活性包装薄膜中活性物质缓释技术研究进展

综述了活性包装薄膜中活性物质缓释技术的国内外研究进展,着重从活性物质释放速率的调控技术、影响因素以及释放动力学模型三方面进行了归纳,并对其未来发展趋势进行了展望。     

Effect of irradiation, active and modified atmosphere packaging, container oxygen barrier and storage conditions on the physicochemical and sensory properties of raw unpeeled almond kernels (Prunus dulcis)

BACKGROUND: The present study investigated the effect of irradiation, active and modified atmosphere packaging, and storage conditions on quality retention of raw, whole, unpeeled almonds. Almond kernels were packaged in barrier and high‐barrier pouches, under N₂ or with an O₂ absorber and stored either under fluorescent lighting or in the dark at 20 °C for 12 months. Quality parameters monitored were peroxide value, hexanal content, colour, fatty acid composition and volatile compounds. Of the sensory attributes colour, texture, odour and taste were evaluated. RESULTS: Peroxide value and hexanal increased with dose of irradiation and storage time. Irradiation resulted in a decrease of polyunsaturated and monounsaturated fatty acids during storage with a parallel increase of saturated fatty acids. Volatile compounds were not affected by irradiation but increased with storage time indicating enhanced lipid oxidation. Colour parameters of samples remained unaffected immediately after irradiation. For samples packaged under a N₂, atmosphere L* and b* values decreased during storage with a parallel increase of value a* resulting to gradual product darkening especially in irradiated samples. CONCLUSION: Non‐irradiated almonds retained acceptable quality for ca. 12 months stored at 20 °C with the O₂ absorber irrespective of lighting conditions and packaging material oxygen barrier. The respective shelf life for samples irradiated at 1.0 kGy was 12 months packaged in PET‐SiOx//LDPE irrespective of lighting conditions and 12 months for samples irradiated at 3 kGy packaged in PET‐SiOx//LDPE stored in the dark. Copyright © 2010 Society of Chemical Industry     

电子束辐照对稻米储藏特性及品质的影响

为考察稻谷、糙米、精米经电子束辐照处理后的保鲜效果及品质变化,选取新收获的晚粳稻为原料,研究0,2,4kGy剂量辐照对稻谷、糙米、精米的保鲜效果,并考察电子束辐照对稻米理化性质,包括水分含量、色泽、脂肪酸值、黏度值和食味值的影响。结果表明,经2,4kGy剂量辐照的稻谷、糙米、精米与未辐照的样品相比,水分含量、色泽无显著变化(P0.05),黏度值显著下降(P0.05),且储藏一段时间后,经电子束辐照过的样品较未辐照的样品脂肪酸值上升更缓慢,食味值变化更小,即储藏期间品质劣变程度更小。电子束辐照技术作为一种冷杀菌技术,可用于保持稻米的品质和营养、延长稻米储藏期。     

高能电子束辐照剂量方式对白酒挥发性成分的影响

采用顶空固相微萃取（HS-SPME）/气-质联用（GC-MS）技术,对高能电子束不同辐照剂量方式处理浓香型白酒的挥发性成分进行了测定与分析。结果表明,经过单圈8 kGy剂量的辐照处理,白酒挥发性成分由76种增至83种,其中酯类增加4种,相对含量由82.2%降至81.13%,酸类种类不变,相对含量由4.03%增至4.21%,这与其他浓香型白酒熟化过程中变化趋势一致,对其具有催陈效果。保持白酒总的辐照剂量不变,分别降低单圈辐照剂量至4 kGy、2 kGy、1 kGy,白酒的挥发性成分由83种分别降至82、74、52种,相对含量由95.54%分别降至83.89%、75.58%和68.16%,除烃类物质增加外,酯类、酸类、醇类、醛类物质相对含量均显著降低。采用单圈辐照剂量处理的方式有助于浓香型白酒熟化,提升了品质。     

The influence of electron beam irradiation of antimicrobial-coated LDPE/polyamide films on antimicrobial activity and film properties

We evaluated the effects of ionizing radiation (1-3 kGy) and incorporation of antimicrobials on the functional properties of low-density polyethylene (LDPE)/polyamide films. We established the antimicrobial effectiveness of several coatings of FDA-approved antimicrobial compounds including sorbic acid, carvacrol, trans-cinnamaldehyde, thymol and rosemary oleoresin using selected food pathogen surrogates. The antimicrobial coatings were applied to one side of the LDPE films and dried. Films were irradiated using a 10 MeV linear electron beam accelerator at room temperature. All films showed inhibition zones in an agar diffusion test against Listeria innocua ATCC 33090 and Escherichia coli ATCC 884. In the liquid culture test, the antimicrobials significantly (p?0.05) reduced the specific growth rate of L. innocua by 3.8-8.5%, and decreased final cell concentration of both strains by 5.7-14.6% and 7.2-16.8%, respectively. All active compounds retained the antimicrobial activity when exposed to 1-3 kGy. Neither the presence of active compound nor dose affected the film's tensile strength and toughness. Additionally, films became more ductile and had improved moisture barrier functionality. Film's oxygen permeability was not affected by either treatment. Results are an initial step toward the development of self-sterile active packaging materials for use in combination with irradiation treatment of foods.     

PLA/PHA活性抗菌薄膜对蓝莓低温保鲜效果的影响

采用流延成膜工艺,分别添加质量分数为5%的茶树精油和尤加利精油,制备聚乳酸/聚羟基脂肪酸酯(PLA/PHA)可降解活性抗菌薄膜。以蓝莓为研究对象,在(4±1)℃贮藏条件下,分别采用PLA/PHA保鲜膜包装、茶树精油/PLA/PHA保鲜膜包装、尤加利精油/PLA/PHA保鲜膜包装处理。通过测定3种薄膜的基本性能,袋内氧气和二氧化碳体积分数,蓝莓的烂果率、失重、硬度、可溶性固形物含量、总酚、花色苷和V_C含量等指标,探讨不同活性抗菌薄膜对蓝莓低温贮藏品质的影响。结果表明:含有精油的活性抗菌薄膜能有效降低蓝莓果实的烂果率、失重率,延缓果实花色苷和V_C含量的降低,一定程度上保持了果实的硬度。其中,尤加利精油/PLA/PHA保鲜膜包装对维持蓝莓果实新鲜度,降低果实水分蒸发,维持总酚含量效果最佳。     

电子束辐照对小麦粉加工特性及馒头食用品质影响的研究

研究了不同剂量电子束辐照对小麦粉理化性质及加工品质的影响,并将其制成馒头,运用物性测试仪和感官评定方法分析了馒头的食用品质。结果显示:随着辐照剂量增加,小麦粉的降落数值及黏度特性显著下降,当辐照剂量达到5 kGy时,降落数值下降了56.2%,峰值黏度下降至42.7%,回生值下降至35.2%,而吸水量略有提高;面团的最大拉伸阻力逐渐降低,降幅随着辐照剂量的增大而增大,延伸度却逐渐增加,拉伸曲线面积则先增后减;物性测试仪测定结果表明,剂量在1.75 kGy以下时,辐照对馒头的黏附性影响较小,但达到2.75 kGy以上时,馒头的黏附性迅速增大,达到对照样品3倍以上;感官评定结果表明,当小麦所受辐照剂量达到5 kGy时,由其所制作的馒头感官评分低于60分,表明已不宜食用。     

Critical review of controlled release packaging to improve food safety and quality

ABSTRACT

Controlled release packaging (CRP) is an innovative technology that uses the package to release active compounds in a controlled manner to improve safety and quality for a wide range of food products during storage. This paper provides a critical review of the uniqueness, design considerations, and research gaps of CRP, with a focus on the kinetics and mechanism of active compounds releasing from the package. Literature data and practical examples are presented to illustrate how CRP controls what active compounds to release, when and how to release, how much and how fast to release, in order to improve food safety and quality.     

电子束辐照对涤纶染色性能的影响

使用不同剂量电子束对涤纶织物进行辐照处理,研究了涤纶织物处理前后结晶度和表面形态的变化,对辐照前后涤纶织物染色,分析辐照对染色性能的影响和色牢度的变化情况。研究表明,100kGy的辐照会造成涤纶结晶度上升,染色速率下降,但最终的染色K/S值增加;200kGy辐照会造成涤纶结晶度下降,染色速率上升,但最终K/S下降;400kGy辐照会造成涤纶表面粗糙化,染色K/S上升。     

Effect of electron beam irradiation on quality indicators of peanut butter over a storage period

Electron beam (e-beam) irradiation is an effective non-thermal processing step for the reduction of Salmonella in peanut butter. The objective of this study was to evaluate the effects of e-beam irradiation on quality indicators of peanut butter. Peanut butter samples were exposed to a range of e-beam doses and examined over a 14-day period at 22 °C. Colour analysis (L^∗, a^∗, b^∗), spreadability, peroxide values (PV) and thiobarbituric acid reactive substances test (TBARS) for lipid oxidation were monitored, fatty acid and amino acid profiles were verified and protein degradation was determined by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE). Changes in colour, PV, and TBARS were observed as e-beam dose increased. No significant changes in spreadability were observed (P > 0.05). When applied to peanut butter, e-beam irradiation will produce significant changes in quality indicators; future studies should include sensory evaluation and consumer acceptance studies.     

电子束辐照对槟榔芋贮藏效果的影响

以槟榔芋为研究对象,利用辐照剂量为0.1,0.3,0.5,0.7,1.0kGy的高能电子束对其进行辐照处理,研究辐照剂量对槟榔芋贮藏效果及抗氧化酶的影响。结果表明,低剂量电子束辐照能显著降低槟榔芋的贮藏腐烂率并较好地控制发芽,但对硬度、色泽变化、感官品质影响不大,同时能维持槟榔芋过氧化物酶、谷胱甘肽还原酶以及过氧化氢酶的活性。槟榔芋贮藏的最佳辐照剂量为0.1⁰.5kGy。     

电子束辐照对鸡肉营养品质的影响

采用高能电子束对冷冻鸡肉进行辐照,考察了辐照前后鸡肉中蛋白质、维生素、脂肪等营养成分的变化。结果表明,在2～10kGy辐照剂量范围内,鸡肉中蛋白质、脂肪以及感官品质未发生明显变化,而几种维生素均有不同程度的损失。     

Effect of temperature,pH and film thickness on nisin release from antimicrobial whey protein isolate edible films

BACKGROUND: An active packaging film based on whey protein isolate (WPI) was developed by incorporating nisin to promote microbial food safety. The effect of temperature and pH on the release of nisin from edible films of different thickness was investigated. The film mechanical properties and inhibitory effect were also evaluated. RESULTS: Nisin release was significantly favoured by low pH, with the highest release after 24 h (1325 IU), which was not significantly affected by temperature (5 or 10 °C). Thickness significantly affected film elongation, with thicker films showing the highest elongation (54.3 ± 2.7%). Water vapour permeability (0.15 ± 0.4 g mm m^?2 kPa^?1 h^?1) and elastic modulus were not significantly affected by thickness. The highest nisin effective diffusivity (5.88 × 10^?14 m² s^?1) was obtained using a solution at pH 4, 112 µm film thickness and a temperature of 5 °C. More than four log cycles of Brochotrix thermosphacta were reduced from the surface of a ham sample after 8 days of incubation at 4 °C by the active WPI film containing 473 IU cm^?2 nisin. CONCLUSION: Nisin diffusivity from WPI edible films was favoured at lower pH and film thickness. This active packaging film may be used to preserve the quality and safety of meat products. Copyright © 2009 Society of Chemical Industry     

Effect of electron beam irradiation on proximate, microbiological and sensory characteristics of chyavanaprash — Ayurvedic poly herbal formulation

This investigation aims to the use of electron beam irradiation for maintaining the quality of chyavanaprash, an ayurvedic poly herbal formulation instead of chemical preservative. Fresh chyavanaprash formulations were treated with electron beam irradiation at doses of 0, 2.5, 5 and 7.5 and 10 kGy. The irradiated and non-irradiated products were stored at room temperature (27 ± 3 °C and 50–70% Rh). Proximate analysis, sensory properties and microbial analysis were carried out. The results indicated that the electron beam irradiation reduced total bacterial and fungal count. The applied doses did not cause any significant changes in the proximate composition of the chyavanaprash. No significant differences were observed in sensory properties between control and irradiated sample.

Industrial Relevance

Ayurvedic products are made up of herbs/plants. These herbal/plant products are natural in origin and often contain high microbial contaminations. Therefore they are treated with one of the methods including heat and addition of preservatives like sodium benzoate, ethylene oxide in order to reduce the microbial contamination. It gives undesirable change in flavour, colour and nutrients. When sodium benzoate mixed with vitamin C which is present in the herbal products, it produces benzene. Benzene is carcinogen. These are harmful when consumed for long time. Irradiation is a technology for sterilizing foods contaminated by bacteria and is expected to reduce the incidence of food borne illness. It is the process of exposing the products to an ionizing radiation, to kill harmful bacteria and other organisms and extend the shelf-life of the products without changing the nature of the product. It is a new technology to enhance ayurvedic products safety and quality.     

Effects of gamma irradiation and electron beam irradiation on quality,sensory, and bacterial populations in beef sausage patties

This study compared effects of gamma ray (GR) and electron beam (EB) irradiation on quality (TBARS value, hardness, color), sensory characteristics, and total bacterial populations in beef sausage patties during accelerated storage at 30 °C for 10 days. Beef sausage patties were vacuum-packaged and irradiated by GR and EB at 0, 5, 10, 15, and 20 kGy at room temperature. The results of quality evaluation showed that the effects of GR irradiation were similar (p ? 0.05) to EB irradiation on lipid oxidation, hardness, color and sensory scores of the beef sausage patties. However, GR-irradiated samples had lower (p < 0.05) total bacterial counts than EB-irradiated samples after irradiation, and during storage regardless of irradiation dose. The results indicate that use of GR irradiation up to 10 kGy on patties should be useful in reducing bacterial populations with no adverse effect on quality and most of sensory characteristics (color, chewiness, and taste).     

LED光照处理对豇豆采后贮藏品质和生理特征的影响

为探究LED单色光照射对豇豆采后生理特征的影响,采用光照强度为40 μmol·m^-2·s^-1的LED白光和蓝光两种单色光,在整个贮藏期照射处理豇豆,测定15 ℃贮藏条件下豇豆贮藏品质和生理特性的变化。结果表明:在15 ℃下,LED光照处理有效地延缓豇豆外观品质的下降和失重率的升高,抑制锈斑的产生和发展,减缓可溶性固形物和叶绿素的降解,抑制MDA的积累,有效维持细胞膜的完整性,保持较好的总酚含量,同时增强了POD和CAT抗氧化酶活性,减轻了活性氧对组织细胞的损伤,其中光照强度为40 μmol·m^-2·s^-1 LED白光的保鲜效果优于光照强度为40 μmol·m^-2·s^-1 LED蓝光。     

电子束辐照灭菌对昭通酱品质影响研究

以昭通酱的感官评价、部分营养及理化成分为评价指标,研究电子束辐照剂量对其品质的影响。结果表明,当电子束辐照剂量为3.68 kGy时,昭通酱感官综合评价较好,真菌、大肠杆菌达到卫生标准,脂肪含量未显著下降（P＞0.05）,过氧化值未显著上升（P＞0.05）,6种大豆异黄酮含量未显著下降（P＞0.05）,必需氨基酸（EAA）、总氨基酸（TAA）、呈味氨基酸（DAA）,条件必需氨基酸（CEAA）未发生显著变化（P＞0.05）,表明该剂量对昭通酱营养成分、理化指标的影响相对较小,且微生物指标达到卫生标准,是昭通酱电子束辐照灭菌的最佳剂量。     

电子束辐照对花斑皮蠹的影响

为了控制花斑皮蠹对储粮及其他仓储物的危害,利用不同剂量的电子束对花斑皮蠹幼虫、成虫进行辐照处理,研究了其辐照效应。结果表明:花斑皮蠹的幼虫、成虫对电子束辐照的敏感性依次降低;幼虫和成虫经辐照后9 d的半致死剂量LD50分别为144.9和164.8 Gy;幼虫经800 Gy剂量辐照后可以完全阻止其发育为成虫,并且幼虫在9 d内全部死亡,而250 Gy剂量辐照可以阻止幼虫产生下一代成虫;成虫经800 Gy剂量辐照后需15 d才能全部死亡,而400 Gy剂量辐照可以阻止成虫产生下一代成虫。因此,400 Gy的剂量可以作为电子束辐照防治花斑皮蠹的参考剂量。     

Release property and antioxidant effectiveness of tocopherol-incorporated LDPE/PP blend films

Low-density polyethylene (LDPE)/polypropylene (PP) blend films in various blending ratios containing 3000?mg?kg^?1 of tocopherol were manufactured by an extrusion process. Tocopherol release properties were characterised and correlated with antioxidant effectiveness in retarding the oxidation of linoleic acid contacting the films at 40°C. The conditions without tocopherol (control) and with instant tocopherol addition corresponding to the amount included in the films were also prepared and compared with the film-contacting solutions. The effect of tocopherol inclusion and the blending ratio on their physical properties was also examined. A wide range of tocopherol diffusivity in 6.6?×?10^?16–4.6?×?10^?14?m^2?s^?1 were obtained by blend films. As PP content increases, the diffusivity decreased sharply at the beginning and levelled off later. The slower release of tocopherol in LDPE/PP blend films corresponding to lower tocopherol diffusivity retained the higher tocopherol concentration in the linoleic acid system providing better antioxidant effectiveness of the extended induction period in oxidation. The tocopherol inclusion reduced tensile strength and transparency significantly in an affordable range with higher tensile strength given by a higher PP ratio. LDPE/PP blending can be a useful tool to modulate the release profile of tocopherol and thus the antioxidant effectiveness of the tocopherol-incorporated antioxidant packaging film.     

电子束辐照进口冷冻牛腩的剂量分布及感官特性研究

目的 确认电子束辐照冷冻牛腩的剂量分布特性,研究不同剂量电子束辐照对冷冻牛腩的杀菌效果及辐照后产品色泽、风味、质构等感官指标的变化.方法 对不同厚度的冷冻牛腩块分别用8 kGy进行单面及双面电子束辐照,检测其内部剂量分布,确定辐照适宜的产品厚度,在此基础上用0、2、4 kGy不同剂量对商品包装(1 kg/袋,最大厚度不...