Differentiation among Young and Market-ready Cabernet Sauvignon, Pinotage and Shiraz Wines: Application of Canonical Discriminant Analysis using Flavonoid and Non-Flavonoid Compositional Data

Various factors affect the polyphenol compound concentrations of red grapes. These include cultivar,vineyard location, viticultural practices, microclimate, soil type and winemaking processes. Polyphenolcompound concentrations of young and market-ready Cabernet Sauvignon, Pinotage and Shiraz wineswere examined for the purpose of discrimination between grape cultivars. Thirty-five individual polyphenolcompounds were quantified using a HPLC-DAD method. Stepwise discriminant analysis (SDA) was usedto select a subset of discriminatory variables. In addition, data was grouped and investigated by canonicaldiscriminant analysis, which showed that polyphenol concentrations can be used to discriminate amonggrape cultivars, young wines and market-ready wines. Flavonol, flavanol and anthocyanin patternswere used as a basis for differentiation of young wines, while flavanols and phenolic acids were used fordifferentiation of market-ready wines. Discriminant analysis performed at 95% significance level revealeda 100% categorisation of market-ready and young wines in terms of cultivar and 77.85% categorisation ofa combination of market-ready and young wines in terms of grape cultivar. This illustrates the validity ofpolyphenols for studies pertaining to grape cultivar discrimination

Investigating the Use of Element Analysis for Differentiation between the Geographic Origins of Western Cape Wines

The aim of this study was to differentiate between the geographic origins of wines produced in the Western Cape on the basis of their element composition. A total of 96 market-ready red and white wines (Pinotage, Shiraz, Merlot, Cabernet Sauvignon, Sauvignon blanc, Chardonnay and Chenin blanc) were analysed by means of inductively coupled plasma atomic emission spectrometry (ICP-AES). The discriminant methods: stepwise discriminant analysis, canonical discriminant analysis and linear discriminant analysis were applied to the data sets. A classification accuracy of 38% for Pinotage, 55% for Shiraz, 68% for Merlot, 75% for Cabernet Sauvignon, 93% for Sauvignon blanc, 68% for Chardonnay and 100% for Chenin blanc was achieved. Subject to the conditions of this study, it was concluded that differentiation between wines according to geographical origin was possible using the elemental composition

Phenolic Compounds in Cork-Closed Bottle-Fermented Sparkling Wines

Bottle fermented sparkling wine in South Africa is known as Méthode Cap Classique which is based onthe method used in France for Champagne. The use of cork, instead of a crown cap during the secondfermentation in sparkling wine was investigated for its effect on the phenolic profile of wines. Phenolicacids susceptible to migration from cork into wine were studied in two-disc corks from three differentcommercial suppliers, coded as Cork A, Cork R and Cork C and a crown cap closure. Gallic, caftaric,caffeic and p-coumaric acids were quantified in all samples using a liquid chromatographic technique.Physicochemical parameters were also measured in the wine using a spectrophotometric technique. Totalacidity and pH were not significantly different among the wines. Cork R wines were however significantlydifferent in alcohol. Residual sugar for all samples was below the limit of detection. Gallic acid wassignificantly highest in Cork A wines, which indicates the contribution of Cork A to the concentration ofthis compound in the wine. Different cork types are assumed to release different concentrations of phenoliccompounds. This may be due to differences in surface roughness of cork that would increase the surfacearea in contact with the wine. Therefore, corks from different origins (suppliers) could be used to bringabout subtle differences to the wine. &nbsp

Effect of Torulaspora delbrueckii Yeast Treatment on Flavanols and Phenolic Acids of Chenin blanc Wines

The non-Saccharomyces yeast Torulaspora delbrueckii contributes positively to the sensory properties of wines by affecting aroma and flavour due to changes in alcohols, esters, fatty acids and lactone levels.  One of the less-studied aspects of T. delbrueckii is its effect on phenolic compounds relating to sensory attributes. An HPLC-DAD technique was used for the quantification of phenolic compounds in Chenin blanc wines made with S. cerevisiae and two T. delbrueckii yeasts over three vintages. Chemical andsensory data were subjected to ANOVA and PCA. VIN13, M2/1 and VIN13+M2/1 had a positive effect on the phenolic compound concentrations of Chenin blanc wines. Mouthfeel was highest in VIN13+654 wines and astringency highest in VIN13 wines. An association was evident between flavanols, astringency and mouthfeel for the VIN13, M2/1 and VIN13+M2/1 wines. Chenin blanc wines made with M2/1 and VIN13+M2/1 may result in increased phenolic compound concentrations and astringency, whereas 654 and VIN13+654 may result in wines with increased mouthfeel properties

Effect of Torulaspora delbrueckii Yeast on the Anthocyanin and Flavanol Concentrations of Cabernet franc and Pinotage Wines

Pinotage and Cabernet franc grape must were inoculated with Saccharomyces cerevisiae and Torulasporadelbrueckii yeasts. Differences in colour were observed between Pinotage (S. cerevisiae) and Pinotage (T.delbrueckii) wines, whereas differences in berry and herbaceous character were observed between Cabernetfranc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Mouthfeel properties between treatmentsfor both wines were not significantly different. Overall quality was slightly higher in wines inoculatedwith T. delbrueckii compared to wines inoculated with S. cerevisiae. Anthocyanins and flavanols measuredin Pinotage wines made with T. delbrueckii were higher compared to Pinotage must inoculated with S.cerevisiae. Cabernet franc wines made with S. cerevisiae were higher in anthocyanin glycoside and flavanolconcentrations compared to Cabernet franc wines made with T. delbrueckii. Insignificant differencesin acetylated and coumarylated anthocyanins were evident between Cabernet franc (S. cerevisiae) andCabernet franc (T. delbrueckii) wines. Principal component analysis showed that epigallocatechin gallate,epicatechin gallate, procyanidin B2, peonidin 3-O-glucoside, delphinidin 3-(6-acetyl) glucoside, petunidin3-(6-acetyl) glucoside, malvidin 3-(6-acetyl) glucoside and malvidin 3-O-glucoside concentrationswere highest in Pinotage wines inoculated with T. delbrueckii. Cabernet franc wines inoculated with S.cerevisiae yeasts were highest in malvidin 3-(6-p-coumaroyl) glucoside, petunidin 3-(6-p-coumaroyl)glucoside, petunidin 3-O-glucoside, epicatechin gallate and epigallocatechin gallate concentrations. Totalanthocyanins were highest in Pinotage (S. cerevisiae) wines and Cabernet franc (T. delbrueckii) wines.Flavanols were highest in Pinotage (T. delbrueckii) and Cabernet franc (S. cerevisiae) wines. It is evidentfrom the results that yeast species has an impact on the flavonoid concentrations within a grape variety

Investigation of biological samples for monofluoroacetate and Dichapetalum cymosum poisoning in southern Africa

A need has existed for the accurate identification of monofluoroacetate (MFA) poisoning in southern Africa. The development of a new method for the determination of MFA has made the analysis of a variety of biological samples (n=50) feasible. The method has been used in the laboratory over 24 months. Monofluoroacetate was present in 66% of samples from cases of suspected poisoning, reflecting the extent of the problem. Stability of MFA in samples was also determined so as to have a time-bound baseline for the acceptance of samples submitted. It was found that there was a decrease in the level of MFA and, after 14 days at room temperature, only 50% of the spiked dose could be identified. It is suggested that samples be analyzed within 7 days of mortality if they not kept frozen.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Effect of gamma and electron beam irradiation on the physico-chemical and nutritional properties of mushrooms: a review

The short shelf-life of mushrooms is an obstacle to the distribution and marketing of the fresh product. Thus, prolonging postharvest storage, while preserving their quality, would benefit the mushroom industry as well as consumers. There has been extensive research on finding the most appropriate technology for mushrooms preservation. Gamma, electron-beam and UV irradiation have been shown to be potential tools in extending the postharvest shelf-life of fresh mushrooms. Studies evaluating the effects of ionizing radiation are available mainly in cultivated species such as Agaricus bisporus, Lentinus edodes and Pleurotus ostreatus. This review comprises a comprehensive study of the effects of irradiation on physico-chemical parameters (weight, colour, texture and pH), chemical compounds including nutrients (proteins, sugars and vitamins) and non-nutrients (phenolics, flavonoids and flavour compounds), and on biochemical parameters such as enzymatic activity of mushrooms for different species and from different regions of the world.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to the research centers CIMO (PEst-OE/AGR/UI0690/2011) and REQUIMTE (PEst-C/EQB/ LA0006/2011). A.S. Fernandes and A.L. Antonio thank FCT, POPHQREN and FSE for their Grants (SFRH/BD/76019/2011 and SFRH/ PROTEC/67398/2010, respectively)

Effect of Grapevine Canopy Side on Selected Sensory Attributes of Pinotage and Cabernet Sauvignon Wines

Grapevine row direction, canopy exposure and grape maturity can define the sensory attributes of wine.  From this perspective, canopy exposure that favours colour intensity, astringency, aroma intensity and balanced acidity could result in improved wine quality. The aim of this study was to examine the effect of canopy exposure on selected sensory attributes of Pinotage and Cabernet Sauvignon wines from Paarl, Durbanville and Darling in South Africa. Pinotage and Cabernet Sauvignon grapes were harvested from both sides of the canopy of vines planted to E-W and N-S directions. Wines were made from the harvested grapes. Grapes and wines underwent physicochemical and sensory analysis. Durbanville CabernetSauvignon from the south side had decreased alcohol content. Total acidity, residual sugar (RS) and pH were not different between sides. Wines from the east side had increased colour, aroma, mouthfeel and overall quality. Paarl Cabernet Sauvignon was not different between sides for any physicochemical characteristics, except TA. Wines from the south side had increased colour, aroma, mouthfeel and overall quality. Darling Pinotage was not different between sides for any physicochemical characteristics. Wines from the west side had increased intensity of aroma and acidity, whereas Durbanville Pinotage from the east side had increased alcohol, pH, TA, colour and aroma intensity, as well as overall quality. The resultsconfirm that canopy exposure has an effect on the wine sensory attributes. This investigation illustrates the variation in sensory attribute scores of Pinotage and Cabernet Sauvignon wines from different canopy sides. Canopy exposure in a vineyard of a specific region, orientated to an E-W or N-S direction, which favours colour intensity, aroma intensity and/or mouthfeel, could result in improved wine quality. Future investigations should focus on samples collected over at least three consecutive vintages, as well as the monitoring of temperature and photosynthetic active radiation