Quality evaluation of citrus varieties based on phytochemical profiles and nutritional properties

Huan Guo; Yin-Jian Zheng; Ding-Tao Wu; Xu Du; Hong Gao; Mutamed Ayyash; De-Guang Zeng; Hua-Bin Li; Hong-Yan Liu; Ren-You Gan

doi:10.3389/fnut.2023.1165841

Quality evaluation of citrus varieties based on phytochemical profiles and nutritional properties

Front Nutr. 2023 May 18:10:1165841. doi: 10.3389/fnut.2023.1165841. eCollection 2023.

Authors

Huan Guo^{1

2}, Yin-Jian Zheng¹, Ding-Tao Wu³, Xu Du¹, Hong Gao², Mutamed Ayyash⁴, De-Guang Zeng⁵, Hua-Bin Li⁶, Hong-Yan Liu¹, Ren-You Gan⁷

Affiliations

¹ Research Center for Plants and Human Health, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, National Agricultural Science and Technology Center, Chengdu, China.
² College of Biomass Science and Engineering and Healthy Food Evaluation Research Center, Sichuan University, Chengdu, China.
³ Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering and Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, China.
⁴ Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al-Ain, United Arab Emirates.
⁵ Pujiang Yuanxiang Modern Agriculture Limited Company, Chengdu, China.
⁶ Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, China.
⁷ Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.

Abstract

Introduction: China is one of the major producers and exporters of various kinds of citrus fruits. As one of China's major citrus planting bases, Sichuan has a citrus planting area that exceeds 400,000 hectares. Meanwhile, citrus cultivation has become one of the important agricultural pillar industries in the region. Citrus fruits are reported to show various health-promoting effects, especially antioxidant activity. However, reports on the functional, nutritional and qualitative characteristics of different citrus varieties in Sichuan are still scarce.

Methods: The quality attributes (color parameters, shape, and size), juice properties (titratable acids and total soluble sugar), mineral elements, and health-promoting nutritional and functional components (protein, carbohydrates, fat, dietary fiber, ascorbic acid, phenolic acids, and flavonoids), as well as antioxidant properties of 10 typical citrus varieties cultivated in Sichuan, were systematically investigated and analyzed.

Results and discussion: Significant differences among different citrus varieties were found. In particular, the total soluble sugar content of Mingrijian was higher than that of other citrus, suggesting its potential for fresh consumption and food processing. Moreover, a total of five flavonoids and nine phenolic acids were identified and quantified. Yuanhong, with higher contents of ascorbic acid and phenolic acids, was considered to be a valuable variety with excellent antioxidant capacity and can be used for value-added processing in the food industry. Principal component analysis and hierarchical cluster heatmap analysis suggested that there were significant differences among the 10 citrus varieties. Correlation analysis confirmed the significant contribution of ascorbic acid and phenolic acids to antioxidant capacity in citrus. The results can provide some references for the cultivation and selection of nutritious citrus fruits.

Keywords: antioxidant activity; citrus; flavonoids; nutrients; phenolic acids.