Mechanical properties of a Gelidium corneum edible film containing catechin and its application in sausages

ABSTRACT:  We prepared an edible Gelidium corneum (GC) film containing catechin and examined the microbial growth and quality change during storage of sausages packaged with the film. Incorporation of catechin in the film improved film tensile strength and water vapor permeability. The film's antimicrobial activity against Eschericha coli O157:H7 increased with increasing catechin concentrations and resulted in a decrease in the populations of the bacteria by 1.93 log CFU/g at 150 mg of catechin. For the sausage samples inoculated with E. coli O157:H7 and Listeria monocytogenes, the samples packed with the GC film showed a decrease in populations of E. coli O157:H7 and L. monocytogenes by 1.81 and 1.44 log CFU/g, respectively, compared to the control after 5 d of storage. In addition, the sausage samples packed with the GC film had lower degrees of lipid oxidation. The results suggest that sausages can be packed with GC film to extend shelf life.     

含精油可食性抗菌膜研究进展

可食性抗菌膜是目前食品包装领域研究的重要方向,含精油可食性抗菌膜是其研究的热点之一。本文介绍含精油的可食性食品包装膜中精油的主要成分及其抗菌特性,概述此类膜的一般制备技术,对含精油膜抗菌的抗菌性能测试方法进行归纳,就精油对可食性膜抗氧化性、机械性能、渗透性及其他理化性能的影响作重点阐述,最后分析含精油可食性抗菌膜可能存在的问题,并预测其发展前景。     

柚子皮基香芹酚抗菌膜的制备及性能

为使柚子皮基膜获得抗菌活性,向其中添加香芹酚,通过流延法制备柚子皮基抗菌膜,研究香芹酚质量分 数对膜的颜色、透光率、微观结构、水蒸气透过系数、力学性能和抗菌活性等的影响。结果表明：随着香芹酚质量 分数的增加,柚子皮基抗菌膜的颜色逐渐偏黄;透光率、水蒸气透过系数和抗拉强度降低;而厚度、断裂伸长率和 抗菌活性增加。综合分析结果可知,香芹酚质量分数为1.0%时的柚子皮基抗菌膜具有相对较好的综合性能,此时其 膜厚度为（0.125±0.021）mm、抗拉强度为（12.53±0.72）MPa、断裂伸长率为（16.29±0.60）%、水蒸气透过系 数为（4.06±0.25）×10－12 g·cm/（cm2·s·Pa）、透光率为（49.97±0.38）%、对大肠杆菌和金黄色葡萄球菌的 抑菌圈面积分别达到（377.62±19.63）mm2和（506.82±11.28）mm2。研究结果可为柚子皮基香芹酚抗菌膜的实际 应用提供理论依据。     

抗菌肽BCp12保鲜膜在乳扇贮藏保鲜中的应用

为延长乳扇的货架期,以酪蛋白、壳聚糖为原料包裹抗菌肽BCp12制备复合保鲜膜。采用单因素试验和正交试验确定最佳制备工艺,以膜的断裂伸长率、拉伸强度及抑菌活性为指标,结合扫描电子显微镜（scanning electron microscopy,SEM）、傅里叶变换红外光谱（Fourier transform infrared spectroscopy,FT-IR）及分子对接探究复合膜的形成机理,并将其应用于乳扇保鲜。结果表明,可食膜的最佳制备工艺为酪蛋白/壳聚糖质量比1∶1.5、BCp12质量浓度1 mg/mL、甘油质量分数1.5%、干燥温度55℃。SEM观察结果显示复合膜具有良好的相容性;FT-IR分析结果显示1 545.67 cm-1处为C—O伸缩振动吸收峰且结构稳定;分子对接结果表明BCp12与酪蛋白、壳聚糖之间主要通过残基Y4与—NH2活性位点产生氢键相互作用。与对照组相比,BCp12膜组乳扇的过氧化值变化较慢且经4℃贮藏后可使保质期延长60 d。综上,该膜能抑制腐败菌的生长,本实验可为BCp12/壳聚糖/酪蛋白复合膜的应用开发提供一定的技术参考。     

Physical Properties of Gelidium corneum–Gelatin Blend Films Containing Grapefruit Seed Extract or Green Tea Extract and Its Application in the Packaging of Pork Loins

ABSTRACT:  Edible Gelidium corneum –gelatin (GCG) blend films containing grapefruit seed extract (GFSE) or green tea extract (GTE) were manufactured, and the quality of pork loins packed with the film during storage was determined. Tensile strength (TS) and water vapor permeability (WVP) of the films containing GFSE or GTE were better than those of the control. The film's antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes increased with increasing antimicrobial concentration, resulting in a decrease in the populations of bacteria by 0.77 to 2.08 and 0.91 to 3.30 log CFU/g, respectively. Pork loin samples were inoculated with E. coli O157:H7 and L. monocytogenes . The samples packed with the GCG film containing GFSE (0.08%) or GTE (2.80%) had a decrease in the populations of E. coli O157:H7 and L. monocytogenes of 0.69 to 1.11 and 1.05 to 1.14 log CFU/g, respectively, compared to the control after 4 d of storage. The results showed that the quality of pork loins during storage could be improved by packaging them with the GCG film containing GFSE or GTE.     

多糖类可食性膜的研究进展

可食性膜是目前食品包装领域研究的重要方向,其中,多糖类可食性膜因具有均匀、透明等特点而备受青 睐。目前,多糖类可食性膜的研究主要集中在改善其应用性能的同时,赋予其抗氧化性、抑菌性等更多的生物活 性,因此展现出良好的应用前景。本文在简要介绍多糖类可食性膜的主要组成、性能的基础上,对其成膜机理、生 物活性及应用发展进行了综述。     

Physical and Mechanical Properties of Pea Starch Edible Films Containing Beeswax Emulsions

ABSTRACT:  Hydrophobic beeswax emulsions were incorporated into hydrophilic starch films to modify physical, mechanical, and thermal properties of the films. Beeswax was added in the film-forming solution of high-amylose pea starch (35% to 40% amylose w/w) at the level of 0%, 10%, 20%, 30%, and 40% w/w of starch with glycerol as a plasticizer (40/60 of glycerol/starch). Addition of beeswax affected mechanical properties, significantly reducing tensile strength and elongation and increasing elastic modulus. Beeswax addition decreased water vapor permeability and increased oxygen permeability. However, the addition of hydrophobic wax particles in starch films marginally affected these physical properties below 30% beeswax in the films. Beeswax addition at the 40% concentration formed amylose–lipid complex that caused the dramatic changes of physical and thermal properties of the films.     

Application of Laminated Edible Films to Potato Chip Packaging

The effects of various stearic-palmitic acid blend concentrations in films, storage temperatures and storage times on potato chip quality were evaluated using Response Surface Methodology. Storage temperature and time affected the quality of potato chips. The maximum storage times for acceptable potato chip quality were: 30 to 43 days, 23 to 25 days, and 11 to 12 days for storage temperatures of 15, 25 and 35°C, respectively. Results were independent of stearic-palmitic acid blend concentrations.     

可食性膜的研究进展

本文从可食性膜的分类及其特点、应用以及发展趋势等几个方面对可食性膜近几年来国内外研究进展进行了综述。     

Apple,Carrot, and Hibiscus Edible Films Containing the Plant Antimicrobials Carvacrol and Cinnamaldehyde Inactivate Salmonella Newport on Organic Leafy Greens in Sealed Plastic Bags

The objective of this study was to investigate the antimicrobial effects of carvacrol and cinnamaldehyde incorporated into apple, carrot, and hibiscus‐based edible films against Salmonella Newport in bagged organic leafy greens. The leafy greens tested included organic Romaine and Iceberg lettuce, and mature and baby spinach. Each leafy green sample was washed, dip inoculated with S. Newport (10⁷ CFU/mL), and dried. Each sample was put into a Ziploc® bag. Edible films pieces were put into the Ziploc bag and mixed well. The bags were sealed and stored at 4 °C. Samples were taken at days 0, 3, and 7 for enumeration of survivors. On all leafy greens, 3% carvacrol films showed the best bactericidal effects against Salmonella. All 3 types of 3% carvacrol films reduced the Salmonella population by 5 log₁₀ CFU/g at day 0 and 1.5% carvacrol films reduced Salmonella by 1 to 4 log₁₀ CFU/g at day 7. The films with 3% cinnamaldehyde showed 0.5 to 3 log reductions on different leafy greens at day 7. The films with 0.5% and 1.5% cinnamaldehyde and 0.5% carvacrol also showed varied reductions on different types of leafy greens. Edible films were the most effective against Salmonella on Iceberg lettuce. This study demonstrates the potential of edible films incorporated with carvacrol and cinnamaldehyde to inactivate S. Newport on organic leafy greens.     

Oral Toxicity of Cold Plasma‐Treated Edible Films for Food Coating

No prior research has investigated whether the cold plasma treatment (CPT) resulted in the formation of toxic compounds. Therefore, this study carried out the experiment to check the safety of edible films treated with cold plasma by examining their acute and subacute oral toxicity in a rat model. Single‐dose acute (5000 mg/kg body weight) and 14‐d subacute (1000 mg/kg body weight/day) oral toxicity of cold plasma‐treated edible films was assessed for male and female Sprague–Dawley (SD) rats. Rats administered 5000 mg/kg of edible film did not show the signs of acute toxicity or death after 14 d of observation. Similarly, no signs of acute toxicity or death were recorded during 14 d in rats administered 1000 mg/kg/day of edible film treated with cold plasma. Although changes in the levels of several blood components (hematocrit, hemoglobin, bilirubin, creatinine, and aspartate aminotransferase) of samples were observed, the changes compared to the control were considered to be toxicologically irrelevant as their levels were within normal physiological ranges. Macroscopic analysis showed there were no changes in color or texture of representative liver sections of SD rats following the oral administration of edible films with CPT (F‐CP) or without CPT (F‐NT). The results demonstrate that the cold plasma‐treated edible film possessed very low toxicity, suggesting that CPT does not generate harmful by‐products in the edible film.     

Edible Apple Film Wraps Containing Plant Antimicrobials Inactivate Foodborne Pathogens on Meat and Poultry Products

ABSTRACT:  Apple-based edible films containing plant antimicrobials were evaluated for their activity against pathogenic bacteria on meat and poultry products.  Salmonella enterica  or  E. coli  O157:H7 (10⁷ CFU/g) cultures were surface inoculated on chicken breasts and  Listeria monocytogenes  (10⁶ CFU/g) on ham. The inoculated products were then wrapped with edible films containing 3 concentrations (0.5%, 1.5%, and 3%) of cinnamaldehyde or carvacrol. Following incubation at either 23 or 4 °C for 72 h, samples were stomached in buffered peptone water, diluted, and plated for enumeration of survivors. The antimicrobial films exhibited concentration-dependent activities against the pathogens tested. At 23 °C on chicken breasts, films with 3% antimicrobials showed the highest reductions (4.3 to 6.8 log CFU/g) of both  S. enterica  and  E. coli  O157:H7. Films with 1.5% and 0.5% antimicrobials showed 2.4 to 4.3 and 1.6 to 2.8 log reductions, respectively. At 4 °C, carvacrol exhibited greater activity than did cinnamaldehyde. Films with 3%, 1.5%, and 0.5% carvacrol reduced the bacterial populations by about 3, 1.6 to 3, and 0.8 to 1 logs, respectively. Films with 3% and 1.5% cinnamaldehyde induced 1.2 to 2.8 and 1.2 to 1.3 log reductions, respectively. For  L. monocytogenes  on ham, carvacrol films induced greater reductions than did cinnamaldehyde films at all concentrations tested. In general, the reduction of  L. monocytogenes  on ham at 23 °C was greater than at 4 °C. Added antimicrobials had minor effects on physical properties of the films. The results suggest that the food industry and consumers could use these films as wrappings to control surface contamination by foodborne pathogenic microorganisms.     

Permeability Properties of Fruit Puree Edible Films

The potential of fruit purees as edible mass transfer barriers was studied. Water vapor and oxygen permeabilities (WVP and O₂P) of peach puree films were evaluated at different relative humidities (RH) and temperatures (T). Peach puree was not a good water barrier. Peach and apricot films exhibited lower WVPs than pear and apple films. Calcium addition, RH increases and T decreases resulted in increased WVP values for peach puree edible films. WVPs of peach films were compared with other edible and synthetic films. Peach puree films were good oxygen barriers. RH increases resulted in exponential increases in O₂P. Most edible and many synthetic polymers showed higher O₂Ps at equivalent conditions.     

小麦谷朊粉制备可食性膜的研究

研究了影响小麦谷朊粉成膜的因素,分析了各因素对其性能的影响,对正交试验结果采用极差分析和综合评分法进行评定,得到制备综合性能好的可食性膜的最佳条件为:乙醇体积分数50%,成膜溶液的pH值10,甘油添加量30%,热处理温度80℃。     

可食性小麦蛋白膜透氧性的研究

一定的条件下 ,以小麦蛋白为原料可以制得具有良好透氧性的薄膜。文中研究了可食性小麦蛋白膜的透氧性能 ,对影响透氧性的 5种因素的影响效果及机理进行了探讨 ,以期望为改善小麦蛋白膜的透氧性提供参考。     

改性淀粉基可食性膜的制备及性能研究

以改性淀粉为成膜基材,采用溶液流延法制备可食性膜.研究了改性淀粉种类及浓度、增塑剂种类、甘油添加量、增强剂种类、普鲁兰多糖添加量对膜性能的影响.结果表明,采用羟丙基交联淀粉为基材,淀粉浓度为5 g/100 mL,增塑剂甘油添加的质量分数为30％,增强剂普鲁兰多糖添加的质量分数为淀粉质量的10％,制备的淀粉膜综合性能较好...     

可食性膜及其在果蔬保鲜中的应用

本文概述了可食性膜的分类、特性及其影响因素以及成形技术,并就其在果蔬保鲜中的应用进行了综述。     

玉米磷酸酯淀粉基可食膜的黏合特性

研究了玉米磷酸酯淀粉基可食膜的黏合机理及适宜的黏合剂和黏合方式,分析了影响封合特性的因素,包括封合温度、封合时间、黏合层厚度以及封口宽度。结果表明,对于可食膜的黏合机理,可以用相互扩散理论来解释;将玉米磷酸酯淀粉膜液作为黏合剂,配合加热压合是淀粉膜最佳的封合方法;选择厚度为0.06mm的膜为研究对象,在黏合层厚为0.05mm,封口宽度为6mm时,在封合温度130℃下停留3.5s,可取得较高的封合强度6.56 N/15mm。     

Sensory Attributes of Whey Protein Isolate and Candelilla Wax Emulsion Edible Films

ABSTRACT: Whey protein isolate (5% w/v) films were plasticized with sorbitol or glycerol, and candelilla wax (0.8% w/ v) was added to produce whey protein isolate and candelilla wax emulsion edible films. The films were cut into 7.62 cm × 2.54 cm strips and evaluated by a 15-member trained sensory panel for milk odor, transparency/opaqueness, sweetness, and adhesiveness using a structured 9-point intensity scale. The films had no distinctive milk odor; however, they were perceived to be slightly sweet and adhesive by the trained sensory panel. Whey protein isolate films without candelilla wax were clear and transparent, whereas candelilla wax containing films were opaque.     

2种淀粉-壳聚糖-纤维素衍生物可食膜特性的对比

研究了2种不同纤维素衍生物对淀粉-壳聚糖可食膜性能的影响,并通过X射线衍射法、扫描电镜、热重分析对可食膜结构进行表征。结果表明:加入羧甲基纤维素钠使可食膜的抗拉强度下降,而伸长率却明显增大;加入甲基纤维素使可食膜的抗拉强度显著增大,而伸长率的变化并不大。2种可食膜对金黄色葡萄球菌和大肠杆菌都有明显的抗菌性,而且对前者的抗菌性明显优于后者。X射线衍射及热重分析结果表明可食膜中纤维素衍生物与淀粉、壳聚糖有较强的相互作用。