Enzymatic hydrolysis, grease permeation, and water barrier properties of zein isolate coated paper

An inexpensive zein-lipid mixture was isolated from yellow dent, dry-milled corn. Grease permeation through zein isolate applied to brown Kraft paper was found to be independent of loading levels at zein isolate levels above 30 mg/16 in.(2). The data shows that water vapor transmission rates depende d on the amount of coating applied. Triacylglycerols were the most abundant lipid in milled corn but were absent in the zein isolate (perhaps due to h ydrolysis by lipases). Zein from the paper was hydrolyzed enzymatically and the hydrolysis monitored by SDS-capillary electrophoresis. At an E:S ratio of 1:100 no further increase in the hydrolysate peak occurred after 10 and 30 min for alpha-chymotrypsin and pancreatin 8x; however, zein and lipid w ere still present 1 h after hydrolysis by pancreatin 1x.