Submitted to: Cereal Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/23/2010
Publication Date: 12/31/2010
Citation: Rose, D.J., Kim, S., Inglett, G.E. 2010. Influence of jet-cooking and pH on extraction and molecular weight of ß-glucan and arabinoxylan from barley (Hordeum vulgare Prowashonupana). Cereal Chemistry. 87(6):607-611. Interpretive Summary: Barley has been an important food grain for centuries (Newman and Newman 2006). While the main use of barley has been for the production of alcoholic beverages, evidence linking barley constituents to human health has excited new food uses of barley. The main component of barley that has attracted food processors to its use in food products is beta-glucan. The benefits of barley beta-glucans are not only related to their concentrations within the grain, but also solubility and molecular weight; in particular, soluble, high molecular weight beta-glucans. Another component of barley is arabinoxylan. Most of the arabinoxylan in barley grain is insoluble. Previous research has established that food processing parameters can affect the functional properties of beta-glucans and arabinoxylans. The purpose of this research was to establish the effect of jet-cooking barley flour on the content, solubility, and molecular weight of beta-glucans and arabinoxylans.
Technical Abstract: Food processing conditions may affect the solubility and molecular weight of beta-glucans and arabinoxylans in cereal products. This can dramatically affect the functional and physiological properties of the final products. Therefore, the purpose of the research was to explore the effects of jet-cooking barley flour on the content, solubility, and molecular weights of these polymers. Barley flours were jet-cooked without pH adjustment or after adjusting the pH to 7, 9, or 11. Jet-cooking without pH adjustment increased the solubility of beta-glucans from 15.4% to 38.0% when extracted with water at 30oC; as pH during jet-cooking increased, the solubility further increased to 63.5% at pH 11. Arabinoxylan solubility was only substantially affected when the pH of jet-cooking was alkaline (solubility increased from 11.4% to 48.5% when jet-cooked at pH 11). Jet-cooking without pH adjustment resulted in slight increases in peak molecular weights for both polymers (beta-glucan increased from 429,000 to 441,000; arabinoxylan increased from 105,000 to 111,000); higher pH values during jet-cooking resulted in similarly minor changes in molecular weights.