Abstract:
Due to their biologically active properties, polyphenols convert waste into attractive sources for the medical and
pharmaceutical products, their traditional management being varied towards other technological processes. The
identification of active principles derived from the polyphenolic extracts obtained from pressed grape marc can help
create an alternative use and recovery of by-products of wine, fact which increases their economic value. It also helps
assess the oenological potential of vine varieties and thus to assess their beneficial properties in maintaining metabolic
balance and health of the human body. In this context, the research in this paper aim to characterise the extracts
obtained from pressed grape marc by identifying and quantifying the major polyphenolic compounds in their
composition. To study the influence of the maceration technology on the content of polyphenolic compounds from byproducts of the winemaking process, grape samples of Fetească neagră, Băbească neagră, Cabernet Sauvignon, Merlot
and Arcaş grape varieties were processed using classical maceration, thermo-maceration, microwave maceration and
rotary tanks maceration (ROTO-tanks). The obtained polyphenolic extracts were analyzed by high performance liquid
chromatography (HPLC), several phenolic acids, stilbenes (trans-resveratrol) non-hydrolysable tannins (catechin and
epicatechin), some flavones (rutin and quercitin), and a number of anthocyan compounds being identified and
quantified. The results of the preliminary characterization showed quite similar values in the content of total
polyphenols and tannoid matters index. The maceration variants did not affect the amount of hydroxybenzoic and
hydroxycinnamic acids. The other polyphenolic compounds that were identified varied depending on the grape variety
and maceration technology used. The obtained data justifies the use of pressed grape marc as raw material to obtain
polyphenolic extracts, recommending further research on its biologically active properties (antiradical, antioxidant,
cytotoxic and cytostatic).
