PASTA FROM YELLOW LENTILS: A GLIMPSE AT THE PROCESSING CONDITIONS

Pulses are sustainable crops with high fibre and protein content suitable for gluten-free products such as pasta. This product is obtained by cooking extrusion of native flours or from conventional extrusion of pre-gelatinized flours, while conventional extrusion performed on native flour leads to an unacceptable product. As for pulse pasta, it is still not clear if pre-gelatinization is required. For this reason, three processes were considered for producing pasta from 100% yellow lentils: - Conventional extrusion of pregelatinized flour - Conventional extrusion of native flour - Extrusion-cooking of native flour. Starch susceptibility to α-amylase (AACCI 76-31.01), pasting properties (MVAG, Brabender©), colour and homogeneity (by image analysis) were assessed on dry pasta. Cooking behaviour (water absorption, cooking loss and texture) was instead studied on cooked pasta. Thermal and pasta-making processes had a slight influence on starch properties. This could be due to the chemical composition and/or starch organisation of pulses. All processes effectively produced pasta with acceptable cooking behaviour. However, the sample obtained from conventional extrusion on pregelatinized flour performed better, showing less heterogeneity before cooking. Moreover, the cooking behaviour of this sample was comparable to that of the commercial product. KEYWORDS: pulses, gluten-free pasta, extrusion-cooking, pre-gelatinization Andrea is a third-year PhD student in Food Systems at the University of Milan. His research activity focuses on understanding the relationship between raw materials, processing conditions and quality of the related final products. He is currently working on the optimization of formulations and processing conditions for the production of pasta, snacks and meat analogues using grains (or their fractions) with high nutritional value in terms of fibre and/or protein. The main raw materials examined in his research project are pulses as they are sustainable crops with a high nutritional profile. Reformulated products are obtained through the extrusion process focusing on the identification of the best conditions and synergy between raw material and process. The research project takes into consideration the extrusion process at three different moisture levels: low moisture (~10%) for snacks production, intermediate moisture (~30%) for pasta production and high moisture extrusion (~50%) for the production of meat analogues. In addition to the effect of hydration, the interactions between biopolymers, such as starch and proteins, are studied. Specifically, the attention is paid on the biopolymer changes induced by both shear and thermal stresses. Such interactions are observed via conventional (empiric rheological tests, physical tests) and advanced (spectroscopy, differential scanning calorimetry, thermogravimetric analysis, etc) approaches. Finally, the effects of those interactions on the characteristics of the end-products, including texture, sensory and nutritional properties, are assessed to evaluate which process is more suitable for each type of pulse.