title: Use of Modified Phenolic Thyme Extracts (Thymus vulgaris) with Reduced Polyphenol Oxidase Substrates as Anthocyanin Color and Stability Enhancing Agents.
abstract: Residual enzymatic activity in certain foods, particularly of polyphenoloxidase (PPO), is responsible for the majority of anthocyanin degradation in food systems, causing also parallel losses of other relevant nutrients. The present work explored the feasibility of modifying phenolic profiles of thyme extracts, by use of chromatographic resins, to obtain phenolic extracts capable of enhancing anthocyanin colour and stability in the presence of PPO activity. Results indicated that pretreatment of thyme extracts with strong-anion exchange resins (SAE) enhanced their copigmentation abilities with strawberry juice anthocyanins. Phenolic chromatographic profiles, by HPLC-PDA, also demonstrated that thyme extracts subjected to SAE treatments had significantly lower concentrations of certain phenolic compounds, but extracts retained their colour enhancing and anthocyanin stabilization capacities though copigmentation. Additional testing also indicated that SAE modified extract had a lower ability (73% decrease) to serve as PPO substrate, when compared to the unmodified extract. Phenolic profile modification process, reported herein, could be potentially used to manufacture modified anthocyanin-copigmentation food and cosmetic additives for colour-stabilizing applications with lower secondary degradation reactions in matrixes that contain PPO activity.
authors.affiliation: Centro de Biotecnología-FEMSA, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Campus Monterrey, Ave. Eugenio Garza Sada 2501 Sur, Monterrey, NL 64849, Mexico. alex.aguilar@itesm.mx.
authors.forename: Oscar
authors.initials: O
authors.lastname: Aguilar
authors.affiliation: Centro de Biotecnología-FEMSA, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Campus Monterrey, Ave. Eugenio Garza Sada 2501 Sur, Monterrey, NL 64849, Mexico. chbrenes@itesm.mx.
authors.forename: Carmen
authors.initials: C
authors.lastname: Hernández-Brenes
mesh_terms: D000837:Anion Exchange Resins / Q000737:chemistry; D000872:Anthocyanins / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001628:Beverages / Q000032:analysis*; D004156:Catechol Oxidase / Q000037:antagonists & inhibitors*; D003116:Color; D005519:Food Preservation / Q000379:methods; D031985:Fragaria / Q000737:chemistry*; D006801:Humans; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D000837:Anion Exchange Resins; D000872:Anthocyanins; D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D004156:Catechol Oxidase
keywords: anthocyanins; copigmentation; phenolics; polyphenoloxidase (PPO); thyme extracts