Clinical, meta-study, as well as epidemiological studies, have shown a strong relationship between metabolic disease such as diabetes and overconsumption of high glycemic foods. Carbohydrate is the energy-supplying substance in the staple food. The postprandial blood glucose response is closely related to the type, quantity, and digestive characteristics of the carbohydrates within food. As the traditional staple food of China, noodles are cooked in a variety of ways; however, the digestion properties of noodles cooked by different methods were rarely investigated. To solve this research question, the Cereal Processing and Quality Control Innovation Team of Institute of Food Science and Technology (IFST) systematically investigated the effects of wheat flour component and ways of noodle cooking and storage conditions on the noodle digestion.

It was found that the ratio of wheat protein showed a significant effect on the digestion properties of noodles. When the gluten content was higher than 14%, the digestion rate and digestibility of noodles were greatly reduced. With a higher gluten content, the structure of noodles became denser, and the gluten will hinder the enzyme to digest starch, similar to the slow digestibility of pasta. Secondly, noodles cooked by five common cooking methods (steaming, boiling, microwave heating, frying and stir-frying) also showed varied digestion properties, that microwaved and fried noodles contained more resistant starch and were slowly digested than conventional cooked noodles (boiling). In addition, it is more beneficial to control the glycemic response by properly storing the cooked noodles (the estimated glycemic response is decreased by 11.34-30.11% after 24 hours storage). Cooked noodles stored at room temperature showed a higher degree of crystallinity and higher ratio of resistant starch than noodles stored at -18 and 4 ℃, which also reduced the digestion rate.

The results were published online in the leading journals in Food Science area, with two papers in Food Chemistry (IF 6.306) and one paper in Foods (IF 4.092). Those research was funded by the Agricultural Science and Technology Innovation Program, CAAS; and Modern Agricultural Industry Technology System [CARS-03].