EFFECT OF ENRICHMENT WITH DIFFERENT CROCUS SPP STIGMAS ON ANTIOXIDANT PROPERTIES OF WHEAT FLOUR PASTA

Introduction: Saffron (Crocus sativus L.; family Iridaceae Juss) is widely used in cookery and in food industry as a flavouring and colouring agent and is well-known also for its antioxidant and beneficial health properties. The properties of saffron stigmas are related to the presence of carotenoid derivatives (crocins, picrocrocin and safranal, responsible of the saffron colour, flavour and aroma, respectively) as well as phenolics, which are among the most important plant antioxidants in the human diet. However, saffron is the most expensive spice in the world due to cultivation and production costs. So, may be interesting to explore the possibility to employ other less expensive and more readily available Crocus spp, of inferior sensory quality but endowed with good bioproperties. At this aim we evaluated the antioxidant properties of fresh pasta (raw and cooked) added with dried stigmas of different wild Sicilian Crocus spp (C. vernus, C. biflorus and C. longiflorus) in comparison with C. sativus L., (obtained from a local supermarket and from a Sicilian farmer classified as I category). Material and methods: Preliminarily toxicity and biocompatibility of wild Crocus samples were tested by brine shrimp (Artemia salina) lethality assay and on 3T3cell line. Therefore, all the pasta samples (with and without Crocus stigma addition) were prepared by mixing wheat flour (70% w/w) and water (30% w/w). Crocus stigma powder was added at a 0.8% w/w concentration. Pasta samples were used for analyses raw or after 1:30 - 3minutes of cooking. Methanolic extracts of freeze-dried pasta samples was evaluated for their antioxidant activity in the Folin-Ciocalteu, TEAC and FRAP assay. Furthermore, pasta extracts were examined by thin layer chromatography (TLC). Results: The stigmas from C. longiflorus, C. biflorus and C. vernus showed to possess an antioxidant activity comparable to that of saffron, despite a lower content in crocins and picrocrocin. Pasta antioxidant properties was ameliorated, in all tests used, not only by addition of saffron but also by addition of C. longiflorus, C. vernus and at a lower extent C. biflorus stigmas. Cooking time influenced the results of the antioxidant activity as evaluated in the Folin assay, and, interestingly, ABTS values increased for all samples after cooking. However, as shown by TLC, the content of crocins and picrocrocin did not decrease after cooking for all Crocus used (included C. sativus L.). Discussion and conclusion: These result suggest the contribution also of compounds other than carotenoids (flavanols, very likely) that influence the total antioxidant activity of the enriched pasta. Pasta is a worldwide known food product and its nutritional properties may be ameliorated by enrichment with functional ingredients such as saffron. Our findings demonstrated that also stigmas from some wild Crocus species can be successfully employed in the food industry, instead of the very expensive saffron, to obtain a fortified food useful to enhance the antioxidant properties of human diet. Further studies, aimed to deepen the knowledge and applications of these drugs in the food industry, are needed to better understand the role of Crocus spp stigma secondary metabolites on pasta antioxidant properties.