Structural Characterization and Antioxidant Capacity of Quinoa Cultivars Using Techniques of FT-MIR and UHPLC/ESI-Orbitrap MS Spectroscopy

Abstract

The existence of more of 16,000 varieties of quinoa accessions around the world has caused a disregard on their structural and phytochemical characteristics. Most of such accessions belong to cultivars settled in Colombia. The goal of this research was to evaluate the structural attributes and antioxidant capacities from six quinoa cultivars with high productive potential from central regions in Colombia. This study used middle-range infrared spectroscopy (IR-MIR) to determine the proteins, starch and lipids distinctive to quinoa grains. Ultra-high-performance liquid chromatography electrospray ionization Orbitrap, along with high-resolution mass spectrometry (UHPLC/ESI-Orbitrap MS), were also used to identify the existence of polyphenols in cultivars. The antioxidant capacity was determined through DPPH, ABTS and FRAP. The spectrums exhibited significant variances on the transmittance bands associated with 2922 cm−1, 1016 cm−1 and 1633 cm−1. Moreover, the intensity variations on the peaks from the secondary protein structure were identified, mainly on the bands associated with β-Sheet-1 and -2, random coil α elice and β-turns-2 and -3. Changes found in the ratios 996 cm−1/1014 cm−1 and 1041 cm−1/1014 cm−1 were associated with the crystalline/amorphous affinity. Regarding the antioxidant capacity, great differences were identified (p < 0.001) mainly through FRAP methods, while the phenolic acids and flavonoids were determined by UHPLC/ESI-Orbitrap MS techniques. The presence of apigenin and pinocembrin on grains was reported for the first time. Titicaca and Nariño were the most phytochemically diverse quinoa seeds.

Diversity of quinoa genetic resources for sustainable production: A survey on nutritive characteristics as influenced by environmental conditions

“…Specific starch and amylopectin structure give quinoa starch various functional properties that can be used in a wide range of food products (Li et al, 2016;Aluwi et al, 2017;Li and Zhu, 2017). Nevertheless, climatic conditions during the growing season may alter final functionality, even though starch biosynthesis is determined primarily by genetics (Garcia-Parra et al, 2021. Additionally, seed color seems to correlate with starch physiochemical properties, as reported by Peng et al (2022), in opposition to Li et al (2016), describing no correlation between the seed color and starch characteristics.…”

“…and Gargiulo et al (2019) discovered protein content of 18.73-20.60%, whileGarcia-Parra et al (2021) andGarcia-Parra et al (2022) achieved lower values (14.5-15.5%, respectively) during experiments conducted in Colombia. Genotype "Cahuil" originating in central Chile was investigated in a total of three studies Miranda et al (2012).…”

Worldwide Evaluations of Quinoa—Biodiversity and Food Security under Climate Change Pressures: Advances and Perspectives

“…Hussain et al [ 24 ] summarized recent findings regarding the nutritional and phytochemical properties of quinoa grains. A spectroscopy analysis of different quinoa cultivars grown under greenhouse conditions was conducted by García-Parra et al [ 25 ] to evaluate the structural characterization and antioxidant capacity of quinoa.…”

Nutritional Evaluation of Quinoa Genetic Resources Growing in the Climatic Conditions of Central Europe

“…On the other hand, the reported nutritional composition and nutrient content of quinoa is highly variable throughout the literature. Besides the effect of genotype, nutrient content and composition of quinoa were previously reported to be influenced by agroecological conditions [ 18 , 19 , 20 ], as well as the metabolomic and morphological characteristics of the plant itself [ 21 ].…”