine exposed to light. Increased methionine concentration resulted in its increased degradation with the consequent formation of volatile sulfur compounds, namely methanethiol, dimethyl disulphide and dimethyl trisulphide. Tannins, especially nut gall tannin, were effective in limiting both methionine degradation and the production of volatile sulfur compounds. Sulfur dioxide enhanced the methionine degradation although the light-struck taste was not perceived when sulfur dioxide concentration was higher than 50 mg/L. In conclusion, the use of hydrolysable tannins can represent a promising tool for protecting white wine against the light-struck taste also limiting the use of sulfur dioxide.

Changes in stilbene composition during postharvest ozone treatment of 'Moscato bianco' winegrapes.

Stilbenes, including trans-resveratrol and its derivatives, are compounds naturally present in grapes and have gained a growing interest due to reported health-promoting properties. The production of resveratrol-enriched table grapes has promoted recent research on stress-induced synthesis of stilbenes. The oxidizing properties of ozone have been successfully exploited to its use as sanitizing agent and stilbene elicitor during table grapes storage. In winegrapes, this study represents the first research focused on the effect of postharvest ozone treatments on the accumulation of stilbene compounds. The study was carried out on Moscato bianco winegrapes (Vitis vinifera L.) and several gaseous ozone treatments were investigated differing in ozone dose (30 and 60 μL/L), exposure time (24 h, 48 h, and several days until 30% of weight loss), and delay time until processing (just after and several days after treatment). The stilbene production induced by ozone exposure was assessed in fresh and partially dehydrated winegrapes up to 5, 10, 15, 20, and 30% of weight loss aiming to evaluate the single and combined effect of oxidative and osmotic stresses. The results obtained showed that short-term exposure of fresh winegrapes at 60 μL/L of ozone for 48 h was not effective in inducing resveratrol accumulation just after treatment, but it had an elicitor effect on total stilbenes (+36%) in grapes subsequently dehydrated up to 20% of weight loss with a significant overproduction of trans-resveratrol and trans-piaceatannol. In addition, long-term and continuous treatments under ozone-enriched atmosphere can be also used during dehydration to sanitize winegrapes without affecting negatively the concentration of stilbenes. Therefore, the use of gaseous ozone during storage and dehydration could be indicated to reduce the use of sulfur dioxide and, depending on ozone dose and exposure time, the synthesis of stilbene compounds could increase.

Reductive leaching of indium-bearing zinc ferrite in sulfuric acid using sulfur dioxide as a reductant

Indium extraction from synthetic indium-bearing zinc ferrite (IBZF) was investigated using sulfur dioxide as a reductant in sulfuric acid medium, and the recovery of indium and the full use of sulfur dioxide were achieved. The leaching kinetics of indium from synthetic IBZF were studied, and the influence of leaching temperature, particle size, initial sulfuric acid concentration and sulfur dioxide partial pressure were investigated. The results showed that the leaching efficiencies increased as the leaching temperature increased from 65 to 85 °C, the initial sulfuric acid concentration increased from 5 to 65 g/L, the sulfur dioxide partial pressure increased from 0.10 to 0.30 MPa, and the particle size decreased from 150–270 μm to 48–58 μm. The unreacted shrinking core model was applied well to the kinetics of indium leaching, which showed that the rate was controlled by a chemical reaction with a calculated activation energy of 57.22 kJ/mol. The order of indium leaching with respect to particle size, initial sulfuric acid concentration and sulfur dioxide partial pressure was −0.2343, 0.02625 and 0.35618, respectively. Meanwhile, sulfur dioxide could reduce the dependency of IBZF dissolution on the initial sulfuric acid concentration.

Biocontrol of postharvest Alternaria decay in table grapes from Mendoza province

Postharvest diseases cause considerable loss of fruit during transportation and storage. Synthetic fungicides are primarily used to control them. However, the recent trend is to shift toward safer and more eco-friendly alternatives for the control of postharvest decays. In Argentina, Alternaria genus was cited as a postharvest pathogen on table grapes for the first time during 2010–2012 seasons. The aim of this study was to identify, by morphological and molecular techniques, Alternaria spp. strains isolated from table grapes cv. Red Globe in different phenological stages of vine and postharvest storage in Mendoza province. In addition, we intended to propose an alternative postharvest management to the use of sulfur dioxide (SO2) generators (traditional method). We searched for a lower environmental impacting substitute using the yeast strain Metschnikowia pulcherrima RCM2 and chitosan coatings as possible control agents. The results showed that the pathogen was present in all the stages studied and the 100% of the strains belonged to the species-group Alternaria alternata. Besides, chitosan coatings showed to be a good alternative method to SO2 generators. This work is focus on the study of the incidence of Alternaria spp. during the phenological cycle and postharvest storage of table grapes cv. Red Globe, and also on the evaluation of alternative strategies to the use of SO2 for the control of this disease during the extended cold storage.

Alternative Methods to SO2 for Microbiological Stabilization of Wine.

The use of sulfur dioxide (SO2 ) as wine additive is able to ensure both antioxidant protection and microbiological stability. In spite of these undeniable advantages, in the last two decades the presence of SO2 in wine has raised concerns about potential adverse clinical effects in sensitive individuals. The winemaking industry has followed the general trend towards the reduction of SO2 concentrations in food, by expressing at the same time the need for alternative control methods allowing reduction or even elimination of SO2. In the light of this, research has been strongly oriented toward the study of alternatives to the use of SO2 in wine. Most of the studies have focused on methods able to replace the antimicrobial activity of SO2 . This review article gives a comprehensive overview of the current state-of-the-art about the chemical additives and the innovative physical techniques that have been proposed for this purpose. After a focus on the chemistry and properties of SO2 in wine, as well as on wine spoilage and on the conventional methods used for the microbiological stabilization of wine, recent advances on alternative methods proposed to replace the antimicrobial activity of SO2 in winemaking are presented and discussed. Even though many of the alternatives to SO2 showed good efficacy, nowadays no other physical technique or additive can deliver the efficacy and broad spectrum of action as SO2 (both antioxidant and antimicrobial), therefore the alternative methods should be considered a complement to SO2 in low-sulfite winemaking, rather than being seen as its substitutes.

Konzerviranje rakova upotrebom sumpornog dioksida i sulfita (E 220 – E 228)

Food additives are substances of known chemical composition that are neither consumed as food nor typical food ingredients, regardless of their nutritional value, but are instead added to foodstuffs to perform certain technological functions and retain certain sensory properties of food. Additives that are widely applied in food industry include sulphur dioxide (SO2) and sulphites (E 220 – E 228). Sulphur dioxide and its derivatives are added to foodstuffs in order to inhibit and control the growth of microorganisms, for the purpose of prevention of non-enzymatic browning and inhibition of enzyme-catalysed reactions, as well as antioxidants and reducing agents.Food to which they are most often added includes various dried fruits, certain species of crabs and molluscs, fruit juices, beer, wine and other products. Since harmful effects of sulphur dioxide and sulphites are most commonly associated with allergic reactions to food, it is, therefore, necessary to inform consumers of their presence in food, even when they are present in very small quantities, because their quantity itself does not exclude the possibility of an allergic reaction. The use of sulphur dioxide and sulphites in the processing of crabs (scampi, shrimp, and lobster) is justified by their preservative effect on slowing the growth of bacteria and preventing the formation of melanomas that manifest by the emergence of black spots on crab shell caused by the polyphenol oxidase enzyme activity. Sulphur dioxide and sulphites are regulated by Regulation (EC) No. 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives as amended by Commission Regulation (EU) No. 1129/2011 amending Annex II to Regulation (EC) No 1333/2008 of the European Parliament and of the Council by establishing a Union list of food additives. In 1993, the International Agency for Research on Cancer (IARC) classified sulphur dioxide and sulphites as Group 3, meaning they are not classifiable as to their carcinogenicity to humans. The European Food Safety Authority (EFSA) has, in its Scientific Opinion on the re-evaluation of sulphur dioxide (E 220), sodium sulphite (E 221), sodium bisulphite (E 222), sodium metabisulphite (E 223), potassium metabisulphite (E 224), calcium sulphite (E 226), calcium bisulphite (E 227) and potassium bisulphite (E 228) as food additives, confirmed that the current acceptable daily intake (ADI) of 0.7 mg SO2 equivalent/kg of body weight per day would remain adequate.

Nutritional evaluation of Glutenol: a co-product of ethanol production.

The objective of this study was to evaluate the nutritional value of Glutenol, a new coproduct of the ethanol industry. Glutenol was produced by Quality Technology International, Elgin, IL, in a modified wet-milling plant using a hybrid process, NextGenFrac, which fractionates the corn kernel components prior to fermentation without the use of sulfur dioxide. Glutenol was analyzed to contain 52.3% CP, 1.7% Met + Cys, 1.32% Lys, 1.69% Thr, and 2.23% Val on a DM basis. Two precision-fed rooster assays with conventional and cecectomized roosters were conducted to determine TMEn and standardized digestibility of amino acids (AA), respectively. The TMEn of Glutenol was determined to be 3,256kcal/kg DM. Standardized digestibility values for Lys, Met, Cys, Thr, and Val were 80.1%, 90.4%, 80.1%, 74.1%, 81.1%, and 84.9%, respectively. In addition, a 3-wk broiler chick assay was conducted with increasing levels of dietary Glutenol. Diet 1 was a standard corn/soybean meal diet with 0% Glutenol. Diets 2, 3, and 4 had increasing levels of Glutenol at 4%, 8%, and 12%, respectively. Diets were fed from 3 to 22 d post-hatch and all diets were formulated to be equal in TMEn and digestible AA. Weight gain, feed intake, and gain/feed ratio were measured. No differences in growth performance were observed among dietary treatments. In conclusion, Glutenol can be fed up to at least 12% in the diet of broiler chickens if diets are formulated to be equal in ME and digestible AA.

Frontispiece: Radicals and Sulfur Dioxide: A Versatile Combination for the Construction of Sulfonyl‐Containing Molecules

Sulfonyl functional groups, such as sulfones, sulfonyl chlorides or sulfonamides, play an important role in organic chemistry, with various applications that include the construction of biologically active compounds. Recently, sulfur dioxide has been used via radical-based transformations to construct molecules with sulfonyl moieties. The Minireview by Manolikakes et al. on page 11852 ff. highlights recent advances in the use of sulfur dioxide in radical reactions, covers some historical background of the field, discusses limitations of existing methods, and examines potential further developments.

SO2, high pressure processing and pulsed electric field treatments of red wine: Effect on sensory, Brettanomyces inactivation and other quality parameters during one year storage

Abstract The use of sulphur dioxide (SO2), high pressure processing (HPP) and pulsed electric fields (PEF) for wine preservation was compared. The difference between HPP and PEF wines and untreated wine after one year's storage, in terms of sensory quality, B. bruxellensis inactivation, colour density, total phenolic content and volatile phenol concentration, was determined. SO2 and HPP led to >5 log inactivation of B. bruxellensis, however SO2 treated cells were able to recover after 10 months storage. PEF treatment provided insufficient inactivation (0.8 log reduction). HPP was the only treatment which prevented Brettanomyces growth and the formation of off-flavours and –odours after storage. SO2 and PEF treatments had no significant effect on wine quality, while the colour and phenolic quality of HPP treated wine deteriorated after six months. HPP and PEF also had no effect on the overall sensory quality of the wines. Overall, HPP was able to produce a microbiologically stable wine, with no effect on the taste of the wine. Industrial relevance Brettanomyces is a spoilage concern in the wine industry, conventionally controlled using SO2. Due to its adverse effects on some consumers, the use of emerging non-thermal technologies has started to garner great interest in the food and beverage industry. The results show that HPP is a non-thermal treatment with the potential to reduce the use of SO2 for the preservation of wine in the industry. However, to extend the quality of HPP treated wine beyond six months storage and retain wine colour and total phenolic content, small doses of SO2 may be required. Since, PEF is a continuous process, integration of this technology into current wine production practices would be less challenging than for HPP. This study also underscores the importance on conducting regular tests for B. bruxellensis contamination in the wine industry, because even when plate counts are negligible this yeast has the ability to recover when conditions become favourable again.

SO2 trajectories in a complex terrain environment using CALPUFF dispersion model, OMI and MODIS data

Latest improvements in the resolution of atmospheric satellite sensors that measure chemical constituents from space have led to enhanced detection of trace gases. This paper explores the use of sulfur dioxide (SO2) level 2 dataset from OMI instrument, in conjunction with aerosol optical depth and Ångström exponent data from MODIS spectroradiometer, to estimate SO2 loads under clear and turbid atmospheres. The spatial patterns of SO2 loads in polluted atmospheric conditions are compared with a regional pollutant dispersion model (CALPUFF) and field observations near the Andes Peruvian city La Oroya, which is one of the most polluted places in the world. The efficacy of this methodology is further examined incorporating synchronous wind vectors. Results show that the spatial-temporal dynamics of OMI SO2 is in agreement with field measurements and CALPUFF. The SO2 satellite data obtained under optimal viewing conditions and clear skies are also compared with field observations. A correlation is found between in-situ measurements and OMI estimations. The correlation increases for days with predominantly fine aerosols when Ångström exponents are between 0.7 and 1. Moreover, pixel averaging techniques and low and high spatial frequency filtration, applied to OMI SO2 data, results in a more reliable representation of the mean SO2 plume. The paper concludes that anthropogenic SO2 can be monitored from space, even for turbid sky conditions. This demonstrates the potential for the use of satellite products to improve the air quality prediction models.

Radicals and Sulfur Dioxide: A Versatile Combination for the Construction of Sulfonyl-Containing Molecules.

Molecules containing a sulfonyl functionality, such as sulfones, sulfonyl chlorides or sulfonamides play an important role in organic chemistry and have found widespread application, especially in the construction of biologically active compounds. Recently, methods for the synthesis of the sulfonyl moiety utilizing sulfur dioxide as a key building block have received considerable attention. In this context, radical-based transformations with sulfur dioxide have emerged as a new and attractive approach for the construction of the sulfonyl functional group. This short review highlights recent advances in the use of sulfur dioxide in radical reactions and covers the historical background, which forms the basis for these current progresses. Limitations of the existing methods and potential further developments will be discussed.

The impact of SO2 on wine flavanols and indoles in relation to wine style and age

Wine has one of the broadest chemical profiles, and the common oenological practice of adding the antioxidant and antimicrobial sulfur dioxide has a major impact on its metabolomic fingerprint. In this study, we investigated novel discovered oenological reactions primarily occurring between wine metabolites and sulfur dioxide. The sulfonated derivatives of epicatechin, procyanidin B2, indole acetic acid, indole lactic acid and tryptophol were synthesized and for the first time quantified in wine. Analysis of 32 metabolites in 195 commercial wines (1986–2016 vintages) suggested that sulfonation of tryptophan metabolites characterised white wines, in contrast to red wines, where sulfonation of flavanols was preferred. The chemical profile of the oldest wines was strongly characterised by sulfonated flavanols and indoles, indicating that could be fundamental metabolites in explaining quality in both red and white aged wines. These findings offer new prospects for more precise use of sulfur dioxide in winemaking.

Evaluation of the use of sulfur dioxide and glutathione to prevent oxidative degradation of malvidin-3-monoglucoside by hydrogen peroxide in the model solution and real wine

In this study the oxidative degradation by hydrogen peroxide of native grape anthocyanin was studied in model solutions and in red wines added with increasing concentration of sulfur dioxide and glutathione (GSH). The presence of hydrogen peroxide and metal ions in traces allowed to investigate the possibility to use GSH to prevent Fenton reaction in wine conditions. Two different pH of wine were considered: 3.20 and 3.80. The protective effect of sulfur dioxide on malvidin 3-monoglucoside degradation was higher at lower pH in model solution. No effect of pH on sulfur dioxide action towards the native anthocyanin in real wine was detected. Surprisingly GSH determined an increase in the degradation of malvidin 3-monoglucoside regardless of pH. Therefore, GSH is not effective in prevent native anthocyanins loss due to the Fenton reaction during red wine aging.

Increasing the shelf life of post-harvest table grapes (Vitis vinífera cv. Thompson Seedless) using different packaging material with copper nanoparticles to change the atmosphere

An effective way to control post-harvest rotting of table grapes is the use of sulfur dioxide (SO2). However, under certain conditions, the use of SO2 can cause significant loss, mainly associated with bleaching of the berries. Therefore, it is believed that the use of bags with and without copper nanoparticles that modify the atmosphere will allow for the control of Botrytis cinerea as well as the ability to dispense with the use of sulfur dioxide generation. The objective of this test is to evaluate the use of bags with and without copper nanoparticles that modify atmosphere and to evaluate their ability to control post-harvest B. cinerea, as well as their effect on the conservation of physical and chemical characteristics of table grapes. The results indicate that the use of air bags with or without copper nanoparticles that modify the atmosphere and do not require sulfur dioxide generation were able to control B. cinerea post-harvest and preserve the physical and chemical parameters of grape table cv. ‘Thompson seedless’. Significant differences were seen in parameters such as whitening, dehydration and incidence of stalk rot. A group of panelists could not distinguish differences in the sensory attributes and acceptability of the grapes regardless of treatment.