Properties of Gelatin Film from Horse Mackerel (Trachurus japonicus) Scale

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film‐forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.45%, depending on the extraction conditions. Among the various extraction times and temperatures, the film from gelatin extracted at 70 °C for 1 h showed the highest tensile strength and elongation at break. Horse mackerel scale gelatin film showed the greatly low water vapor permeability (WVP) compared with mammalian or fish gelatin films, maybe due to its containing a slightly higher level of hydrophobic amino acids (total 653 residues per 1000 residues) than that of mammalian, cold‐water fish and warm‐water fish gelatins. Gelatin films from different preparation conditions showed excellent UV barrier properties at wavelength of 200 nm, although the films were transparent at visible wavelength. As a consequence, it can be suggested that gelatin film from horse mackerel scale extracted at 70 °C for 1 h can be applied to food packaging material due to its lowest WVP value and excellent UV barrier properties.     

Permeability and Mechanical Properties of Cellulose-Based Edible Films

Factors affecting barrier properties [oxygen permeability (OP) and water vapor permeability (WVP)] and mechanical properties [tensile strength (TS) and elongation (E)] were investigated for methyl cellulose (MC) and hydroxypropyl cellulose (HPC) films. OP, WVP and TS of MC and HPC films increased as the molecular weight (MW) of the cellulose increased. E of MC films increased as MW increased, but E of HPC films was highest for the intermediate MW of 370,000. OP, WVP and TS of MC films were not a function of thickness, but E slowly increased as film thickness increased. OP and WVP of HPC films were not relatable to film thickness, but TS and E of HPC films slowly increased as film thickness increased. TS decreased and E increased for both film types as concentration of plasticizers was increased. Plasticizers enhanced or retarded OP and WVP of cellulose-based films, depending on their concentrations.     

普鲁兰、甘油共混对结冷胶食用膜性能的影响

研究了普鲁兰、甘油共混对结冷胶食用性膜的机械性能、水蒸汽透过率、阻氧性和吸水率的影响。结果表明,普鲁兰的添加,提高了结冷胶食用膜的延展性、水蒸汽透过率和阻氧性,但降低了结冷胶食用膜的抗拉强度和吸水率;甘油增加了膜的延展性和水蒸汽透过率,但降低了膜的阻氧性。     

Characterization of gelatin films prepared from under-utilized blue shark (Prionace glauca) skin

Gelatin film from blue shark (Prionace glauca) skin was investigated in order to utilize what is one of the most serious marine wastes in Japan. Film properties from shark skin such as tensile strength (TS), elongation at break (EAB) were evaluated. The TS of gelatin film from shark skin was affected by the protein concentration (1, 2 and 3%) of the film-forming solution (FFS). TS of the film from a 2% protein FFS was the highest. EAB and water vapor permeability (WVP) increased with increasing FFS protein concentration. WVP of shark skin gelatin was evidently low as compared to gelatin films from other fish. An increase in the FFS protein concentration decreased transparency at almost all wavelengths. Furthermore, opacity at 280 nm was characteristically high as compared to films from bony fish skin. The addition of glycerol improved flexibility and enhanced the UV barrier property at 280 nm. However, transparency at the visible range and WVP increased with increasing glycerol content.From the above, it was suggested that shark skin gelatin film technology can be applied to pharmaceutical products or rich-fat food due to its excellent water and UV barrier properties.     

添加单宁对明胶可食膜性质的影响

如何提高明胶膜的机械性能和阻隔性能,一直以来是可食膜研究领域的重要内容。本文以不同剂量(0 mg/g、10 mg/g、20 mg/g、30 mg/g和40 mg/g)单宁添加于明胶液并以浇注法成膜,然后对膜的理化性质进行分析。研究结果发现单宁有效提高了明胶膜的拉伸强度,但降低了其断裂伸长率;当单宁添加量为30 mg/g(明胶干基)时,其拉伸强度最大(22.10 MPa),断裂延伸率最小(40.12%)。与对照膜相比,单宁的添加降低了复合膜水溶性,水蒸气透过率和氧气透过率。在单宁含量添加范围内,水蒸气透过性最低为1.49×10-11 g/(Pa·s·m);水溶性最低为27.76%,氧气透过率最低为21.63 meg/kg。同时,DSC分析表明单宁提高了明胶膜的热稳定性。FT-IR图谱表明单宁与明胶之间发生了以氢键和疏水键为主的物理交联作用。所以,单宁-明胶复合膜在食品包装方面具有潜在的开发价值。     

Physical properties and internal microstructures of films made from catfish skin gelatin and triacetin mixtures

Gelatin from catfish skin was obtained by thermal extraction. Triacetin was added to the gelatin at 0, 50, 100, and 150% of the gelatin content to improve the hydrophobic properties of the resulting films. Tween 80 (10% of triacetin amount) was also added as an emulsifier. Internal microstructures of the films were examined using a transmission X-ray microscope (TXM). Other film properties, such as thickness, mechanical properties, water vapor permeability, water solubility, light transparency, and thermal properties were also evaluated. Possible relationships between the internal microstructures and the film properties were hypothesized. The triacetin distribution changed from homogeneous to heterogeneous with its increased content in the films. The addition of triacetin resulted in decreased tensile strength (TS) and increased percent elongation (%E), water solubility, UV and visible light barrier properties, and protein denaturation temperature of the films. Water vapor permeability of the films increased in some treatments (100% and 150% triacetin) possibly due to the heterogeneous distribution of the triacetin and also the increased Tween 80 amount in the films.     

低温储藏条件对大豆分离蛋白膜理化特性的影响

以大豆分离蛋白为原料制得可食性膜,研究在不同低温储藏条件下其功能特性,包括机械性能和阻隔性能的变化。结果显示:随冷藏温度的升高,其功能特性变化较为缓慢。而随冻藏温度的降低,断裂延伸率下降尤为明显,抗拉强度和脂质阻隔能力变化趋势次之,水蒸气透过率升高缓慢。冷藏时间与断裂延伸率呈显著正相关(p<0.05)。冷藏时间与水蒸气透过率和油脂渗透系数均呈极显著正相关(p<0.01)。冻藏时间与水蒸气透过率和油脂渗透系数呈显著正相关(p<0.05)和极显著正相关(p<0.01)。     

还原剂影响可食性大豆分离蛋白膜性能的研究

研究了还原剂对可食性大豆分离蛋白 (SPI)膜性能的影响。结果表明 ,还原剂可明显提高SPI膜的抗拉强度 (TS) ,降低水蒸气迁移系数 (WVP) ,但伸长率 (E)有所下降。添加还原剂的SPI膜在 pH 7时机械强度和阻隔性最好 ,其中添加半胱氨酸的SPI膜 TS最大 ,为14.4 8MPa ,WVP最小 ,为 4 .6 1g·mm/m2 ·d·kPa     

膜液质量浓度对MC/WG可食性复合膜性能的影响

研究膜液质量浓度对甲基纤维素(MC)/小麦面筋蛋白(WG)可食性复合膜性能的影响。结果表明：MC/WG复合膜的抗拉强度、阻氧性能随着膜液质量浓度的增大而显著提高;断裂伸长率、透光率随着膜液质量浓度的增大而降低;水蒸气透过系数则随着膜液质量浓度的增大先减小后增大,在膜液质量浓度为50g/L时最小。各个质量浓度下的复合膜均可完全溶于水,具有良好的水溶性。综合比较复合膜在不同质量浓度下的性能,MC/WG质量浓度以50g/L为宜。     

Mechanical and water vapor barrier properties of extruded and heat-pressed gelatin films

Gelatin-based edible films were produced by extruding hot melt of gelatin-based resins through a die with slot orifice and followed by heat-pressed method. The resins were plasticized with glycerol, sorbitol and the mixture of glycerol and sorbitol (MGS). The effect of type of plasticizer on extruded and heat-pressed (EHP) film-forming capacity was studied, and the mechanical and water barrier properties of resulting EHP gelatin films were compared with those of gelatin films prepared by solution casting method. Stretchable films were formed when glycerol or MGS were used as plasticizer, whereas resins plasticized with sorbitol were extruded in non-stretchable sheets. Glycerol plasticized gelatin film showed the highest flexibility and transparency among the EHP films tested. Tensile strength (TS), elongation (E) and water vapor permeability (WVP) of glycerol plasticized EHP gelatin films were 17.3 MPa, 215.9% and 2.46 ng m/m² s Pa, respectively, and EHP gelatin films had higher E values, lower TS values and higher WVP values compared to the glycerol plasticized cast gelatin films.     

热处理和碱处理对可食性大豆分离蛋白膜性能的影响

研究了热处理和碱处理对可食性大豆分离蛋白(SPI)膜性能的影响。对成膜液进行适当的加热和调节pH可以提高SPI膜的抗拉强度(TS)和伸长率(E),降低水蒸气透过系数(WVP)。调节成膜液的pH到9,在70℃加热20min,所得到的膜机械性能和阻湿性能最好。     

桔子精油优化鱼鳞明胶膜性能的作用研究

为改善鱼鳞明胶膜的性能,测定添加明胶质量的0%、25%、50%、75%、100%桔子精油的可食膜的厚度、机械性能、水溶性、水蒸汽透过率、色泽、透明度和透光率、热性能、红外光谱和抑菌活性。结果表明:随着精油浓度的增加,鱼鳞明胶膜的厚度、断裂伸长率增加,拉伸强度、透光率、水溶性降低,水蒸汽透过率呈现先增加后降低的趋势;差示扫描量热法(DSC)和傅里叶变换红外光谱(FTIR)分析结果表明,鱼鳞明胶分子与桔子精油的部分成分发生相互作用,在一定程度上改善了明胶膜的热稳定性;桔子精油的添加还赋予了鱼鳞明胶膜抑菌作用。综合评价得出75%质量浓度的桔子精油添加量对鱼鳞明胶膜各项性能优化效果最好,本实验结果可为生产高性能的鱼鳞明胶膜提供理论基础。     

Characterization and antimicrobial activity of sweetpotato starch-based edible film containing origanum (Thymus capitatus) oil

The objectives of this research were to characterize the mechanical and barrier properties of sweetpotato starch (SPS)-based film (SPSF) and to investigate the antimicrobial activity of SPSF containing origanum oil (OG) against foodborne pathogenic bacteria. The SPSF was fabricated with the SPS extracted from commercial sweetpotato roots. Tensile strength (TS), percent elongation at break (E), and water vapor permeability (WVP) were determined to characterize the SPSF fabricated with selected SPS concentrations, plasticizers, and the concentrations of plasticizers. The agar diffusion assay was used to determine the antimicrobial activity of SPSF containing selective concentrations of OG against Salmonella Enteritidis, Escherichia coli O157:H7, and Listeria monocytogenes. The SPSF fabricated with 2.5% SPS exhibited the greatest TS (4.58 MPa). The TS, E, and WVP of SPSF plasticized with 40% sorbitol exhibited 7.96 MPa, 77.92%, 0.212 ng m/m(2) S Pa, respectively. Therefore, the SPSF fabricated with 2.5% SPS and 40% sorbitol was determined as the optimum film. The antimicrobial activity of the SPSF containing OG increased as the concentration of OG increased. And the SPSF containing OG exhibited greater inhibitory effects against the gram-negative bacteria such as S. Enteritidis and E. coli O157:H7 than the gram-positive L. monocytogenes. The greatest antimicrobial activity was observed against S. Enteritidis when the SPSF containing 2% OG was applied, and the maximum square of zone width was 18.43 mm(2).     

大豆组分对腐竹性能的影响

主要研究了大豆分离蛋白、脂肪和蔗糖以不同配比复合制得的腐竹的抗拉强度、延伸率、水蒸汽透过率等性能,并通过以不同品种的大豆为原料制成的腐竹来验证.结果表明,脂肪比例升高,腐竹抗拉强度、延伸率和透水率都下降;蔗糖比例升高,腐竹抗拉强度下降,延伸率上升,透水率先增后降;蛋白质亚基的差异有重要的影响,含有11S多的蛋白,其抗拉强度和阻水性明显提高,影响程度要比脂肪和蔗糖大得多.     

香豆素对鱼鳞明胶可食性膜结构及性能的影响

为开发天然的可食性包装材料,以罗非鱼鱼鳞明胶为原料制备可食性膜,将不同添加量（0、0.03、0.06、0.09、0.12、0.15?g/100?mL）香豆素添加到鱼鳞明胶膜中,研究其对鱼鳞明胶膜物理性质及微观结构的影响。结果表明,香豆素的加入对明胶膜的厚度和含水量无显著影响,但明显降低明胶膜的水蒸气透过率（water vapor permeability,WVP）,且香豆素添加量为0.09?g/100?mL时WVP最小。随着香豆素添加量的增加,明胶膜的拉伸强度和断裂伸长率呈现先上升后下降的趋势,在添加量为0.09?g/100?mL时达到最大值。差示扫描量热分析结果表明香豆素与明胶膜有较好的相容性,且明显提高明胶膜的玻璃化转变温度。扫描电子显微镜、傅里叶红外光谱结果表明香豆素与明胶发生交联作用,在香豆素添加量0～0.09?g/100?mL范围内,随着添加量的增加,二者作用增强,明胶膜表面更均一紧致;继续增加香豆素添加量,复合明胶膜性能和结构发生劣变。添加香豆素能有效降低明胶膜的紫外和可见光透光度。结果表明：0.09?g/100?mL添加量的香豆素更有利于开发阻湿性能好、机械性能高和表面均一的包装材料,具有良好应用前景。     

甘油与甲基纤维素对高直链玉米淀粉- 壳聚糖复合膜性能的影响

以高直链玉米淀粉(HACS)和壳聚糖(CS)为基本材料,甘油为增塑剂,甲基纤维素(MC)为增强剂制备可食性复合膜,研究高直链玉米淀粉与壳聚糖的质量比,甘油的添加量以及甲基纤维素的添加量对复合膜物理性能的影响,包括抗拉强度(TS)、断裂伸长率(E)、水蒸气透过系数(WVP)和色度。结果表明,壳聚糖添加量的增大与甘油添加量的增加都使高直链玉米淀粉- 壳聚糖复合膜的抗拉强度降低,断裂伸长率和WVP 显著增大,膜颜色变黄;甲基纤维素的添加改善了复合膜的机械性能和WVP,随着甲基纤维素添加量的增加,复合膜的抗拉强度和断裂伸长率都随之增大,WVP 逐渐降低,且对膜的颜色没有显著影响。     

Effect of glycerol on the physicochemical properties of films based on legume protein concentrates: A comparative study

The overall goal of this research was to examine the mechanical, water vapor barrier properties and opacity of films prepared using legume protein concentrates (faba bean, pea, lupin, lentil, and soy) as a function of glycerol concentration (50, 75, or 100% [wt/wt]—relative to the protein weight). Overall, tensile strength (TS) decreased with increasing glycerol concentration, whereas tensile elongation (TE) and water vapor permeability (WVP) increased with increasing glycerol concentration. Film opacity was independent of glycerol concentration. The effect of protein‐type varied considerably depending on the functional property of the film being measured; TS was greatest with faba bean and lowest with lupin, whereas TE was highest for pea, and lowest for soy. Lentil protein films had considerably higher WVP, at the 100% glycerol concentration, as compared to the other protein concentrates. Findings from this study indicate that legume protein concentrates are capable of forming biodegradable, edible films. Overall, pea protein concentrate films showed the most promise for application in terms of strength, elongation, and moisture barrier properties.     

Genipin交联明胶/溶菌酶缓释抗菌膜材料的微结构与性能研究

针对亲水明胶膜材料对抗菌剂缓释能力较差的问题,采用生物交联剂(genipin)调节膜材料微结构,制备出新型控释明胶/溶菌酶复合膜材料。系统研究了复合膜材料的力学性能、水汽阻隔性能、膨胀性和热性质等物理性能,并用AFM研究了膜材料的表面微结构,探讨了其结构-性能之间的关系。结果表明:genipin交联显著改善复合膜材料的力学性能,TS值从9.72 MPa逐渐增加至18.80 MPa;复合膜材料的膨胀度(swelling)随genipin浓度增加急剧下降,从1316%降至~200%;genipin交联提升复合膜材料的热稳定性。复合膜材的表面粗糙度依赖于genipin浓度,在低浓度段(0~1.0%),膜材料呈现平整表面微结构;高浓度(2.0%)时,膜表面出现不规则的突起,变得粗糙。适度的genipin交联有助于形成有序的三维网络结构,改善复合膜材料的物理性能;高浓度的genipin过度交联明胶基质,形成团聚状聚集物,及弱化明胶分子间相互作用,进而弱化膜材料的水汽阻隔能力。     

马哈鱼鱼皮明胶提取温度和甘油质量浓度对其成膜特性的影响

明胶提取温度和甘油质量浓度是影响明胶膜性质的基本因素。本研究以马哈鱼（Oncorhynchus keta） 鱼皮为原料,采用不同温度（40、50、60、70、80、90 ℃）提取明胶,考察不同甘油质量浓度（1.1、1.2、 1.5 g/100 mL）下明胶膜的厚度、机械性能、光学性质、微观结构和红外特性。研究发现,40、50、60 ℃明胶 膜的厚度高于70、80、90 ℃明胶膜的厚度（P＜0.05）。50、60 ℃膜的拉伸强度（tensile strength,TS）高于 70、80、90 ℃膜的（P＜0.05）;添加1.5 g/100 mL甘油,膜的断裂伸长率随提取温度升高而上升（P＜0.05）; 50、70、80 ℃膜的TS随甘油质量浓度升高而下降（P＜0.05）。色差分析表明,膜的a*值随提取温度升高而上升 （P＜0.05）。水蒸气透过率随提取温度和甘油质量浓度的升高而升高（P＜0.05）。明胶膜于200、280 nm波长处 的透光率为0.00%,350～800 nm范围内的透光率为46.53%～74.57%,60 ℃膜的透光率低于40、50 ℃膜的透光率 （P＜0.05）。衰减全反射傅里叶变换红外光谱分析表明膜的图谱呈现典型酰胺A、B、Ⅰ、Ⅱ、Ⅲ带,酰胺A带随 提取温度的升高向低波数移动,且振幅随甘油质量浓度升高而增加。扫描电子显微镜结果显示,膜的截面和表面未 呈现明显断裂或空隙。以上结果表明,温度对马哈鱼鱼皮明胶膜的机械性能、透水性、颜色、透光率影响显著,甘 油质量浓度仅对前二者影响显著,可通过优化提取温度与甘油质量浓度改善马哈鱼鱼皮明胶膜性质。     

Mechanical Properties, Water Vapor Permeabilities and Solubilities of Highly Carboxymethylated Starch-Based Edible Films

ABSTRACT: Tensile strength (TS), elongation (E), water vapor permeabilities (WVP) and solubilities were determined for highly carboxymethylated starch (HCMS)-based edible films plasticized with sorbitol (S), xylitol (X), mannitol (M) and glycerol (G). TS and E of HCMS-based film increased as the concentration of plasticizer S, M or × increased. TS of the HCMS-based film containing combined plasticizers were higher than those of films containing single plasticizer. The WVP of HCMS-based films seemed to decreased as the concentration of M, X or G plasticizer increased. Increasing plasticizer concentrations in HCMS-based film resulted in decreasing solubility of the films.