Survey of Anthocyanin Composition and Concentration in Diverse Maize Germplasms

Increasing consumer demand for natural ingredients in foods and beverages justifies investigations into more economic sources of natural colorants. In this study, 398 genetically diverse pigmented accessions of maize were analyzed using HPLC to characterize the diversity of anthocyanin composition and concentration in maize germplasm. One hundred and sixty-seven accessions were identified that could produce anthocyanins in the kernel pericarp or aleurone and were classified into compositional categories. Anthocyanin content was highest in pericarp-pigmented accessions with flavanol–anthocyanin condensed forms, similar to the Andean <i>Maı́z Morado</i> landraces. A selected subset of accessions exhibited high broad-sense heritability estimates for anthocyanin production, indicating this trait can be manipulated through breeding. This study represents the most comprehensive screening of pigmented maize lines to date and will provide information to plant breeders looking to develop anthocyanin-rich maize hybrids as an economic source of natural colorants in foods and beverages

Processing Method and Corn Cultivar Affected Anthocyanin Concentration from Dried Distillers Grains with Solubles

Anthocyanins are water-soluble pigments with health benefits and potential use as food colorants. The objectives of this work were to (1) determine optimum parameters for the extraction of anthocyanins from dried distillers grain with solubles (DDGS), (2) develop a method of anthocyanin extraction from DDGS, (3) quantify and identify the extracted anthocyanins, and (4) determine the effect of processing methods and corn cultivars on anthocyanin concentration. DDGS samples were prepared from purple (PC) and dark (DC) corn and processed using conventional enzymes (C) and granular starch hydrolyzing enzymes (GC). Three independent variables (ethanol concentration (0, 12.5, and 25%); liquid-to-solid ratio (30:1, 40:1, 50:1 mL/g); and extraction temperature (4, 22, and 40 °C)) and two dependent variables (anthocyanin concentration and <i>a</i>-value (redness)) were used. Results showed that dark corn DDGS gave anthocyanin concentration higher than that of purple corn. The GC process showed total anthocyanin concentration higher than that of the conventional method of DDGS production. The maximum anthocyanin concentration was obtained at 12.5% ethanol, 40:1 liquid-to-solid ratio, and 22 °C for C-PC [321.0 ± 37.3 μg cyanidin-3 glucoside (C3G) equivalent/g DDGS]. For GC-PC, 25% ethanol, 30:1 liquid-to-solid ratio, and 22 °C gave 741.4 ± 12.8 μg C3G equivalent/g DDGS. For GC-DC, 12.5% ethanol, 40:1 liquid-to-solid ratio, and 40 °C extraction gave 1573.4 ± 84.0 μg C3G equivalent/g DDGS. LC/MS-MS analysis showed that the major anthocyanins were cyanidin-3-glucoside, cyanidin-3-(6″-malonyl) glucoside, and peonidin-3-(6″malonyl) glucoside. In conclusion, anthocyanin extraction from colored corn DDGS can be optimized using 12.5% ethanol, 40:1 mL/g ratio, and 22 °C

Temperature Dependency of Shelf and Thermal Stabilities of Anthocyanins from Corn Distillers’ Dried Grains with Solubles in Different Ethanol Extracts and a Commercially Available Beverage

The objective was to determine the shelf and thermal stabilities of anthocyanins from distillers’ dried grains with solubles (DDGS) extracted with different ethanol concentrations as well as a semi-purified Maiz Morado (purple corn) anthocyanin extract added to a commercially available beverage. Storage for 6 weeks of DDGS showed an overall reduction of anthocyanins from 6.8 to 73.7%. In DDGS, an ethanol increase from 0 to 25% resulted in less sensitivity of anthocyanin to temperature changes. Acylation resulted in faster degradation and higher reaction rate constants than their corresponding non-acylated forms. Anthocyanin changes were accompanied by an overall increase in lightness and a decrease in redness. Storage of beverage for 12 weeks at 4 °C resulted in a 25.5% reduction of anthocyanin. Results have important implications in selecting colored corn as an economical source of food colorants