Puffing and jet cooking affect solubility and molecular weight of barley beta -glucans.

摘要

Foods containing barley or oats are often marketed as healthy because of the dietary fibre (1->3) (1->4)- beta -D-glucan. Processing conditions can affect the molecular structure of these dietary fibers, which in turn affect quality and properties of the products. In this study, the effects of puffing and jet cooking conditions on the solubility and molecular weight of barley beta -glucans were investigated. Barley flour was processed in a pasta extruder to produce particles similar in size and shape to rice. These particles were puffed at 230, 250 and 270 degrees C for 6, 8 and 10 seconds in a rice cake machine. The solubility and molecular weight of barley beta -glucans were determined by using water extracts (25 or 65 degrees C). The amount of beta -glucan extracted in water at 25 degrees C increased from 41.1% in cakes puffed at 230 degrees C/6 seconds to 69.7% in cakes puffed at 270 degrees C/10 seconds. The amount of beta -glucan extracted in water at 65 degrees C increased from 63.6% in samples puffed at 230 degrees C/6 seconds to 99.1% in samples puffed at 270 degrees C/10 seconds. The molecular weight of beta -glucans in barley was reduced by puffing and jet cooking treatments.