Advances in phenolic compounds analysis of aromatic herbs and their potential applications.

Introduction: Herbs can be considered important sources of antioxidants and have a long history of medicinal and culinary applications. The use of plants as sources of antioxidants for nutritional and preservation purposes in the food industry is currently growing. Materials and Methods: An extensive bibliographic review on the methods for analysis of phenolic compounds present in herbs was carried out. Results, Discussion and Conclusion: Plant derived phenolic compounds can be divided in four groups: phenolic acids, phenolic diterpenes, flavonoids and volatile compounds. Considering the first three groups, the identification and quantification of the compounds in the literature is accomplished using High Performance Liquid Chromatography while for volatile compounds, the identification and quantification is accomplished with Gas Chromatography. Several herbs, such as sage (Salvia officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), oregano (Origanum majorana), dandelion (Taraxacum officinale), peppermint (Mentha piperita) and basil (Ocimum basilicum) were analyzed in different studies regarding their phenolic compounds. The major phenolic acids found in herbs were ferulic, caffeic, neochlorogenic and rosmarinic. In terms of phenolic diterpenes, carnosol, rosmanol and carnosic acid were the most reported. Regarding flavonoids, luteolin, quercetin and apigenin were predominant. Concerning volatile compounds, thymol, carvacrol and eugenol were the most common. The herbs with more antioxidant potential regarding their composition on phenolic compounds were compared and the potential of utilisation of these food matrices for newer applications such as active packaging was discussed.