DETERMINATION OF THE CHEMICAL COMPOSITION OF THE GRAPE POMACE OF DIFFERENT VARIETIES OF GRAPES

I.M. Pop, Silvia Mariana Pascariu, D. Simeanu, Cristina Radu-Rusu, Aida Albu

Abstract
    The by-products of the winemaking industry can be a source of animal feed, but they are still insufficiently studied in Romania in terms of their composition and nutritive value. The objective of the hereby study was the comparative assessment of the chemical content of the grape pomace, resulted from the winemaking process, of the white grapes (Aligoté variety, from Huşi area) and red grapes (Black Maiden, from Iaşi area), in two variants: with and without a stalk; the grape pomace was dried naturally at 20ºC. Measurements targeted the dry matter content (DM%); crude ash (CA%); crude protein (CP), crude fat (EE), crude fiber (CF) and total polyphenols (TP). The results obtained highlighted the significantly higher content of red grape pomace of CA, CP, EE and TP compared to the white grape pomace. The additional removing of the stalks in the case of the red pomace caused a significant increase of CF content and the EE content, without significant changes in the CP and TP content. The chemical composition, especially the content of CP, EE and TP are arguments in favour of the usage of grape pomace in the farm animals' nutrition, with the crude fibre level being limited for the poultry.

Key words: grape pomace, chemical composition, polyphenols, red and white grape