Enzymatic Hydrolysis, Grease Permeation, and Water Barrier Properties of Zein Isolate Coated Paper

Abstract

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 depended 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 hydrolysis 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 8 x; however, zein and lipid were still present 1 h after hydrolysis by pancreatin 1 x.

State of the Art in the Development and Properties of Protein-Based Films and Coatings and Their Applicability to Cellulose Based Products: An Extensive Review

“…Although grease resistance was lowest for the lowest coating weight, there was no significant difference in grease resistance between 7.9 and 15.8 g/m 2 . Other authors [235] observed, that grease permeation through zein isolate levels above a specific value is independent on coating weight. However, water vapor permeation correlated with coating thickness.…”

“…Parris et al [235] evaluated the hydrolysis of zein by R-chymotrypsin, pancreatin 8ˆand pancreatin 1ˆ. After 10 and 30 min, no additional growth in the hydrolysate peak arose for R-chymotrypsin and pancreatin 8ˆ.…”

“…When applied as coatings, more results deal with plastic coatings than with paper and board coatings. In consequence to this, the application on paper has been studied only for a few proteins such as whey proteins [8,9,32,33], isolated soy proteins [214,[278][279][280][281][282], caseinates [1,7,115,121], wheat gluten [32,280,[283][284][285] and corn zein [1,37,234,235]. As could be observed so far, the literature is countless and it is of course also expected that some of the results on standalone films and on coatings on different substrates can be transferred to paper at least as trends.…”

“…The use of proteolytic enzymes (R-chymotrypsin, pancreatin) can affect the rate of protein degradation [235].…”

Bio-Based Coatings for Paper Applications

“…The coated paper with corn zein can be used as wrapping paper for sandwich packaging, having grease barrier properties as effective as PE coated papers [72]. By spray coating the corn zein on Kraft paper, an improvement in grease resistance and WVP properties was seen along with the possibility of easy recycling and repulping through enzymatic hydrolysis in comparison with wax-treated papers [31].…”