Effect of insoluble dietary fibre addition on technological, sensory, and structural properties of durum wheat spaghetti

Insoluble fibres are important in human health and disease prevention and can be incorporated into food. High fibre pasta prepared with bran is typically inferior quality compared to durum pasta. This study compared spaghetti prepared from durum semolina substituted with various amounts of either durum bran or germ (pollard) dried at high temperature. Pasta was evaluated for cooking properties, texture, sensory, fibre content, antioxidant status (AO) and in vitro starch digestibility to determine the dose producing acceptable quality. Pollard at 10% substitution had minimal impact on quality with higher AO and fibre. Above 30%, pasta had undesirable colour, sensory properties and higher starch digestion. Although bran substituted pasta had undesirable sensory and technological properties, especially at 30% incorporation, it does provide more dietary fibre and antioxidants than regular pasta and does not affect starch digestibility. Interestingly, a significant amount of AO was retained in the cooked pasta. The study illustrates the value of structural analysis to explain observed technological properties of the product with fibre inclusion.

► Substitution of semolina for bran (0–30%) or pollard (0–60%) improved fibre and antioxidants in pasta.
► Pollard at 10% has minimal impact on pasta but levels >30% is deleterious.
► Bran causes deterioration in eating quality of pasta but still provides enhanced fibre and antioxidants.
► Significant amounts of antioxidants are retained in cooked pasta.
► Microscopy provides information for the impact of fibre on pasta–fibre properties.