Elsevier

Food Research International

Volume 105, March 2018, Pages 286-297
Food Research International

Comparison of chemical, color stability, and phenolic composition from pericarp of nine colored corn unique varieties in a beverage model

https://doi.org/10.1016/j.foodres.2017.11.038Get rights and content

Highlights

  • V6 corn variety had high condensed form, high C3G and longest anthocyanin half-life.

  • V5 and V6 corn varieties had some of the smallest changes in color over time.

  • Abundance of condensed forms with C3G in corn extracts contributed to stability.

  • V3, V5 and V6 corn varieties were the most stable after 12 weeks in a beverage.

Abstract

The objective was to compare the chemical stability and color of nine unique anthocyanin-rich colored corn varieties named/coded as V1, V2, V3… V9. Extracts were added to a beverage model and stored at 4 °C, 22 °C, or 32 °C for 12 weeks. After 12 weeks of storage at 32 °C, variety V6 [high condensed form (CF), high cyanidin-3-O-glucoside (C3G)] had the longest anthocyanin half-life, based on the quantification by HPLC. V3 [high pelargonidin (Pg), high acylated form (C3-mal)] and V5 (high CF, high C3G, high C3-mal) had the most favorable hue. V5 and V6 had some of the smallest changes in color over time. These findings suggest that an abundance of condensed forms with C3G in corn extracts could contribute to the improved stability. Beverage storage parameters also influenced color parameters; low temperatures and low pH enhanced color and anthocyanin stability. The most promising corn varieties for future experiments are V3, V5, and V6 based on color retention.

Introduction

Despite some consumer concerns regarding the use of artificial food colorants (Feingold, 1975, Stevens et al., 2014, Weiss, 2011) the Food and Drug Administration (Barrows, Lipman & Bailey, 2003) accepted the increase in the amount of added colorants in food products > 5-fold from 1950 (12 mg/capita/day) to 2012 (68 mg/capita/day).

Anthocyanins (ANC) are possible alternative to artificial colorants (Dia et al., 2015). Pelargonidin, cyanidin, delphinidin, petunidin, peonidin, and malvidin are the six major anthocyanidins from which the majority of ANC found in food are derived (de Pascual-Teresa and Sanchez-Ballesta, 2008). Once glycosylated, ANC can be further modified by the addition of acyl groups or by condensation via covalent bonding to flavan-3-ols. ANC can be found in a variety of plants such as dried purple waxy corncobs (Intuyoda et al., 2014), blueberries (Esposito, Chen, Grace, Komarnytsky, & Lila, 2014), Chinese bayberries (Zhang et al., 2011), among others. Many species of corn are produced around the world and grow in a variety of colors such as red, yellow, purple, green, blue, brown, and white. Some of the different types of ANC in corn include cyanidin 3-O-β-d-glucoside, pelargonidin (Pg) 3-O-β-d-glucoside, cyanidin 3-O-β-d-(6-malonyl-glucoside), pelargonidin 3-O-β-d-(6-malonyl-glucoside), and peonidin (Pn) 3-O-β-d-(6-malonyl-glucoside) (Aoki, Kuze, Kato, & Gen, 2002). Many of which were isolated from Peruvian purple corn grains (Zea mays L.) with cyanidin 3-O-β-d-glucoside having the largest concentration (Aoki et al., 2002). Even though there are several methods to improve natural pigments stability (Cortez, Luna-Vital, Margulis, & Gonzalez de Mejia, 2017), it is also relevant to generate plant varieties with more stable compounds (Marcon et al., 2016).

The stability of ANC is a significant factor that affects the quality of these critical natural pigments. It has been claimed that acylation with various phenolic acids makes specific ANC more heat resistant and enhance overall stability (Xu et al., 2015). ANC are compounds that might determine the quality of colored foods and their corresponding final products. The stability of ANC is determined by many factors that must be taken into consideration. For instance, pre-press procedures, processing, freezing and thawing, mashing and pressing, clarification, concentration, and storage will further reduce the final ANC concentration (Weber & Larsen, 2017).

The effects of gallic, ferulic, caffeic acids on ANC stability was studied by Qian, Liu, Zhao, Cai, and Jing (2017). Interestingly, ANC degradation was faster than the color fading. In this study, gallic, ferulic, caffeic acids showed a hypochromic effect. However, these copigments did not protect ANC from thermal degradation. Authors proposed that the ANC self-stacking might offer better thermal resistance than the copigmentation with phenolics; additional phenolic acids might interrupt ANC self-stacking or self-association and accelerate the pigment degradation.

There is a need to meet the consumer desire to find foods with natural colorants that will be functional for the food industry. The purpose of this study was to test and compare the stability of the phenolic composition and color of nine ANC rich colored corn variety extracts in a beverage model at 4 °C, 22 °C, and 32 °C over a 12-week period.

Section snippets

Chemical and reagents

Varieties of purple corn each distinguished by their unique pigment composition were generated at the University of Illinois at Urbana-Champaign (UIUC) from materials collected from the North Central Regional Plant Introduction Station (PI; Ames, IA, USA), the Maize Genetic Cooperation Stock Center (MGCSC; Urbana, IL, USA) or Siskiyou Seeds (Williams, OR, USA). Pericarp was removed from each variety as previously described (Somavat, Li, Gonzalez de Mejia, Liu, & Singh, 2016). Some of the key

Tristimulus colorimetric measurements

Color squares of the nine corn varieties presented in Fig. 1 shows the degradation of color over time for each temperature. Colors from ANC-rich extracts were acceptable for all varieties at week 0 based on industry standards. Corn varieties V3 and V5 retained their color best of the nine varieties. V3 contained high Pg, low condensed forms, low Pn, high C3-mal, high Pg3-mal, and high Pn3-mal; and V5 had low levels of Pn, high condensed forms, high C3G, low Pg, high C3-mal, and low acylated

Conclusion

Nine unique ANC-rich colored corn extracts were added to a beverage model and stored at different temperatures for 12 weeks. It was found that the high presence of condensed forms with C3G in the pigments from corn pericarp could potentially contribute to the color parameters and stability. Corn samples with high Pn had less stable pigments. Low temperatures and low pH promoted color and ANC stability. The ideal pigment composition for purple corn varieties with stable pigments are those similar

Conflicts of interest

None.

Funding

This work was partially supported by the Kraft-Heinz company #C3745.

Acknowledgements

Dr. Pavel Somavat for separating pericarp from corn kernels, undergraduate research assistants: Regina Cortez, Sharon Li, and Thomas Novak for their technical assistance.

References (39)

  • C. Alcalde-Eon et al.

    Color stabilization of red wines. A chemical and colloidal approach

    Journal of Agricultural and Food Chemistry

    (2014)
  • H. Aoki et al.

    Anthocyanins isolated from purple corn (Zea mays L.)

    Foods and Food Ingredients Journal of Japan

    (2002)
  • J.N. Barrows et al.

    Color additives: FDA's regulatory process and historical perspectives

    Food Safety Magazine

    (2003)
  • R. Boulton

    The copigmentation of anthocyanins and its role in the color of red wine: A critical review

    American Journal of Enology and Viticulture

    (2001)
  • J.A. Cardona et al.

    Color and polyphenolic stability in extracts produced from muscadine grape (Vitis rotundifolia) pomace

    Journal of Agricultural and Food Chemistry

    (2009)
  • R. Cortez et al.

    Natural pigments: Stabilization methods of anthocyanins for food applications

    Comprehensive Reviews in Food Science and Food Safety

    (2017)
  • V.P. Dia et al.

    Processing method and corn cultivar affected anthocyanin concentration from dried distillers grains with solubles

    Journal of Agricultural and Food Chemistry

    (2015)
  • D. Esposito et al.

    Inhibitory effects of wild blueberry anthocyanins and other flavonoids on biomarkers of acute and chronic inflammation in vitro

    Journal of Agricultural and Food Chemistry

    (2014)
  • B.F. Feingold

    Hyperkinesis and learning disabilities linked to artificial food flavors and colours

    American Journal of Nursing

    (1975)
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