Comparative characterization of nutritional and aroma profiles among seven Chinese flowering cabbage (Brassica rapa var. parachinensis L.) varieties.

Abstract

This study systematically compared nutritional and aroma profiles of Chinese flowering cabbage varieties, including conventional (pointed- and round-leaf) and late-maturing types. Late-maturing varieties had higher soluble sugars, vitamin C, free amino acids, and glucosinolates, while conventional types were richer in protein, flavonoids, phenolics, and chlorophyll. HS-SPME-GC-MS-O detected 48 volatiles and 22 aroma-active compounds, most abundant in late-maturing varieties and simplest in round-leaf types. Fifteen key aroma compounds were identified via OAVs, reconstitution, and omission tests. Six glucosinolate degradation products (isothiocyanates and nitriles) were major contributors to pungency, while aldehydes, ketones, alcohols, and esters provided green, fruity, and floral notes that balanced the pungency; representative compounds included (E)-2-hexenal, benzeneacetaldehyde, nonanal, β-cyclocitral, and β-ionone. HS-GC-IMS identified 92 C2-C10 VOCs, mainly esters, alcohols, ketones, and aldehydes. Electronic nose analysis confirmed the VOC composition patterns. Multivariate analyses (PCA and PLS-DA) effectively differentiated the varieties and identified 22 marker VOCs.