Gluten-free pasta : cereal vs pulses : what to know

Nowadays, consumers are more conscious about the environmental and nutritional benefits of food. Pulses - thanks to their nutritional and health-promoting properties, together with the low environmental impact - have become increasingly popular and suitable for food production, including pasta. Despite the advantages of using pulses, some factors – including sensory and technological issues - limit their use on an industrial scale. Moreover, since pulses are traditionally consumed as grains, no information is available about their use as ingredients in gluten-free (GF) pasta. Due to their different starch structure and amylose content compared to cereals, pulses exhibit low gelatinization and retrogradation starch properties, which are pre-conditions for GF pasta production. This study aims at understanding if it is possible to transfer knowledge from cereals to pulses, in order to develop 100% pulse pasta. Specifically, this work will provide insights on: (i) the effects of seed/flour pre-gelatinization on flour functionality; (ii) the most suitable pasta-making process to be used with pulses. In the first part of the study, two batches of red and yellow lentils were pre-gelatinized in a vertical cooker, commonly used to pre-gelatinize rice and corn. The characteristics of the related flours were studied before and after treatment and compared with those made from rice and corn. In the second part, pulse flours were pre-gelatinized by extrusion-cooking, which promotes structural changes in starch as a result of the synergistic effects of heating and shear-stress. Finally, pasta was produced from raw, pre-gelatinized grains and extruded flours. Pre-gelatinization was more effective in cereals than pulses; this could be due to their compact starch structure, which is typical of pulses, and the high amylose ratio that limits gelatinization. Indeed, after pulse treatment, starch susceptibility to enzymatic hydrolysis slightly increased, while in the case of corn and rice the value increased up to more than 45%. As regards pasting properties, pre-gelatinized pulses present an opposite trend to corn and rice. While viscosity decreased after corn and rice pre-gelatinization, it increased in the case of pulses. Flour pre-gelatinization by extrusion-cooking was more effective in modifying starch properties. As regards pasta, contrary to what has been shown for corn and rice, it is possible to produce pasta using all the technologies considered, even starting from raw (uncooked) flour with no additives. However, the best results were obtained when pre-gelatinized flour was used. Further studies will focus on the effects of pre-treatments and pasta processing on protein organization. Understanding the relation between processing and product characteristics will enhance the use of pulses as ingredients in several products to meet growing consumer demand for natural healthy food products.