Published: October 30, 2011 r2011 American Chemical Society 12330 dx.doi.org/10.1021/jf202662a | J. Agric. Food Chem. 2011, 59, 12330–12341 ARTICLE pubs.acs.org/JAFC Comparative Evaluation of the Antioxidant Potential of Infant Cereals Produced from Purple Wheat and Red Rice Grains and LC-MS Analysis of Their Anthocyanins Rhanissa Hirawan, † William Diehl-Jones, ‡ and Trust Beta* ,†,^ † Department of Food Science and ‡ Faculty of Nursing, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 ^ Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Smart Park, Winnipeg, Manitoba, Canada R3T 2N2 b S Supporting Information ABSTRACT: Cellular oxidative damage by endogenous and exogenous sources of free radicals and reactive oxygen species is a particular threat in infants. Antioxidant protection is normally achieved through a balance between pro-oxidants and endogenous and/or dietary antioxidants. Comprehensive research is required on optimization to achieve good antioxidant protection through infant foods, in particular, the commercially available infant cereals. This study therefore investigated the properties of whole purple wheat, unpolished red rice, and partially polished red rice before and after processing to produce infant cereals. Total phenolic content (TPC), total anthocyanin content (TAC), oxygen radical absorbance capacity (ORAC), individual anthocyanin components, and cellular antioxidant activity were measured. Home-made and laboratory-made pigmented infant cereals differed in that the latter required longer exposure to higher temperature and enzymatic hydrolysis. Home-made and laboratory-made unpolished red rice infant cereals showed higher total phenolic contents and peroxyl radical scavenging activity than home-made and laboratory-made purple wheat infant cereals; however, the latter had higher TAC. Pigmented infant cereals generally had higher TPC, TAC, and ORAC than the commercial ones (p < 0.05). Anthocyanins were identified in whole purple wheat, but they were not detected in unpolished red rice. C-Glycosyl apigenin was found in both whole purple wheat and unpolished red rice. Processing significantly decreased anthocyanin and C-glycosyl apigenin contents (p < 0.05). Purple wheat infant cereals had higher cellular antioxidant activity than unpolished red rice ones (p < 0.05). Whole purple wheat infant cereals showed higher antioxidant activity than the commercial infant cereal, suggesting a possibility of improving infant antioxidant status by incorporating this grain in their diet. KEYWORDS: infant cereals, purple wheat, red rice, antioxidant activity, anthocyanins ’ INTRODUCTION Infancy is the key developmental stage in life during which exponential growth and maturation occur. Oxidative stress, which is an imbalance between oxidants and reductants, can occur as a result of exposure either to inadequate endogenous antioxidant systems or via an overload in pro-oxidants. The resultant cellular and molecular damage is linked to a variety of pathologies, and thus proper antioxidant protection is required. 1 Dietary or “natural” antioxidants may be obtained through the diet. In this context, infant cereals, commonly introduced to babies at 4À6 months of age, may have the antioxidant potential to help mitigate oxidative stress. An inverse relationship between intake of whole grains and their products and the risk of chronic diseases has been shown in epidemiological studies. 2,3 Commercial infant cereals vary widely in composition. They are manufactured according to the dietary requirements of each major developmental stage of the infant. Infant cereals are primarily composed of cereal grains; however, there are addi- tional ingredients such as fruits, prebiotics, added nutrients (iron and vitamins), emulsifiers, whey protein concentrate, honey, plant oils, milk, and beetroot powder. Issues regarding the use of these semisolid foods include stage of introduction and allergic reactions. Processing of infant cereals includes toasting, boiling, drying, and hydrolysis to improve flavor and texture qualities, digestibility (mainly of starch), safety, and shelf life. 4 Pigmented grains, in particular, have been shown to have higher antioxidant potential than the regular nonpigmented cereals. 5À8 Red rice and purple wheat were selected for the model study of pigmented infant cereals because partially polished red rice infant cereal is a commonly consumed product in Indonesia and purple wheat is grown in Saskatchewan, Canada. Red rice anthocyanins are mainly in the form of cyanidin 3-glucoside, which is also found in purple wheat as the predominant constituent in addition to other anthocyanins. 7 Condensed tannins are also found in purple and red rice. 8 Red rice and purple wheat exhibited higher antioxidant activities in in vitro and in vivo models compared to nonpigmented rice and wheat. 5,6 The present study aimed to prepare prototype infant cereals using pigmented grains as primary raw ingredients and two types Received: July 4, 2011 Revised: October 27, 2011 Accepted: October 30, 2011