Wine industry by-product: Full polyphenolic characterization of grape stalks

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Teixeira, N (Author) Other; Nuno Mateus (Author) FCUP; Victor de Freitas (Author) FCUP; Joana Oliveira (Author) FCUP

Journal

Title: Food Chemistry

Vol. 268

Pages: 110-117

ISSN: 0308-8146

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 43 Citations

Scopus - 50 Citations

Other information

Authenticus ID: P-00P-D9P

DOI: 10.1016/j.foodchem.2018.06.070

Abstract (EN): In this research work grape stalk samples from the Douro region were analyzed concerning polyphenolic composition. Different solid-liquid extraction conditions were tested for reaching the optimal parameters to obtain higher amounts of polyphenols. In general, the best conditions comprise the use of a mixture of acetone/ethanol/water (1:1:1) at room temperature during 20 min, using a pre-wash treatment with deionized water. The polyphenolic extractions with acetone are generally more effective than without acetone. Total phenolic determination (Folin-Ciocalteu), antioxidant capacity (DPPH/FRAP) and more accurate methods such as HPLC-DAD and HPLC-ESI-MS were performed. An intensive polyphenolic characterization (including a possible identification of a new polyphenol) and compound quantification was achieved. A comparative study between these two analysis approaches was accomplished, which allowed to conclude that the Folin-Ciocalteu and DPPH/FRAP determinations do not always allow a direct correspondence between high phenolic content or antioxidant/reducing capacity and real high polyphenolic content on crude polyphenolic extracts.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8