Modelling grape and wine quality through PLS Spline statistical method

Secondary (or specialised) metabolites such as terpenes and phenolic compounds are produced by plants for various roles which include defence against pathogens and herbivores, protection against abiotic stress, and plant signalling. Additionally, these metabolites influence grapevine quality traits such as colour, aroma, taste, and nutritional value. However, the biosynthesis of these metabolites is often complex and controlled by multiple genes which in grapevine are predominantly uncharacterised.

Many of the world’s vineyard regions are located in regions of complex terrain, with the result there is significant local climate variation.

The ripening of grapevine berries encompasses complex morphological and physiological processes, especially at veraison. Berry shrivel (BS) is a ripening physiological disorder affecting grape berries with visible symptoms appearing short after veraison. The main symptoms of BS are a strong reduction in sugar accumulation, inhibited anthocyanin biosynthesis and high pH values. The most popular red grape cultivar in Austria “Blauer Zweigelt” (Vitis vinifera L.) is specifically prone to develop the BS ripening disorder and up to date a no specific cause or causes could be identified. Recently omics approaches have identified and characterized key processes during grapevine ripening. Among them a small subset of genes, called SWITCH, have been described as markers for the onset of the ripening process in fruits.

Vineyards are strongly exposed to fungal diseases, attacks from insects and competition with weeds. Most treatments used on grape vines contain synthetic active substances, which may be transferred to the wine. Such pesticides have a negative image because many active substances are potential health hazards. A specific oenological treatment allowing the reduction of pesticide residues in wine based on activated vegetable fibres (AVF) is under examination by the International Organisation for Vine and Wine. This technique works efficiently and alters the wine only little (Lempereur et al. 2014).

Considering that „prevention requires information”, in 2007, the european education program wine in moderation (wim) started. The common message of responsible and only moderate wine consumption is implemented in each participating country, adapted to national circumstances. In germany, besides recruiting new wim members from the wine sector, the deutsche weinakademie focusses also on information and education of future wine makers and cellar men in professional schools. The seminars cover basic information about the existing legal framework (youth protecting law, drink driving laws, etc.), the self regulation code of conduct for commercial communications (advertising) of alcoholic beverages as well as the health effects of alcoholic beverages, and of wine in particular.