Željko Andabaka

In vitro introduction of healthy and virus-infected genotypes of native Croatian grapevine cultivars

We evaluated the response of eight economically important Croatian grapevine cultivars and studied the impact of their sanitary status on in vitro introduction, by comparing the response of healthy and virus-infected genotypes of one cultivar. Nodal explant survival on three media, M1 (half-strength MS), M2 (full-strength MS) or M3 (full-strength MS with 4.4 µM L−1 benzylaminopurine) was measured after 2 weeks and regrowth after 8 weeks. After 8 weeks, average shoot length and node number were significantly higher on M2 compared to M1 and M3. M3 induced significantly shorter average internode length, compared to M1 and M2. Survival of one healthy and of five cultivar Plavac mali genotypes infected with GFLV, GLRaV-1, GLRaV-3, GLRaV-3+GVA and GLRaV-1+GLRaV-3 was 97.5 and 82.8–87.5%, respectively. Regrowth of the healthy genotype reached 95.5%, but dropped to 5.5–31.4% in infected ones. The healthy genotype showed significantly higher shoot length (6.3 cm) and node number (7.3) compared to infected genotypes, with shoot length between 1.2–2.6 cm and node number between 1.2–3.0. By contrast, internode length was not significantly different between the healthy and the infected genotypes. The present work represents the first successful in vitro introduction for three of the eight native Croatian cultivars studied.

Polyphenolic Composition of the Berry Skin of Six Fungus-Resistant Red Grapevine Varieties

Phenolic compound profiles were investigated by high-performance liquid chromatography-diode array detector in three vintages to assess genotypic variation in berry skins of six resistant grapevine varieties: “Cabernet Cortis,” “Chancellor,” “Léon Millot,” “Maréchal Foch,” “Monarch,” and “Regent.” The research has revealed a significant difference among the varieties in the total phenolic content, anthocyanins, flavanols, and flavan-3-ols. A clear differentiation of all varieties by means of the polyphenol profile using discriminant analyses has been achieved. “Regent” reached the significantly highest total polyphenol content, as well as total anthocyanin and total flavonol content. The polyphenol profile of “Chancellor” was quite different from all of the other studied varieties. Although being closely related, “Maréchal Foch” and “Léon Millot” showed qualitatively and quantitatively quite different polyphenol contents. No clear connection between the genetic origin of the varieties and their polyphenol profiles has been found.

Extraction Methods of Polyphenol From Grapes: Extractions of Grape Polyphenols

Abstract The grape is one of the most important horticulture crops in the world and a reliable source of polyphenolic compounds. Nowadays, there are many papers concerning the analysis and especially the extraction of polyphenolic compounds from various parts of the grape berry. Numerous extraction techniques are applied for the recovery of polyphenolic compounds from grape berries including solid-liquid extraction, ultrasound-assisted extraction, microwave-assisted extraction, enzyme-assisted extraction, etc. For all of these techniques, there are numerous published methods, but there is no standardized one. Thus, the aim of this chapter is to unify the known data concerning the extraction methods for the recovery of polyphenols from grapes.

Influence of Pectolytic Enzymes and Selected Yeast Strains on the Chemical Composition of Blackberry Wines

Abstract The aim of this study was to determine concentrations of individual o rganic acids, polyphenolic and aromatic compounds in blackberry wine, and to define the influence of different yeast strains (Uvaferm BDX and Lalvin 71B) and pectolytic enzymes (L allzyme OE and Lallzyme EX-V) on the chemical composition and quality of the wine. Blackberry wines were produced in five variants, depending on yeasts and enzymes used: BDX OE, BDX EX-V, 71B OE, 71B EX-V, and Control without the addition of selected yeasts and enzymes. All blackberry wine variants were defined by a relatively high sum of organic acids. The citric acid was the predominant one, which concentrations ranged from 5.42 to 7.31 g/L. The concentration of gallic acid ranged from 19 to 37 mg/L and was in dependence of the yeast strain used. The concentration of procyanidin B2 which was the predominant flavan-3-ol compound, ranged from 103 to 117 mg/L, and there were no significant differences between individual wine variants in the experiment. Rutin is the predominant compound in the flavonol group, followed by quercetin-3-O-glucoside. The predominant one among the anthocyanins was cyanidin-3-O-glucoside whose concentrations ranged from 134 to 229 mg/L. According to the obtained results, the yeast strain and pectolytic enzymes had a significant impact on the concentration of individual anthocyanins in the analyzed wines. The predominant group of aromatic compounds was monoterpenes, among which linalool was the most prominent in all of blackberry wine variants, except in Control.