ABSTRACT
The grape pomace, the main by-product from the winemaking industry, contains many bioactive substances that must be valorized. The aim of this study was to assess the total phenolic content (TPC), phenolics profile by using HPLC and the antioxidant activity (AOA). The results showed a TPC of 38.86 ± 5.22 g gallic acid equivalent (GAE)/kg while an AOA of 247.84 ± 18.65 µmol Trolox equivalent (TE)/g. Epicatechins were the most representative phenolic compound, according to the HPLC analysis. Then, the grape pomace powder (GPP) was tested in the Rancimat equipment as a natural antioxidant for delaying the corn oil oxidation. Results showed statistically significant differences between the corn oil treated with GP and the control, so the GPP could be a promising natural antioxidant to tackle the oxidation vulnerability of corn oil.
Subject(s)
Vitis , Antioxidants , Corn Oil , Fruit/chemistry , Phenols/analysis , PowdersABSTRACT
The aims of this research are to compare and to monitor two conditions for preserving the total phenolic content (TPC) and the antioxidant activity (AOA) of grape pomace (GP) processed as powder and its corresponding extract at room and freezing temperature, respectively. The highest TPC and AOA were obtained in the GP extracted in a ratio 1:10 (w/v) with ethanol at 50% for 45 min at 50 °C. After 9 months of room temperature (RT) storage, the GP powder obtained a significantly higher AOA than the initial condition and the extract frozen-stored the same time.
