Recovery of phenolic antioxidants from wine industry by-products

Ultrasound-assisted Extraction of Polyphenols from Red-grape (Vitis Vinifera) Residues

“…In a more recent study, Medina et al (2002) reported that non purified extracts from grape bagasse, with a high content of glycoside compounds concentration, were not efficient whilst purified fractions were able to delay oxidative rancidity in oils and emulsions. These results agree with Louli et al (2004) who stated that in order to improve the antioxidant activity, it is necessary to purify the obtained extract by removing all inert and undesirable components. According to above, it might be possible that the antioxidant activity of the extracted polyphenols was diminished due to the presence of other components in the extract.…”

“…Thus, these results validate the comparison of sonicated samples against the controls that were utilized in the preset study. It is important to stand out that similar studies (Pinelo, 2004;Louli et al, 2004) reported TEY from red-grape residues between 12.3 and 14.9%, which are a bit higher from the values reported for control samples in the present study. However, these differences may correspond to differences in grape varieties or perhaps due to differences in the initial moisture content.…”

Production trials to improve the nutritional quality of biscuits and to enrich them with natural anthocyanins

“…Major interest was put toward grape and grape marc because of their large availability in the area where the research was carried out. In particular, the use of grape marc, an abundant and low-cost by-product of wine making, has been recently proposed for the extraction of antioxidant phenolic compounds (Fiori, De Faveri, Casazza, & Perego, 2009;Louli, Ragoussis, & Magoulas, 2004;Pinelo et al, 2007). Higher levels of anthocyanins were observed in grape skin than in whole berries (table grape, cv.…”

Grape by-products: extraction of polyphenolic compounds using supercritical CO2and liquid organic solvent – a preliminary investigation Subproductos de la uva: extracción de compuestos polifenólicos usando CO2supercrítico y disolventes orgánicos líquidos – una investigación preliminar

“…Arce, Lista, Rios, and Valcarcel (2001) and Palenzuela, Rodriguez-Amaro, Rios, and Valcarel (2002) developed different systems for the on-line screening of polyphenols extracted from grape marc by supercritical fluid; various cultivars were tested and the total content of polyphenols resulted in the range 81-192 mg/kg (Palenzuela et al, 2002). Louli, Ragoussis, and Magoulas (2004) presented a procedure to recover phenolic antioxidants from grape marc; the process involved two basic steps: liquid solvent extraction and purification of the dried extract by means of supercritical CO 2 . Ashraf- Khorassani and Taylor (2004) extracted Chardonnay grape seeds by means of three different steps in the following sequence: supercritical pure CO 2 was used to remove the oil, then 40% methanol-modified CO 2 was used for the extraction of monomeric polyphenols, finally pure methanol at high pressure was used to recover polyphenolic dimers and trimers and procyanidins.…”