Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1) Contini M., Baccelloni S, Massantini R, Anelli G. (2008). Extraction of natural antioxidantsfrom hazelnut (Corylus Avellana L.) shell and skin by-products by long maceration at roomtemperature. Food Chemistry 110, 659-669.The feasibility of obtaining antioxidant phenolic extracts from hazelnut by-products was investigated by longmaceration at room temperature. The materials studied were hard shells and defatted skins of both whole andchopped roasted hazelnut kernels. The three selected solvent systems included aqueous methanol, ethanol andacetone. Extraction yields as well as phenolic contents varied according to the by-product and the solvent used.Among the studied samples, the skin of whole roasted hazelnuts gave remarkably high extraction yields (about30%) and extracts with the richest phenolic content (up to 502 mg/g, expressed as gallic acid equivalents). Extractswere screened for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidation of linoleic acid in vitro model systems.The extracts from the skin of whole roasted hazelnuts manifested the strongest antioxidant activity, similaror superior to butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylicacid (Trolox) and α-tocopherol, at equivalent concentrations. The presence of hazelnutfragments in the skin residue lowered the yield and the antioxidant activity of the extract. All the extractswere found to be very rich in tannins.2) Contini M., Baccelloni S, Massantini R, Anelli G, Manzi L, Merendino N. (2008). In-vitroand in-vivo antioxidant potential of phenolic extracts obtained from hazelnut skin by-products.Acta Horticulturae, 7th International Congress on Hazelnut. Viterbo, Italy, 23-27 June 2008.Recently, a growing interest in replacing synthetic antioxidants with natural ones has fostered research on thescreening of plant materials in order to evaluate new antioxidants. Phenolic compounds are the major plant metaboliteswith antioxidant properties; many of these can be potentially exploited as antioxidant agents andnutraceuticals. The aim of this research was to evaluate the antioxidant potential of a crude phenolic extract obtainedwith 80% ethanol from hazelnut (Corylus avellana L.) skin by-products by means of an improved extractionprocedure. The extract was screened for in-vitro antiradical, reducing and chelating activity. Moreover, anin-vivo test carried out on rats was performed. The long-term stability of the extract dissolved in ethanol wastested during storage for six months at room temperature and under refrigerated conditions. The results showedthat the defatted hazelnut skin by-product is an excellent source of natural and very efficient phenolic antioxidants.The defatted skins provided a high yield in the crude extract (over 30%). The extract was characterized bya very high phenolic content (743.5 mg gallic acid equivalent/g d.w.), high antiradical efficiency (superior topure BHT, BHA, Trolox and α-Tocopherol), Fe(III) reducing activity and Fe(II) chelating capacity. The in-vivostudy showed an evident biological activity of the extract, which was able to improve the antioxidant potential ofplasma in rats. The results of the storage tests demonstrated that the hazelnut skin extract can be kept at roomtemperature for several months maintaining its antioxidant capacity high. Because of their potential antioxidantand nutraceutical properties, phenolic extracts derived from hazelnut skin could satisfy the demand for new naturalproducts in the preparation of innovative foods and beverages with a high dietetic/functional value.3) Contini M., Baccelloni S, Anelli G. (2007). Estrazione di antiossidanti naturali daisottoprodotti di lavorazione della nocciola (Recovery of natural antioxidants from hazelnutby-products. In Atti VIII Congresso Italiano di Scienza e Tecnologia degli Alimenti(CISETA). Milano. 7-8 Maggio, Pinerolo: Chiriotti.Dai gusci legnosi e dagli scarti pellicolari sgrassati di nocciole intere e granellate sono stati ricavati, utilizzandomiscele acquose di metanolo, etanolo o acetone, estratti grezzi arricchiti in componenti fenolici. Le rese diestrazione, nonché i tenori fenolici e l’attività antiossidante degli estratti sono risultati legati sia alla materiaprima che al solvente impiegato. Tra i campioni testati, i migliori risultati sono stati forniti dai residui dispellatura delle nocciole intere. In tutti gli estratti è stata evidenziata una cospicua componente tannica. Dairisultati della ricerca emerge che i sottoprodotti di lavorazione della nocciola, e in special modo i residuipellicolari, potrebbero costituire un’ottima fonte a basso costo per l’estrazione di composti fenolici naturali,dotati di attività antiossidante particolarmente potente.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it469