Antimicrobial Activity and Chemical Characterization of a Non-Polar Extract of Saffron Stamens in Food Matrix

Abstract

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.

Comparative analysis of apocarotenoids and phenolic constituents of Crocus sativus stigmas from 11 countries: Ecological impact

“…The ethanolic C. sativus stigma extract showed the highest activity (about 20 mm inhibition zone) against Staphylococcus aureus followed by the water extract, which showed less pronounced activity (15.30 ± 0.30 mm inhibition zone). As a rule, in previously published works on the antibacterial activity of saffron extracts, [ 55–58 ] the presence of the antibacterial activity of Crocus stigmas is explained precisely by the presence of crocin, picrocrocin, and safranal. [ 59,60 ] However, phenol carboxylic acids and flavonoids provide synergistic components and enhance the antimicrobial, and antifungal effects of saffron.…”

Ethnobotanical survey of herbs used in the preservation of food products in Fez, Morocco

“…Some alkaloids from plants have also been used as antimicrobials in food [ 49 ]. Recently, many studies have investigated the antibacterial effect of phytochemical extracts against foodborne pathogens, which makes it possible to make healthy and efficient preservatives [ 50 – 52 ].…”

Evaluation of Microwave-Assisted Extraction as a Potential Green Technology for the Isolation of Bioactive Compounds from Saffron (Crocus sativus L.) Floral By-Products

“…Bioactive compounds such as carotenoids, terpenes, and flavonoids are the major compounds reported in saffron varieties [ 4 ]. Despite the well-known saffron characterization, recent studies showed that saffron floral by-products, such as tepals, are rich in valuable bioactive molecules such as flavonols, flavonoid glycosides and anthocyanins, which have positive biological effects such as their antioxidant and antimicrobial activities [ 5 , 6 ]. The valorization of this by-product through the development of innovative high added-value functional ingredients with new applications in food, pharmaceutical and or cosmetic industries could lead to the minimization of the environmental impact and to the potentially increase of saffron demand on the market [ 7 , 8 ].…”