Function analysis of essential oils as environmental scents for improving undergraduate students emotional state

Plant essential oils are increasingly recognized for their potential to enhance emotional well-being in environmental fragrance design. However, studies on the specific effects of different essential oils in this context remain limited. This study evaluated the effects of 29 plant essential oils on emotional regulation among 1013 university students. The results showed that nine essential oils significantly improved emotional states, with sweet orange oil demonstrating the most notable effect, resulting in changes of −20.27 % and + 26.71 % in emotional indicators in the Profile of Mood States (POMS) and Semantic Differentiation Scale tests, respectively. Water lily, clove, and lavender oils also effectively alleviated stress and negative emotions, promoting calmness and positive feelings. Inhalation of water lily and sweet orange oils significantly reduced blood pressure, heart rate, and nervous system excitation while modulating electroencephalogram parameters. Specifically, water lily oil decreased levels of "Attention" and "Stress" by −15.68 % and −24.28 %, respectively, while sweet orange oil reduced "Focus" by −22.06 %. Furthermore, individual preferences for specific essential oils were positively correlated with their emotional benefits. These findings provide robust evidence that plant essential oils can regulate nervous system activity, improve emotional states, and alleviate stress. This study highlights their practical value as natural tools for fostering positive learning and living environments, offering scientific evidence and applications for emotional management in educational and indoor settings. • Conducted a large-scale evaluation of essential oils for emotional improvement. • Identification of nine essential oils with significant emotional benefits. • Inhalation of specific oils can lower physiological stress markers. • Highlighting the dual impact of some oils on emotional stress and attention.