Characterisation of different rice varieties: effect of different cooking methods

• Autor(a) principal: Cardoso, Inês Nunes
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/14289
• topic: Biotecnologia alimentar; Arroz; Nutrição

Rice (Oryza sativa) is one of the leading food crops in the world and it is consumed by more than half of the world’s population. Although its characteristics and composition vary, in general, milled rice is composed of starch, water, proteins, lipids, dietary fibre, vitamins and minerals. Parboiled rice, a differently processed rice, represents a significant percentage of the total worldwide rice production. Due to the current lifestyle and increasing use of microwave ovens, freezers and refrigerators, consumers tend to store food leftovers more than ever. Milled rice is one of the most consumed form of rice, being cooked with various different methods. Rice composition highly influences its cooking characteristics and determines rice preference by consumers. This work intended to characterise the different rice varieties commercialised by the company Novarroz in terms of size, whiteness and composition. The varieties chosen belong to the types aromatic, agulha, agulha South America, agulha parboiled, carolino, medium, risotto, round and round parboiled. Different cooking methods, such as using a microwave oven and steam, were also tested and compared with the ordinary boiling method. Strong correlations were found between the size, whiteness and composition parameters analysed. It can be concluded that rice’s composition, such as resistant starch content, has a great influence on the cooking times and appearances registered. From the three cooking methods tested, the pre-cooking of rice for 10 minutes, followed by freezing and later de-frosting and post-cooking by using a microwave oven allowed the fastest cooking method, considering the consumer point of view. The obtained cooked rice, with exception of some varieties, was visually appealing. A wide range of rices cooked with a “sticky” appearance, but some were also found to provide a “non-sticky” end result.