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Fac-simile Scheda Linee di Ricerca - Federalimentare

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During gel ageing, a noticeable increase of G’ and G” was observed only for the milled rice varieties Asia,Gange, Fragrance and Vialone Nano, characterised by a high amylose content. No further hardening was foundeither for the other milled varieties or for all the brown samples. The methods used in this work (dynamic oscillatoryrheometry and FT-NIR spectroscopy) turned out to be very useful in the definition of rice starch gels ageing.2. Lucisano, M., Pagani, M.A., Lupotto, E., Mariotti, M., Bottega, G. (2007). Quality evaluationof tra<strong>di</strong>tional and aromatic Italian rice varieties. Procee<strong>di</strong>ngs of the “4 th International TemperateRice Conference”, Novara, Italy, June, 25-28; Bocchi, S., Ferrero, A., Porro, A. Eds;pp: 178-179.Eleven Italian varieties of rice (six tra<strong>di</strong>tional and five aromatic) were analyzed for protein, starch, amylose, extentof alkali degradation, pasting and cooking behaviour. The rheological parameters measured on cooked kernelmade it possible to <strong>di</strong>fferentiate the group of the tra<strong>di</strong>tional varieties from the aromatic types characterized byhigh amylose content. The texture characteristics of cooked samples were statistically correlated with the amylographicin<strong>di</strong>ces (gelatinisation temperature, maximum viscosity, final viscosity and setback), thus confirming theimportance of the latter parameters in pre<strong>di</strong>cting cooking behaviour. PCA analysis showed that <strong>di</strong>scriminationamong the samples was based not only on amylose, viscoamylographic in<strong>di</strong>ces but also on protein content.3. Catenacci, F., Fongaro, L., Mariotti, M. (2007). Image analysis: a method for an objectiveevaluation of the alkali <strong>di</strong>sintegration property of rice. Procee<strong>di</strong>ngs of the “4 th InternationalTemperate Rice Conference”, Novara, Italy, June, 25-28; Bocchi, S., Ferrero, A., and Porro,A. Eds; pp: 368-369.Starch gelatinization, the irreversible <strong>di</strong>sruption of the molecular order within the starch granules heated in presenceof water, is one of the most important events influencing rice cooking behaviour. Different methods havebeen used to study this phenomenon; the alkali test, in particular, has been extensively employed as an in<strong>di</strong>rectestimation of the gelatinization temperature, a parameter correlated with the quality characteristics of cookedrice. The test measures the extent of <strong>di</strong>sintegration of rice kernels in alkali solution (1.5% KOH) after 23 hours atroom temperature, assigning sprea<strong>di</strong>ng scores from 1 (kernels not affected by alkali) to 7 (kernels completely<strong>di</strong>spersed and intermingled) by a visual inspection. As a consequence, the interpretation of the results is largelysubjective. This limit could be overcome by Image Analysis, an objective technique characterized by a good accuracyand high repeatability. The aim of this study was the improvement of the alkali test by means of ImageAnalysis. Several rice varieties grown in Italy (6 tra<strong>di</strong>tional, 5 aromatic) were used for this purpose. The alkalitest was carried out under conventional con<strong>di</strong>tions. At the same time, the samples were monitored during the testby collecting the picture of the progressive <strong>di</strong>sintegration of the kernels at constant times. Images were capturedusing a flatbed scanner and processed with a specific software (Image Pro-Plus®); in particular, the proportionalincrease of the rice kernel <strong>di</strong>sintegration area (named RDA%) was determined, both at the end and during thetest, thus obtaining the final value and the kinetic of the phenomenon respectively. The alkali sprea<strong>di</strong>ng scoreswere significantly related (r=0.959, P

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