How to replace gluten functionality in gluten-free pasta? : traditional and novel technologies

Defining and optimizing the technological process for gluten-free (GF) products still represent a challenge for researchers and industry. As concerns pasta, the GF pasta currently on the market is still far from what the consumer is looking for, despite the great efforts made in the last few decades to obtain a product with sensory characteristics similar to those of durum wheat products. Several ingredients (modified starch, additives, texturing proteins, etc.) have been used as alternatives to gluten in order to create a starch-based network that can withstand the physical stresses of cooking and, at the same time, impart firmness to the cooked product. In this frame, different variations of noodle-making technology have been proposed to simplify the artisan process based on repeated heating and cooling steps on the intermediate product, which are difficult to control and monitor. This presentation will present an overview on how to replace gluten functionality in GF pasta. Most studies refer to laboratory scale pasta-making, neglecting the issues associate with transfer to an industrial scale. Moreover, most of the work done so far adopt an empiric approach (that is, varying ingredients and processing conditions) as opposed to understanding the macromolecule organization associated with cooking quality. It is presented here evidence that improved understanding of the relationship between starch structure and processing conditions may help the industry to re-formulate and develop products with the desired texture as well as improved nutritional properties. In particular, the use of different thermal treatments, on their effect on the physical properties of GF flours, and on their impact on the structure and cooking behaviour of a GF pasta obtained without the use of additives (monoglicerides, etc.) will be presented. The presentation will focus on how different starch 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, and presence/absence of specific regions that are all relevant to the product's properties.