Nutritive importance of by-products from winemaking process for feed industry interest

The objective of this work was to study the nutritional composition of winemaking by-products as grape marc (GM) of the varieties Tamaioasa romaneasca (TMGM), Burgund mare (BMGM), Merlot (MGM) and Riesling Italian (RIGM) cultivated under the Controlled Designation of Origin (DOC) of Wines in Pietroasa vineyard, Romania. GM samples were conditioned in a forced air oven at 55 degrees C for 24 h. Dry matter, crude protein, cellulose, crude ash, crude lipids, fatty acids and amino acids of the GM by-products from the winemaking processes were analysed. TRGM variety showed the highest amount of total amino acids compounds (8.5 g/100 g) compared to RIGM variety (7.7 g/100 g). A source of linolenic acid (omega-3 fatty acids) was found for BMGM variety (0.31 g/100 g total FAME) and linoleic acids (omega-6 fatty acids) for the MGM (63.54 g/100 g total FAME) and RIGM (61.39 g/100 g total FAME) samples. Infrared spectroscopy (ATR-FTIR) was used to qualitatively determinate the chemical functional groups of GM samples. Differences between the samples spectra in region of 1800-700 cm(-1) (fingerprint) were detected. The results prove the importance of these added-value by-products with great applicability in feed industry.