Biowastes generated from agricultural industries constitute a new source for added value products that can be used in the polymer industry. Grape marc, a residue of the winery industry, is well‐known to be a rich source of polyphenols. The present work reports the use of polyphenol cocktail extracted from black Pinot grape marc as natural antioxidant in polyolefins. The purpose is to advance in the field of green stabilizer, by using an innovating approach based on the direct use of an efficient cocktail rather than a single original molecule to stabilize polymer. The antioxidant efficiency of polyphenol cocktail is measured against photo‐ and thermo‐oxidation conditions in the well‐known polypropylene polyolefin. Attention is paid to molecular structure evolution by rheology, and the efficiency to delay oxidation by‐product formation is monitored with infrared. The results confirm that cocktail approach is a promising route to develop green stabilizers.