Sure because secondary metabolites extraction varies from solvent to solvent.

Yes, Arvind, solvent have a crucail importance! There are some antioxidants (tocopherol) what require non-polar solvent. Moreover, solvent is cruail alos for stabiluty of some antioxuants. For exmap0le, for ascorbate and gluthatione racid pH (3 of 6% MPA) is require to keep stabilty and prevent oxidation. Some of summary you can find here: Kothari, V., Gupta, A., & Naraniwal, M. (2012). Comparative study of various methods for extraction of antioxidant and antibacterial compounds from plant seeds. Journal of Natural Remedies, 12(2), 162-173.

Yes

Dear Researcher

Solvent extraction is most frequently used technique for isolation of plant antioxidant compounds. However, the extract yields and resulting antioxidant activities of the plant materials are strongly dependent on the nature of extracting solvent, due to the presence of different antioxidant compounds of varied chemical characteristics and polarities that may or may not be soluble in a particular solvent. Polar solvents are frequently employed for the recovery of polyphenols from a plant matrix. The most

suitable of these solvents are (hot or cold) aqueous mixtures containing ethanol, methanol, acetone and ethyl acetate. Methanol and ethanol have been extensively used to extract antioxidant compounds from various plants and plant-based foods.

Yes proper solvent selection for extraction of antioxidants is very important step. The extractability of antioxidant compound primarily depends on the type solvent (polar, mid polar or non-polar). 

While type of extraction technique, temperature, time and others are all seccondary factors in antioxidants extraction

The solvent is very important for extracting antioxidants. For example, antioxidant abietanes bearing quinone moieties need just acetone with the use of soxhlet while polyphenols extractions need more polar solvents like alcohols see food chemistry 2007, 102, 1281-1287.

Good luck

Yes solvent is most essential step to isolate anti-oxidant compounds that after solubilization chances are conversion of functional groups, or liberation of free radicals, or release of ionization groups will be there, it will effect artificially free radical determination in DPPH assay. Polarity is also important that keeps a check over the formation of free radicals in weak sate or dissolution of any terminal groups.

Of course dear Arvind,  solvent  has the vital role in extraction of antioxidant phychemicals from plant s/natural source.

Yes solvent very important to extraction but there is a difference in the ability of the solvent and water is also considered one of solvents used to extract antioxidants.

Currently, there are many research using green solvents in the process of extraction antioxidants

So we suggest that you first choose the type of method used in the extraction and then choose the type solvent and most of the research used methanol, but the risk to health

Yeah,  solvent polarity certainly affect the composition in antioxidant constituents of the resulting extract. Carefully select the solvent  to be used as extracts have solvent-dependent  antioxidant effects.

Yes sir, all bio-molecules require an medium to release on the basis of their polarity. Antioxidant can't be rely on gases phase and liquid phase is best to dissolve the antioxidant and preserve as well. Hence, solvents are must to extract polyphenols or antioxidants.