Journal
FOOD AND BIOPROCESS TECHNOLOGY
Volume 6, Issue 5, Pages 1281-1289Publisher
SPRINGER
DOI: 10.1007/s11947-012-0869-7
Keywords
Grape pomace; Pulsed ohmic heating; Cell membrane denaturation; Polyphenol content
Categories
Funding
- society KSARA (Lebanon)
Ask authors/readers for more resources
The present work is devoted to the investigation of the effect of pulsed ohmic heating (POH) on cells membrane damage and intensification of polyphenols extraction from red grape pomace. Untreated, POH-treated and freeze-thawed samples were compared. The effects of electric field strength (E = 100-800 V/cm) and the percentage of ethanol in water (E/W = 0-50 %) on polyphenols extraction were discussed. Measurements of electrical conductivity and electric energy consumption were performed for POH pretreatment optimization. Results show that POH treatment results in cells membrane denaturation. This permeabilization increases with the elevation of electric field strength and temperature. POH pretreatment accelerates the extraction kinetics of total polyphenols from grape pomace. Freeze-thawed samples are always accompanied with a high degree of cell damage and high concentration of polyphenols in the extract. The highest extraction yields were obtained with a POH pretreatment at 400 V/cm followed by a diffusion step for 60 min at 50 A degrees C and with a solvent composed of 30 % of ethanol in water. In these conditions, the polyphenol content was 36 % more than untreated samples. The proposed technique (POH pretreatment) appears to be promising for future industrial applications of polyphenols extraction from pomace.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available