Dissecting the determinants of "structure ability" in complex food systems

Structure of food relates to the interaction among micro- and macromolecules, with water and soluble/insoluble polymers (including starch and proteins) most often playing prominent roles. Pasta will be considered here as an example of complex food system. In spite of the relatively simple technology involved in pasta production, a molecular understanding of this product is complicated by the nature of the interacting macromolecules (all insoluble) and by the absence of detailed information on the molecular mechanisms that govern their participation to the product's properties. This comes into play when it comes to substituting some of the ingredients of traditional pasta, as required for instance in the case of gluten-free products. Several ingredients (modified starch, GF flours, additives) have been used as alternatives to gluten in order to create a network that can withstand the physical stresses of cooking and impart firmness to the cooked product. Moreover, different variations of noodle-making technology have been proposed to simplify the traditional process based on repeated heating and cooling steps, which are difficult to control and monitor. This presentation will overview how to replace gluten functionality in GF pasta. We present here evidence that a molecular-based understanding of the relationships between food structure and processing conditions is the key for developing products with texture similar to wheat-based goods. In particular, we will focus on how different starch and/or protein rearrangements - affecting GF pasta functionality - can be assessed by using a multidisciplinary approach, that combines information related to ultrastructure, thermal properties, crystalline order, molecular size distribution, enzymatic susceptibility, protein structure, and presence/absence of specific regions/residues that are all relevant to the product's properties. This work was supported in part from funds from the GRISP Project "New Products".