PRODUCTION OF A FUNCTIONAL BEVERAGE FROM WINEMAKING BY-PRODUCTS: A NEW WAY OF VALORISATION

Microplastics can alter physicochemical and biogeochemical processes in the soil, but whether these changes have further effects on soil fertility, and if so, whether these effects vary depending on the type of soil in the vineyard and the type of plastic used in the vineyard. Knowing what types of plastics are currently used in vineyards in Slovenian viticultural regions as strings to tie vines to the stake, the aim of our study was to assess the effects of microplastic particles from polypropylene (PP) and polyvinyl chloride (PVC) on the availability of macro (potassium (K), Potassium (K), calcium (Ca), magnesium (Mg) and phosphate (P)) and micronutrients (iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn)) in two vineyard soils contrasting in pH and mineralogy. For this purpose, a short-term soil incubation experiment (120 days) was carried out in which the soil samples were enriched with micro-PP and micro-PVC particles. After the incubation period, macro- and micronutrient availability were measured.

In Italy, in the past two decades, the rate of temperature increases (0.0369 °C per year) was slightly higher compared to the world average (0.0313 °C per year). It has also been indicated that the number and intensity of heat waves have increased considerably in the last decades. (IEA, 2022). Viticultural zones can be classified with climatic indexes. Huglin’s index (HI) considers the temperature in a definite area and has been considered as reliable to evaluate the thermal suitability for winegrape production (Zhang et al., 2023).

Mousy off-flavor is one of the defects of microbial origin in wine. It is described as a particularly unpleasant defect reminiscent of rodent urine (a “dirty mouse cage”), and grilled foods such as popcorn, rice, crackers, and bread crust. Prior to the 2010s, mousiness was very uncommon but it has been becoming more frequent in recent years. It is often associated with an increase in pH as well as certain oenological practices, which tend to significantly decrease the use of sulfur dioxide.

Quercetin (Q) is present in grape in form of glycosides and as aglycone. These compounds are extracted from grape skins during winemaking. In wines, following the hydrolysis reactions, the amount of quercetin aglycon can exceed its solubility value. Unfortunately, a threshold solubility concentration for quercetin in wine is not easy to determine because it depends on wine matrix (Gambuti et al., 2020).

Interspecific hybrid winegrapes are of growing interest in the context of climate change based on their disease resistance and cold hardiness. In addition to a need for increased understanding of their chemical composition, there is little empirical evidence on the consumer perception of non-vinifera wine. Phenolic compounds, and particularly color, play an important organoleptic and quality determination role in wine, but can vary significantly in interspecific hybrid wines compared to wines produced from Vitis vinifera cultivars [1, 2, 3]. Anecdotally, the variation in anthocyanin species, interactions, and concentrations in interspecific hybrids could result in a variance from“vinifera-like” wine color.