Parameter Optimization of Protein Film Production Using Microbial Transglutaminase

Abstract

Sodium caseinate films were produced using microbial transglutaminase as a protein cross-linking biocatalyst. Basic parameters for the film production, such as buffer type and concentration, pH, temperature, plasticizer concentration and its influence on transglutaminase activity, mold material for film casting, specimen width, and cutting method, were investigated and compared with standardized methods (DIN EN ISO 527-3). Surprisingly, a previously described sodium phosphate buffer (50 mM, pH 8.0) resulted in crystals after drying the films for 48 h. To avoid this deteriorating effect, the buffer system was optimized and finally a Tris-HCl buffer (20 mM, pH 7.0) was chosen for the production of transparent, smooth films without crystallization. Incubation time and temperature during enzyme treatment had a considerable influence on the mechanical properties of the films.

Roles of Soft Segment Length in Structure and Property of Soy Protein Isolate/Waterborne Polyurethane Blend Films

“…Soy protein isolate (SPI), a protein with reproducible resource, good biocompatibility, biodegradability, and processability described in our previous review, exhibits a significant potential in food industry, agriculture, bioscience, and biotechnology. , In particular, SPI has been fabricated as edible and nonedible packaging materials due to its excellent film-forming characteristic as well as good barrier performance against aroma, oxygen, and lipid. , However, the poor mechanical property and water resistance are two major problems for SPI-based materials, which seriously limit their extensive applications. Therefore, up to date, a variety of physical, − chemical, − and enzymatic modifications , have been applied to lower the brittleness and water sensitivity of SPI, among which blending SPI with another polymer has been proved to be the most effective approach . Different natural and synthetic polymers, such as chitosan, , alginate, cellulose, − gelatin, , casein, poly­(vinyl alcohol), , poly ε-caprolactone, , and poly­(lactic acid) , have up to now been used as the secondary components for SPI-based materials.…”

“…1,2 However, the poor mechanical property and water resistance are two major problems for SPI-based materials, which seriously limit their extensive applications. Therefore, up to date, a variety of physical, 3−8 chemical, 9−14 and enzymatic modifications 15,16 have been applied to lower the brittleness and water sensitivity of SPI, among which blending SPI with another polymer has been proved to be the most effective approach. 17 Different natural and synthetic polymers, such as chitosan, 4,18 alginate, 19 cellulose, 20−22 gelatin, 23,24 casein, 25 poly(vinyl alcohol), 26,27 poly ε-caprolactone, 28,29 and poly(lactic acid) 30,31 have up to now been used as the secondary components for SPI-based materials.…”

Treatments of protein for biopolymer production in view of processability and physical properties: A review

“…The incorporation of microbial transglutaminase (MTG) was found to be able to induce crosslinking of the sodium caseinate film during the wet‐casting process, as proven by the increase in the molecular weight shown in the SDS‐PAGE results (Figure ) . Stolte et al .…”

“…The incorporation of microbial transglutaminase (MTG) was found to be able to induce crosslinking of the sodium caseinate film during the wet-casting process, as proven by the increase in the molecular weight shown in the SDS-PAGE results ( Figure 7). 81 Stolte et al studied the effects of temperature and air humidity during the drying process on the mechanical properties of MTG-crosslinked sodium caseinate and the additive (potassium nitrate) crystalline structure in the resultant biopolymer films. 12 Sodium caseinate films showed the best mechanical performance when dried at 758C and 50-75% relative humidity with and without MTG.…”

Molecular crowding elicits the acceleration of enzymatic crosslinking of macromolecular substrates

“…10 Owing to its strong ligation capacity, various studies have revealed the potential of MTG for preparing hybrid materials that consist of a protein and various compounds and materials such as small molecules, 11 drugs, 12 lipids, 13 peptides, 14 DNA, 15 RNA, 16 proteins, 17 synthetic polymers, 18 and paper sheets. 19 Although Patzsch et al have investigated MTG activity in solutions of glycerol, 20 the catalytic behavior of MTG in crowded conditions remains unclear.…”