Metabolomics profiling and techno-functional characterization of freeze-dried pumpkin flower (Cucurbita maxima) powder for food fortification

Abstract Traditionally valued for their aesthetic and aromatic appeal, edible flowers are now recognized for their nutritional and medicinal benefits. They represent an affordable and sustainable plant-based food source with growing potential in functional food applications. This study aimed to determine the most suitable drying method for maintaining the nutritional quality of pumpkin flowers. Freeze-drying emerged as the optimal technique, effectively preserving vital nutrients. The resulting freeze-dried pumpkin flower powder underwent comprehensive evaluation, including physicochemical properties, proximate composition, bioactive compounds, and techno-functional attributes. Advanced characterization techniques such as X-ray diffraction, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and high-resolution mass spectrometry revealed an amorphous structure in the powder, indicated by a broad peak at 2θ = 21.57°. HR-MS analysis showed the presence of different functional compounds such as β-carotene, α-carotene, different types of flavonoids, organic acids, etc. The analysis identified key bioactive compounds, including beta-carotene, alpha-carotene, flavonoids, and organic acids, contributing to its high antioxidant activity (90.52%). Additionally, the powder demonstrated excellent solubility and thermal stability, making it suitable for various food applications. Elemental analysis confirmed a rich composition, with notable proportions of carbon (42.1%), nitrogen (8.1%), oxygen (43.4%), potassium (4.4%), and calcium (1.3%). These findings highlight the potential of freeze-dried pumpkin flower powder as a nutrient-dense, functional ingredient for fortified food products. This research underscores the viability of freeze-drying in enhancing the shelf life and nutritional value of edible flowers, positioning them as a promising ingredient in the health food industry. Graphical Abstract