Comprehensive quality assessment of peppermint oils and commercial products: An integrated approach involving conventional and chiral GC/MS coupled with chemometrics

•A comprehensive study was conducted on a large set of peppermint EOs.•Conventional and chiral GC/MS along with chemometrics were utilized.•Substandard or adulterated EOs could be identified by single or combined methods.•Commercial oils originating from US, India or blend were predicted by chemometrics.•Possible forms of adulteration were explored.