Polyphenols in Raw and Cooked Cereals/Pseudocereals/Legume Pasta and Couscous

Abstract

Pasta and couscous are popular foods manufactured (in their traditional form) from durum wheat semolina. In recent years, the consumers’ quest for novel, functional, gluten-free, wholegrain foods has prompted the industry to manufacture new pasta and couscous products in which durum wheat has been partially or totally replaced by other vegetable flours. Besides dietary fibre, these raw materials might be an interesting source of phytochemicals. In this work, 16 commercial samples of pasta and four samples of couscous representative of the new products and made of refined and wholegrain flours of different species of cereals, pseudocereals and legumes were analysed for free, hydrolysable bound and total polyphenol content by means of the Folin-Ciocalteu procedure. Analyses were repeated on cooked samples to assess the quantity of polyphenols ingested by the consumers. The raw legume and pseudocereal products had a total polyphenol content higher than most cereal products (up to 1743.4 mg of Gallic Acid Equivalent (GAE) per 100 g dry weight). Wholegrain products had higher contents than refined products. The free fraction underwent up to 46% loss with cooking, probably because of solubility in water. The water absorption of pasta and couscous during cooking was in a ratio of 2:3, resulting in higher dilution of polyphenols in the cooked couscous.

Keywords

• pasta
• couscous
• cooked pasta
• cooked couscous
• total polyphenols
• free polyphenols
• bound polyphenols