Bicomponent Solutions of Food Polysaccharide and Edible Films on Their Basis

The study of the rheological properties of aqueous solutions of corn starch (CS) blends with sodium alginate (SA) and agar-agar (AA) as well as the physical and mechanical properties of bicomponent films on their basis has been carried out. The data show that adding of both polymers to starch solution causes an increase in viscosity which is higher in the case of SA. Activation energy for viscosity flow of solutions of CS blended with SA has minimum value at CS:SA ratio = 98:2. The above mentioned dependence is not typical for AA, as flow activation energy in this case raises steadily with the growth of AA content in the solution, like viscosity of the CS:AA. The extreme behavior of polymer blends with low content of one of the polymers is described in terms of mutual solubility or thermodynamic compatibility. There is a tendency that mechanical properties and water solubility increase with the increasing of SA and AA polymers in corn starch matrix. Obtained data evidence the benefits of bicomponent films production instead of starch-based films.

Effect of Antimicrobial Edible Films on the Sensory and Physical Properties of Organic Spinach in Salad Bags

The effects of antimicrobial edible films containing carvacrol and cinnamaldehyde on organic baby spinach were determined via sensory analysis and changes in physical properties. Edible films made from pulp of hibiscus, apple, or carrot containing carvacrol or cinnamaldehyde at 0.5%, 1.5%, or 3% concentrations were added to organic baby spinach in plastic bags. These bags were stored at 4°C for 20-24h before performing sensory evaluation and measuring changes in physical properties. A randomized block design with an affective test was used. Preference liking was evaluated based on a 9-point hedonic scale for aroma, color, freshness, mouthfeel, flavor, and overall acceptability. Additionally, panelists quantified each sample using a 5-point hedonic scale for pungency, browning, bitterness, off-odor, and sourness. The color and texture of spinach samples were measured. Edible films containing cinnamaldehyde had the highest preference liking based on aroma, color, freshness, mouthfeel, flavor, and overall acceptability than those containing carvacrol and were the most likely to be purchased by panelists;therefore, cinnamaldehyde can potentially be used as an alternative sanitization option. There were no significant (p ≤ 0.05) changes in firmness or color values between spinach treated with antimicrobial films and controls. The results provide the produce industry with options for incorporating antimicrobial films into salad bags without influencing the physical or sensory properties of baby spinach.

Rheological Properties of Casting Solutions for Starch Edible Films Production

Rheological properties of corn starch and sodium alginate blend solutions have been measured at different polymer ratios in the temperature range from 303 to 343 K bya R/S Brook field rheometer with аcoaxial cylinder measuring unit. Dynamic viscosity of blends has been shown to decrease with shear rate increase and to increase with sodium alginate content increase. The influence of shear rate on activation energy of viscous flow depends on sodium alginate content and is different for below and over 5% (mass) content. Applicability of Ostwald-de-Waele, Herschel-Bulkley, Bingham and Casson models for the description of CS:SA blend solutions flow has been analyzed. Rheological properties of CS:SA blend solutions allow one to look at them as an alternative to starch solutions for edible films casting and production by dry method.

A Soy Protein-Based Composite Film with a Hierarchical Structure Inspired by Nacre

Soy protein-based composite film is a potential replacement for petroleum-based film with multipurpose applica-tions and cleaner production.It is difficult to improve both the tensile strength and toughness of a protein-based film without sacrificing its elongation.In this study,inspired by the hierarchical structure of nacre,a facile yet delicate strategy was developed to fabricate a novel bio-based film with excellent toughness and high strength.Triglycidylamine(TGA)crosslinked soy protein(SPI)as hard phase and thermoplastic polyurethane elastomer(TPU)as soft phase comprise an alternative lay-up hierarchical structure.The interface of these two phases is enhanced using triglycidylamine(TGA)surface-modified TPU(MTPU).The tensile strength of SPI/MTPU/TGA films increases by 392%to 7.78 MPa and their toughness increases by 391%to 8.50 MJ/m^(3) compared to soy protein/glycerol film.The proposed hierarchical structure can also be extended to other high-performance materials and polymers.

Development of hyaluronic acid-based edible film for alleviating dry mouth

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were compared.The concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the solubility.The 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among samples.All of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%humidity.The optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years old.By the sensory test,800 F was also the most acceptable.Based on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

Bioavailability of Soy Protein and Corn Zein Films

The in vivo bioavailability of soy protein isolates and corn zein film material before and after film formation by heat/ pressure was determined. The In vitro digestibility of corn zein before and after film formation was also measured. Films were produced from anhydrous protein with 30% glycerol added using a heat-press method with no use of casting solvents or cross-linking agents. Corn zein raw and film material were ground under liquid nitrogen then digested in two enzyme-acid cocktails with free amino acid analysis before and after digestion. The protein efficiency ratio and net protein ratio were determined for both zein and soy protein using a weanling Sprague-Dawley descended rat feeding study. The In vitro digestibility study indicated that the non-heat pressed corn zein was more digestible than the heat pressed zein. However, the in vivo results indicated that corn and soy protein were equally bioavailable whether they were derived from film mixture prior to or after film formation. Both corn zein and soy protein material had lower protein efficiency ratio than the control diet. Furthermore, soy protein films materials had a higher protein efficiency ratio than corn zein.

Determination of Antimicrobial Activity of Methyl Cellulose Films Enriched with Some Essential Oils on Listeria innocua

Essential oils are effective antimicrobials on important some pathogenic bacteria and can be added packaging materials due to absorb various surfaces. In this study, the aim is to determinate of antimicrobial effects of methyl cellulose films with containing various proportions thyme, rosemary, coriander, basil and pimento berry oils （1%, 2%, 3% and 4% g/cc） against important bacteria as a surface contaminant Listeria innocua by in vitro. For this purpose, 1 cm diameter discs were cut from methyl cellulose films containing essential oils and inhibition zone diameter which were measured by the agar diffusion method. As the results of these analyses, all prepared active edible methyl cellulose films were antimicrobial effects on Listeria innocua. The most powerful antimicrobial effect achieved with methyl cellulose film including coriander oil on Listeria innocua. And also the weakest antimicrobial effect achieved with methyl cellulose film including rosemary oil on Listeria. All results were significant by statistically （p 〈 0.01） and all analyses were replicated in three times.

Edible films based on milk proteins release effectively active immunoglobulins

Objectives:The goal of this study was to develop novel compositions of edible protein coatings based on immunoglobulin(Ig)fraction from bovine milk.Protein coatings can be used to protect foods against microbial,chemical,and physical damage.We developed novel compositions of edible protein coatings based on immunoglobulin(Ig)fraction from bovine milk.A lot of Ig could be obtained from under-utilized side streams of dairy industry.To the best of our knowledge,such use of the Ig fraction has not been published earlier.Materials and Methods:Bovine colostral Ig’s were incorporated in edible films based on various milk proteins and investigated the characteristics of the films including solubility of Ig’s and nisin and on technological properties of films.Ig’s specific to cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus were produced to colostrums by hyperimmunizing cows before parturition.Results:The milk Ig rich fraction suited well as a component of milk protein films.The Ig’s dissolved from the films very rapidly.Nisin,commoly used for food protection,was used as a model of antimicrobial peptide.Nisin was released biologically active from bothβ-lactoglobulin(β-lg)andβ-lg/Ig films.Nisin exerted its bactericidal effect at clearly lower concentrations in theβ-lg/Ig films when compared withβ-lg film.Nisin also retained its activity better in film containing Ig-enriched whey.Incorporating Ig-enriched whey into films enhanced adhesion and tensile strength of the films.The Ig-enriched whey also affected strongly on the appearance of films based on commercial whey protein concentrate in a dose-dependent way by making the films more smooth,transparent,and clear which are all favoured properties in most food and pharmaceutical applications.Conclusions:Biologically active Ig’s can be successfully incorporated in and released from milk protein based edible films.The content of Igs in films affected considerably technological properties of these films.Composition of other proteins in films had effect on preservability and release of Igs.

基于鲜切苹果保鲜的可食性复合保鲜膜配方优化

以海藻酸钠、羧甲基纤维素钠、壳聚糖为主要原料制备可食性复合保鲜膜。由单因素实验制得复合膜,根据复合膜的性能及其对鲜切苹果的保鲜效果获得最优的单因素。在此基础上,应用响应面法优化复合膜的工艺组合并验证其保鲜效果。结果表明,经响应面法优化后的复合膜主要原料配方为:壳聚糖添加量0.98 g,海藻酸钠添加量1.55 g,羧甲基纤维素钠添加量1.31 g。应用该复合保鲜膜进行鲜切苹果保鲜,得到处理样品的色差a值5.95、DPPH自由基清除率35.27%、ABTS自由基清除率34.43%,而对照样品的a值9.10、DPPH自由基清除率21.31%、ABTS自由基清除率27.62%。该可食性复合保鲜膜具有良好的保鲜效果,为生态复合保鲜膜的研发与果蔬保鲜提供参考。

新型植物源可食性包装膜研究进展

随着环境友好型包装材料需求的增加,新型植物源可食性包装膜备受关注。综述了最近研究的含植物源的可食性包装膜,介绍了成膜材料,并着重阐述植物源可食膜的活性物质来源、性能特点以及在果蔬、肉制品及海鲜中的应用研究,提出了当前植物源可食性包装膜研究和应用中存在的问题及未来发展趋势,为植物源可食性包装膜领域的研究提供新的思路和方向,推动环境友好型食品包装的发展和创新。

虾活性肽微胶囊复合可食膜的制备及其保鲜作用

针对南美白对虾易腐败和黑变问题,以羟丙甲基纤维素(HPMC)、虾活性肽微胶囊为成膜原料,研发具有保鲜功能的复合可食膜。采用单因素实验,以膜的机械性能、水蒸气透过率等为指标,考察羟丙甲基纤维素添加量、甘油添加量及虾活性肽微胶囊添加量对复合可食膜的成膜效果及膜性能的影响,并进一步研究虾活性肽微胶囊添加量对复合可食膜的红外光谱和自由基清除能力的影响,优化复合可食膜制备工艺;开展覆膜包装贮藏实验,以感官评分、pH、挥发性盐基氮含量、菌落总数等为指标,探究复合可食膜对南美白对虾的保鲜作用。结果表明,经单因素实验优化,复合可食膜的最佳膜材添加量为:羟丙甲基纤维素12%、甘油0.4%、微胶囊3%,此条件下,膜的综合性能佳。由膜抗氧化性能测定实验可得,当微胶囊添加量为3%及以上时,膜的抗氧化性能较好。傅里叶红外光谱显示,微胶囊添加量为3%~4%时,微胶囊与膜组分的交联作用较强。贮藏实验证实,复合可食膜可抑制虾体腐败,改善虾体感官,减缓机体pH上升、挥发性盐基氮激增和菌落总数增加等腐败现象,其贮藏期较无保护组可延长3~4 d,且总体保鲜效果优于HPMC空白膜甚至保鲜(PE)膜,展现出对南美白对虾的良好保鲜作用。

用于阻隔奶油和茶汤快速融合的玉米醇溶蛋白纳米颗粒-柠檬酸交联淀粉复合可食薄膜的制备

为有效解决奶茶的奶油顶在出品后短时内易与茶汤快速结合的问题,该文以玉米淀粉为成膜基质,柠檬酸为交联剂、玉米醇溶蛋白纳米颗粒(zein nanoparticles,ZNP)为疏水性增强剂,制备一种阻水性能、机械性能良好的ZNP-柠檬酸复合薄膜。通过傅里叶红外光谱、扫描电镜、热重分析和X-射线衍射对复合薄膜结构进行表征,探究薄膜的机械性能、防水性能和光学性能等物理参数。此外,探究了复合薄膜在不同茶汤(茉莉绿茶、四季春、大红袍、锡兰红茶)、不同温度(4、37、45℃)和不同保留时间(0.5、1.0、1.5、2、4、24 h)下的耐水性测试,并验证了复合薄膜在奶茶奶油顶的应用效果。结果表明,淀粉可作为ZNP的优良载体,复合薄膜具有良好的热稳定性、机械性能和阻隔性能。其中,拉伸强度达到4.35 MPa、断裂伸长率达到44.21%,水蒸气透过率为3.07×10^(-12)g·cm/(cm^(2)·s·Pa)。在不同茶底的应用中,复合薄膜的水溶性在大红袍茶汤中最高;在1.5 h时水溶性、溶胀性达到最低值,放置ZNP-柠檬酸淀粉复合薄膜的奶茶在60 min时才开始奶油与茶底进行融合。综上,ZNP-柠檬酸复合薄膜可以应用在奶油顶奶茶中,有效阻隔短时间内奶油塌陷快速与茶汤混合,可作为一种新型的食品专用材料。

亚油酸含量对大豆11S球蛋白膜理化性质的影响

为探究成膜液和膜中脂质和蛋白之间的相互作用,研究了亚油酸含量(蛋白质量的0%、10%、20%、30%和40%)对11S球蛋白成膜液的黏度及膜的微观结构和理化性质的影响。共聚焦激光扫描显微镜图像显示,成膜液中油滴尺寸均随亚油酸含量增加而增大,干燥成膜后油滴尺寸进一步增大。扫描电子显微镜结果显示,添加亚油酸后光滑致密的蛋白膜上表面出现油滴聚集,而下表面变得粗糙,但未出现油滴。添加40%亚油酸后,膜的玻璃化转变温度、抗拉伸强度和水蒸气透过系数分别由53.50℃、12.67MPa和2.52×10^(-10)g/(m·Pa·s)降低至50.38℃、7.30 MPa和1.83×10^(-10)g/(m·Pa·s),而断裂延伸率由95.58%增加至198.15%。分子动力学模拟结果表明,11S球蛋白与亚油酸分子在200 ns内没有发生相互作用。添加亚油酸会导致11S球蛋白膜中离子键和二硫键比例下降,而疏水相互作用和非二硫键共价键比例增加。以上结果表明,添加亚油酸可以通过改变膜中蛋白间的化学相互作用,从而影响膜的理化性质。研究结果将为大豆蛋白乳液膜成膜机制的研究提供理论参考。

改性类黑精-刺梨渣提取物-淀粉-明胶复合保鲜膜的制备及其对核桃贮藏品质的影响

为探究改性类黑精和刺梨渣提取物添加量对淀粉-明胶复合保鲜膜性能的影响及其对核桃的保鲜效果,以淀粉-明胶为基质,添加类黑精和刺梨渣提取物,筛选最佳成膜配方,并应用于核桃保鲜。结果表明当类黑精和刺梨渣提取物添加量为0.75%和0.4%时,成膜性能最佳;复合膜抗氧化能力与类黑精和提取物添加量成正比;复合膜有效保鲜核桃。因此,添加改性类黑精和刺梨渣提取物的复合保鲜膜成膜性良好,有利于延长坚果类食品货架期。

基于酪氨酸酶交联的豌豆蛋白-绿原酸-壳聚糖复合膜的构建及相关品质分析

以豌豆蛋白(pea protein,PP)为成膜基质,壳聚糖(chitosan,CS)为改善成膜性材料,绿原酸(chlorogenic acid,CA)为功能性成分,酪氨酸酶(tyrosinase,Tyr)为PP、CS和CA的交联剂,以甘油为增塑剂制备PP-CA-CS复合膜,测定PP-CA-CS复合膜物理指标以及微观结构表征,旨在探究PP与CS比例、CA添加量与Tyr添加量对PP-CA-CS复合膜结构及性能的影响,研究其组分间的作用机制。结果表明,添加CA后PP-CA-CS复合膜抗氧化性和机械性能有显著提高,并且在Tyr催化条件下,CA可与PP和CS进行共价交联,随着CA和Tyr的添加,交联度和力学性能得到进一步改善。当PP与CS比例为1∶1、CA添加量为20 mmol/L、Tyr添加量为18 U/mL时,PP-CACS复合膜的机械性能、抗氧化性能、水蒸气阻隔性能表现最优。此时膜的抗拉强度为130.78 MPa,1,1-二苯基-2-三硝基苯肼自由基清除率为69.05%,改善后的PP-CA-CS复合膜与空白膜相比,机械性能增强了2.6倍,抗氧化性能提高了2.2倍,水蒸气透过率降低了8%。扫描电子显微镜测定结果表明,PP-CA-CS复合膜具有光滑、致密性好的特点,从而具有较优的水蒸气阻隔性能,并且通过红外光谱的分析,在成膜过程中没有产生新的官能团。本研究为新型食品包装领域开拓了新的研究思路,为可食用膜的开发提供了数据支持和理论支撑。

壳聚糖-留兰香精油复合膜对酱牛肉保鲜效果的影响

肉制品行业近年来发展势头较好,但贮藏时间短、易变质等问题影响着行业发展。为了延长酱牛肉的贮藏时间,研制高效、经济的复合保鲜剂是目前较热门的研究方向。文章通过复配不同浓度的壳聚糖与留兰香精油,制备复合膜以包裹酱牛肉,测定了贮藏过程中酱牛肉的色泽、pH值、挥发性盐基氮(TVB-N)值、菌落总数、大肠菌群和感官品质,对比不同浓度的留兰香精油对酱牛肉保鲜效果的差异。结果表明,壳聚糖与留兰香精油的复合有助于酱牛肉的储存保鲜,能较好地保留色泽,抑制其氧化腐败和表面的菌群生长,延长酱牛肉的保鲜时间。其中,4%浓度的留兰香精油的保鲜效果最好。因此,壳聚糖-留兰香精油复合膜可作为一种创新保鲜材料应用于酱牛肉的包装中,同时为开发新型天然保鲜剂提供了参考依据。

葡萄皮渣多酚-壳聚糖复合可食膜的性能及应用

为提高可食膜的保鲜性能,有效利用葡萄皮渣中含有的大量多酚类物质,以膜的机械性能、阻隔性能和抗氧化性能为依据,通过单因素和响应面法优化多酚复合膜中多酚提取液、壳聚糖和甘油的添加量,并将优化后的多酚复合膜进行冷鲜鱼肉的涂膜保鲜。结果表明,多酚复合膜的最优制备工艺为壳聚糖、甘油、葡萄皮渣多酚质量浓度分别为2.5,1.1,3.2 g/(100 mL),制备的复合膜的性能综合评分为0.779分。将此多酚复合膜涂膜鱼肉保鲜9 d后,可抑制52.87%的挥发性盐基氮、19.66%的菌落总数和43.46%的脂肪氧化分解,并延缓鱼肉0.3个pH值的上升。研究为生鲜水产品的保鲜应用提供理论依据。

豆渣可溶性膳食纤维的提取及其制备可食用膜的研究

豆渣是大豆加工的大宗副产物,富含膳食纤维。采用微波辅助酶解水提法提取豆渣可溶性膳食纤维(SDF),然后将其制成可食用膜。通过单因素试验和正交试验优化后的提取工艺参数为水料比25∶1(mL/g)、纤维素酶添加量3%、水解时间2 h,此条件下豆渣SDF提取率为18.65%。然后通过正交试验优化了用豆渣SDF制备可食用膜的配方为SDF 1.0 g、甘油4.5 g、CMC 1.0 g、海藻酸钠1.5 g。用最优配方制备的可食用膜具有良好的性能:膜厚度0.032 mm、透明度13.26%、溶解速度25 s/g、水蒸气透过系数0.61 g·mm/m^(2)·d·kPa、透油系数4.15 g·mm/m^(2)·d。该研究可为豆渣的深加工提供方法参考,所制备的可食用膜有望用于食品加工、包装行业。

可食性膜复合天然保鲜剂在肉品保鲜中应用的研究进展

可食性膜主要通过阻止水分、气体和溶质的迁移等提高食品的新鲜度和机械性能,大量应用在果蔬、肉制品、水产品及其他食品中,具有天然性、安全性和生物可降解性等特点。天然保鲜剂来源广,种类多,抑菌机理各不相同,是食品中常用的添加剂,可防止食品在加工、运输、销售的过程中发生腐败变质,具有适用范围广、安全性高、保鲜效果好等优点。可食性膜复合天然保鲜剂技术已经成为肉制品保鲜方法中的研究热点。本文简要介绍了可食性膜的制备和分类、常用的天然保鲜剂种类以及可食性膜复合天然保鲜剂在食品保鲜中的应用。同时分析了其在肉制品保鲜应用中存在的问题,可为肉制品保鲜的研究提供技术借鉴。

A novel edible packaging film based on chitosan incorporated with persimmon peel extract for the postharvest preservation of banana

This study aimed to develop a novel edible packaging film for the postharvest preservation of banana based on chitosan(CS)and persimmon peel extract(PPE).Scanning electron microscopy analysis showed that PPE was evenly distributed in the CS matrix and Fourier transform infrared spectroscopy analysis showed that CS and PPE interacted to form hydrogen bonds,demonstrating good compatibility.Simultaneously,the addition of PPE also significantly improved the physical properties and antioxidant activity of the CS film.Among them,the CS film containing 10%PPE(CS-PPE 10)showed the optimal mechanical properties,water vapor barrier properties and oxygen barrier properties.The CS film containing 15%PPE(CS-PPE 15)exhibited the best thermal stability,UV-Vis barrier properties and antioxidant activity.In the experiment on banana preservation,CS-PPE 10 film obtained optimal performance on decreasing senescence spots,weight loss,fruit softening,and cell wall degradation,inhibiting the activities of polyphenol oxidase and cell wall-degrading enzymes and maintaining the content of total soluble sugar and ascorbic acid during the storage period.Consequently,CS-PPE 10 film was expected to be a novel edible packaging material to maintain banana quality and prolong shelf life.