Valorising Saffron Petal, a Study on Nutritional Potential; Phytochemical, Antimicrobial and Antidiuretic Activity of a Promising Agro by Product

Crocus sativus L. yields substantial by-products especially petals which are abundant in bioactive compounds that have valuable nutritional potential. The aim of this study is to analyse the techno-functional, antioxidant, antimicrobial and antidiabetic activity of saffron petal extracted by ultrasound, microwave and conventional extraction techniques. Techno-functional analysis revealed ash, protein and fibre content was found to be 7.31%, 9.46% and 15.15%, respectively. In addition, petal showed high concentration of minerals like potassium (97.5 ppm), calcium (22.16 ppm) and iron (30 ppm). High performance liquid chromatography analysis detected bioactive compounds with vanillin acid (22.44 mg/mL), ellagic acid (218.18 mg/mL) and quercetin (65.04 mg/mL) as dominant compounds. Anthocyanins such as delphinidin, petunidin 3-glucoside and malvidin glycoside were also detected. Amongst extraction techniques, ultrasound assisted petal extract exhibited high anthocyanin content (200.10 mg G₃G 100 g^− 1), phenolic (297.13 mg GAE/g), total flavonoid (40.10 mg CE/g) and carotenoid content (2100 µg/g), respectively. The fourier transform infrared spectroscopy spectra revealed distinctive peaks and a range of functional groups. All the petal extracts exhibited significant antidiabetic activity and antimicrobial inhibitory activity against Serratia marcescens and Escherichia coli. In summary saffron petals are a valuable source of bioactive compounds but employing innovative extraction techniques can result in a high yield of phytochemicals, which could serve as natural antioxidant and antimicrobial agents.