Nutritional and phytochemical compositions and their interrelationship in succulent pods of pigeonpea (Cajanus cajan [L.] Millsp.)

Abe Shegro Gerrano; Abueng Moalafi; Hlabana A Seepe; Stephen Amoo; Hussein Shimelis

doi:10.1016/j.heliyon.2022.e09078

Nutritional and phytochemical compositions and their interrelationship in succulent pods of pigeonpea (Cajanus cajan [L.] Millsp.)

Heliyon. 2022 Mar 8;8(3):e09078. doi: 10.1016/j.heliyon.2022.e09078. eCollection 2022 Mar.

Authors

Abe Shegro Gerrano^{1

2}, Abueng Moalafi¹, Hlabana A Seepe¹, Stephen Amoo^{1

3

4}, Hussein Shimelis⁵

Affiliations

¹ Agricultural Research Council - Vegetables, Industrial and Medicinal Plants, Private Bag X293, Pretoria, 0001, South Africa.
² Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa.
³ Department of Botany and Plant Biotechnology, Faculty of Science, University of Johannesburg, South Africa.
⁴ Indigenous Knowledge Systems Centre, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa.
⁵ African Center for Crop Improvement, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa.

Abstract

Malnutrition remains one of the major human health issues affecting millions of people in sub-Saharan Africa (SSA). Hence, the objective of this study was to quantify the nutritional and phytochemical compositions of immature pods of pigeonpea genotypes to select promising lines with unique nutritional quality for production and cultivar development. Seven preliminarily tested and identified pigeonpea genotypes were grown under field conditions using a randomized complete block design with three replicates to quantify the nutritional and phytochemical contents in the immature pods. Significant (P ≤ 0.01) genotype effect was detected for the assessed nutritional and phytochemical compositions. Relatively higher contents of iron (15.53 mg/100g), zinc (1.59 mg/100g), magnesium (114.60 mg/100g) and total flavonoid (8.47 mg CE/g) were present in genotype Ilonga_14m1 ICEAP-0054. Higher compositions of beta-carotene (2.84 mg/100g), total phenolics (20.42 mg GAE/g), and vitamin-C (95.84 mg/100g) were detected in genotypes, Mali ICEAP-00046, PigeonP-3018 and Kiboko ICEAP-00932, respectively. Cluster analysis allocated the tested genotypes into three main groups. Significant (P ≤ 0.05) positive correlations were recorded among the assessed nutritional and phytochemical compositions that will allow direct and indirect selection of the evaluated genotypes for nutritional and phytochemical quality improvement. The principal component analysis resolved four components that cumulatively explained 76.85% of the total genetic variation in nutritional and phytochemical compositions among the tested genotypes of pigeonpea. Genotype PigeonP-3021 exhibited high levels of beta-carotene and vitamin C, while Kiboko ICEAP-00932 and PigeonP-3018 had high contents of aluminium, iron, phosphorus and total phenolics. Genotype Ilonga_14m1 ICEAP-0054 had high compositions of zinc, potassium, magnesium, copper and calcium. Unique pigeonpea genotypes (i.e., PigeonP-3021, Kiboko ICEAP-00932, and PigeonP-3018) were identified for quality breeding or direct production with promising nutrient profiles for food and nutrition security.

Keywords: Cluster analysis; Mineral elements; Phytochemicals; Pigeonpea; Principal component analysis.