Institute of Agrochemistry and Food Technology (IATA-CSIC), Spain
Title: Use of ancient Latin-American crops in bread. Effect on mineral availability and glycemic index
Since the early stages of Haros’ career she has mainly been engaged in research in the Cereal Science and Technology field. The major theme in Haros’ research is the utilization of different strategies to improve nutritional and/or functional value of cereal by-products or cereal ingredients. These strategies include the use of different physical, biochemical or biological treatments during milling cereal process; development of new cereal by-products by including novel ingredients; use of new starter phytase producers for regulating content and composition of lower myo-inositol phosphates in cereal by-products with clear nutritional and health benefits.
Products with whole grains generally have a lower glycemic index (GI) than their fibre-free counterparts, maintaining better control of blood sugar levels. However, whole grains contain significant amounts of phytates, a well-known inhibitor of mineral, proteins and trace elements bioavailability. This study evaluates the effect of replacing wheat flour by amaranth, quinoa or chia, three ancient Latin-American crops, on nutritional and functional bread features. GI (AUC, %) and mineral bioavailability were studied using in vitro and in vivo methodologies, and wheat- and whole-wheat bread as controls. The replacement of wheat flour by Andean grains significantly increased the content of proteins, lipids, dietary fibre and minerals in the final product compared to control sample. Amaranth and quinoa flours made wheat flour replacement possible, increasing nutritional value of bread with slight depreciation of it, whereas chia showed higher technological and sensory quality than wheat bread. GI was lower in breads with chia (81±2%), amaranth (66±3%) and whole wheat bread (71±4%), whereas the formulation with quinoa did not modify this parameter. Breads formulated with whole grains had higher levels of minerals relative to controls. Their bioavailability depends on the formulation and breadmaking process, basically because of the presence of phytates, as predicted by inhibitory threshold values for mineral absorption predicted by phytate/mineral molar ratios. Animals fed with whole wheat- (14.7±1.3g/dL), chia- (17.4±2.8g/dL) and amaranth-bread (16.4±2.2g/dL) showed higher haemoglobin concentration than those fed with control bread (12.3±0.2g/dL). Only animals fed with samples with chia had values of mean corpuscular haemoglobin, 31±5pg, higher than controls.