AUTHOR=Ranilla Lena Gálvez , Zolla Gastón , Afaray-Carazas Ana , Vera-Vega Miguel , Huanuqueño Hugo , Begazo-Gutiérrez Huber , Chirinos Rosana , Pedreschi Romina , Shetty Kalidas 

TITLE=Integrated metabolite analysis and health-relevant in vitro functionality of white, red, and orange maize (Zea mays L.) from the Peruvian Andean race Cabanita at different maturity stages

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1132228

DOI=10.3389/fnut.2023.1132228

ISSN=2296-861X

ABSTRACT=The high maize (Zea mays L.) diversity in Peru has been recognized worldwide, but the investigation focused on its integral health-relevant and bioactive characterization is limited. This research aimed at studying the variability of the primary and the secondary (free and dietary fiber-bound phenolic, and carotenoid compounds) metabolites, the in vitro antioxidant potential, and α-amylase and α-glucosidase inhibitory activities relevant for hyperglycemia management of three Cabanita maize types (white, red, and orange) at different maturity stages (milk-S1, dough-S2, and mature-S3). Results revealed a high effect of the maize type and the maturity stage. All maize types had hydroxybenzoic (HBA) and hydroxycinnamic acids (HCA) in their free phenolic fractions, whereas major bound phenolic compounds were ferulic acid, ferulic acid derivatives, and p-coumaric acid. Flavonoids such as luteolin derivatives and anthocyanins were specific in the orange and red maize, respectively. The orange and red groups showed higher phenolic ranges (free+bound) (223.9-274.4 mg/100 g DW, 193.4-229.8 mg/100 g DW for the orange and red maize, respectively) than the white maize (162.2-225.0 mg/100 g DW). Xanthophylls including lutein, zeaxanthin, neoxanthin and a lutein isomer were detected in all maize types. However, the orange maize showed the highest total carotenoid contents (3.19-5.87 µg/g DW). Most phenolic and carotenoid compounds decreased with kernel maturity in all cases. In relation to the primary metabolites, all maize types had similar fatty acid contents (linoleic acid>oleic acid>palmitic acid>α-linolenic acid>stearic acid) which increased with kernel development. Simple sugars, alcohols, amino acids, free fatty acids, organic acids, amines, and phytosterols declined along with grain maturity and were overall more abundant in white maize at S1. The in vitro functionality was similar among Cabanita maize types, but it decreased with the grain development, and showed a high correlation with the hydrophilic free phenolic fraction. The nutraceutical characteristics of orange and white maize are better at S1 and S2 stages because of their high phenolic, carotenoid contents (orange maize), in vitro functional properties, phytosterols, and better ω-6:ω-3 PUFAs (polyunsaturated fatty acids) ratios. The red Cabanita maize would be more beneficial at S3 due to its higher total anthocyanin and phenolic contents.