Sviluppo di alimenti funzionali e innovativi a base di cereali con ridotta risposta glicemica

In recent decades, consumer demands for cereal-based products with low glycemic impact and high commercial quality have changed considerably. For this reason, during this Ph.D. project, starch availability and product quality were influenced positively at the same time by using innovative and functional ingredients. Four starchy products characterized by different glycaemic responses were studied, in order to highlight how the production process and the final product structure influence starch digestibility. This research primarily focused the attention on the relationship between rheological properties, microstructure, and in vitro digestion of the food. Strategies to alter the glycaemic response of products were obtained by adopting different technological approaches, related to common (cooking-extrusion) and alternative (high-pressure homogenization) processing and formulation interventions. Psyllium, a soluble dietary fibre with interesting health benefits, and oleuropein, an olive-derived polyphenol, were directly incorporated in pasta and bread products, respectively. On the other hand, rice bran, a by-product of the rice industry, and chia flour were both subjected to technological treatments and added to expanded snacks and layer cakes, respectively. Findings showed the possibility to modulate the glycaemic response by altering the food structure. In addition, technological processing could be used in combination with formulation interventions to enhance ingredient technological properties and consequently to reduce the glycaemic impact of carbohydrates. The approach of this Ph.D. research highlighted the importance of always promoting high-quality and attractive products with healthy properties.

Lo scopo di questo progetto di ricerca è stato quello di investigare strategie che consentano di ridurre la risposta post-prandiale di prodotti a base di cereali e di studiare la relazione tra le proprietà reologiche, microstruttura e digeribilità dell’amido. Sono stati valutati sistemi innovativi e funzionali in grado di influenzare positivamente il metabolismo dell’amido, rallentandone la digestione. Tali sistemi funzionali sono stati ottenuti attraverso l’utilizzo di diversi ingredienti (fibre dietetiche, composti antiossidanti, prodotti di scarto) e/o interventi tecnologici. I risultati ottenuti hanno evidenziato che modificare la struttura di un prodotto alimentare è molto importante per la formulazione di nuovi prodotti funzionali con bassa risposta glicemica.