Nutritional evaluation of carbohydrates in the Spanish diet: Non-starch polysaccharides and in vitro starch digestibility of breads and breakfast products

Non-starch polysaccharides (NSP) and the in vitro starch digestibility of b reads and breakfast products typically consumed in Spain were studied. Tota l (TS), rapidly digestible (RDS), slowly digestible (SDS) and resistant (RS ) starch fractions were determined, as well as starch digestion rate indexe s (SDRI) and rapidly available glucose (RAG) values as indicatives of the a mount of glucose likely to be liberated into the blood stream. Total NSP co ntents were relatively low, varying from 8.7% to 6.3% in some breakfast cer eals and wholemeal breads, respectively, to only 0.5% in other breakfast pr oducts. Insoluble hemicelluloses were the main NSP. Starch was rapidly dige stible, resulting in SDRI over 90% in most cases. In general, RAG values we re high, mainly in some breakfast products due to the presence of high amou nts of free glucose. Typical Spanish breakfast products and breads are thus characterised by their potentially high glycaemic and insulinemic response s. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.