Consumer interest in vegetable crops as sources of functional and health-promoting compounds has markedly increased in recent years. However, knowledge regarding the seasonal dynamics of chemical composition in perennial Allium species remains limited, representing a gap in understanding the nutritional optimisation of these species. This study aimed to characterise the seasonal variation in chemical properties of five perennial Allium species cultivated under uniform field conditions in Lithuania during 2023–2024. The concentrations of total sugars, ascorbic acid, soluble solids, dry matter, and nitrates were determined using standard analytical methods. The results showed that the highest levels of total sugars, ascorbic acid, soluble solids, and dry matter were recorded in spring, followed by gradual declines in summer and autumn. A. schoenoprasum L. and A. ursinum L. exhibited the highest dry matter (14.9–15.9%), total sugars (5.4–5.7%), and total soluble solids (11.5–12.0%). A. ursinum L. exhibited the highest ascorbic acid content (97.0 mg 100 g−¹ FW) and the lowest nitrate concentration. These findings emphasise the importance of harvest timing in maximising the nutritional and functional potential of perennial Allium species and provide valuable information for breeding and cultivation strategies aimed at diversifying high-value vegetable crops under temperate climatic conditions.
Čepulienė et al. (Tue,) studied this question.