Polysaccharide families of lyophilized extracts obtained from unfermented varietal grape pomaces

The ongoing climate change implies an increasing mean air temperature, which is signified by weather extremes or sudden changes between drought and local heavy rainfalls. These changing conditions are especially challenging for the established grapevine varieties growing under cool climate conditions due to an increased risk for fungal diseases like downy mildew (DM) and Botrytis bunch rot (BBR) as well as for grape sunburn. To meet that demand, the scope of most grapevine breeding programs is the selection of mildew fungus-resistant and climatic adapted grapevines with balanced, healthy yield and outstanding wine quality.

The agri-food industry is constantly searching for ingredients of high functional value, healthy and of natural origin. One species of particular interest is Vitis vinifera, due to its recognized antioxidant potential. Among the grape varieties, one group possesses these antioxidant compounds not only in the skin, but also in its pulp: Teinturier. The red grape has traditionally been used for color correction purposes in winemaking, however, its high antioxidant content transforms it into a raw material of high potential for new formulations of ingredients and foods for the health and wellness market.

Contamination problems arising from the use of pesticides in viticulture have raised concerns. One of the alternatives to reduce contamination is the use of elicitors, molecules capable of stimulating the natural defences of plants, promoting the production of phenolic compounds (PC) that offer protection against biotic and abiotic stress. Previous studies on Cabernet-Sauvignon seedlings demonstrated that foliar application of elicitors methyl jasmonate (MeJ) and benzothiadiazole (BTH) increased proteins and PC involved in grapevine defence mechanisms. However, no trials had been conducted on Monastrell seedlings, a major winegrape variety in Spain.

Botrytis cinerea, a fungal pathogen commonly known as grey mold, which under specific climatic conditions can develop into a desirable form known as noble rot. In this process the fungus penetrates the grape skin, allowing water evaporation and concentration of sugars and flavors, while profoundly affects the metabolite composition of grapes, leading to the production of unique and desirable compounds in the resulting wines. The result is a unique and complex wine with a luscious sweetness, heightened aromatics, and a distinct character.

Changes in the rainfall and temperature patterns affect the increase of drought periods becoming one of the major constraints to assure agricultural and crop resilience in the Mediterranean regions. Beside the adaptation of agricultural practices, also the microbial compartment associated to plants should be considered in the crop management. It is known that the microbial community change according to several factors such as soil composition, agricultural management system, plant variety and rootstock.