Gluten-free fresh pasta enriched with bioactive compounds

Doutoramento em Engenharia Alimentar / Instituto Superior de Agronomia. Universidade de Lisboa

Sustainability of the agri-food chain is on today’s agenda, whether through the use of industrial byproducts or the investigation of alternative sources of ingredients. The increasing number of individuals with gluten-related diseases, but also consumers following a gluten-free diet are the drivers for the continually growing number of gluten-free products launched in the market. However, in addition to their still limited commercial availability and high price compared to their wheat counterparts, gluten-free products show nutritional deficiencies. Following the current consumer trends for healthy foods with underlying sustainable principles (ingredients and processes), this thesis aimed the development of a gluten-free fresh pasta based on rice flour from broken grains and Psyllium husk, enriched with Arthrospira platensis, Laminaria ochroleuca and potato peel. Firstly, the gelatinisation (5 – 26%) of rice flour from broken rice (rice processing industry by-product) was performed to assess the optimum conditions for producing gluten-free pasta. Afterwards, the pasta formulation (50% gelatinised rice flour/rice flour) was successfully optimized, and its structure reinforced with 4% Psyllium husk gel. This gluten-free pasta was then enriched with bioactive compound sources (Arthrospira platensis, Laminaria ochroleuca and potato peel) incorporated as lyophilised biomass, gel or liquid extract obtained by subcritical water extraction (autohydrolysis), an eco-friendly technology. The pastas developed were characterized in terms of cooking quality parameters, texture, colour, rheology, nutritional composition, antioxidant activity, in vitro digestibility and sensory analysis. It was found that autohydrolysis was a suitable technology for the valorisation of distinct materials, namely marine and industrial. Pastas with Laminaria ochroleuca provided a high mineral and fibre contents, and low-fat content, so that could bear nutritional claims. On the other hand, Arthrospira platensis incorporation proved to have a positive effect on the pasta antioxidant activity and overall sensory analysis without affecting the in vitro digestibility. Pasta with potato peel extract presented a high total phenolic content and antioxidant activity. All formulations presented good overall cooking quality and texture and rheology properties

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