Copper contents in grapes and wines from a Mediterranean organic vineyard

This work was conducted in an organic vineyard in Bari (South-Eastern Italy) to evaluate copper concentrations in grapes and wines of four local and international varieties (Chardonnay, Primitivo, Uva di Troia and Negroamaro) and to relate these contents to total and available copper concentrations in soil. Approximately 7.4 kg/ha of copper were used in the trial year. Soil copper availability was higher in the 0–20 cm (10.3%) than in the 20–40 cm layer (4.7%). No copper phytotoxicity was observed on leaves. Copper residues on berries and in wines resulted below the maximum residue levels (MRLs). Concentrations in berries increased with applications number and varied according to the variety. Copper content in the white wine (Chardonnay) was higher with respect to red ones (Primitivo, Uva di Troia and Negroamaro). Results provided evidence that in the natural conditions typical of a Mediterranean environment, characterised by calcareous soils and a dry climate, the use of copper formulations in vineyards according to European legislation guidelines should not raise any concern with regards to human health.     

Occurrence of ochratoxigenic fungi and ochratoxin A in grapes from a Tunisian vineyard

The occurrence of ochratoxin A (OTA) and the identification of the ochratoxigenic microbiota in Tunisian grapes were studied for the first time. Black aspergilli were the dominant genus among the filamentous fungi isolated from grapes and were the only potential OTA-producing fungi found. The most abundant species were member of Aspergillus niger aggregate (63%) and Aspergillus carbonarius (36%). Uniseriate aspergilli were rarely present (1%). Of the A. carbonarius isolates, 97% were OTA positive but only 3% of the A. niger aggregate isolates were OTA positive. During grape maturation, the frequency of black aspergilli increased due to increase of the numbers of A. carbonarius. Musts (n=24) obtained from grapes collected at the different sampling times were analyzed for their OTA content. Up to 37% of the musts contained OTA at levels varying between 0.59 and 2.57 microg/l. The amounts of OTA in musts increased as grapes matured. These results indicate that A. carbonarius is the main cause of OTA contamination of Tunisian grapes.     

Ochratoxigenic species from Spanish wine grapes

The ochratoxigenic mycobiota of grapes belonging to representative wine regions located along the Mediterranean coast of Spain at different developmental stages was identified. During the development of the berries, the occurrence of Aspergillus spp. increased while the percentage of berries contaminated by non-ochratoxin A (OTA) producing species such as Alternaria spp. and Cladosporium spp. decreased. Penicillium verrucosum, the only confirmed Penicillium spp. that is able to produce OTA, was not isolated. The contamination by OTA-producing species comes from the surface of the berries and not from the inner fruit. Black aspergilli were predominant among the different Aspergillus spp. isolated. All the Aspergillus carbonarius isolates were able to produce OTA at different concentrations. None of the isolates belonging to Aspergillus niger aggregate and to Aspergillus japonicus var. aculeatus were able to produce OTA. These results are a strong evidence of the contribution of A. carbonarius in the OTA contamination in wine grapes, mainly at the last developmental stages of the berries.     

Presence of enological microorganisms in the grapes and the air of a vineyard during the ripening period

This study looks at the presence and evolution of yeast and lactic bacteria in the air of a vineyard during the 4 weeks up to harvesting. The work was conducted in two successive harvests (2008 and 2009) in a vineyard of Tempranillo grapes cultivated under the DOCa Rioja (Spain). The microorganisms collected from the air were compared with those isolated at the same time from the grape clusters, in order to analyze the air as a means of dispersal of the microorganisms present on the grapes inside the vineyard. A very low number of bacteria were detected on the clusters and in the air, but they all belonged to the group of lactic bacteria of enological interest. In the case of yeasts, the results obtained indicate that their presence in the air is much lower than that detected on the clusters, but that there continues to be a growing evolution in both media throughout the ripening period. In addition, the main species detected are similar in both cases, so that it can be suggested that the yeasts detected in the air are representative of the ones found on the grapes. However, although we isolated the main agents of alcoholic and malolactic fermentation, Saccharomyces cerevisiae and Oenococcus oeni, from the grapes, these were not found in the air.     

RFLP characterization of Aspergillus niger aggregate species from grapes from Europe and Israel

In order to characterize by molecular methods the Aspergillus niger aggregate species involved in the ochratoxin A (OTA) contamination of European wine grapes and table grapes from Israel, a total of 173 strains were studied. The ITS-5.8S rDNA fragments of 173 A. niger agreggate strains from grapes included in this study were amplified and their PCR amplicons were RsaI digested in order to classify the strains in the RFLP types, N and T. All of the strains belonging to the A. niger aggregate were classified into the two RFLP types previously defined: type N (43%) and type T (57%). Twenty out of the 173 strains of A. niger aggregate produced OTA (0.1 to 10.5 mug g(-1)). All the OTA producing species belonged to the N-RFLP type.     

Phenolic composition of Merlot and Cabernet-Sauvignon grapes from Bordeaux vineyard for the 2009-vintage: Comparison to 2006, 2007 and 2008 vintages

Cabernet-Sauvignon and Merlot skin and seed extracts from Bordeaux grapes were investigated to determine both grape variety and vintage effect on phenolic composition. The total content of polyphenols and tannins in Merlot seeds was higher than that of Cabernet-Sauvignon allowing to discriminate the varieties. HPLC analyses underlined significant differences in the absolute concentration of proanthocyanidins amongst the two varieties and in their composition: mean degree of polymerisation (mDP) and percentage of galloylation of seed extracts were good indicators of grape variety. The vintage effect on the phenolic composition was confirmed for 2009 in comparison to previous vintages. Low values of mDP and concentrations of proanthocyanidins and anthocyanins were found in 2009 seeds and skins. The climatic conditions of 2009 (high rainfall before flowering followed by a strong hydric stress during berries development until ripening) let us hypothesise a lower activation of flavonoid pathway.     

A comparative study to distinguish the vineyard of origin by NIRS using entire grapes,skins and seeds

BACKGROUND: Interest in high‐quality products with a clear geographical origin is increasing. For the wine industry and market sector, identity preservation is of fundamental importance owing to the large number of geographical classifications. Nowadays, there is a growing demand for analytical methods for tracing grapes and wines. In the oenological sector, infrared spectroscopy is becoming an attractive tool allowing simultaneous measurement of several analytical parameters and enabling real‐time decision making. RESULTS: Discriminant partial least squares, a supervised pattern recognition technique, was employed to discriminate between vineyards of origin using the near‐infrared spectra of intact grapes, skins or seeds. In order to compare the three sample presentations, a receiver operating characteristic curve was used. The best results were obtained using intact grape seeds, with prediction rates of samples correctly classified of about 95%, although the good results obtained with entire grapes (about 93% of samples correctly classified) and the simplicity of use of the fibre optic probe could advise using entire grape presentation for comprehensive studies. CONCLUSION: The procedure reported here seems to have excellent potential for a fast and reasonably inexpensive analysis of the origin of samples. It is noted that such classification can be made at any time of ripening. This paper provides information of interest to develop new and extensive models in the future. © 2012 Society of Chemical Industry     

Bacterial populations associated with a sorghum-based fermented weaning cereal.

Microbiological surveys, to determine the quality and safety, were conducted on 45 sorghum samples comprising dry powders (n = 15) and corresponding fermented (n = 15) and cooked fermented porridge (n = 15) samples collected from households in an informal settlement of the Gauteng Province of South Africa. Mean aerobic plate counts, Gram-negative counts and bacterial spore counts of sorghum powder samples decreased in fermented and cooked fermented porridge samples. However, mean lactic acid bacteria counts increased in fermented porridge samples, but decreased slightly in cooked fermented porridge samples. The mean pH value of sorghum powder samples decreased in fermented and cooked fermented porridge, respectively. Bacillus (B.) cereus was detected in all 15 sorghum powder samples, while Escherichia (E.) coli was detected in 53%, Clostridium perfringens in 27%, Listeria monocytogenes in 13% and Aeromonas spp., Salmonella spp., Staphylococcus aureus, Shigella spp. and Yersinia spp., each in 7% of sorghum powder samples. Of the fermented porridge samples, 40% contained B. cereus and 7% contained E. coli. None of the pathogens tested for were detected in cooked fermented porridge samples. B. cereus (53%), B. subtilis (21%), B. thuringiensis (13%), B. licheniformis (10%) and B. coagulans (3%) were identified from 120 isolates randomly selected from spore count plates of the highest dilution showing growth.     

Determination of ochratoxin A in grapes of Greek origin by immunoaffinity and high-performance liquid chromatography

A simple analytical method for ochratoxin A (OTA) determination in grapes is described, using aqueous methanolic extraction, an immunoaffinity column clean-up step and high-performance liquid chromatography with fluorescence detection. Mean recovery was 94% (RSD = 4.0%) with a detection limit of 0.4 ng g^-1 and quantification limit of 1.20 ng g^-1. Repeatability (r) and reproducibility (R) were 1.17 and 1.34, respectively. OTA determinations were applied to 50 grape samples (23 different varieties) originating from representative regions of Greece. Results showed the presence of OTA in 86% of samples tested (n = 50). Traces were found in 56% of samples but OTA was not detectable in 14% of samples. Traces were also found in 4% of red, organically grown samples. The most contaminated were three samples of red grapes, two from Central Greece (2.69 and 1.41 ng g^-1), both table and wine-making grapes. The third sample (1.46 ng g^-1), originating from the island of Samos, was used only in wine-making. Mean (1.06 ng g^-1) and median (0.76 ng g^-1) OTA concentrations in red grapes were slightly higher compared to the mean (0.82 ng g^-1) and median (0.65 ng g^-1) concentrations in white grape samples. The study shows that the potential risk for a person of 60 kg ranged from 0.9 to 9 ng kg^-1 bw day^-1 and is dependent on the quantity of grapes consumed daily.     

Bacterial populations associated with meat from the deboning room of a high throughput red meat abattoir

Developing countries are faced with high incidences of food poisoning outbreaks, with obvious economic consequences. In highly perishable foodstuffs such as fresh red meat the threat of food poisoning is particularly intense. In this study, red meat samples were collected from a deboning room of a high throughput abattoir. The samples were analysed for the presence of Bacillus cereus., Staphylococcus aureus., Pseudomonas spp., Listeria monocytogenes., Escherichia coli and Salmonella spp. The aerobic plate counts as well as Enterobacteriaceae were also enumerated. Almost without exception the counts exceeded the microbiological guidelines for raw meat as proposed by the South African Department of Health. The average B. cereus count over the sampling period was 8.32 × 10(3) cfu, g (-1), for S. aureus and Pseudomonas spp. 1.72 × 10(5) and 1.7 × 10(5) cfu g(-1) respectively and for E. coli 3.4 × 10(5) cfu g(-1). Sixty percent of the samples were positive for presumptive Salmonella spp. while 52% of the samples tested positive for the presence of L. monocytogenes. The aerobic plate and Enterobacteriaceae counts were 1.7 × 10(7) and 4.6 × 10(6) cfu g(-1), respectively. The data highlighted the need for a more systematic approach to ensuring safe food through implementing quality control methods to prevent the entry and proliferation of pathogens in meat and meat products, especially during processes with a high degree of handling, such as deboning.     

Bacterial populations associated with poultry processing in a South African abattoir

Bacteria were isolated from yeast extract supplemented tryptone soya agar (TSAYE) plates (357 isolates) and violet red bile glucose agar (VRBGA) plates (311 isolates) of micro- biological surveys in a South African Grade B poultry abattoir. Bacterial populations from TSAYE plates of carcasses (neck skin) were dominated byAcinetobacterspp.,Escherichia coli, Micrococcusspp. andFlavobacteriumspp., which collectively comprised 75.4% of isolates, while isolates from VRBGA plates showed dominance ofEscherichia coli(80.0%). Environmental isolates dominant on TSAYE plates wereMicrococcusspp. from equipment surfaces and air samples of the defeathering area of the abattoir (48.5 and 68.7%, respectively) andBacillusspp. from air samples of the packaging area (37.4%). Isolates from TSAYE plates of scald tank water were dominated byE. coli(47.8%) andMicrococcusspp. (39.1%), while isolates from immersion chiller water were predominantlyE. coli(54.1%). Environmental isolates dominant on VRBGA plates wereE. coliin water samples and air of the defeathering and packaging areas (from 93.7 to 100%).E. coli, Enterobacterspp. andSerratiaspp. were dominant on VRBGA plates of equipment surfaces, collectively comprising 77.8% of isolates.     

Bacterial counts associated with recycled newspaper bedding

Bacterial counts associated with recycled newspaper, wood shavings, and pelleted corn cobs used as bedding for lactating dairy cows were compared. Chopped newspaper and pelleted corn cobs had similar gram-negative bacterial, coliform, and streptococcal bedding counts. Staphylococcal counts in pelleted corn cobs were greater than in chopped newspaper. Conversely, gram-negative bacterial, coliform, and staphylococcal counts in chopped newspaper were greater than in wood shavings. Coliform and streptococcal counts did not differ between chopped newspaper and wood shavings bedding materials. Teat swab counts from cows bedded on pelleted corn cobs were greater than those from cows bedded on chopped newspaper for gram-negative bacterial, coliform, Klebsiella species, and staphylococci. Streptococcal teat swab counts did not differ between cows bedded on chopped newspaper and pelleted corn cobs. Cows bedded on chopped newspaper and wood shavings had similar gram-negative bacterial, coliform, and Klebsiella species teat swab counts. Streptococcal and staphylococcal teat swab counts were greater from cows bedded on chopped newspaper than those from cows bedded on wood shavings. Teat swab and bedding counts were correlated. In general, bacterial counts in bedding suggest no advantage in using chopped newspaper over pelleted corn cobs or wood shavings in reducing exposure of teats to environmental mastitis pathogens.     

Bacterial communities associated with retail alfalfa sprouts

Fresh produce, including salad, is increasingly implicated in foodborne outbreaks. Although studies have been carried out to detect specific human pathogens from fresh produce, the total bacterial community associated with fresh produce is poorly understood. In this study, we characterized the bacterial community associated with alfalfa sprouts, using a culture-independent method. Four retail-purchased alfalfa sprout samples were obtained from different producers, and the bacterial community associated with each sample was determined by 16S rDNA profiling. Our results indicate that alfalfa sprouts sampled in our study shared significant similarities in their bacterial communities. Proteobacteria was the dominant phylum detected from all alfalfa sprout samples, with Enterobacteriaceae, Oxalobacteraceae, Moraxellaceae, and Sphingomonadaceae as the most frequently detected families. These results indicate that growth conditions of alfalfa sprouts should be taken into consideration to prevent the proliferation of pathogenic proteobacteria such as Escherichia coli O157 and Salmonella.     

Reduction of point contamination sources of pesticide from a vineyard farm

Although plant protection products are already regulated in Europe under Directive 91/414/EEC, there is increasing concern about the pollution of ground and surface water caused by point sources of pesticides, such as tank filling, spillages, faulty equipment, washing, waste disposal, and direct contamination. One tool for the reduction of pesticide point source contamination is a biological system where chemicals are bound and biologically degraded. This paper presents an offset lined system where wastewaters containing pesticide residues leach through a biomix. A pump system is provided to pump the water onto the surface of the biomix and allow it to drain under gravity, keeping the biomix wet. The analysis of residues of nine pesticides in the water, biomix, and sediment inside the tank showed the biobed to function well, with a water decontamination greater than 90%. The use of this system mitigated the potential for pollution (pesticide concentrations higher than 0.1 microg/L) of 1 km of the river system surrounding the farm.     

Bacterial populations associated with pasteurized vacuum-packed Vienna sausages

Predominant bacterial populations were isolated from vacuum-packaged Vienna sausages exposed to three in-package pasteurization treatments of increasing severity (Past1, 2 and 3) and non-pasteurized controls stored at 8°C for 128 days. The majority (>52%) of isolates from pasteurized and non-pasteurized sausages were lactic acid bacteria (LAB); the remainder includedBacillus, Gram-positive, catalase-positive cocci and enterobacteriaceae. In-package pasteurization of sausages reduced proportions of LAB from 84.4% in non- pasteurized samples, to 74.6%, 66.4% and 52.9% in Past1, 2 and 3 treated samples, respectively. In non-pasteurized sausages, leuconostocs and homofermentative lactobacilli jointly comprised the highest proportion (83.3%) of LAB isolates, whereas pediococci were isolated at a lower frequency of 16.7%. As a result of all pasteurization treatments, proportions of leuconostocs and homofermentative lactobacilli decreased toc. 40% of isolates, whereas proportions of pediococci increased to 50% or more. Although pasteurization led to a diversification of lactic spoilage populations, it did not prevent product spoilage by eliminating these bacteria. Because severe heating also increased the predominance ofBacillus, in-package pasteurization of vacuum-packaged Vienna sausages might, however, compromise product safety.     

Quantification and characterization of microbial populations associated with naturally fermented Greek dry salami

The microbial flora associated with the natural fermentation and ripening of five batches of Greek dry salami was enumerated and characterized over time. Micrococci-staphylococci increased at a level of 10⁷ cfu g^-1 during early fermentation. By day 4, lactic acid bacteria outnumbered Micrococcaceae in all batches, since they exceeded — with the exception of batch III — 10⁸ cfu g^-1. Yeasts remained below 10⁶ cfu g^-1 during the whole process, but tended to increase at a late ripening stage. Almost all colonies grown on mannitol salt agar were catalase positive cocci. Nitrate-reducing micrococci were progressively replaced by less acid-sensitive staphylococci. A high proportion (62·5%) of 112 Staphylococcus isolates grew weakly under anaerobic conditions. Typical staphylococci were less capable of reducing nitrate. Yeast populations mainly comprised Debaryomyces strains. Characterization of 348 lactic isolates indicated that the salami microflora was dominated by homofermentative lactobacilli (61·4%) and leuconostoc-like bacteria (24·9%). Most lactobacilli (51·4%) belonged to the formerly-called ‘atypical' meat streptobacteria. Typical streptobacteria (10·0%), heterofermentative lactobacilli (10·0%) and homofermentative cocci (3·1%) were mainly isolated during the first days of fermentation and failed to compete with the other two groups. The microbial interactions as reflected by the distribution and succession of different general/subgenera in each batch and their possible effect on physicochemical and sensory characteristics of the sausages were discussed.     

葡萄表面所得酵母菌的筛选及其鉴定

从市售葡萄表面分离出两株酵母菌,经形态、培养特征、酵母菌假菌丝和酵母菌子囊孢子的观察和生理生化实验及发酵特性的研究,鉴定出这两株酵母菌分别为布鲁塞尔德克酵母(Brettanomyces bruxellensis)和酿酒酵母(Saccharomyces cerevisive).     

宁夏贺兰山东麓酿酒葡萄建园的基本经验及成龄园改造技术

宁夏葡萄产业从玉泉营农场起步,1982年该场率先从河北省昌黎引进龙眼、玫瑰香、红玫瑰等酿酒与鲜食兼用品种种条,采用土炕催根育苗,建立了全区第一个大型葡萄农场;1998年又从法国直接引进12个酿酒葡萄种条,培育并栽植了160万株国外著名酿酒葡萄品种,基地面积达到800ha。1997年银广夏葡萄酒公司创立,开创了在宁夏荒漠沙丘上种植酿酒葡萄的先河,目前酿酒葡萄基地在贺兰山东麓总面积已达2,000ha。1999年5月自治区农科院与民族化工集团联手,在芦花台园林场定植了400ha酿酒葡萄园。同时,上海慧彬公司、维邦公司、大武口贺东庄园、香山集团及青铜…