Antioxidant activity of yerba mate extracts. Interactions between the individual polyphenols

JULIA VALERGA; ROBIN W SHORTHOSE; MARIA CECILIA LANARI

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2013 vol. 2013 p. 513 - 525

1438-7697

Yerba mate extracts contains strong antioxidants like chlorogenic (CL) and its derivatives, caffeic (C), quercetin (Q), rutin (R) and kaempferol (K) that may improve food products nutritional quality and rancidity. To obtain products with consistent activity and composition, we analysed the effect of yerba´s industrial processing on extracts composition, radical scavenging capacity (AA), inhibition of β-carotene/linoleic acid oxidation (AI) and ferric reducing/antioxidant power (RP).  We also determined the relationship between the composition of a mixture of C, CL, K, Q and R and their AA, RP and AI values. Industrial processing modified polyphenol composition and antioxidant activity of the yerba extracts. Pre-dried and dried/canchada leaves were the most appropriate raw materials combining optimum AA, RP and AI levels. Extract´s capacity to improve ground beef´s lipid stability was better than similar levels of α-tocopherol. Relationships between AA, RP or AI and polyphenol composition were satisfactorily predicted by a quadratic, a full or a reduced cubic models respectively. Simultaneous optimization of all models allowed determining the best and worst performing blends. Extracts contents of caffeic, chlorogenic and its derivatives, quercetin and rutin were within or under the limits of the least active region predicted and may account for the low activity levels observed.