Title: Nutritional composition of gluten free products; inclusive of laboratory analysis of calcium and iron.
Funder: Coeliac UK

Abstract: A recognised limitation of analysing the nutrition composition of a gluten free diet of individuals and population groups is the very limited micronutrient data of GF foods (Mazzeo et al. 2014; Barne & Powell 2017;Fry et al. 2017). Iron and calcium are particularly relevant micronutrients for people with coeliac disease, as there is an increased prevalence of iron deficiency anaemia at diagnosis and osteoporosis associated with coeliac disease. Barne & Powell (2017) reported that in a gluten containing (GC) diet 30% of calcium and 44% of iron intake comes from cereals and cereal products. Whilst it is legislation that GC flour is fortified with calcium, this is not the case for GF flour. Fewer gluten-free products are fortified with calcium and iron compared with their GC counterparts, of concern, even less of commercially available GF compared to prescription only GF products are fortified with calcium and iron (Barne & Powell 2017). In many of the GF products the calcium and iron content are uncertain as they have not been measured (Fry et al. 2017). Removal of gluten from the diet can reduce the consumption of dietary fibre, and several studies have reported potential negative implications of a GF diet on long-term colonic health. In particular, GFD is associated with a reduction in the population of bifidobacteria, a genus of bacteria widely regarded as beneficial. Aim: Determine the nutritional composition of five GF food categories based on data from food labels and laboratory analysis of fibre, calcium and iron. Methods: Data will be collected from food outlets (including internet sources) and GF food product providers. Data collected will include all available nutrient information: energy, macro and micronutrient composition for five GF and gluten containing (GC) food categories. Laboratory analysis will be undertaken to quantitatively determine the calcium and iron content of GF foods in the food laboratory. Ten samples from each food category will be analysed via traditional chemical techniques. Nutrient data will be calculated per 100 g of GF product. Food categories to be investigated: breads (fortified and non-fortified), crackers, pizza bases, flour, savoury biscuit, and sweet biscuits. Laboratory Analysis: Titrimetric Determination of Calcium content in foods (Garvey et al., 2015). Spectrophotometric method for the determination of iron in foods (Garvey et al., 2015). Contribution for the carbohydrates/dietary Fibre assay kit (AACC Method 32-05-01) Project Outcomes: Primary outcome – Comparison between the nutritional composition of GF and GC breads (fortified and nonfortified), crackers, pizza bases, flour, savoury biscuit, and sweet biscuits, based of food labels. Secondary outcome – Quantitative values on the fibre, calcium and iron content of GF breads (fortified and nonfortified), crackers, pizza bases, flour, savoury biscuit, and sweet biscuits. Discussion: The study has several strengths. The nutritional information based on the quantitative assessment of calcium and iron will provide new insights into the nutritional quality of GF products across food domains that are consumed in large quantities by people with Coeliac disease. The findings will be published to enable clinicians and researchers to more accurately determine the micronutrient content of GF diets.


Research activity codes: 3.5 RESOURCES AND INFRASTRUCTURE (PREVENTION);3.3 NUTRITION AND CHEMOPREVENTION
Health categories: INFLAMMATORY AND IMMUNE SYSTEM