Applicazione di protocolli semplificati di Image Analysis nella caratterizzazione di salumi tipici della Campania

Un protocollo d’Analisi dell’Immagine è stata messo a punto per la determinazione di misure specifiche e globali dei lardelli di due tipologie di salami tipici campani. Sono stati considerati otto produttori rappresentativi dell’eterogeneità della totalità dei produttori campani. L’elaborazione delle immagini è stata effettuata direttamente sull’immagine acquisita. Come output del software sono stati considerati: l’area di ciascun lardello, l’area della fetta, l’indice di rotondità di ogni lardello di grasso, il numero di lardelli. Da questi sono stati estratti ed elaborati gli indici più idonei per la caratterizzazione dei salami in termini di determinazione della dimensione e della distribuzione dei lardelli di grasso. La tecnica è risultata molto efficace, veloce e riproducibile. L’indagine ha evidenziato la possibilità di definire parametri oggettivi inerenti l’apparenza (qualità visiva) dei salami, un problema affatto irrilevante per il perfezionamento dei disciplinari di produzione e per la difesa della tipicità

Protein-polysaccharide interactions: Phase behaviour of pectin-soy flour mixture

Biopolymers mixed systems have been widely studied in the past two decades, resulting in advances in knowledge of the key parameters involved in macromolecules-macromolecules interactions. Sound understanding and control of these parameters should enable food scientists to design coating or film with desired functional properties. In this study the phase behaviour of high methoxyl pectin and soy flour at pH 4.6 was investigated. The aim was to investigate the effect of different concentrations of pectin (P) and soy flour (SF) solution and different P/SF ratios on mixture phase behaviour. Pectin suspensions at 16 mg ml(-1) and 8 mg ml(-1) concentrations and soy flour suspensions at 13 mg ml(-1) and 6.5 mg ml(-1) concentrations were prepared and mixed together in different ratios (10/90, 25/75, 50/50, 75/25, 90/10). Turbidity and theological measurements were performed to obtain information on pectin-soy flour interaction in electrostatic compatibility conditions. The experimental data show that soy flour solution is a non-stable system in which complexes may be formed during aging. It becomes insoluble and settles to the bottom of the suspension. By blending charged soy flour, at high concentration, with anionic pectin an associative interaction between biopolymers occurs which stabilizes the protein in solution. The best pectin and soy flour suspension for forming film with a continuous network was at concentrations of 16 mg ml(-1) and 13 mg ml(-1)

Predicting texture attributes from microstructural, rheological and thermal properties of hazelnut spreads

Eight trained assessors evaluated one visual, eight texture and four gustative attributes of 15 commercial spreads. In addition, 100 consumers evaluated the acceptability of the spreads. Rheological behavior of the samples was evaluated in transient (stress–relaxation test) and dynamic (strain and frequency sweep test) shear mode. Thermal measurements were also performed. Finally, the microstructure of the samples was analyzed by scanning electron microscopy. Partial least squares regression was used to predict acceptability from sensory attributes and texture from instrumental data. Scanning electron micrographs indicated that spreads differed in morphology, size and distribution of hazelnut particles. Overall liking of the spreads was found to be related to hazelnut flavor and texture attributes. Prediction of the most important texture properties from instrumental measurements was quite successful, especially for spreadability which was found negatively related to the consistency and flow indices and, secondly, for meltability which was found to be strongly dependent on measured thermal parameters