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ARS Home » Research » Publications at this Location » Publication #125186


item Johnston, David

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2002
Publication Date: 2/15/2002
Citation: N/A

Interpretive Summary: Currently most of corn in the US is processed into starch and other products by the use of the conventional wet milling process. The foremost operation of the corn wet milling process is hydration of corn in warm sulfurous acid for extended periods of time. Sulfites (sulfurous acid and its other species) are a major health and environmental concern. Recently, ,a corn wet milling process that is environmentally benign and replaces the use of sulfites with enzymes has been developed. The enzymatic corn wet milling process has several other advantages over the conventional process. The prime product (starch) yields with enzymatic wet milling procedure are comparable or higher than the conventional wet milling process. There are also savings associated with capital and operating cost with the enzymatic wet milling procedure. In this study the pasting properties of starch samples obtained from the enzymatic wet milling process were compared with the pasting properties of starch from the conventional process. The results showed that some of the pasting properties of starch from the enzymatic corn wet milling process were significantly different from the conventional process.

Technical Abstract: In this study, pasting properties and surface characteristics of starch obtained from six different enzyme treatments (three glycosidases; beta-glucanase, cellulase and xylanse, and three proteases; pepsin, acid protease and bromelain) using the enzymatic corn wet-milling procedure were evaluated and compared to starch obtained using the conventional corn wet-milling procedure. Significant effects from enzymatic milling were observed on all the three starch pasting properties (peak, shear-thinning and setback). The set back viscosities of all enzyme treatments were significantly lower compared to the control sample, indicating that starch polymers in samples from enzymatic corn wet-milling, do not re-associate to the same extent as with the control sample. Comparison between bromelain treatment and the control sample showed that starch samples obtained from bromelain treatment are very similar to control starch samples in their water binding capacity, molecular breakdown and their time to swell when cooked in water. Significant effects from enzymatic milling were observed on the surface characteristics of starch granules. The glycosidase treatments, especially the beta-glucanase samples, showed holes in the starch granules. No visual differences were observed in starch granules between bromelain and control samples.