Effect of Melanin-Free Ink on Mechanical Properties and Yellow Discolouration of Protein Film from Washed Sardine Mince

The effect of the melanin-free ink (MFI) at different concentrations (0, 0.1, 0.2, 0.3 and 0.4 gL^?1 of film forming solution (FFS)) on the properties and yellow discolouration of films from washed sardine mince was studied. Tensile strength (TS) of the film increased with increasing MFI concentration (P < 0.05). Conversely water vapour permeability (WVP) of films decreased as the concentration of MFI increased (P < 0.05). Fourier transform infrared (FTIR) spectra of films showed a slight shift to lower wavenumber of amide-B band of film added with MFI, indicating protein cross-linking. The microstructure showed slightly rough surface of the films when amount of MFI increased. However, cracks in the films were much decreased when MFI at higher levels was incorporated. Films added with MFI had lower thiobarbituric acid reactive substances (TBARS) value, indicating the lowered lipid oxidation. The addition of MFI also decreased the yellow discolouration but increased the transparency of film in a dose-dependent manner.     

Effect of Longan Seed Extract and BHT on Physical and Chemical Properties of Gelatin Based Film

Gelatin films developed from fish skin incorporated with longan seeds extract (LS) or butylated hydroxytoluene (BHT) at different concentrations were prepared and characterized. The film thickness was in the range of 35 to 37 μm, and the transparency was 3.24 to 3.36 for the films with and without the addition of LS or BHT (p?<?0.05). Significant increases in redness (a*) and yellowness (b*) values were observed when the concentration of LS increased (p?<?0.05). Water vapour permeability (WVP) slightly decreased when the concentration of LS increased, while no significant change was observed between the control and the BHT films (p?>?0.05). Tensile strength (TS) and elongation at break (EAB) were in the range of 48 to 53 MPa and 16 to 19 %, respectively. The highest (65.7 J/g) and lowest (38.7 J/g) transition enthalpy was found in the control and LS 500 ppm films, respectively. Slight differences in protein pattern were observed under SDS-PAGE between treatments of the film. These differences were also observed in the FTIR spectrum. Films incorporated with LS or BHT showed the preventive effect on lipid oxidation of soybean oil during 30 days of storage. At the level of 500 ppm, LS provided the highest efficacy for lipid oxidation retardation as evidenced by lower peroxide value (PV), and thiobarbituric acid reactive substances (TBARS) values (p?>?0.05). The addition of LS or BHT had an impact on the film properties derived from fish skin gelatin, especially when high levels were added.     

Effect of pH on the properties of protein-based film from bigeye snapper (Priacanthus tayenus) surimi

The effects of the pH and protein content on the properties and compositional changes of protein-based films from bigeye snapper (Priacanthus tayenus) surimi were investigated. Tensile strength of bigeye snapper surimi films prepared at the acidic (pH 3) and alkaline (pH 11) conditions were not significantly different (P > 0.05). Nevertheless, elongation at break of films prepared at pH 3 was higher than that at pH 11 (P < 0.05). The acidic and alkaline conditions had no effect on water vapor permeability of the films obtained. However, the film prepared at acidic condition was more yellowish than that prepared at alkaline pH. Protein content influenced the mechanical properties and color of films.     

Properties of blend film based on cuttlefish (Sepia pharaonis) skin gelatin and mungbean protein isolate

Blend films based on cuttlefish (Sepia pharaonis) ventral skin gelatin (CG) and mungbean protein isolate (MPI) at different blend ratios (CG/MPI = 10:0, 8:2, 6:4, 4:6, 2:8 and 0:10, w/w) prepared at pH 11 using 50% glycerol (based on total protein) as plasticizer were characterized. CG films incorporated with MPI at increasing amounts had the decreases in tensile strength (TS) (p < 0.05). The increases in elongation at break (EAB) were observed when CG/MPI ratios of 6:4 or 4:6 were used (p < 0.05). Decreased water vapor permeability (WVP) was obtained for films having the increasing proportion of MPI (p < 0.05). CG/MPI blend films with higher MPI proportion had lower film solubility and L*-values (lightness) but higher b*-values (yellowness) and ΔE*-values (total color difference) (p < 0.05). Electrophoretic study revealed that disulfide bond was present in MPI and CG/MPI blend films. However, hydrogen bonds between CG and MPI in the film matrix were dominant, as elucidated from FTIR spectroscopic analysis. Moreover, thermal stability of CG/MPI blend film was improved as compared to that of films from respective single proteins. Differential scanning calorimetry result suggested solid-state morphology of CG/MPI (6:4) blend film that consisted of amorphous phase of partially miscible CG/MPI mixture and the coexisting two different order phases of individual CG and MPI domains. Thus, the incorporation of MPI into gelatin film could improve the properties of resulting blend film, which were governed by CG/MPI ratio.     

Properties,Microstructure and Heat Seal Ability of Bilayer Films Based on Fish Gelatin and Emulsified Gelatin Films

Bilayer films prepared by the lamination of fish gelatin film (GF) and its corresponding emulsified film (EF) with different thickness ratios (7:3, 5:5 and 3:7) were characterized. Bilayer films had the similar tensile strength (TS) to EF (p > 0.05) but showed lower elongation at break (EAB) (p < 0.05). All bilayer films showed the lower water vapor permeability (WVP) but higher oxygen permeability (OP) than GF. Bilayer films had varying ΔE* (total color different), where the highest value was observed in that laminated with higher thickness ratio of EF (p < 0.05). Lower light transmission and higher transparency value were obtained for bilayer films, compared to GF (p < 0.05). Based on scanning electron microscopic (SEM) cross-section micrographs, all bilayer films consisted of two layers. Differential scanning calorimetric (DSC) analysis revealed that the bilayer films had the higher glass transition temperature (T _g) than GF but lower than EF. All bilayer films were heat sealable, however their seal strength and seal efficiency were lower than those of GF (p < 0.05). Therefore, the thickness ratios of GF and EF had a marked effect on the mechanical and barrier properties as well as heat sealing ability of resulting bilayer films.     

Properties and microstructure of protein-based film from round scad (Decapterus maruadsi) muscle as affected by palm oil and chitosan incorporation

The properties of protein-based film prepared from round scad (Decapterus maruadsi) muscle in the absence and the presence of palm oil and/or chitosan were investigated. Films added with 25% palm oil (as glycerol substitiution) had the slight decrease in water vapor permeability (WVP) and elongation at break (EAB) (p < 0.05). WVP and tensile strength (TS) of films increased but EAB decreased when 10–40% chitosan (as protein substitution) was incorporated (p < 0.05). Hydrophobic interactions and hydrogen bonds, together with disulfide and non-disulfide covalent bonds, played an important role in stabilizing the film matrix. The a* and b*-values increased with increasing chitosan levels (p < 0.05). Films added with chitosan were less transparent and had the lowered transmission in the visible range. The incorporation of 25% palm oil and 40% chitosan yielded the films with the improved TS but decreased water vapor barrier property. Apart from film strengthening effect, chitosan inconjunction with Tween-20 most likely functioned as the emulsifier/stabilizer in film forming solution containing palm oil.     

Production and properties of edible film using whey protein

The utilization of exces whey is necessary to reduce dairy waste because the large amount of whey disposal in waste streams has caused environmental problems. During whey protein film production as the effective means of utilization of excess whey, we have examined the effects of pH, temperature, and plasticizers for water vapor permeability (WVP), tensile strength (TS), and elongation rate (%E) of the whey protein films. The 10% whey protein films had the highest WVP (28.73 g·mm/kPa·day·m²) and TS (1.85±0.11 Mpa). But, in this case, an increase of WVP was caused by the thickness of whey protein films. At the concentration of 8% whey protein, appropriate thickness was obtained. Whey protein films prepared at the pH 6.75 and 95°C showed lower WVP (28.38 g·mm/kPa·day·m²) and elongation rate (12.9%) and higher TS value (3.769±0.407 MPa) than at the pH 6.75 and 75°C. As the temperature increased, WVP of films decreased slightly and tensile strength increased slightly, while elongation rate decreased significantly. Higher WVP and TS were observed at pH 6.75 compared to pH 7–9. In contrast, significantly higher elongation was observed at pH 9 compared to pH 6.75–8. Among the plasticizer type used, the addition of sorbitol showed the highest TS value (6.244±0.297 MPa) at the concentration of 0.4 g sorbitol and elongation rate (49%) at the concentration of 0.6 g sorbitol.     

Aging properties of films of plasticized vital wheat gluten cast from acidic and basic solutions

In order to understand the mechanisms behind the undesired aging of films based on vital wheat gluten plasticized with glycerol, films cast from water/ethanol solutions were investigated. The effect of pH was studied by casting from solutions at pH 4 and pH 11. The films were aged for 120 days at 50% relative humidity and 23 degrees C, and the tensile properties and oxygen and water vapor permeabilities were measured as a function of aging time. The changes in the protein structure were determined by infrared spectroscopy and size-exclusion and reverse-phase high-performance liquid chromatography, and the film structure was revealed by optical and scanning electron microscopy. The pH 11 film was mechanically more stable with time than the pH 4 film, the latter being initially very ductile but turning brittle toward the end of the aging period. The protein solubility and infrared spectroscopy measurements indicated that the protein structure of the pH 4 film was initially significantly less polymerized/aggregated than that of the pH 11 film. The polymerization of the pH 4 film increased during storage but it did not reach the degree of aggregation of the pH 11 film. Reverse-phase chromatography indicated that the pH 11 films were to some extent deamidated and that this increased with aging. At the same time a large fraction of the aged pH 11 film was unaffected by reducing agents, suggesting that a time-induced isopeptide cross-linking had occurred. This isopeptide formation did not, however, change the overall degree of aggregation and consequently the mechanical properties of the film. During aging, the pH 4 films lost more mass than the pH 11 films mainly due to migration of glycerol but also due to some loss of volatile mass. Scanning electron and optical microscopy showed that the pH 11 film was more uniform in thickness and that the film structure was more homogeneous than that of the pH 4 film. The oxygen permeability was also lower for the pH 11 film. The fact that the pH 4 film experienced a larger and more rapid change in its mechanical properties with time than the pH 11 film, as a consequence of a greater loss of plasticizer, was presumably due to its initial lower degree of protein aggregation/polymerization. Consequently, the cross-link density achieved at pH 4 was too low to effectively retain volatiles and glycerol within the matrix.     

Effect of phenolic compounds on protein cross-linking and properties of film from fish myofibrillar protein

The effects of several phenolic ocmpounds (caffeic acid, catechin, ferullic acid and tannic acid) at various concentrations (1, 3 and 5% based on protein) on cross-linking and properties of film from myofibrillar proteins of bigeye snapper (Priacanthus tayenus) were investigated. Among all phenolic compounds used, tannic acid exhibited the highest cross-linking ability on myofibrillar protein as evidenced by higher decrease in free amino groups with coincidentally lower band intensity of myosin heavy chain (MHC). In addition, the extent of protein cross-linking increased with increasing concentration of phenolic compounds. Addition of phenolic compounds could enhance mechanical properties of the resulting films. As phenolic compounds content increased, Young's modulus (E) and tensile strength (TS) of the films increased, while their elongation at break (EAB) decreased (P<0.05), suggesting stronger and stiffer film structure. At the same concentration used, tannic acid rendered the film with higher mechanical properties, compared to others. Phenolic compounds decreased film transparency and affected color of the films differently, depending on types and concentrations used. Films from myofibrillar proteins with and without polyphenol generally had the excellent barrier properties to UV light at the wavelength of 200-800nm. Therefore, it could potentially be used as inner packaging material for high-fat foods to prevent the lipid oxidation and thus prolonging the shelf-life of foods during storage.     

Markers of oxidative stress in diabetic mothers and their infants during delivery

Oxidative stress is probably a pathophysiological process leading to disadvantageous outcomes in diabetic pregnancies. We aimed to map a complex of potential markers of oxidative stress in this condition. Diabetic mothers had significantly higher concentrations of thiobarbituric acid reactive substances in the plasma [TBARS] both before (p<0.0001) and after (p<0.001) delivery and also their newborns showed higher values of TBARS (p<0.0001) in comparison with the control group. Diabetic mothers also showed lower concentrations of reduced glutathione in erythrocytes [GSH] both before (p<0.05) and after (p<0.01) delivery and their infants also had lower levels of GSH (p<0.0001). We found a lower total antioxidative capacity of plasma [AOC] before delivery (p<0.05) in the diabetic group in comparison with the control group. Newborns of diabetic mothers had higher plasmatic concentrations of apolipoproteine B [apo B] (p<0.05), higher erythrocyte glutathione peroxidase [GPx] activity (p<0.05) and lower pH (p<0.001) in the umbilical cord blood, when compared with infants of control non-diabetic mothers. We conclude that pregestational and gestational diabetes mellitus represent increased oxidative stress for both mother and her infant. TBARS in plasma are a valuable marker of oxidative stress in this condition. Disruption of glutathione peroxidase/glutathione pattern can be involved in pathophysiology of enhanced oxidative stress in diabetic pregnancies.     

Effects of Hasten Drying and Storage Conditions on Properties and Microstructure of Konjac Glucomannan-Whey Protein Isolate Blend Films

Impact of drying process and storage conditions on properties of konjac glucomannan (KGM) and whey protein isolate (WPI) blend films was investigated. Hundred grams of film solution contained 0.4 g KGM, 3.8 g WPI and 1.5 g glycerol. During drying process, air velocity was varied to produce fast drying (3 h) and slow drying (15 h) in tray dryers under 50 °C. The high air velocity resulted in a significant higher drying rate in fast drying than low air velocity in slow drying. Drying curves from both processes were well-fitted with Page model and Henderson and Pabis model (R² ≥ 0.98). Fast drying improved transparency and mechanical properties without impairing color, solubility or water vapor permeability (WVP). Fast-dried film had less surface roughness and contained larger protein clusters. It also had greater melting enthalpy of protein aggregates, implying stronger networks. For stability study, fast-dried film was stored at 4-35 °C for 24 days. Transparency decreased over time. Overall mechanical properties have improved during storage. Color, solubility and WVP did not significantly change over time at all conditions (p?>?0.05). Microstructure of aged films was relatively similar to that of the freshly prepared film. Overall, the fast-dried KGM-WPI film exhibited reasonable storage stability.     

Properties of film from splendid squid (Loligo formosana) skin gelatin with various extraction temperatures

Properties of film from splendid squid (Loligo formosana) skin gelatin extracted at different temperatures (50-80°C) were investigated. Tensile strength (TS) and elongation at break (EAB) of films decreased, but water vapour permeability (WVP) increased (P<0.05) as the extraction temperature increased. Increase in transparency value with coincidental decrease in lightness was observed with increasing extraction temperatures. Electrophoretic study revealed that degradation of gelatin became more pronounced with increasing extraction temperatures. As a consequence, their corresponding films had the lower mechanical properties. FTIR spectra of obtained gelatin films revealed the significant loss of molecular order of the triple helix. Thermogravimetric analysis indicated that F80 exhibited the higher heat susceptibility and weight loss. Loosen structure was observed in film prepared from gelatin with increasing extraction temperatures. Thus, the temperature used for gelatin extraction from splendid squid skin directly affected the properties of corresponding films.     

The whereabouts of transmembrane proteins from rat brain synaptosomes during two-dimensional gel electrophoresis

Little is known about what happens to transmembrane proteins (TMP) in 2-DE. In order to obtain more insight into the whereabouts of these proteins we prepared membrane-enriched synaptosomes from rat frontal cortex and washed them with 7 M urea or Na(2)CO(3). From each preparation, 200 microg protein was loaded on 2-DE gels covering the 4-7 and 6-11 pH ranges, respectively. MALDI-MS/MS analysis detected only 3 TMP among 421 identified spots. However, when the samples had been washed with Na(2)CO(3), only few well-focused spots remained detectable on the gel covering the pH 6-11 range. Instead, a heavily ruthenium-stained smear became visible at the upper edge of the gel at the location where the samples had been applied by cup loading. LC-MS/MS analysis revealed that this smear contained 38 unfocused TMP with up to 12 transmembrane helices. After transfer to the second dimension, no major areas of protein staining were left on the IPG strips. This indicates that after extraction and denaturation the TMP may form high-molecular aggregates, due to their "hydrophobic interactions". These aggregates enter the IPG strips, but do not focus regularly. They are then transferred onto the 2-DE-gels, where they remain caught at the upper edge.     

Impaired glucose tolerance: its relevance to early endothelial dysfunction.

We studied the effects of acute glycemia on plasma nitric oxide (NO; nitrite plus nitrate) levels, Cu-Zn Superoxide dismutase (Cu-Zn SOD) activity and thiobarbituric acid-reactive substances (TBARS) levels in age-matched female subjects before and two hours after glucose loading. According to the results of glucose loading, subjects were divided in the three groups as normal (n = 13, NGT), impaired (n = 11, IGT) and diabetic glucose tolerance (n = 10, DGT). Plasma NO levels were significantly higher in subjects with DGT than in subjects with NGT (p< 0.001) and IGT (p< 0.05) at baseline. Two hours after glucose loading, plasma NO levels were significantly decreased in subjects with IGT and DGT (p< 0.001 and p< 0.001). Although plasma TBARS levels in subject with NGT did not change from the baseline levels after glucose loading, TBARS levels were significantly elevated in subjects with DGT and IGT (p< 0.001 and p< 0.001). Plasma Cu-Zn SOD activities were within a similar range in all subjects at baseline. Cu-Zn SOD activities were significantly increased in subjects with NGT, and were significantly decreased in subjects with IGT and DGT (p< 0.001 and p< 0.001) after glucose loading. There was a positive correlation between NO and glucose in subjects with NGT (r = 0.34, p< 0.01) and a negative correlation between NO and TBARS in IGT sum DGT during glucose tolerance (r= -0.38, p< 0.01). We suggest that NO availability was decreased when the blood glucose levels were only moderately elevated above normal levels. This might be related with the enhanced oxidative stress.     

Aerobic and anaerobic training effects on the antioxidant enzymes of the blood.

The purpose of the present study was to investigate the effects of aerobic and anaerobic training on serum lipid peroxidation levels and on antioxidant enzyme activities. Long distance runners for aerobic training group, and wrestlers for anaerobic training group were chosen. Non-sporting men were used as control group. When the aerobic power was compared; indirect VO2max of long-distance runners were found higher than wrestlers and control group (p<0.001, p<0.001). When lipid peroxidation levels were compared; levels of the thiobarbituric acid reactive substances (TBARS) of long distance runners were found to be lower than those in the control group (p<0.05), but similar to those found in wrestlers. Comparison of antioxidant enzyme activities in erythrocytes show that there were no significant difference among the groups in superoxide dismutase enzyme activities, but glutathione peroxidase (GPx) activity of long distance runners was higher than that measured in wrestlers (p<0.05). These results suggest that aerobic training increased in erythrocytes GPx activity with a subsequent decrease in plasma TBARS levels but anaerobic training had no effect on this process.     

Effects of supplementing two levels of magnesium aspartate and transportation stress on pork quality and gene expression of 𝛍-calpain and calpastatin of finishing pigs

The objective of this study was to investigate the effects of supplementing swine finishing diets with two levels of magnesium aspartate (MgAsp) and short-term transportation stress on blood parameters, pork quality and the mRNA abundance of μ-calpain and calpastatin in muscles of finishing pigs. Thirty-six crossbred finishing pigs (mean BW 90 kg) were assigned randomly to 0, 1000, or 2000 mg supplemental Mg from MgAsp per kg of diet for five days before slaughter. Then six pigs from each dietary treatment were subjected either to no transportation stress (NTS) or 2 h of transportation stress (TS). Transportation stress resulted in higher concentrations (p < 0.01) of serum calcium, glucose and cortisol, lower pH (p < 0.01), higher Warner-Bratzler shear force (WBSF) (p < 0.05) and higher calpastatin mRNA abundance (p = 0.05) of longissimus muscle (LM) compared with NTS treatments. Supplementation of MgAsp in TS treatments increased serum Mg concentration (p < 0.05) at 2000 mg of Mg/kg, reduced drip loss (p < 0.05) and improved pork quality colour (p < 0.05) at 2000 mg of Mg/kg, and decreased 1-day and 3-day WBSF (p < 0.05) at 1000 mg of Mg/kg compared with TS treatments fed the control diet. It is concluded that supplementation of MgAsp improves water-holding capacity and pork colour, and alleviates the negative effects of transportation stress on meat tenderness.     

3种假单胞菌CaCl2法感受态细胞制备及转化条件

假单胞菌因其生境和代谢类型的多样性,在污染环境修复、生物转化、生物防治等领域具有广阔的应用潜力;外源基因的导入是假单胞菌遗传改造的重要环节,而感受态细胞的制备和转化方法的建立是导入外源基因的重要方法学基础.本研究以从石油污染土壤中分离筛选的假单胞菌属的3个菌株Pseudomonas putida TS11、P. stutzeri DNB、P. mendocina JJ12为对象,通过3因素4水平正交实验设计,研究了不同CaCl₂浓度、热激时间及复苏时间对不同假单胞菌感受态细胞制备及转化效率的影响.结果表明： CaCl₂浓度是影响假单胞菌转化效率的最主要因素(P<0.05),且在制备感受态细胞之前用无菌蒸馏水多次洗涤菌体细胞,转化率明显提高.3种假单胞菌的CaCl₂转化优化条件分别为：100 mmol·L^-1 CaCl₂,热激3 min,复苏1.5 h;50 mmol·L^-1 CaCl₂,热激6 min,复苏1.5 h;75 mmol·L^-1 CaCl₂,热激4.5 min,复苏0.5 h.在上述转化条件下,3种假单胞菌的外源质粒转化效率均达到10.5个转化子·μg^-1 DNA水平.     

Oxidative stress implication in a new phenotype of amyotrophic quadricipital syndrome with cardiac involvement due to lamin A/C mutation

This study aimed at evaluating OS in an amyotrophic quadricipital syndrome with cardiac impairment in a family of 80 members with a mutation in lamin A/C gene. Twelve patients had cardiac involvement (5 cardiac and skeletal muscles impairment). OS was evaluated in blood samples (thiobarbituric acid-reactive substances (TBARS), carbonylated proteins (PCO)) 6 “affected patients” with phenotypic and genotypic abnormalities without heart failure and 3 “healthy carrier” patients. OS was higher in affected patients than in healthy, as shown by the higher TBARS and PCO values. Patients with cardiac and peripheral myopathy exhibited a higher OS than patients with only cardiac disease (TBARS: 1.73 ± 0.05 vs. 1.51 ± 0.04 mmol/l (p = 0.051), PCO: 2.73 ± 0.34 vs. 0.90 ± 0.10 nmol/mg protein (p = 0.47)), and with healthy carriers patients (TBARS: 1.73 ± 0.05 vs. 1.16 ± 0.14 mmol/l (p = 0.05), PCO: 2.73 ± 0.34 vs. 0.90 ± 0.20 nmol/mg protein (p = 0.47)).

OS may thus contribute to the degenerative process of this laminopathy. ROS production occurs, prior to heart failure symptoms. We suggest that the extent activation may also promote the variable phenotypic expression of the disease.     

Cross-linking of horseradish peroxidase adsorbed on polycationic films: utilization for direct dye degradation

Horseradish peroxidase (HRP) was immobilized on the polyaniline (PANI) grafted polyacrylonitrile (PAN) films. The maximum HRP immobilization capacity of the PAN-g-PANI-3 film was 221?μg/cm(2). The HRP-immobilized PAN-g-PANI-3 film retained 79?% of the activity of the same quantity free enzyme. The HRP-immobilized PAN-g-PANI-3 film was operated for the decolorization of two different benzidine-based dyes in the presence of hydrogen peroxide. The maximum decolorization grade was obtained at pH 6.0 for both dyes. The HRP-immobilized PAN-g-PANI-3 film was very effective for removal of Direct Blue-53 compared to Direct Black-38 from aqueous solutions. The immobilized HRP exhibited high resistance to proteolysis by trypsin compared to the free counterpart. Immobilized HRP preserved 83?% of its original activity even after 8?weeks of storage at 4?°C, while the free enzyme lost its initial activity after 3?weeks of storage period.     

Effect of transglutaminase treatment on the properties of cast films of soy protein isolates

The objective of this work was to investigate the effect of microbial transglutaminase (MTGase) treatment on the properties and microstructures of soy protein isolate (SPI) films cast with 0.6 plasticizer per SPI (gg(-1)) of glycerol, sorbitol and 1:1 mixture of glycerol and sorbitol, respectively. Tensile strength (TS), elongation at break (EB), water vapor transmission rate (WVTR) or water vapor permeability (WVP), moisture content (MC), total soluble matter (TSM), lipid barrier property and surface hydrophobicity of control and MTGase-treated films were evaluated after conditioning film specimens at 25 degrees C and 50% relative humidity (RH) for 48 h. The treatment by 4 units per SPI (Ug(-1)) of MTGase increased the TS and surface hydrophobicity by 10-20% and 17-56%, respectively, and simultaneously significantly (P< or =0.05) decreased the E, MC and transparency. The WVTR or TSM of SPI films seemed to be not significantly affected by enzymatic treatment (P>0.05). The MTGase treatment also slowed down the moisture loss rate of film-forming solutions with various plasticizers during the drying process, which was consistent with the increase of surface hydrophobicity of SPI films. Microstructural analyses indicated that the MTGase-treated films of SPI had a rougher surface and more homogeneous or compact cross-section compared to the controls. These results suggested that the MTGase treatment of film-forming solutions of SPI prior to casting could greatly modify the properties and microstructures of SPI films.