Impact of wine manufacturing practice on the occurrence of fining agents with allergenic potential

Proteinogenic wine fining agents are hidden allergens and could present a risk for consumers with allergies. Therefore, the European Parliament adopted Directive 2003/89/EC amending Directive 2000/13/EC to declare ingredients, contaminations and processing aids that are known to trigger allergic reactions. The Amendment Regulation (EU) 1266/2010 excluded the labelling of wines which are processed with hen’s egg and products thereof until 30 June 2012 to get more scientific findings. After 1 July 2012 wine fining agents have to be declared if above 0.25 mg l^–1 (Regulation (EU) 579/2012 in conjunction with article 120 g of Regulation (EU) 1234/2007). The Organisation International de la Vigne et du Vin (OIV) advises this limit of detection (LOD) for potential allergenic residues of proteins. Wine fining agents are processing aids and according to the wine producer’s knowledge will be removed after coagulation by filtration or other production steps. Due to lack of scientific data, residues of fining agents in the final product could not be excluded. In this risk assessment, highly sensitive ELISA methods for ovalbumin of known origin for wine have been developed. The objective was to investigate the presence of allergen residues in wine after certain technological treatments were applied to remove the wine fining agents. For all developed ELISA methods the LODs are in the low µg l^–1 range between 5 and 10 µg l^–1 fining agent, whereas the LOQ varies between 5 and 80 µg l^–1 fining agent. The results of the investigation of well-known wines and fining agents demonstrate that white wines fined with white or ovalbumin from hen’s egg could retain allergens. The use of certain technological procedures during wine processing leads to different results. In white wine, bentonite or sheet filtration followed by sterile filtration lead to wines containing no detectable amounts of ovalbumin. In red wine, especially the final sterile filtration removes the fining agents.     

The allergenicity of ovomucoid and the effect of its elimination from hen's egg white

In order to remove the ovomucoid from hen's egg white, chitin and hydrazide polystyrene beads were used as affinity ligands with 8.9 and 7.1 mg trypsin g^?1 ligand respectively. Ovomucoid was successfully depleted using the trypsin affinity column without hydrolysation of the other egg white constituents. The components of the egg white were purified by high‐performance liquid chromatography, and then the allergenicity of each of these components was compared with that of pooled human serum derived from patients who are allergic to hen's eggs. The importance of using pure protein for studies of the allergenicity of egg white is highlighted, and it was determined (using an enzyme‐immunosorbent assay) that ovomucoid and ovalbumin are major allergenic proteins in egg white. The ovomucoid‐eliminated egg white preparation exhibited significantly less IgE‐binding activity than normal egg white. The ovomucoid‐specific IgE antibodies may have important implications with regard to the egg‐allergic reaction in humans. © 2001 Society of Chemical Industry     

Lupine,a source of new as well as hidden food allergens

The present review summarizes current knowledge about lupine allergy, potential sensitization routes, cross‐reactions between lupine and other legumes, and the respective IgE‐binding proteins. Since the 1990s, lupine flour is used as a substitute for or additive to other flours, mostly wheat flour, in several countries of the EU. In 1994, the first case of an immediate‐type allergy after ingestion of lupine flour‐containing pasta was reported. Since then, the number of published incidents following ingestion or inhalation of lupine flour is rising. So far, the Lupinus angustifolius β‐conglutin has been designated as the allergen Lup an 1 by the International Union of Immunological Societies Allergen Nomenclature Subcommittee. Initially, publications focussed on the fact that peanut‐allergic patients were at risk to develop anaphylaxis to lupine due to cross‐reactivity between peanut and lupine. At present, however, the ratio between cases of pre‐existing legume allergy (mostly peanut allergy) to de novo sensitization to lupine seed is nearly 1:1. Although in December 2006, lupine and products thereof were included in the EU foodstuff allergen list according to the Commission Directive 2006/142/EC amending Annex IIIA of Directive 2000/13/EC in order to prevent severe reactions caused by “hidden food allergens”, the majority of patients and medical personnel are still not aware of raw lupine seed as potentially dangerous food allergen.     

Detection of Traces of Ovalbumin and Casein in White and Red Wines by Quantitative Western Blotting

Fining of wine with agents containing cow's milk or hen's egg white is a common and traditional procedure. In light of increasing food allergies all over the world, the presence of fining residues has been subject of intense debate. Switzerland does not make exception, and since 2009 the Federal Department of Home Affairs has modified its food regulations stating that the labels must show if traces of fining agents are present. Nevertheless, the application of this regulation is not based on an official analytical method. In this study we show that immunoblotting is an efficient technique to detect and quantify ovalbumin and casein residues in bottled wine. We showed that final filtration is an essential step to remove finings in red wine, and that overfining of white wine may result in fining residues in finished products. Finally, for the first time in Switzerland, 22 samples were taken by food safety inspectors and officially analyzed for the regional food control authority of the Canton of Vaud. These samples were allergen free, but a larger study is currently planned in collaboration with other regional authorities of Switzerland to complete these results and make a complete picture of the Swiss wine production.     

Technological use of donkey milk in cheesemaking

The efficacy of donkey milk as an alternative to hen's egg white lysozyme in preventing cheese blowing during ripening of Italian Grana cheeses was tested. Indices of proteolysis and lipolysis did not differ between the different cheesemaking processes. All tested products showed good microbiological and sensorial quality.     

Lysozyme in Wine: An Overview of Current and Future Applications

Lysozyme, a muramidase enzyme from egg whites (EC 3.2.1.17), is widely used in soluble form to control lactic acid bacteria in different foods. Moreover, hen egg white lysozyme is a hydrolytic enzyme that can be used to the control malolactic fermentation (MLF) during winemaking. MLF is only desirable in red and in some white wine, this suggest that MLF is at fault and needs to be controlled in all other types of wine. Lysozyme exhibits selective antimicrobial activity based on the hydrolysis of peptidoglycan cell wall constituents in lactic acid bacteria. In the last decade, several studies identified allergic reactions due to the presence of lysozyme in food. Given this relatively high incidence of lysozyme sensitization, and in accordance with the recently changed EC food legislation (1266/2010/CE), the use of lysozyme as an additive has to be declared on the ingredient label. To overcome this problem, the immobilization of the enzyme on insoluble supports, which allows the enzyme to be removed, has been the preferred strategy. In this context, this article offers a review of reports on lysozyme enological use over the last decade. It surveys the immobilization techniques and support materials used for lysozyme food preservation. This study attempts to provide useful guidance from the wealth of available immobilization data in the literature and, more importantly, to develop an integrated perspective on how to customize lysozyme for future enological uses.     

Quantification of lupine (Lupinus angustifolius) in wheat flour using real-time PCR and an internal standard material

In the European Union, labelling of the 14 food allergens listed in Annex IIIa of Directive 2000/13/EC is mandatory. The implementation of upper limits for these allergens is under discussion. Therefore, quantitative analytical methods will be needed to verify compliance with regulatory requirements and to provide an improved basis for the legal assessment of allergen labelling. In this study, the lupine flour content in wheat flours was determined using real-time PCR and statice seeds as internal standard material. The method proved to be applicable to the quantification of lupine contents from 1 to 10?mg/kg, which is in the range relevant for allergic consumers.     

The chemical and sensorial effects of lysozyme addition to red and white wines over six months' cellar storage

Lysozyme is an enzyme with muramidase activity which can lyse Gram-positive bacteria, including wine lactic acid bacteria. This enzyme provides a practical method for delaying or preventing the growth of Oenococcus oeni and consequently the onset of malolactic fermentation during the vinification of red and white wines. This paper reports the impact of lysozyme on the chemical and sensorial properties of commercially vinified red (Cabernet Sauvignon and Shiraz) and white (Riesling) wines. The addition of lysozyme to these wines had little or no effect on the content of alcohol, free and total sulfur dioxide and titratable acidity, and pH value. The lysozyme retained 75–80% activity in the Riesling wine after six months, however no detectable activity remained in the Cabernet Sauvignon and Shiraz wines after two days. Upon addition of lysozyme to both of the red wines, a rapid initial decrease (up to 17%) in red wine colour density and phenolic content occurred in association with the formation of a light precipitate. The reduction in red wine colour was also noted by the sensory panel. When added to the Riesling wine, lysozyme did not cause an increase in browning over the six month storage time, but did induce heat instability (haze), suggesting that white wines may require protein stabilisation following treatment with lysozyme. Sensory assessment by triangle difference testing revealed that, during the six month storage period, treatment with lysozyme did not cause important changes to either the aroma or palate of the red and white wines tested.     

Collaborative Interlaboratory Studies for the Validation of ELISA Methods for the Detection of Allergenic Fining Agents Used in Wine According to the Criteria of OIV Resolution 427–2010 Modified by OIV–Comex 502–2012

The clarification or fining of wine removes undesired substances (mainly proteins, phenols, and tannins), which would roil the wine and cause bitterness and astringency. A common fining agent, egg white, can be directly added to wine through the inlet of a circulating pump, but more typically egg white comes as commercial preparation in powdered form (commercially named egg albumin). Skimmed milk or more frequently purified caseinates are used to remove bitterness and hardness of white wine and sherry. Both egg white and caseinates are fining agents with optimal enological properties, but their residues could represent a risk for subjects suffering from food allergy. The rules for allergen labeling were detailed in Directives 2003/89/EC, and Directive 2005/26/EC established a list of food ingredients provisionally excluded from labeling, that included wine fining agents. Extended till June 2012, wine labeling exemption can be now maintained only if (1) egg and milk derivatives are not used and cross-contamination is under control; and (2) wine clarified with such products is negative for the presence of residues using techniques with detection and quantification limits of 0.25 and 0.5 ppm, respectively. Analytical requirements were defined in the OIV resolution 427–2010 (OIV 2010) modified by OIV/COMEX 502–2012 (OIV 2012). On the basis of a previous experience, an interlaboratory collaborative trial was organized to validate a commercial ELISA kit designed to measure allergenic residues in red wine fined with egg white proteins. In the meantime, the performance of the commercial caseinate ELISA kit for white wine was rechecked according to the new limit of detection and limit of quantification values, recommended by OIV in 2012. The collaborative interlaboratory studies showed that both ELISA kits had good reproducibility, repeatability, and robustness in detecting residues of allergenic fining agents in wine, in good agreement with the requirements of the OIV resolution 427–2010 modified by OIV/COMEX 502–2012.     

Cover Picture: Mol. Nutr. Food Res. 11'2009

Regular issues provide a wide range of research and review articles covering all aspects of Molecular Nutrition & Food Research. Selected topics of issue 11 are: Variation in the human lipidome associated with coffee consumption as revealed by quantitative targeted metabolomics Purified berry anthocyanins but not whole berries normalize lipid parameters in mice fed an obesogenic high fat diet The anti‐diabetic effect of anthocyanins in streptozotocin‐induced diabetic rats through glucose transporter 4 regulation and prevention of insulin resistance and pancreatic apoptosis Influence of thermal processing on IgE reactivity to lentil and chickpea proteins Lysozyme in wine: A risk evaluation for consumers allergic to hen's egg     

Collaborative Tests of ELISA Methods for the Determination of Egg White Protein and Caseins Used as Fining Agents in Red and White Wines

Methods are needed for detecting allergenic proteins in wine after fining processes, both for legal requirements and to estimate any risk for allergic individuals. Two of the critical allergens in this case are the protein fraction from egg white and caseins. Requirements for methods were set up both by the International Organisation of Vine and Wine (OIV) and the European Commission and included collaborative tests to determine repeatability, reproducibility, limit of detection (LOD), and recovery. Two collaborative tests with 18 participants from all over the world were conducted using commercial enzyme-linked immunosorbent assay kits to quantify egg white protein and casein. For each analyte, nine red and white wines (RW and WW, respectively) with different analyte concentrations were prepared and sent to the participants. Resulting sets of data were analyzed according to the AOAC by eliminating outliers and calculating the performance statistics for each assay. For wines with no or very low analyte concentrations, the values were extrapolated from the calibration curve and the resulting LODs are in accordance with the performance criteria set by the OIV method OIV-MA-AS315-23: R2012. For casein in WW and egg white protein in RW, all Horwitz ratio values for samples with concentrations above the required limit of quantification (0.5 mg/L) were below 2. While the recovery of egg white protein from RW is 90 % or more, the recovery of casein from WW is between 73 and 76 %, which is attributable to the instability/solubility of casein in wine.     

鸭蛋清溶菌酶的分离纯化及致敏性评估

鸭蛋中含有丰富的蛋白质和营养成分,鸭蛋清中含有溶菌酶,溶菌酶具有致敏性,食用鸭蛋后有可能产生过敏的风险。采用超滤法与离子交换层析法结合的方法分离纯化鸭蛋清溶菌酶,利用聚丙烯酰胺凝胶电泳法比对,能得到纯度较高的溶菌酶。采用免疫印迹的方法,分析抗溶菌酶的兔多抗血清和禽蛋过敏患者混合血清池分别与鸭蛋清溶菌酶IgE的结合能力,进行鸭蛋溶菌酶的致敏性评估,实验证明IgE结合能力非常显著,溶菌酶存在交叉反应。同时证实了食用鸭蛋会引起过敏反应,也为过敏患者能否食用鸭蛋提供了有效的信息。     

Occurrence of ethyl carbamate in three types of Chinese wines and its possible reasons

A total of 75 wines including 30 white wines, 31 red wines, and 14 sparkling wines were obtained from several regions in China (Sinkiang, Tonghua, Huailai, Yantai, Changli, Shanxi, Gansu, and Ningxia). Ethyl carbamate (EC) was detected by gas chromatography mass spectrometry. The EC concentration ranged from less than 1.16 to 38.56 μg/L, and the concentrations in 17 wines exceeded the U.S. limit for table wines (15 μg/L). The concentrations of EC increased in the order of white, red, and sparkling wines with the corresponding mean concentrations of 6.12, 9.22, and 14.03 μg/L. The relationship between EC concentration and wine type suggested that EC concentrations in wines might be affected by vinification patterns, most likely due to the difference between EC precursors in different vinification processes. This work provides a novel clue for EC contamination in different wines.     

两种澄清剂对4种鲜葡萄酒的下胶效果分析

选用保香皂土和蛋清作为下胶澄清剂对4种鲜葡萄酒下胶,分析2种下胶澄清剂的下胶量对4种鲜葡萄酒热稳定性及感官质量（包括外观、香气和口感）的影响。结果表明,鲜酒轻柔桃红葡萄酒、鲜酒轻柔红葡萄酒和鲜酒浓甜红葡萄酒选用保香皂土下胶,下胶量为1.0 g/L时,3款葡萄酒的热稳定性均合格且风味物质损失最少,感官评分分别为92、91、93;鲜酒轻柔干红葡萄酒选用蛋清下胶,下胶用量为0.07 g/L时,轻柔干红葡萄酒热稳定性合格且风味物质损失最少,感官评分为93分。     

Changes in aliphatic ester composition of white wines during exposition to light. An HS-SPME-GC-MS study

The irradiation of four Italian white wines with a visible light comparable to that encountered in the market place showed a modification in the amount of aliphatic esters in the wines. Aliphatic esters are responsible for fruity aromas in wines. The first wine studied was the Gewürztraminer, a white wine from Alto Adige (Northern Italy). The amounts of the esters presents in the wine decreased. All the curves follow a pseudo-first-order kinetics. This behaviour can be explained assuming a photooxidation process catalysed by riboflavin. When Arneis Blangè was irradiated, ethyl acetate showed an increase after one day of irradiation; its content then decreased and after five days' irradiation its concentration reached a maximum. Conversely, the concentration of other aliphatic esters decreased after one day's irradiation and then increased progressively to reach a maximum after five days' irradiation. The same behaviour was observed with Pecorino wine. In this case, the concentration of the aliphatic esters decreased until the second day of irradiation but increased after five days' irradiation. In the case of the irradiation of Lighea Zibibbo all the esters showed an increase in concentration after one day of irradiation. The concentration decreased after two days' irradiation, and then increased to reach a maximum after seven days of irradiation. The increase in the amount of esters in some wines and, by contrast, the decrease in the same compounds in Gewürztraminer can be explained by considering that, during the irradiation, the pH of Gewürztraminer did not change, while the pH of Arneis Blangè changed following a curve similar to that showed by the concentration of esters. The pH change can be explained assuming the presence of a photocatalytic process induced by the presence of metals in the wines and influencing the amount of tartaric acid.     

Assessing the Potential Content of Ethyl Carbamate in White,Red, and Rosé Wines as a Key Factor for Pursuing Urea Degradation by Purified Acid Urease

The ethyl carbamate (EC) content of a wine after a given temperature‐time storage was theoretically predicted from the potential concentration of ethyl carbamate (PEC), as determined via an accelerated EC formation test. Such information was used to decide whether an enzymatic treatment was needed to reduce the wine urea level before bottling/aging. To this end, 6 white, red, and rosé wines, manufactured in Italy as such or enriched with urea, were tested for their PEC content either before or after enzymatic treatment using a purified acid urease preparation derived from Lactobacillus fermentum. The treatment was severely affected by the total phenolic content (TP) of the wine, the estimated pseudo‐first‐order kinetic rate constant for NH₃ formation reducing by a factor of approximately 2000 as the TP increased from 0 to 1.64 g L^‐1. Such a sensitivity to TP was by far greater than that pertaining to a killed cell‐based enzyme preparation used previously. Urea hydrolysis was successful at reducing EC concentration in wines with low levels of TP and other EC precursors.     

Climate and Bordeaux wine quality: identifying the key factors that differentiate vintages based on consensus rankings

The climate of Bordeaux, France, was examined to determine if climatic factors can distinguish between consensus vintage rankings, developed using eight ratings sources, of red and sweet white wines from 1961 to 2009. Climate variables were computed for the growing season and average plant phenological stages and were compared between the 10 highest and lowest ranked vintages. Good vintages exhibited higher heat accumulation during the growing season and a general lack of rainfall, particularly during veraison. Most climate factors were consistent for both red and sweet white wines. Mean maximum temperature during the growing season was an important discriminator between good and poor vintages for both reds and whites, although sweet white wines were also affected by growing season precipitation and temperatures during the vine's dormant period. In general, consensus vintage quality is consistent between reds and whites (Spearman's ρ?=?0.66, p?相似文献   

Effects of fining agents on trans-resveratrol concentration in wine

Resveratrol has been identified as a wine component related to moderate wine consumption and a reduction in serum cholesterol levels. Processes such as wine fining that result in loss of resveratrol during winemaking are therefore of interest, and led to these present studies. A number of agents were compared and were found to lower resveratrol levels in all wines to some extent. Results from two studies (1996 and 1997) are reported. The standard addition method was used in combination with High Pressure Liquid Chromatography to calculate resveratrol levels. In Study 1 (1996), recommended maximum levels of all fining agents (Level 3), bentonite, egg white, gelatin + kieselsol and polyvinylpolypyrrolidone (PVPP), lowered resveratrol levels significantly compared to controls (Level 0). Nevertheless, addition of fining agents at Level 0 resulted in resveratrol levels that were significantly higher than those at Level 3, but resveratrol levels in wine from Level 0 were not significantly different from Level 1. In Study 2 (1997), carbon + egg white, and gelatin + kieselsol fining was studied, and their effects differed according to grape variety. Least removal of resveratrol by carbon fining occurred in wine from Cabernet Sauvignon (Vitis vinifera) whereas most removal occurred in wines from Cynthiana (Vitis aestivalis) and Noble (Vitis rotundifolia). Resveratrol levels of control wine were significantly higher than resveratrol levels of wine treated with recommended maximum addition of fining agent in all varieties. Taken overall, any addition of any fining agent lowered resveratrol levels in all wines to some extent, but complex interactions between fining agent and wine variety resulted in different regression trends. While recognising the constraints set by our particular data that could reflect unique circumstances, we are nevertheless able to infer from these trends that low levels of fining agents can be used without statistically significant loss of resveratrol.     

Off-flavours in wines through indirect transfer of volatile organic compounds (VOCs) from coatings

This paper assesses the impact of volatile organic compounds (VOCs) from the drying of coatings on the sensory characters of corks and wines. According to Italian National Standard Method 11021:2002, a small-scale chamber was used (1) to expose wines to the drying of coatings with both low and high VOCs, and (2) to expose corks to the same coatings. After exposure to the coatings, the corks were then placed in direct contact with wine. Different styles of white, red and rosé wines were tested. In both directly exposed wines and in wines after contact with the exposed cork, the taste and smell off-flavour perception and intensity were assessed by a panel of eight experienced wine tasters using a five-point numerical scale according to International Organization for Standardization (ISO) standard methods. The results showed that the sensory characters of wines, especially taste, were influenced by the VOC content of the coatings. The taste off-flavour perception was found to be higher than the smell in wines exposed to coatings with either high or low VOCs contents. Analysis of variance (ANOVA) and Duncan analysis prove that: (1) panellist's answers were significantly different, (2) it was difficult to differentiate the off-flavour perception on the high-level scale, and (3) the panellist off-flavour perceptions versus wine style discriminated the wines into two groups (red and white/rosé). For all the wine styles, Pearson's test showed no significant correlation between off-flavour perception levels and the main chemical characters of the wines. For the wines that were in direct contact with the exposed corks, the panellists detect the off-flavours according to the levels of VOCs in the coating and wine styles and they assessed the highest levels of alteration were to the taste.     

Measurement of the colour of white and rosé wines in visual tasting conditions

We have designed a colour measurement method that reproduces the conditions found during visual colour assessment of wines. In particular the illumination, background, wine sampler and the relative positions of sampler, illumination and observer have been controlled. Using this method, the colour of 33 white wines and 33 rosé wines was measured and expressed in terms of the CIELAB colour coordinates. Colour of wine samples was also assessed by expert wine tasters. White wines were classified into three colour categories: Straw-yellow, Yellow-gold and Yellow-green. Rosé wines were classified into four colour categories: Raspberry, Strawberry, Redcurrant and Salmon. The performance of CIELAB colour coordinates to reproduce the observed classification has been established using discriminant analysis. The central region of the wine surface gives the best results having lower measurement errors and higher classification performance. For white wines a*, b* and h _ab are the relevant colour coordinates scoring 84.8% of correctly classified samples. In rosé wines L*, a* and h _ab in the central region correctly classify 100% of the samples. This study demonstrates that colour of white and rosé wines can be measured in the same conditions that are found in the visual colour assessment when precise information on the visual colour appearance of wines is required.