Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1. Valentini N., Rolle L., Stévigny C., Zeppa G. (2006) Mechanical behaviour of hazelnuts usedfor table consumption under compression loading. J. Sci. Food Agric 2006, 86 (8), 1257-1262.Nuts of four hazelnut varieties and five new selections used for table consumption were compressed at the moisturecontent of 6% wet basis to measure shell resistance to breakage. Rupture force, rupture energy and nut specificdeformation were measured under three compression loading positions. Physical parameters of nuts werealso evaluated to relate them to the data obtained by compression test measurements. Rupture force and nut specificdeformation are the most discriminant parameters that can be used to describe the behaviour under compression,while rupture energy values show fewer differences among the considered varieties. The values of force requiredto break nut shell ranged from 322.2 to 769.3 N. The lowest values of force were generally obtained alongthe y-axis, the transverse axis containing the major dimension at right angles to the longitudinal axis. Nut specificdeformation ranged from 3.35 to 11.76%. Correlations between physical and texture parameters showed that valuesof force, energy and deformation were dependent on different parameters that varied in the three consideredaxis. The most used varieties, Ennis and Barcelona, showed high mean values of force rupture to break shell andlow deformability, while Tonda Giffoni and Tonda Bianca were easy to break. Among the new selections, L35and B6, with mean values of force rupture less than 428 N and values of nut specific deformation higher than8%, were suitable for table consumption.2. Stevigny C., Rolle L., Valentini N., Zeppa G. (2007) Optimization of extraction of phenoliccontent from hazelnut shell using response surface methodology. J Sci Food Agric, 87, 2817-2822Response surface methodology was applied to predict the optimum conditions for extraction of phenolic compoundsin hazelnut shell. The phenolic content in the shell extract was determined spectrophotometrically accordingto the Folin-Ciocalteu method and expressed as gallic acid equivalent (mg GAE g−1). Two central compositedesigns were used to investigate the effects of two independent variables, namely solvent composition (%)and extraction time (min), on phenolic extraction. In a first series of repeated batch extractions, the solvent consistedof different methanol percentages in distilled water at pH 4, while in a second series methanol was substitutedby ethanol. The highest phenolic content (6.67mg GAE g−1 of shell) was predicted at the extraction conditionsof 55.7% ethanol and 108.7min. These best conditions, obtained and applied to 13 different cultivars,showed values varying from 9.18mg GAE g −1 of shell for Barcelona to 3.00mg GAE g −1 of shell for Tonda diGiffoni.3. Prosperini S., Ghirardello D., Scursatone B., Gerbi V., Zeppa G. (2008) Identification of solublephenolic acids in hazelnut (Corylus avellana L.) kernel. 7° International Congress on hazelnut,Viterbo (I), 23-27 June, P5-12-63A, 170.Phenolic acids are a subclass of a larger category of compounds commonly referred to as “phenolics”. They are avery important group of secondary plant metabolites whose roles are still unknown. Due to their antioxidant behaviourand the potential health benefits associated with these simple phenolic compounds, many authors haveproposed different techniques to extract these compounds from vegetable foods. Therefore, the aim of this workis to compare the experimental conditions commonly used to detect soluble phenolic acids (both free and esterified)in order to investigate the phenolic constituents in hazelnut kernel extracts. Phenolic compounds present indefatted samples were extracted using different solvent mixtures under reflux conditions at different temperatures;afterwards, the extraction and hydrolysis of phenolic acids was performed. HPLC analysis of the extractsobtained highlighted the presence of twelve phenolic acids. The main compounds identified were gallic acid, caffeicacid, p-cumaric acid, ferulic acid and sinapic acid. In all extracts, gallic acid was the most abundant, in boththe free and esterified form. Ethanol solution (80% v/v) at 80 °C was the most effective solvent for the quantitativeextraction of benzoic acid derivatives, but extract obtained with acetone solution (80% v/v) at 50 °C showedthe highest number of identified phenolic acids. All the other suggested methods showed low extraction capacityfor these compounds. Using these optimized methods, new researches are in progress to define the effect of storageand roasting on these compounds.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.it449