Occurrence of ochratoxin A before bottling in DOC and DOCG wines produced in Piedmont (Northern Italy)

Italy is one of the countries where ochratoxin A (OTA) contamination in wine poses more risks. Previous surveys on the occurrence of OTA have poorly considered north Italian wines. In this study, 1206 red and white DOC and DOCG wines produced in Piedmont (Northern Italy) from 2000 to 2007 have been analyzed for OTA level (0.116 μg l⁻¹) and incidence (68.0%). The monitoring – the widest per number of Italian wine samples considered – analyzed the OTA contamination of wines in tanks just before bottling. OTA level and incidence were significantly higher in red (0.121 μg l⁻¹, 69.4%) than in white (0.086 μg l⁻¹, 61.3%) wines. Among the white wines, the incidence was significantly lower in the Moscato wines (7.3%), due to the different wine processing. The differences in the mean OTA level in the three main grapevine varieties of red wines could be related to the harvest period. Among the Nebbiolo appellations, a reduction of the OTA level was noticed with increasing the wood aging period. A significant effect of the vintage year was also registered.     

The development of an activated carbon from cherry stones and its use in the removal of ochratoxin A from red wine

The ability of activated carbon (AC) prepared from cherry stones (CS) by activation with H₃PO₄, ZnCl₂ or KOH to remove ochratoxin A (OTA) from two Italian red wines has been studied. AC was characterized in terms of texture and surface chemistry. OTA was analyzed by reversed-phase high-performance liquid chromatrography, using a fluorescence detector. The content of OTA in the starting wines is 7.38 and 2.36 μg/L. The adsorption of OTA is high only for one AC, which was prepared by KOH activation at 900 °C, using the 3:1 KOH:CS impregnation ratio. It possesses a large apparent surface area (S_BET = 1620 m²/g) and a high volume of large size macropores (1.84 cm³/g). It also contains narrow mesopores and intermediate size and wide micropores. Its content of acidic oxygen surface groups is low, whereas the content of basic groups is high (2.62 meq/g). The treatment of the wines with such an AC results in a decrease of the initial OTA content of more than 50%. However, the changes produced in the total polyphenolic index, color intensity, and hue are small (i.e. ～8%, ～5.5% and ～1.2%, respectively).     

Characterization and suitability of polyphenols-based formulas to replace sulfur dioxide for storage of sparkling white wine

The sparkling wine protection against air is of interest for maintaining its sensorial profile and it is achieved through the use of antioxidants while disgorging. Sulfur dioxide (SO₂) is commonly added, but its amount should be limited due to human health problems. The suitability of three polyphenols-based commercial formulas containing plant gallic and ellagic acids extracted from grape (Vitis vinifera L.) (AO1), plant ellagic acid and gum arabic (AO2), and plant gallic, ellagic acids and Saccharomyces cerevisiae cell-wall fractions (AO3) was evaluated after 7 months storage (at 15 °C and 25 °C) of disgorged sparkling white wine. The phenolic composition of these formulas was investigated through spectrophotometric measurements. Moreover, the phenols were characterized and quantified by HPLC-MS analyses. The sotolon concentration and the absorbance values at 420 nm were determined in wines. The HPLC-MS analysis showed that the formula AO1 mainly contained gallotannins, ellagic tannins and flavan-3-ols, while AO2 had high levels of flavan-3-ols and gallotannins. Flavan-3-ols were the only phenols found in AO3. The addition of these formulas increased the yellow hue. Sotolon was higher than the perception threshold in the samples with AO2 and at trace amount in the samples with both AO1 and AO3 only stored at 25 °C. The tested antioxidant formulas seemed to be less effective of SO₂ for the storage of sparkling white wine. However, the investigation of phenolics in antioxidant formulas could be helpful for the proper choice of a potential substitute of SO₂ due to increase interest in sulfur-free wine production.     

Ochratoxin A levels in Greek retail wines

A three years survey was carried out by the accredited Toxin Analysis Lab of the University of Patras “ELETOX” in order to investigate the level of Ochratoxin A (OTA) in Greek retail wines. Sixty samples of different type of wines (white, rose and red), dry or sweet, from different regions of Greece (western Greece, central Greece and Thessalia) were analyzed by using immunoaffinity column for clean-up purification and HPLC/FLD for detection. From the results, 47 out of 55 samples of dry wines (white, red and rose) and 5 out of 5 samples of sweet wines (white and red) were found to be infected by OTA. The level of infection in 55 samples was below of the EU limit (2 ng mL⁻¹) while in 5 samples was exceeded that limit. More specifically, dry wines from Thessalia were contaminated with OTA ranging from 0.04 to 2.52 ng mL⁻¹ while for samples from central and western Greece the contamination level was below of 0.51 ng mL⁻¹. Finally, the findings of the present work are compared with those given in the literature.     

Evaluation of biogenic amines in wine: Determination by an improved HPLC-PDA method

An improved, simple and sensitive method to quantify the biogenic amines ethanolamine, methylamine, ethylamine, isoamylamine and the usually investigated β-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, spermine has been developed and validated in red and white wines. The analytes were derivatised with dansyl chloride and separated by HPLC coupled with PDA detector. The calibration curves showed good linearity (r > 0.9990) and biogenic amines recovery varied from 72 to 97%. The repeatability ranged from 1 to 8% for red wine and from 1 to 5% for white wine. The detection and quantification limits were from 0.02 to 0.10 mg/L and from 0.08 to 0.30 mg/L, respectively. The method was successfully applied to detect and quantify biogenic amines in Italian red and white wines from Abruzzo Region. The proposed method is suitable for simultaneous detection and for accurate and precise quantification of eleven biogenic amines in wines.     

trans-Resveratrol in wines from the major Greek red and white grape varieties

Stilbenes, in particular trans-resveratrol and its glucoside, are widely reported to be beneficial to health, having been shown to posses anti-oxidative, anti-carcinogenic, and anti-tumour properties. trans-Resveratrol (trans-3,5,40-trihydroxystilbene), a phenolic compound present in grapes, wines, and peanuts, has been reported to have health benefits including anti-carcinogenic effects and protection against cardiovascular diseases. A direct injection-HPLC method, based on existing methods slightly modified was used to analyze wines from the major red and white Greek grape varieties (Vitis vinifera L.) for their trans-resveratrol content. Red wines were found to have higher concentrations of trans-resveratrol (0.352–1.99 mg/l) compared with those produced from white varieties (0.005–0.57 mg/l). It was also interesting that red wines produced from the native Greek varieties, Kotsifali, Mandilaria and Agiorgitico, appeared to contain important amounts of trans-resveratrol.     

Aflatoxin M1 contamination in dairy products marketed in Iran during winter and summer

In the present study, 298 dairy product samples consisting of pasteurized milk (91 samples), yoghurt (68 samples), white cheese (72 samples), butter (31 samples) and ice cream (36 samples) collected from popular markets in four large Iranian cities were examined for aflatoxin M₁ (AFM₁) by thin layer chromatography (TLC) technique. The toxin was detected in 66 (72.5%) pasteurized milk samples (mean: 0.052 μg/l; range: 0.013–0.250 μg/l), 45 (66.1%) yoghurt samples (mean: 0.032 μg/kg; range: 0.015–0.119 μg/kg), 59 (81.9%) white cheese samples (mean: 0.297 μg/kg; range: 0.030–1.200 μg/kg), 8 (25.8%) butter samples (mean: 0.005 μg/kg; range: 0.013–0.026 μg/kg) and 25 (69.4%) ice cream samples (mean: 0.041 μg/kg; range: 0.015–0.132 μg/kg). The concentration of AFM₁ in 36.2%, 20.6%, 30.5%, 9.6% and 27.7% of pasteurized milk, yoghurt, white cheese, butter and ice cream samples, respectively, were higher than Iranian national standard limits. Levels of AFM₁ in samples of pasteurized milk, yoghurt, butter and ice cream collected in winter were significantly higher (P < 0.05) than those collected in summer. In the case of white cheese, level of AFM₁ was higher in winter than in summer, but the difference was not statistically significant (P > 0.05). The results indicated that the contamination of the dairy products in such a level could be a serious public health problem at the moment.     

Occurrence of aflatoxin M1 in raw milk in South Korea using an immunoaffinity column and liquid chromatography

The level of aflatoxin M₁ (AFM₁) contamination in raw milk produced in South Korea was investigated using immunoaffinity column chromatography and high performance liquid chromatography with fluorescence detector. A total of 100 raw milk samples were collected from 100 cattle ranches located in three different provinces of South Korea. Forty eight out of 100 raw milk samples contained AFM₁ at low level (0.002–0.08 μg/L) with mean value of 0.026 μg/L. Among the AFM₁ contaminated samples, 29 raw milk samples contained only traceable amount of AFM₁ below the limit of LOQ, 0.02 μg/L. None of samples exceeded the maximum level (0.5 μg/L) of Korean regulation for AFM₁ in milk. The limit of detection was 0.002 μg/L. The result of recovery test with 0.5 μg/L AFM₁ in raw milk sample was 96.3% (SD 3.6, n = 5). This is the first pioneering study to investigate the level of AFM₁ in raw milk used in dairy industries in South Korea.     

Mass spectrometry detection of egg proteins in red wines treated with egg white

The need of label declaration for egg proteins is temporarily suspended when they are used as a processing aid in winemaking, because of a lack of scientific data concerning their actual permanence as residual proteins in fined wines.The possibility to detect residual egg proteins in red wines treated with a commercial egg white preparation was studied. By using an immunochemical method residual egg proteins were detected in the experimental red wines only for doses of fining agent of 50 g/hL or higher, whereas no residual proteins were detected by this system in a commercial red wine.A simple method based on the recovery and identification of the wine fining proteins by liquid chromatography coupled with tandem MS (LC-MS/MS) in a gel-free approach was developed. This allowed the detection of egg proteins in red wines fined down to 5 g/hL of commercial egg white preparation and also in the commercial red wine. These results indicate that the analytical approach here suggested is superior to the immunochemical methods in detecting egg proteins in wines. Therefore hypersensitivity reactions after consumption of wines treated with egg proteins can be a real risk for egg-allergic people.     

Evaluation of volatile compound and food additive contents in blackberry wine

In addition to the biologically nutritious components present in wine, there can be substances that are harmful to human health. For this reason, the purpose of this study was to evaluate the contents of volatile compounds and food additives in blackberry wine samples produced from conventionally and organically grown blackberries and compare their concentrations with the maximum acceptable levels in wines for the first time. Volatile compounds were analyzed in 15 blackberry wines using a GC-FID method, while the contents of food additives were determined using a newly developed HPLC method. Both methods were validated for their linearity, sensitivity, repeatability, and intermediate precision. The major volatile compound in blackberry wine samples was ethanol (7.11–15.33%). The second most prevalent volatile compound found in all blackberry wine samples was methanol (174.2–641.4 mg/L), which is highly toxic. The amount of ethyl acetate in the investigated samples ranged from 53.8 to 188.4 mg/L, while propan-1-ol was found in three of the organic samples. Although isoamyl alcohol was found in all samples, the measured values ranged from 56.7 to 226.9 mg/L. The obtained results demonstrated that the concentrations of benzoic acid in the analyzed blackberry wines varied from 4.36 to 18.55 mg/L. The presence of sorbic acid has was detected in seven samples, and the values were in the range of 1.43–54.48 mg/L. Salicylic acid is a natural component of blackberry fruit, and the contents of this phytochemical in the studied wines were between 1.99 and 13.55 mg/L. The saccharin concentrations were detected in three samples, and the highest value was 31.51 mg/L. The concentrations of amyl alcohol, acesulfame, aspartame and caffeine were found to be below the quantitation limits of the method in the investigated blackberry wines. Furthermore, the obtained data provide evidence that the contents of methanol in blackberry wines were above the permissible limits, except for four conventional blackberry wines. Thus, the concentrations of analyzed volatile substances measured in blackberry wines necessitate more extended investigations of these volatile compounds in this popular fruit wine.     

Aflatoxigenic fungi and aflatoxins occurrence in sultanas and dried figs commercialized in Brazil

The presence of aflatoxins, Aspergillus flavus and Aspergillus parasiticus in dried fruits was investigated. A total of 62 dried fruit samples were analyzed (24 black sultanas, 19 white sultanas and 19 dried figs). A total of 10 A. flavus isolates were found, nine in one white sultana sample (corresponding to 18% infection) and one isolate in dried figs (2%), and all of them were aflatoxin B₁ and B₂ producers. A. parasiticus was not found. Aflatoxins were detected in 3 of 19 (16%) white sultana samples analyzed and, the limits were not higher than 2.0 μg/kg. In dried figs 11 of 19 (58%) samples were contaminated with aflatoxins and, with exception of one sample that was contaminated with 1500 μg/kg of B₁ aflatoxin, the others had less than 2.0 μg/kg. Neither aflatoxigenic or aflatoxins contaminated black sultanas.     

Balsamic vinegar from Modena: An easy and effective approach to reduce Listeria monocytogenes from lettuce

The microbiological safety of fresh produce is a significant concern of consumers and industry. After applying at an inoculated level (6–7 log CFU/mL) of Listeria monocytogenes on Iceberg lettuce, the antilisterial properties of balsamic vinegar from Modena, white wine vinegar and acetic acid solutions were investigated.Different proportions of the vinegars, acetic acid (58.7 g/L), and deionized water were evaluated to determine the role of those solutions at the stage of washing Iceberg lettuce to remove L. monocytogenes. The maximum observed log reduction of L. monocytogenes was 2.15 ± 0.04 for balsamic vinegar (50% (v/v)), 1.18 ± 0.06 for white wine vinegar ((50% (v/v)) and 1.13 ± 0.06 for acetic acid ((50% (v/v)). Washing with water only reduces 0.05 ± 0.04 log CFU/mL of L. monocytogenes numbers.Listeria reductions observed for balsamic vinegar are similar or higher than those of chlorine-based sanitizers evaluated in other studies with lettuce. In the case of balsamic vinegar solutions, Listeria inhibition followed a linear reduction according to the model: Log (N/N₀) = −4.09 × balsamic vinegar proportion % (v/v) − 0.13; R² = 0.95. Balsamic vinegar washings may be a promising method for reducing other foodborne pathogens present in produce or other foods, at home and retail environments.     

Organic wine safety: UPLC-FLD determination of Ochratoxin A in Southern Italy wines from organic farming and winemaking

A fast reversed-phase UPLC method was utilized for Ochratoxin A (OTA) determination in 55 different wine samples (red and white) produced in Southern Italy, during two vintages. All the samples came from vineyards in which the plants were subjected to organic farming and were produced according to an organic winemaking, following strict rules on processing aids. Analytical methods included the clean-up purification by using commercial immunoaffinity columns and an Acquity UPLC^® system equipped with a fluorescent detector; the sensitivity of the analytical method was 0.01 ng mL⁻¹. OTA was detected in all wine samples analyzed and the levels were always below the maximum tolerable EU limit (2 ng mL⁻¹); the red wine samples proved to be more contaminated than the white ones.The occurrence incidence of OTA in wines produced according organic farming and winemaking was comparable with that of commercial wines conventionally produced and wines obtained from organic farming only. The results of this study indicate a low risk of exposure to OTA by consumption of these wines.     

Natural occurrence of aflatoxin B1 and aflatoxin M1 in “halva” and its ingredients

A total 431 samples including halva (56), pistachio (71), almond (63), semolina (69), cardamom (34), raisins (46), halva puri (39) and wheat powder (53) were analyzed using HPLC equipped with florescence detector. The results have shown that 32 (57%) samples of halva, 45 (63%) pistachio, 43 (68%) almond, 46 (67%) semolina, 21 (62%) cardamom, 19 (41%) raisins, 21 (54%) halva puri and 22 (42%) of wheat powder samples were found contaminated with AFB₁, and 11 (20%), 23 (32%), 34 (54%), 12 (17%), 11 (32%), 7 (15%), 9 (23%) and 11 (21%) samples, respectively were above the European Union permissible limit (2 μg/kg). The results have shown that 20 (59%) samples of halva that contained milk were found contaminated with AFM₁ and 3 (9%) samples were found above the recommended limit for AFM₁ i.e. 0.05 μg/kg. Limit of detection (LOD) and Limit of quantification (LOQ) for AFB₁ and AFM₁ were 0.04 μg/kg, 0.12 μg/kg, and 0.004 μg/L, 0.012 μg/L, respectively.     

Ethyl carbamate in alcoholic beverages from China: Levels,dietary intake,and risk assessment

A national survey of ethyl carbamate (EC) in alcoholic beverages from the fourth and fifth Chinese total diet study (TDS) performed in 2007 and 2009 was conducted for the first time. Alcoholic beverages samples were collected from 16 provinces representing the average dietary patterns of various provinces of China and covering about 60% of the total Chinese population. The results showed that the average EC level in alcoholic beverages (19.8 μg/kg) in the fifth TDS was higher than that of the fourth TDS (8.5 μg/kg). The dietary intake of EC from the Chinese population was estimated to be 8.27 ng/kg bw per day for average population and 45.67 ng/kg bw per day for high consumers (the 97.5th percentile) in the fifth TDS. The average and high-end estimated daily intakes of EC for the alcoholic beverages were both lower than estimated daily intake (EDI) value (80 ng/kg bw per day) suggested by JECFA, indicating low health risk of EC dietary exposure among Chinese adults at present.The Chinese rice wines, as a kind of traditional fermented alcoholic beverages in China, has a high level of EC and an obvious consumption regional disparity, thus the health risk of EC in Chinese rice wines should be of concern. To estimate the daily intake of EC from Chinese rice wines consumed in China, 890 Chinese rice wines samples including 468 commercial wines and 422 base wines were collected from various regions. The distribution of EC varied significantly among 468 commercial wines, ranging from 6.3 to 775.8 μg/L (mean: 232.9 μg/L). Based on the intake data for Chinese rice wines from the food consumption survey, the daily intake of EC was estimated to be 290.6 ng/kg bw per day for average consumers and 1848.4 ng/kg bw per day for high consumers (the 97.5th percentile). In this study, the estimated daily intake of EC for Chinese rice wines in China was far higher than EDI value suggested by JECFA indicating that Chinese rice wines were the main exposure origin of EC in alcoholic beverages. Health risk assessment of EC using a margin of exposure (MOE) approach recommended by the European Food Safety Authority (EFSA) suggested unlikely health concern with respect to current dietary intake of EC for alcoholic beverages in China. However, a relatively high health risk of EC dietary exposure in Chinese rice wines was observed in some provinces. Therefore, some adapted strategies should be developed and used in industrial scale to control the level of EC for Chinese rice wines.     

Determination of Aflatoxin B1 levels in powdered red pepper

Insufficient hygiene conditions during drying, transport and storage stages in the production of red pepper could cause microbiological and mycological growth which could result in the formation of mycotoxins. This study was designed to assess the aflatoxin B₁ levels in 100 samples of powdered red pepper randomly obtained from markets in Istanbul using microtitre plate Enzyme Linked Immunosorbent Assay (ELISA). Aflatoxin B₁ levels were below the minimum detection limit (0.025 μg/kg) in 32 samples, between 0.025 and 5 μg/kg in 50 samples, whilst 18 samples had unacceptable contamination levels higher than the maximum tolerable limit (5 μg/kg), according to the Turkish Food Codex and the European Commission.     

Antimicrobial phenolic extracts able to inhibit lactic acid bacteria growth and wine malolactic fermentation

The purpose of this study was to determine whether phenolic extracts with antimicrobial activity may be considered as an alternative to the use of sulfur dioxide (SO₂) for controlling malolactic fermentation (MLF) in winemaking. Inhibition of the growth of six enological strains (Lactobacillus hilgardii CIAL-49, Lactobacillus casei CIAL-52, Lactobacillus plantarum CIAL-92, Pediococcus pentosaceus CIAL-85, Oenococcus oeni CIAL-91 and O. oeni CIAL-96) by phenolic extracts (n = 54) from different origins (spices, flowers, leaves, fruits, legumes, seeds, skins, agricultural by-products and others) was evaluated, being the survival parameter IC₅₀ calculated. A total of 24 extracts were found to significantly inhibit the growth of at least two of the LAB strains studied. Some of these extracts were also active against two acetic acid bacteria (Acetobacter aceti CIAL-106 and Gluconobacter oxydans CIAL-107). Transmission electron microscopy of the bacteria cells after incubation with the phenolic extract confirmed damage of the integrity of the cell membrane. Finally, to test the technological applicability of the extracts, the eucalyptus extract was added (2 g/L) to an industrially elaborated red wine, and the progress of the MLF was evaluated by means of residual content of malic acid. Addition of the extract significantly delayed the progress of both inoculated and spontaneous MLF, in comparison to the control wine (no antimicrobial agent added), although not as effective as K₂S₂O₅ (30 mg/L). These results demonstrated the potential applicability of phenolic extracts as antimicrobial agents in winemaking.     

HPLC determination for prostaglandins from seaweed Gracilaria gigas

Seaweed (Gracilaria gigas) is an edible red alga and occasionally induces food poisoning cases. Prostaglandin E₂ (PGE₂) has been reported to be possible causative agent. In this study, a simple, sensitive, rapid and accurate HPLC method was developed for quantifying prostaglandins in seaweed. The mobile phase was gradient acetonitrile (35–60%) and 0.017 M phosphoric acid at flow rate of 1 mL/min within 30 min. The standard curves of prostaglandins were extremely linear (R² > 0.999) with low correlation coefficients (less than 4.7) in the range of 5–50 μg/mL. To obtain maximum prostaglandins amount, the optimal ratio of seaweed (wet weight) to arachidonic acid was 10 g:2 mg and oxygen was needed in reaction.     

Investigation of different sample pre-treatment routes for liquid chromatography–tandem mass spectrometry detection of caseins and ovalbumin in fortified red wine

Different sample treatment protocols for the liquid chromatography–electrospray-tandem mass spectrometry (LC–ESI-MS/MS) analysis of potential residuals of ovalbumin and caseins added to red wines were developed. In particular, attention was paid to the simultaneous detection and quantitation of fining agent residues, i.e. ovalbumin, α- and β-casein, in wine samples. The different sample treatment methods were compared in terms of protein recovery. The use of denaturing agents combined with size exclusion concentration and purification allowed to obtain a reproducible (RDS < 20%) analytical protocol with good recoveries (73(±2) – 109(±4)% range) for digested proteins from 12.5 mL of wine sample. Matrix-matched calibration from LC–ESI-MS/MS analysis indicated that the devised method allowed detection of target peptides in the 0.01–0.8 μg/mL range. Finally, method applicability and selectivity was demonstrated by using fining agents commonly exploited in winery industry and by analyzing 20 commercial red wine samples.     

Antimicrobial activity of açaí against Listeria innocua

A study was carried out to evaluate antimicrobial activity of açaí against Listeria innocua, as a non-pathogenic surrogate for Listeria monocytogenes, at different temperatures (37, 22, and 10 °C), from a kinetic point of view. With this aim, first the Minimum Inhibitory Concentration (MIC) under optimal growth conditions was established (37 °C), and then the effect of 3 non-inhibitory doses (3, 5, and 7 g/L) at 37, 22, and 10 °C was evaluated on the basis of the kinetic parameters lag time (λ) and maximum specific growth rate (μ_max). The Total Phenolic Content (TPC) of the samples tested as a function of açaí concentration was also determined. Results obtained showed that the MIC was 10 g/L, containing 2154.91 ± 126.10 mg of Gallic Acid Equivalents (GAE)/L. At non-inhibitory doses, regardless of temperature, the higher the açaí concentration, the higher the value of λ, and the effect of a variation in açaí concentration on λ was greater at high temperatures. Therefore, the addition of non-inhibitory doses of açaí could provide a means of controlling the growth of L. monocytogenes if a cold chain failure occurs, or if any other reason compromises the microbiological safety of minimally processed foods. Consequently, the present study is important both for the science community and for the food industry because it provides the first mathematical characterization of açaí antimicrobial activity and reveals its potential use to control the concentration and growth of pathogenic bacteria in foods free of non-synthetic additives.