Iñigo Arozarena

Multivariate differentiation of Spanish red wines according to region and variety

A total of 20 analytical parameters, including alcohols, total polyphenols and anthocyanins, colour and several normal oenological variables such as pH, total acidity and dry extract, were analysed in 66 red wines from two regions of Spain (Aragon and Navarra), made with seven different varieties of grapes (Graciano, Tempranillo, Grenache, Carignan, Merlot, Ruby Cabernet and Cabernet Sauvignon). Factor analysis of raw data provided a good description of the differences between production zones. With the exception of Ruby Cabernet, which presented very outstanding characteristics, grape variety characterisation was more difficult. In this sense, better results were obtained by means of stepwise discriminant analysis. At the end of the discriminant selection process, 94% of the training wines and 85% of the test wines were correctly classified by variety. These percentages were 89% (training sample set) and 92% (test wines) in the classification model obtained from the region. © 2000 Society of Chemical Industry

Color, Ellagitannins, Anthocyanins, and Antioxidant Activity of Andean Blackberry (Rubus glaucus Benth.) Wines

Twenty-eight blackberry ( Rubus glaucus Benth.) wines elaborated under different processing conditions were analyzed for total phenolics, ellagitannins, anthocyanins, color, and antioxidant activity. Ellagitannins were the main phenolic compounds and the most determinant factor in the antioxidant capacity of wines (r = 0.980). The major anthocyanins were cyanidin 3-rutinoside (64 ± 6%) and cyanidin 3-glucoside (19 ± 4%), followed by several minor compounds (17 ± 4%). Two of them were native blackberry anthocyanins, namely, cyanidin 3-rutinoside-5-glucoside and cyanidin 3-xylorutinoside. The remaining seven compounds were anthocyanin-related pigments generated during and after the alcoholic fermentation, identified as A-type and B-type vitisins and hydroxyphenylpyranoanthocyanins. The presence of fruit solids in contact with the liquid fraction during fermentation and the ratio of water to fruit employed in the preparation of the musts had a great impact on the content of ellagitannins, total phenolics, and the antioxidant activity of wines and a minor impact on their color and anthocyanin composition.

Microencapsulation of Grape Seed Extracts

Grape seed extracts (GSE) from vinification by-products are an abundant and inexpensive source of polyphenols. They can be used as functional ingredients in the food industry due to their beneficial effects on human health. GSE can also substitute for synthetic anti-oxidants in organic or all-natural products. Despite the beneficial effects of the GSE, its use in the food industry is limited because it has limited solubility in water, it is unstable at high temperatures, and its bioavailability is low. Microencapsulation can be employed to overcome these drawbacks and facilitate the incorporation of GSE in food products. Microcapsules of GSE have been made using a wide variety of methods and materials, and show improvements in one or more of the problems with using the extracts. The aim of this chapter is to summarize studies of the microencapsulation of GSE, as well as GSE’s composition and benefits.