Identification and Quantitation of Phenolic Compounds from the Seed and Pomace of Perilla frutescens Using HPLC/PDA and HPLC-ESI/QTOF/MS/MS

IntroductionPerilla frutescens (L.) Britt., an essential traditional Asian crop and Chinese medicine, potentially exerts anti-oxidation effects through its phenolic compounds. These compounds have already been reported in perilla seed, however, little is reported in Perilla pomace, the primary waste during oil production of Perilla seed. ObjectiveTo investigate major phenolic compounds in perilla seeds and pomaces in order to check whether the pomace could be an alternative resource to the seed for nutritional and medical purposes. MethodsCompounds in extracts of perilla seeds and pomaces were separated by high-performance liquid chromatography and detected by photodiode array, and by electrospray ionisation with quadrupole time-of-flight tandem mass spectrometry. Herb-markers selected by principal components analysis were then quantified in both seeds and pomaces. Moreover, a fingerprinting approach and multiple discriminant analysis were applied to screen the phenolic markers in 22 samples. ResultsTen phenols were tentatively identified, among which four (rosmarinic acid, luteolin, apigenin and rosmarinic acid-3-O-glucoside) were selected as herb-markers. Perilla seeds and pomaces showed similar phenol profiles, however, the pomaces contained almost two times the amount of the four herb-markers than the seeds. ConclusionThe results indicated perilla pomace is a promising alternative source of phenolic compounds that could be recovered and potentially used as natural anti-oxidants. Copyright (c) 2014 John Wiley & Sons, Ltd. Phenolic compounds of Perilla frutescens were considered as major contributors for their anti-oxidation effects. A fingerprinting approach combined with multiple discriminant analysis were adopted to analyse phenolic compounds from perilla seeds and their pomaces by HPLC/PDA and HPLC-ESI/QTOF/MS/MS. Ten phenolic compounds were identified. The fingerprinting patterns were very similar between seed and pomace, however, the contents of four major phenols were about twofold greater in pomaces than in perilla seeds, indicating that perilla pomace is a promising source of phenolic compounds.