Survey of mycobiota,black <Emphasis Type="Italic">Aspergillus</Emphasis> and ochratoxin A occurrence on Brazilian wine grapes

The southern state of Brazil is responsible for 90 % of the wine produced in the country; however, the mycobiota and the occurrence of ochratoxin A (OTA) on wine grapes produced in this region has never been fully characterized. To evaluate the fungal and OTA contamination in wine grapes of two varieties cultivated in southern Brazil, a survey was conducted in three regions with slightly different climates. From each region, samples were obtained at early ripeness and at harvest stage. Eight genera were isolated; Alternaria and Trichoderma were the most prevalent. Within the Aspergillus genus, the section Nigri was predominant. One uniseriate black Aspergillus was able to produce OTA under the conditions tested but no detectable levels of OTA were found in the grape samples. The low overall incidence of black Aspergillus and the absence of OTA on the grapes may be explained by the meteorological conditions at the analyzed regions, and characterizes a high quality of this product regarding mycotoxigenic contamination. This is the first study to fully describe the mycological biota of two wine grape varieties produced at three different regions of Rio Grande do Sul state.     

Aspergillus niger and Aspergillus carbonarius in Corinth Raisin and Wine-Producing Vineyards in Greece: Population Composition, Ochratoxin A Production and Chemical Control

Vineyard surveys of Corinth raisin cultivar carried out in the Peloponnese region of Greece during 2002 and of wine‐producing grape cultivars (Cabernet Sauvignon and Grenache Rouge) on the island of Rhodes, Greece, during 2003, demonstrated the occurrence of various Aspergillus spp. in berries of bunches at harvest. Aspergillus niger and A. carbonarius were predominantly isolated from sampled berries. Although the prevailing Aspergillus spp. isolates belonged mainly to A. niger aggregate, isolates of A. carbonarius were by far the most efficient Ochratoxin A (OTA) producers as revealed by the enzyme‐linked immunosorbent assay test. This study provides the first evidence concerning the composition of Aspergillus populations in raisin and wine‐producing vineyards and offers convincing data for their ability to produce various levels of OTA in Corinth raisins and wine‐producing grapes in Greece. Furthermore, it demonstrates that chemical applications with the fungicide Switch, especially under low to intermediate Aspergillus infection of vineyards, could both significantly reduce the occurrence of OTA‐producing Aspergillus spp. and restrict sour rot severity. In contrast, vineyard applications with the fungicides Carbendazim or Chorus were ineffective in controlling the fungus in Corinth raisin cultivar.     

Isolation and identification of ochratoxin A-producing Aspergillus section Nigri strains from California raisins

Aims: To determine incidence and levels of ochratoxin A (OTA) in California raisins and to isolate and characterize OTA‐producing fungi from California raisin vineyard populations. Methods and Results: Forty raisin clusters sampled from four California vineyards in the San Joaquin Valley were analysed for OTA content using immunoaffinity and HPLC methods. OTA was detected in 93% of the samples, at levels from 0·06 to 11·4 ng g^?1. From these raisin samples, a total of 400 strains of Aspergillus were isolated and analysed for OTA production. Twelve isolates (3%), from five raisin samples, produced OTA. These isolates were identified as Aspergillus carbonarius, based on morphological characteristics and multilocus sequence analysis. Levels of OTA produced by these isolates on raisin agar ranged from 0·9 to 15 μg g^?1. Conclusions: OTA is a common contaminant of raisin vineyards, but average levels are much lower than EU regulatory limits for dried fruit. The primary species responsible for OTA contamination in California raisins is A. carbonarius. Significance and Impact of the Study: This study illustrates that low‐level OTA contamination of raisins occurs in California and that ecological studies of A. carbonarius within the Aspergillus section Nigri population on raisins are warranted to monitor ochratoxigenic potential of the crop.     

Identification of Ochratoxigenic Aspergillus Section Nigri Isolated from Grapes by ITS‐5.8S rDNA Sequencing Analysis and In Silico RFLP

To characterize Aspergillus section Nigri strains involved in the ochratoxin A (OTA) contamination of Tunisian wine and table grapes, a total of 33 strains were analysed. A molecular characterization of the isolates was performed by the amplification of internal transcribed spacer (ITS1‐5.8S rDNA‐ITS2) region combined with amplicon sequencing. Analysis of similarity between the obtained sequences and those deposited in the GenBank database was performed. Twelve strains were confirmed to belong to the Aspergillus carbonarius species. Strains belonging to the Aspergillus niger aggregate group were classified by in silico RFLP assay into two patterns N and T, corresponding to A. niger and Aspergillus tubingensis. Among the 21 OTA producing isolates analysed, 13 showed the T‐type pattern and 8 showed the N‐type pattern. The presented method showed to be a reliable alternative to the classic RFLP method. Our findings unambiguously revealed that multiple aspergilli species isolated from wine and table grape in Tunisia are able to produce OTA.     

Occurrence of Ochratoxin A-Producing Fungi in Commercial Corn Kernels in Argentina

Potentially ochratoxigenic Aspergillus and Penicillium species were identified and the natural occurrence of ochratoxin A (OTA) in corn kernels was evaluated. Likewise, the capacity to produce OTA by Aspergillus section Nigri and Circumdati was investigated. A total of 50 corn samples for human consumption was collected in the south of Córdoba Province. The surface-disinfected method for mycobiota determination was used. The OTA detection was performed by HPLC. OTA production was tested in strains belonging to section Nigri and Circumdati. Statistical analysis demonstrated that the specie A. flavus was isolated in higher frequency (p<0.01) from corn kernels in DRBC and DG18 media. The percentage of corn kernels contaminated by A. niger var. niger was similar in DRBC and DG18 media. The frequency of grains contaminated by A. flavus and A. niger var. awamori was higher than A. niger var. niger and A. japonicus var. japonicus (p<0.01) in DG18 media. The other potentially ochratoxigenic species, A. ochraceus, was isolated between 5% and 10% of the corn kernels in DG18 and DRBC media, respectively. The OTA producing species P. verrucosum was not isolated. All samples of corn were OTA negative (<1 ng g⁻¹). Thirty strains (25%) of the black Aspergillus were OTA producers. From four strains of A. ochraceus isolated, only one produced OTA. Due to the storage variable conditions could not be adequate in this substrate, the presence of ochratoxigenic strains of section Nigri and OTA needs to be evaluated for a longer time to establish the toxicological risk for human beings. The contamination of stored corn kernels with A. flavus and Aspergillus section Nigri was significant.     

Growth and ochratoxin A production by Aspergillus carbonarius at different pHs and grape maturation stages

Aims: The objective of this work was to study the effect of some factors, linked to grape composition during ripeness process, on the growth and ochratoxin A (OTA) production of Aspergillus carbonarius isolated from grapes. Methods and Results: Aspergillus carbonarius isolates were tested (i) in vitro, in Czapek yeast autolysate agar (CYA) at different pHs (2·5–4·5) and incubation times (2–6 days), and (ii) in situ, in fresh grapes collected at different maturation stages. Aspergillus carbonarius was able to grow with the same intensity at the different maturation stages and pH levels tested. In general, a similar trend of OTA production by A. carbonarius in response to acidity in media and in grape was observed. Low pH level seemed optimal for maximum OTA production. Conclusions: Aspergillus carbonarius strains can strongly grow and produce OTA on grape from the early stages of maturation. Extrinsic environmental conditions at the harvest period and skin thickness are, probably, the mains factors contributing to OTA contamination of grapes at the end of maturation. Significance and Impact of the Study: The results lead to a better understanding of the critical point during grape maturation for the growth of ochratoxigenic fungi and the toxin production.     

河西走廊不同产地‘赤霞珠’酿酒葡萄果实品质评价

为了确定河西走廊地区‘赤霞珠’酿酒葡萄核心品质指标,建立‘赤霞珠’酿酒葡萄品质综合评价模型。从张掖、武威、嘉峪关3个酿酒葡萄主产市的代表性果园采集6份‘赤霞珠’葡萄样品进行品质测定,通过主成分分析和聚类分析法确定‘赤霞珠’葡萄核心品质指标,运用层次分析法确定指标权重并建立‘赤霞珠’葡萄品质综合评价模型。结果表明:(1)不同产地‘赤霞珠’酿酒葡萄品质指标存在明显差异性,张掖市国风葡萄酒庄园的‘赤霞珠’葡萄果糖、蔗糖、草酸、柠檬酸含量均高于其他地区,且可溶性固形物、可溶性糖、总酚、苹果酸含量在各产地中也均保持在最高水平。(2)相关性分析发现,葡萄果实葡萄糖含量与可溶性固形物含量、果糖与可溶性糖含量之间呈极显著正相关,固酸比和糖酸比均与可滴定酸含量呈极显著负相关关系。(3)综合主成分分析、聚类分析和相关性分析结果,确定维生素C(Vc)、单宁、果糖和固酸比是‘赤霞珠’葡萄核心品质指标,应用层次分析法建立了‘赤霞珠’葡萄品质综合评价模型为Y=0.0960×Vc含量+0.1611×单宁含量+0.2771×果糖含量+0.4568×固酸比(各指标含量均经过标准化处理)。研究发现,河西走廊地区‘赤霞珠’葡萄果实品质最佳产地是张掖市,果实Vc、单宁、果糖和固酸比是‘赤霞珠’葡萄的核心品质指标,以其建立的评价模型可用于‘赤霞珠’葡萄品质的综合评价。     

2-Methoxy-3-isobutylpyrazine in grape berries and its dependence on genotype

2-Methoxy-3-isobutylpyrazine (MIBP) contributes a bell pepper aroma to many grape cultivars and has a reported aroma threshold of ～2 ng L(-1) in water. The purpose of this study was twofold: (1) develop a procedure using headspace solid phase micro-extraction combined with GC-MS in the selected ion monitoring mode (HS-SPME-GC-MS-SIM) for analysis of MIBP in grape berries, and (2) determine the location of MIBP biosynthesis in grapevines by approach grafting clusters of Vitis vinifera L. cvs Cabernet Sauvignon and Muscat blanc onto each other. The soluble solids and pH of the grape juice/homogenate matrix from different grape berry developmental stages influenced the method precision; therefore, quantification via the method of standard addition was used. Using our developed method, the limit of detection (LOD) and limit of quantitation (LOQ) of MIBP were 0.1 ng L(-1) and 2 ng L(-1), respectively, measured in a model juice and non-MIBP containing Chardonnay juice. Spiked recoveries averaged between 91% and 112% in Cabernet Sauvignon and Pinot noir homogenates and the overall relative standard deviation was less than 10%. The method was used to analyze MIBP in 29 grape cultivars and in fruit from clusters grafted to Cabernet Sauvignon or Muscat vines. Quantifiable levels were found only in Cabernet franc, Cabernet Sauvignon, Merlot, Sauvignon blanc and Semillon, providing information on the genetic connection for the occurrence of MIBP in grapes. No MIBP was detected in the berries of Muscat blanc clusters grafted onto Cabernet Sauvignon vines when sampled at fruit maturity. MIBP was detected in all berries of Cabernet Sauvignon regardless the graft configuration. The data indicate that MIBP or its precursors originate in the berry and its formation depends upon grape genotype.     

Mycotoxigenic fungi in peanuts from different geographic regions of Egypt

To understand the importance of mycotoxigenic fungi in Egyptian peanuts, samples from five regions (Alexandria, El-Beheira, El-Sharqiya, El-Daqahelaya in northern Egypt and Asyut, southern Egypt) in two seasons (2007, 2008) were collected. Aspergillus was consistently the most frequent genus in seeds and in-shell peanuts and was the dominant mycotoxigenic component of the mycobiota. There was no direct correlation between the moisture content of the samples and the fungal populations on peanut seeds tested from different regions. The most common species were from Aspergillus section Flavi (4.7-78.3%), Aspergillus section Nigri (9.4–52.6%) and Aspergillus section Circumdati (5.1–30.9%). In the in-shell peanut samples, the lowest populations were recorded in El-Beheira and Asyut (3.7–4.0 log₁₀ CFU g^-1) and the highest in Alexandria and Elsharqiya (4.1–6.0 log₁₀ CFU g^-1). Aspergillus section Flavi and section Nigri were the most dominant, and Aspergillus section Circumdati were only found in samples in 2008. Both qualitative (coconut cream agar) and quantitative analyses (HPLC) were used to analyse the potential mycotoxin production by strains isolated from peanuts. Of a total of 88 Aspergillus section Flavi strains examined, 95% were A. flavus based on production of aflatoxin B₁ on yeast extract sucrose (YES) medium and confirmation using molecular analyses. Of 64 Aspergillus section Circumdati strains only 28% produced ochratoxin A (OTA), and were identified as A. westerdijkiae. No Aspergillus section Nigri strains produced OTA, and they were identified as A. niger (uniseriate). The presence of these toxigenic fungi indicates that there is a potential risk of mycotoxin contamination in Egyptian peanuts and suggests that problems can arise from contamination with both aflatoxins and perhaps also OTA.     

Brief in vitro study on Botrytis cinerea and Aspergillus carbonarius regarding growth and ochratoxin A

Aims: To evaluate the effect of Botrytis cinerea growth on ochratoxin A (OTA) production by Aspergillus carbonarius and degradation. Methods and Results: OTA‐producing A. carbonarius and B. cinerea were grown on grape‐like medium at 20°C for 7 days. Radii of colonies were daily recorded and OTA was analysed. In addition, each B. cinerea isolate was inoculated on grape‐like synthetic nutrient medium (SNM) paired with each A. carbonarius isolate at a distance of 45 mm. Botrytis cinerea isolates were also grown in OTA‐spiked SNM. Growth rates of B. cinerea and A. carbonarius were 20 and 7·5 mm day^?1, respectively. The growth of the colonies of each species stopped when they contacted each other in paired cultures. OTA production by A. carbonarius in the contact area was affected by B. cinerea, but no clear trend was observed. All B. cinerea isolates showed to degrade between 24·2% and 26·7% of OTA from spiked SNM. Conclusions: The ecological advantage of B. cinerea, in terms of growth rate, vs. OTA‐producing Aspergillus in some wine‐growing regions and its ability to degrade OTA may explain the low levels of this toxin in noble wines. Significance and Impact of the Study: At determinate conditions, the presence of B. cinerea in grapes with A. carbonarius may help in reducing OTA accumulation.     

First Report on Mould and Mycotoxin Contamination of Pistachios Sampled in Algeria

Mycotoxin contamination of pistachios represents a serious food safety hazard. The aim of this study was to evaluate fungal contamination and aflatoxin (AF) and ochratoxin A (OTA) occurrence in pistachio sampled in Algeria and to study the mycotoxigenic capacities of the isolates. A total of 31 pistachio samples were collected from retail outlets from different regions of Algeria. The most frequently found fungi were Penicillium spp. (38%), Aspergillus section Nigri (30%) and A. flavus (22%). A total of 56.5% of A. flavus isolates were able to produce AFB₁ and AFB₂. No A. section Nigri uniseriate isolate was OTA producer, whereas OTA production capacity was detected in 33.3% of the A. section Nigri biseriate. At least one of the potentially ochratoxigenic species was found in 64.5% of samples. Despite the high number of pistachio samples containing AFs and OTA-producing isolates, only two samples contained AFs (always below the EU maximum tolerable level) and only one sample showed OTA contamination. This is the first report on the occurrence of toxigenic moulds and mycotoxins in pistachios from Algerian market.     

南亚热带酿酒葡萄品种(系)引种研究

1998～1999年,对8804、真芳德(Zinfandel)、梅尔诺(Merlot Noir)、赤霞珠(Cabernet Sauvignon)等4个欧亚种优良酿酒葡萄品种(系)在我国南亚热带季风气候下的栽培适应性做了初步观察.结果表明,8804具有较强的抗病性和早期丰产性;真芳德早期丰产性突出,但抗真菌病害能力较差;梅尔诺和赤霞珠早期丰产性较差,抗病性一般,能获得较好的成熟度.     

Hydro- and thermotimes for conidial germination kinetics of the ochratoxigenic species Aspergillus carbonarius in vitro,on grape skin and grape flesh

The objective was to compare the ability of spores of Aspergillus carbonarius to germinate in vitro, in situ on grape skin and grape flesh in relation to temperature (15–40 °C) and different relative humidities (100–85 % RH). Spores were inoculated as a spore suspension (10⁶ spores ml⁻¹) onto the surface of white organic grapes and directly onto cut grape flesh. For comparison, spores were spread plate onto a synthetic grape juice medium (SGM) modified to the equivalent water activity (a_w) range of 0.995–0.85. This showed that conidia germinated more rapidly on grape flesh (6 h) followed by that on the SGM medium (9 h) and then grape skin (24 h) under optimal condition of 30–35 °C and 100 % RH. At marginal conditions, such as 15 °C and 85–90 % RH, germination was very slow. The time to 5 % germination was significantly shorter on grape flesh than in vitro on grape medium and slowest on grape skin. This suggests that damaged grapes provide the main method of infection and contamination of grapes and grape products with ochratoxin A (OTA). The combined effect of temperature and RH on conidial germination of A. carbonarius on SGM and grape skin was described by combining Beta and polynomial equations. The equations developed in this work provided a good fit of the biological processes; they could be integrated in a predictive model for infection and OTA prediction in ripening grapes.     

Molecular characterization and toxigenic profile of Aspergillus section Nigri populations isolated from the main grape-growing regions in Argentina

Aims: The objective of this study was to evaluate the biodiversity of Aspergillus section Nigri populations from Argentinean vineyards by morphological, toxigenic and AFLP analysis. Materials and methods: Five hundred and thirty‐eight strains were isolated from grapes during 2006/07 and 2007/08 vintages. The morphological identification and toxigenic profile for all strains isolated were performed. Eighty‐eight strains were selected for characterization at species level by AFLP markers. Cluster analysis showed a clear separation into four main groups: A. carbonarius, A. tubingensis, A. niger‘aggregate’ and Aspergillus‘uniseriate’. A. carbonarius strains constituted a homogeneous group, while a high degree of genetic diversity was found within the A. niger‘aggregate’ and ‘A. uniseriate’ clusters. The A. tubingensis cluster was the most prevalent group and was clearly separated from A. niger‘aggregate’. Ten strains showed 45% homology with A. tubingensis FRR 5720 ex‐type strain and were considered as ‘atypical’ or a closely related species. AFLP results indicate that no genotypical differences can be established between ochratoxigenic and nonochratoxigenic strains. Conclusions: Aspergillus section Nigri populations on grapes were represented mainly by four groups. A. tubingensis species were separated from A. niger‘aggregate’ group and some of their strains produced OTA. Significance and Impact of the Study: This study provides new data on molecular characterization of Aspergillus section Nigri populations in Argentina.     

Susceptibility of cold hardy grapes to Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Diptera: Drosophilidae), known commonly as spotted wing drosophila, is a vinegar fly originating from South‐East Asia and a major pest to many soft‐skinned fruits. Due to the species recent arrival in North America in 2008, many fruit varieties are yet untested for susceptibility to infestation. While previous work has focused on Vitis vinifera, this study aimed to determine grape susceptibility of cold hardy varieties based on hybrids of V. labrusca, V. riparia and V. vinifera. Field sampling was conducted in Southern Wisconsin (USA) vineyards to establish adult and larval abundance and determine whether the number of adults caught in traps correlates with fruit infestation. Host susceptibility was further assessed through no‐choice bioassays of both intact and damaged fruits. The field study found D. suzukii adults present in all varieties, low larval abundance and no correlation between adult abundance and larval presence. Peak adult abundance occurred mid‐season between veraison and harvest, while larval infestation rates were highest near harvest. In laboratory no‐choice tests, significantly more eggs, larvae and adults occurred in damaged than undamaged grapes. In damaged grapes, larvae and adult abundance was comparable between varieties and to the highly susceptible control of undamaged raspberry; however, D. suzukii developed significantly faster in raspberry than grapes. Fruit characteristics (°Brix, titratable acidity, pH) in grapes were uncorrelated with D. suzukii performance. Together, these findings suggest that cold hardy grapes are overall resistant to D. suzukii if intact and highly susceptible if damaged.     

Study of Spanish Grape Mycobiota and Ochratoxin A Production by Isolates of Aspergillus tubingensis and Other Members of Aspergillus Section Nigri

The native mycobiota of five grape varieties grown in Spain has been studied. Four (Bobal, Tempranillo, Garnacha, and Monastrell) were red varieties and one (Moscatel) was white. The main fungal genera isolated were Alternaria, Cladosporium, and Aspergillus. The isolation frequency of Aspergillus spp. section Nigri in contaminated samples was 82%. Ochratoxin A (OTA) production was assessed using yeast extract-sucrose broth supplemented with 5% bee pollen. Cultures of 205 isolates from this section showed that 74.2% of Aspergillus carbonarius and 14.3% of Aspergillus tubingensis isolates produced OTA at levels ranging from 1.2 to 3,530 ng/ml and from 46.4 to 111.5 ng/ml, respectively. No Aspergillus niger isolate had the ability to produce this toxin under the conditions assayed. Identification of the A. niger aggregate isolates was based on PCR amplification of 5.8S rRNA genes and its two intergenic spacers, internal transcribed spacer 1 (ITS1) and ITS2, followed by digestion with restriction endonuclease RsaI of the PCR products. The restriction patterns were compared with those from strains of A. niger CECT 2807 and A. tubingensis CECT 20393, held at the Spanish Collection of Type Cultures. DNA sequencing of the ITS1-5.8S rRNA gene-ITS2 region of the OTA-producing isolates of A. tubingensis matched 99 to 100% with the nucleotide sequence of strain A. tubingensis CBS 643.92. OTA determination was accomplished by liquid chromatography with fluorescence detection. OTA confirmation was carried out by liquid chromatography coupled to ion trap mass spectrometry. The results showed that there are significant differences with regard to the isolation frequency of ochratoxinogenic fungi in the different grape varieties. These differences were uncorrelated to berry color. The ability of A. tubingensis to produce OTA and the influence of grape variety on the occurrence of OTA-producing fungi in grapes are described in this report for the first time.     

Effect of temperature and water activity on growth and ochratoxin A production boundaries of two Aspergillus carbonarius isolates on a simulated grape juice medium

Aims: To develop and validate a logistic regression model to predict the growth and ochratoxin A (OTA) production boundaries of two Aspergillus carbonarius isolates on a synthetic grape juice medium as a function of temperature and water activity (a_w). Methods and Results: A full factorial design was followed between the factors considered. The a_w levels assayed were 0·850, 0·880, 0·900, 0·920, 0·940, 0·960, 0·980 and the incubation temperatures were 10, 15, 20, 25, 30, 35 and 40°C. Growth and OTA production responses were evaluated for a period of 25 days. Regarding growth boundaries, the degree of agreement between predictions and observations was >99% concordant for both isolates. The erroneously predicted growth cases were 3·4–4·1% false‐positives and 0·7–1·4% false‐negatives. No growth was observed at 10°C and 40°C for all a_w levels assayed, with the exception of 0·980 a_w/40°C, where weak growth was observed. Similarly, OTA production was correctly predicted with a concordance rate >98% for the two isolates with 0·7–1·4% accounting for false‐positives and 2·0–2·7% false‐negatives. No OTA production was detected at 10°C or 40°C regardless of a_w, and at 0·850 a_w at all incubation temperatures. With respect to time, the OTA production boundary shifted to lower temperatures (15–20°C) as opposed to the growth boundary that shifted to higher temperature levels (25–30°C). Using two literature datasets for growth and OTA production of A. carbonarius on the same growth medium, the logistic model gave one false‐positive and three false‐negative predictions out of 68 growth cases and 13 false‐positive predictions out of 45 OTA production cases. Conclusions: The results of this study suggest that the logistic regression model can be successfully used to predict growth and OTA production interfaces for A. carbonarius in relation to temperature and a_w. Significance and Impact of the Study: The proposed modelling approach helps the understanding of fungal‐food ecosystem relations and it could be employed in risk analysis implementation plans to predict the risk of contamination of grapes and grape products by A. carbonarius.     

赭曲霉毒素A的产生、毒性机制与生物合成研究进展

赭曲霉毒素A(ochratoxin A, OTA)是曲霉属和青霉属等真菌的次生代谢物,广泛污染谷物、葡萄、坚果等农产品和饲料,造成严重的经济损失。此外,OTA的肝肾毒性和三致作用(致畸、致癌、致突变)已经得到越来越多的数据支撑,证实其对人类健康存在巨大威胁。OTA及其衍生物的理化性质已经有较为全面的研究,但是其合成过程及调控机理尚不明确。本文整理了赭曲霉毒素A的理化性质及产毒菌株,总结了OTA污染及致病情况的最新研究进展和各国的限量标准,最后分析了OTA的合成机制,讨论了未来OTA理论及应用层面的研究方向,为赭曲霉毒素A的风险评估提供数据支持,同时为OTA生物合成和调控机制提供理论参考。     

Croatian Wines from Native Grape Varieties Have Higher Distinct Phenolic (Nutraceutic) Profiles than Wines from Non‐Native Varieties with the Same Geographic Origin

Croatian wines made from native (Plavac mali and Teran) and non‐native grape varieties (Cabernet Sauvignon and Merlot), all grown in Croatian coastal regions, were investigated. Analyses included measurements of antioxidant activities, total phenolic contents and concentrations of non‐colored phenolic compounds, chosen based on their known nutraceutical properties. Plavac mali wines were distinguished by higher antioxidant activity, total phenolic content and catechin concentrations but lower flavonol concentrations. Teran wines had higher hydroxytyrosol, myricetin and resveratrol concentrations. Merlot and Cabernet Sauvignon wines had higher flavonol concentrations (except myricetin). Canonical analysis was successful in discriminating Plavac mali from Teran wines, and both varieties were separated from non‐native varieties. The results indicate distinct genetic potentials of studied varieties and enable wine authentication based on the investigated bioactive compounds.