Effect of vine vigour of Vitis vinifera cv. Nebbiolo clones on wine acidity and quality

The grapevine cv. Nebbiolo grown in northern Italy produces high-quality red wines, of which Barolo and Barbaresco are the best known. During a clonal selection project, clones of this variety were assessed for their agronomical and enological value. Different degrees of vegetative vigour were found among them, and this was related to modifications of must and wine composition, with particular respect to the acidity. Over 4 years of observations, vigorous clones produced musts and wines of higher pH, regardless of the amount of titratable acidity. This was associated with a higher malic acid content in the juice and with a higher concentration of potassium in the wine. In addition, wines from vigorous clones showed an unbalanced ratio of colour components. They ranked at the lowest score in the sensory evaluation tests

Use of winemaking by-products as an ingredient for tomato puree : the effect of particle size on product quality

Formulations of tomato puree with grape skin fibres (Chardonnay variety) having varying particle sizes were studied. The contents of flavonoids (by HPLC\u2013DAD) and proanthocyanidins (n-butanol/HCl assay), reducing capacity (ferric ion reducing antioxidant power, FRAP) and anti-glycation activity by a bovine serum albumin (BSA)/fructose model system were analysed in vitro. A liking test was performed with consumers. Stabilization was carried out by either an intensive autoclave treatment or an optimised microwave-treatment achieving 6D-reduction of the target microorganism (Alicylobacillus acidoterrestris). In the fortified tomato purees, the solubility of proanthocyanidins decreased, but was partly restored by autoclave treatment, which also caused deglycosylation of flavonol glycosides. Microwave treatment did not show any effect on phenolics. The reducing capacity and ability to inhibit protein glycation greatly increased in the fortified purees. The particle sizes of solids in the formulations played a major role with respect to the consumers\u2019 liking, with the smallest fraction showing maximum ratings