Journal of Food and Nutrition Research, 2016, Vol. 4, No. 12, 760-772 Available online at http://pubs.sciepub.com/jfnr/4/12/1 ©Science and Education Publishing DOI:10.12691/jfnr-4-12-1 Total Phenolics and Antioxidant Capacity of Vegetables Grown in the Southwestern Andes Region of South America Fuentes Jocelyn 1 , Montoya Paulina 1 , Vio Fernando 1 , Speisky Hernan 1,2,* 1 Nutrition and Food Technology Institute (INTA), University of Chile, Santiago, Chile 2 Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile *Corresponding author: hspeisky@inta.uchile.cl Abstract The antioxidant richness of 69 species and/or varieties of vegetables grown in the southwestern Andes region of South America, including some endemic varieties, was evaluated in terms of their total phenolics (TP) and oxygen radical absorbance capacity (ORAC). Parsley, basil and coriander rank notably higher among those species that are commonly consumed in their raw state, exhibiting TP and ORAC values that are comparable to those reported earlier by us for various antioxidant-rich indigenous berries. For a given species, major differences were also seen among its varieties; in the case of tomatoes and lettuce, the maximal-to-minimal differences in ORAC values reached 16- and 28-fold, respectively. For those vegetables that are not consumed raw, the boil-cooking process affected differentially the antioxidant richness; for instance, while in the case of asparagus, chard, and lima beans boil-cooking induced major drops in ORAC (40-60%), in the case of artichoke bottoms a marked increase (35%) in ORAC was seen. Within the frame of building rankings of antioxidant richness, in the present work substantial data are also presented to highlight the concept that when assessing the antioxidant supply potential of any vegetable, besides quantifying its antioxidant richness per 100 g, considering its actual portion of consumption is also fundamental. On such basis, among the 29 vegetables analyzed in their cooked state, the endemic and regionally-grown Michuñe, Cabrita, and purple varieties of potatoes emerge as the top 3 antioxidant-rich plant foods. Keywords: antioxidants, vegetables, total phenolics, ORAC Cite This Article: Fuentes Jocelyn, Montoya Paulina, Vio Fernando, and Speisky Hernan, “Total Phenolics and Antioxidant Capacity of Vegetables Grown in the Southwestern Andes Region of South America.” Journal of Food and Nutrition Research, vol. 4, no. 12 (2016): 760-772. doi: 10.12691/jfnr-4-12-1. 1. Introduction The continuing interest in characterizing the antioxidant richness of fruits and vegetables (F&V) emerged from the early recognition that these foods can be an excellent source of antioxidants, and that by elevating their consumption the relative risk of developing certain cardiovascular and tumoral diseases can be significantly lowered [1,2,3,4,5,6]. Although several etiologic factors are likely to be involved in the initiation and/or progression of such diseases, most facts support the hypothesis that preventing the occurrence of oxidative stress and/or ameliorating its effects be fundamental towards achieving several of the health-beneficial effects associated with a higher consumption of antioxidant-rich F&V [6,7]. However, the protective cardiovascular (CV) effects of incrementing F&V consumption seems to arise not only from the ability of some of its bioactive compounds to act as antioxidants, but also from their ability to exert anti-inflammatory, anti-thrombotic, endothelial dysfunction-lessening, blood pressure-lowering, and/or lipid profile-normalizing actions [8]. In the case of tumoral diseases, although the overall cancer-preventive effects of enhancing the consumption of antioxidant-rich F&V in humans are still inconclusive [9], a broadly accepted scientific notion exists that some of the compounds present in F&V, besides having antioxidant properties, have the potential to exert chemotherapeutic actions [10]. From a mechanistic point of view, some of the antioxidant activity-carrying molecules could also exert anti-tumoral effects by promoting anti-mutagenic, anti-proliferative, pro-apoptotic, and/or anti-angiogenic actions [11,12]. With very few exceptions, phenolic compounds account for most of the antioxidant activity found in F&V, and although some of these foods can also be an excellent source of certain non-phenolic antioxidants, vitamins, trace minerals and dietary fiber, the high presence of polyphenols is still regarded as a major contributor to the CV benefits associated with an elevated consumption of F&V [13]. In view of the latter, the total content of these compounds (i.e., total phenolics or TP) has been long assayed as an indirect but suitable form of estimating the polyphenol-related antioxidant richness of plant-derived foods. At the epidemiological level, inverse correlations between the dietary intake of flavonoids and the incidence