Nutritional and physicochemical characteristics of purple sweet corn juice before and after boiling

PLoS One. 2020 May 11;15(5):e0233094. doi: 10.1371/journal.pone.0233094. eCollection 2020.

Abstract

Sweet corn juice is becoming increasingly popular in China. In order to provide valuable health-related information to consumers, the nutritional and physicochemical characteristics of raw and boiled purple sweet corn juices were herein investigated. Sugars, antinutrients, total free phenols, anthocyanins, and antioxidant activity were analyzed by conventional chemical methods. The viscosity and stability of juices were determined by Ubbelohde viscosity meter and centrifugation, respectively. Boiling process could elevate viscosity, stability and sugar content, and reduce antinutrients, total free phenols, anthocyanins, and antioxidant activity in corn juice. In addition, short time boiling efficiently reduced the degradation of anthocyanins during subsequent refrigeration. The content of amino acids, vitamin B1/B2 and E were detected by High Performance Liquid Chromatography. Gas Chromatography Mass Spectrometry was used for the analysis of fatty acids and aroma compounds. Several aroma compounds not previously reported in corn were identified, including 1-heptanol, 2-methyl-2-butenal, (Z)-3-nonen-1-ol, 3-ethyl-2-methyl-1,3-hexadiene, and 2,4-bis(1,1-dimethylethyl)phenol. Interestingly, the boiling process had no apparent effect on the amino acids profile, but it caused a 45.8% loss of fatty acids in the juice by promoting the retention of fatty acids in the corn residue. These results provide detailed information that could be used for increasing consumers' knowledge of sweet corn juice, further development of sweet corn juice by food producers, and maize breeding programs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / analysis
  • Amino Acids / analysis
  • Anthocyanins / analysis
  • Antioxidants / analysis
  • Chromatography, High Pressure Liquid
  • Gas Chromatography-Mass Spectrometry
  • Heptanol / analysis
  • Phenols / analysis
  • Plant Extracts / analysis
  • Riboflavin / analysis
  • Thiamine / analysis
  • Zea mays / chemistry*

Substances

  • Aldehydes
  • Amino Acids
  • Anthocyanins
  • Antioxidants
  • Phenols
  • Plant Extracts
  • 2-methyl-2-butenal
  • Heptanol
  • Riboflavin
  • Thiamine

Grants and funding

YL received two fundings. The National Key Research and Development Program of China (2018YFD0100100) and Science and technology support program of Sichuan province, China (2016NYZ0029). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.