46C-32 |
Antioxidant and antimicrobial capacity of Mexican Oregano |
R. AVILA-SOSA, A. Avila-Camacho, J. V. Torres-Muñoz, M. G. Gastélum-Franco, and G. V. Nevárez-Moorillón. Food Science and Technology Graduate Program, Universidad Autonoma de Chihuahua, P.O.Box 1542-C, Chihuahua, 31170, Mexico Mexican Oregano (Lippia berlandierii) grows widely in the semiarid zone of the north part of Mexico. It is mainly used as condiment, and is known to have antimicrobial properties due to the high content of phenolic compounds. Oregano is also known to have antioxidant properties, which can be used as additives to foods. The two main components responsible for those properties are carvacrol and thymol, but some other compounds might have those capacities as well. The objective of this work was to evaluate the antimicrobial and antioxidant properties of different organic fractions of oregano from Chihuahua, Mexico. Fractions were obtained based on organic structure. Six fractions were obtained from a total plant chloroform extract by column chromatography, based on polarity. Two fractions (phenolic and non-phenolic) were obtained by liquid-liquid extraction. From the phenolic extraction, eighth fractions were separated by thin layer chromatography. All fractions were evaluated by inhibition of growth of three microorganisms (E. coli, S. aureus and B. cereus) for antimicrobial capacity. Antioxidant properties were determined by inhibition of oxidation of linoleic acid. All fractions were antimicrobials, with a higher effect against Gram positive. From the column chromatography fractions, Fraction III had the higher inhibition value. Non phenolic fraction inhibited B. cereus, and the firsts five fractions from the phenolic part were the most antimicrobials. Column chromatography fraction V had a high antioxidant capacity, as well as phenolic fraction 2. The later had a similar effect of a 0.1% BHT (positive control) at a 0.8% concentration Some of the fractions with antimicrobial or antioxidant capacities have no odor or color characteristic of oregano, and can be considered as by-products from oregano processed to obtain essential oil. Further study by GC/MS of all fractions is underway.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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