Nutritional quality assessment and germplasm screening of Moringa tender shoots as a novel woody vegetable: a multi-index comprehensive evaluation

Abstract

Abstract

Introduction Tender shoots of Moringa , a genus of perennial woody plants, offer a sustainable nutrient source with potential to diversify diets and support food security. Methods We conducted a comprehensive analysis of tender shoots from six Moringa accessions representing three species ( Moringa stenopetala (Baker f.) Cufod., Moringa concanensis Nimmo, and Moringa oleifera Lam.), assessing heavy metal contaminants, proximate composition, minerals, amino acids, bioactive compounds, and antioxidant capacity, and benchmarking them against six common vegetables using the index of nutritional quality (INQ), amino acid ratio coefficients, and multivariate statistics. Results All samples complied with national safety limits for the five heavy metals tested. The shoots combined high protein (28.04%–33.86% DW), low fat (2.49%–3.47% DW), and high vitamin C (150.22–235.54 mg/100 g FW) with a high-K, low-Na mineral profile and marked Se enrichment (0.68–2.05 mg/kg DW; Se INQ 5.17–15.70), far exceeding the reference vegetables. Sulfur-containing amino acids (Met + Cys) were the first limiting amino acids. Antioxidant capacity was strongest in the M. concanensis accessions and was tightly coupled to total phenols, carotenoids, and the mineral cofactors Ca, Mn, and Cu. An unsupervised PCA on 22 independent indicators ranked the accessions as BF1 > BF2 > DY > ZG1 > XB > ZG2, and OPLS regression identified nine core indicators (TAA(DPPH), TAA(ABTS), TAA(FRAP), Ca, carotenoids, SRC, Mn, total phenols, and Cu), with the composite ranking corroborated by single-indicator cross-validation. A 100-g serving of fresh shoots exceeds the adult vitamin C recommended intake, and 10 g of dried shoot powder supplies 11%–34% of the adult Se reference intake. Discussion These findings identify M. concanensis (BF1 and BF2) as elite germplasm for breeding high-quality woody vegetables and ZG1 as a candidate for Se-enriched products, and provide a replicable multi-index framework for evaluating woody vegetable resources.