Determination and Comparison of Fat and Fibre Contents in Gluten-Free and Gluten-Containing Flours and Breads: Nutritional Implications.

Abstract

The absence of gluten is a technological challenge that requires the addition of components to replace the unique viscoelastic properties of gluten, thus altering the nutritional composition of gluten-free (GF) breads. Moreover, GF flours may have different compositions as compared to gluten-containing (GC) counterparts because of a different origin. This may impact the nutritional quality of GF diets. The aim of the study is to provide updated analytical data on moisture, fat, and fibre contents in GF flour and bread samples, and compare them with their GC counterparts, as well as to analyse ingredients and how they impact nutritional quality. A total of 30 different flours and 24 types of bread were analysed using AOAC methods. GF cereal flours contain more fat than GC flours (3.5 ± 2.1% vs. 2.5 ± 2.1%, p < 0.001), as well as GF flours from pseudocereals, except for wholemeal buckwheat (2.6 ± 0.1%). Fibre content is lower in GF flours (3.6 ± 3.1% vs. 7.1 ± 3.9%, p = 0.03), except for GF pseudocereal and legume flours. GF breads contain almost twice as much fat 6.6 ± 2.3% vs. 1.4 ± 0.2%, p < 0.001, and 4.2 ± 1.2%, p < 0.001) and fibre (7.3 ± 2.4% vs. 2.8 ± 0.5%, p < 0.001, and 4.9 ± 2.1%, p = 0.002) as GC breads. This is due to the raw materials themselves and to the addition of ingredients, such as regular and high oleic sunflower oil, and psyllium. Fibre ingredients and additives are more frequently used in ready-to-eat GF flours and breads, and more GF breads also contain fat-based ingredients, as compared to GC. Amaranth and chickpea flours are good alternatives to produce breads with better nutritional quality. Analysis of GF products for critical nutrients is peremptory because of continuing technological and nutritional innovation.