技术转让项目介绍

十六、香蕉保鲜剂本品以蔗糖酯为主要原料的无毒保鲜剂,在常温条件下,可使香蕉保鲜三个星期,比对照样品延长18天;在低温(16～28℃)延长30天,6～19℃延长40天,除去保鲜包装后其香蕉可正常成熟,品质风味正常。每公斤香蕉需药费0.006元。     

不同膜的真空包装对澄海猪头粽的保鲜性研究

通过涂膜法制备得到壳聚糖/PE复合膜和壳聚糖/纳米ZnO/PE复合膜,并分别对澄海猪头粽进行真空包装,在储存期第0、2、4、6天,通过测量感官特性、色度、TBARS值,比较膜的保鲜效果。结果发现,随着储存时间的增加,每组猪肉粽都出现了不同程度的腐变。与普通PE膜的真空包装相比,壳聚糖/PE复合膜和壳聚糖/纳米ZnO/PE复合膜对猪头粽都有一定的保鲜效果,其中壳聚糖/纳米ZnO/PE复合膜的保鲜效果略好。     

聚乙烯醇/马齿苋提取物保鲜膜对猪肉的抑菌保鲜效果研究

针对猪肉极易受到微生物污染、货架期较短的缺点,以马齿苋为原料采用酶解⁃超声波辅助乙醇法对其黄酮类化合物进行提取,研究马齿苋提取液抗氧化抑菌活性的影响。马齿苋提取液与聚乙烯醇（PVA）复合膜应用于猪肉的保鲜试验中,验证其抑菌保鲜效果。结果表明,马齿苋黄酮提取液对羟基（OH）、羟基、a⁃二苯基联吡啶肼（DPPH）自由基均具有清除能力,并且对DPPH自由基的清除率在黄酮浓度为0.02 mg/mL就达到了90 %以上。对金黄色葡萄球菌有较大的抑制作用。PVA与马齿苋提取液比例为30∶20的保鲜膜,能显著抑制冷却肉的菌落总数、酸度值（pH值）、硫化氢（H₂S）、丙二醛、 挥发性盐基氮（TVB⁃N） 含量的增长速率,延长其货架期。     

不同阻隔包装猪肉光照下品质变化

室温25℃,用高阻隔、低阻隔包装材料,真空包装、普通包装方式包装新鲜猪肉,研究光对阻隔包装猪肉过氧化值(POV)、p H值、挥发性盐基氮(TVB-N)含量的影响。结果表明:光照下阻隔包装猪肉的过氧化值、p H值、挥发性盐基氮含量均随着贮藏时间的延长而增加;过氧化值先升后降,整体呈现出不规则上升变化趋势;光照条件下贮存的包装猪肉p H值增加量均高于避光贮存;挥发性盐基氮值在贮存后期变化速度比前期大,光照对挥发性盐基氮值影响较小。     

天然复配抗氧化剂在水果中的应用研究进展

在水果生长期间,土壤、光照和微生物等环境因素会对果实产生影响,有害病菌会致使果实氧化变质,如何有效保证果实品质、延长果实货架期是水果保鲜的重点.目前,主要通过添加抗氧化剂延缓水果腐烂变质的速度从而达到保鲜的目的.本文通过对迷迭香、抗坏血酸等单元天然抗氧化剂以及壳聚糖-纳他霉素、茶多糖-海藻酸钠等复配型抗氧化剂在水果中的...     

Nisin生物保鲜剂对冻藏金枪鱼的影响

采用质构仪的TPA模式对冻藏金枪鱼肌肉的硬度、弹性、凝聚性等进行测试,并研究Nisin生物保鲜剂对其质构的影响。结果表明,在-18℃的冻藏条件下,随着贮藏时间的增加,金枪鱼肌肉质构的硬度、弹性和凝聚性均呈不同程度的下降趋势,Nisin保鲜液能减少其硬度、弹性和凝聚性的下降,其中0．4g／L的Nisin保鲜液效果最好。同时研究了金枪鱼肌肉的a^＊值和TVB—N值的变化,结果表明,Nisin保鲜液能适当延长冻藏金枪鱼的保鲜期,其最适浓度为0．4g／L。     

不同脱乙酰度的壳聚糖对黄瓜的保鲜研究

选用脱乙酰度不同的壳聚糖作保鲜剂,对黄瓜进行涂膜处理,室温下袋装贮藏,研究壳聚糖涂膜黄瓜的保鲜效果.在贮藏期间,对黄瓜的外观、失水率、叶绿素含量和维生素c含量进行测定.结果表明,壳聚糖的脱乙酰度越高,涂膜黄瓜的综合保鲜效果就越好,室温下贮藏可延长黄瓜的货架期.     

国内快讯

INTERNALEXPRESS低温高收缩真空包装膜哈尔滨工业大学中翰科技发展有限公司针对我国生肉食品包装的现状和要求,组织教授专家科研攻关,最近成功地研制出低温(83℃～85℃,瞬间)高收缩新型生肉食品真空包装膜、袋,目前已推向市场。该真空包装膜为国内首创,其指标达到了国外同类产品水平,主要适用于牛、羊、猪肉等生肉的保鲜冷藏,也可用于水产品及工业产品的包装。该包装膜以尼龙为主要成分,配合聚烯烃共聚物、粘合剂经五层共挤、两段双向拉伸而制得的低温高收缩膜,可有效阻隔氧气,防止污染,使被包装物延长保鲜期。该产品阻隔性能高,收缩…     

壳聚糖复合茶粉对广式豆沙月饼的保鲜研究

本文采用壳聚糖和茶粉为保鲜剂,以菌落总数、酸价(AV值)、过氧化值(POV值)作为月饼保鲜评价指标,研究月饼在常温保存时的品质变化规律。结果表明,经过壳聚糖涂膜和茶粉添加处理的广式豆沙月饼菌落总数、AV值、POV值均明显低于对照实验组。壳聚糖和茶粉对广式豆沙月饼的保鲜有协同增效作用,最佳保鲜效果的复配组合为:浓度为1. 5%相对分子质量为4 k Da的壳聚糖与浓度为2. 0%相对分子质量为200 kDa壳聚糖的混合配比分别为45%、55%,茶粉添加量为3. 5%。     

哈工大研制出新型低温高收缩真空包装膜

哈尔滨工业大学中翰科技发展有限公司于近日研制成功低温( 83～85℃,瞬间)高收缩新型生肉食品真空包装膜、袋,并推向市场。该真空膜为国内首创,其指标达到了国外同类产品水平,主要适用于牛、羊、猪肉等生肉的保鲜冷藏,也可用于水产品及工业产品的包装。该包装膜以尼龙为主要成分,配合聚烯烃共聚物、粘合剂经五层共挤、两段双向拉伸而制得的低温高收缩膜,可有效阻隔氧气,防止污染,使被包装物延长保鲜期。哈工大研制出新型低温高收缩真空包装膜     

纳米抗菌高阻隔包装膜的研制与应用

采用流涎共挤技术生产纳米抗菌高阻隔包装膜,该包装膜具有较好的抗菌性及高阻隔性,与传统铝塑复合槟榔包装相比,可提高槟榔保质期及降低成本。     

高阻隔纳米抗菌包装膜的研制与应用

采用聚乙烯、(乙烯/乙烯醇)共聚物通过流延共挤技术生产出高阻隔纳米抗菌包装膜,考察了包装膜的抗菌性及阻隔性.结果表明,该包装膜具有较好的抗菌性及高阻隔性,与传统铝塑复合槟榔包装相比,可提高槟榔保质期及降低成本.     

不同包装处理对花生仁贮藏品质影响研究

研究包装处理对花生仁保鲜效果的影响。分别对花生仁进行普通包装、真空包装、充氮包装,监测存储期间花生仁水分含量、过氧化值、酸价的变化,对比3种包装花生仁的贮藏品质。结果表明:包装处理能够明显改善花生仁的贮藏品质,其中包装的阻隔性对花生仁的保鲜效果影响显著,真空包装和充氮包装花生仁的过氧化值和酸价分别低于普通包装31%~50%、26%~47%,对两重要品质指标的劣化有明显的抑制作用,说明阻隔性包装能够有效提高花生仁的贮藏品质。     

Storage Stability of Carrot Chips

Water activity combined with the glass transition temperature can be used to predict the shelf life of foods. Water sorption isotherms and glass transition as a function of moisture content were determined for carrot chips after vacuum frying. The GAB model was fitted to the measured sorption data while the Gordon Taylor equation was used to model the water plasticization effect. The critical moisture content and the critical water activity at which the glass transition occurs were obtained at selected storage temperatures. The changes in moisture content, fat content, water activity, breaking force, β-carotene content, ascorbic acid, and acid value of vacuum-fried carrot chip at selected storage temperatures (0, 10, 25°C) during a 6-month storage period were investigated. The estimated shelf life of carrot chip, defined by the degradation time of the acid value at different storage conditions, was determined.     

Storage Stability of Carrot Chips

Water activity combined with the glass transition temperature can be used to predict the shelf life of foods. Water sorption isotherms and glass transition as a function of moisture content were determined for carrot chips after vacuum frying. The GAB model was fitted to the measured sorption data while the Gordon Taylor equation was used to model the water plasticization effect. The critical moisture content and the critical water activity at which the glass transition occurs were obtained at selected storage temperatures. The changes in moisture content, fat content, water activity, breaking force, β-carotene content, ascorbic acid, and acid value of vacuum-fried carrot chip at selected storage temperatures (0, 10, 25°C) during a 6-month storage period were investigated. The estimated shelf life of carrot chip, defined by the degradation time of the acid value at different storage conditions, was determined.     

Food packaging based on polymer nanomaterials

Since its starting in the 19th century, modern food packaging has made great advances as results of global trends and consumer preferences. These advances are oriented to obtain improved food quality and safety. Moreover, with the move toward globalization, food packaging requires also longer shelf life, along with the monitoring of safety and quality based upon international standards. Nanotechnology can address all these requirements and extend and implement the principal packaging functions - containment, protection and preservation, marketing and communications. Applications of polymer nanotechnology in fact can provide new food packaging materials with improved mechanical, barrier and antimicrobial properties, together with nano-sensors for tracing and monitoring the condition of food during transport and storage.The latest innovations in food packaging, using improved, active and smart nanotechnology will be analyzed. It will be also discuss the limits to the development of the new polymer nanomaterials that have the potential to completely transform the food packaging industry.     

Oxidation of gamma‐irradiated ultrahigh molecular weight polyethylene

Ultrahigh molecular weight polyethylene (UHMWPE), the current polymer of choice in orthopedic prosthetic devices, is typically sterilized by exposure to Co‐60 gamma irradiation prior to packaging for long‐term storage. However, the exposure to Co‐60 irradiation generates free radicals along the polymer chain that can participate in a series of reactions commencing with the oxidation of the free radicals to form reactive peroxy radicals. This study was undertaken to identify the role of hydroperoxide species in shelf‐aged and accelerated aged UHMWPE samples by using a nitric oxide derivatization technique. It is shown that the concentration of hydroperoxides did not change appreciably with shelf aging. However, during accelerated aging the hydroperoxide concentration increased to a plateau and then decreased, suggesting its role as an intermediate in the process. By contrast, the concentrations of carbonyl species continued to increase during shelf aging and accelerated aging. The effects of several packaging materials on the oxidation characteristics were also investigated. A vacuum foil package is shown to be effective in preventing oxidation to a significant extent during accelerated aging. However, accelerated aging after removal from the foil pack resulted in oxidative degradation. Extended vacuum to remove dissolved oxygen and a 5‐week room‐temperature healing process in the foil pack were shown to be ineffective in reducing oxidative degradation. It also was shown that increased moisture content in the aging environment did not affect the degradation process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2525–2542, 2000     

Innovative technologies in the control of lipid oxidation

Transition metal promoted oxidative degradation reactions impact quality, shelf‐life, and nutritional content of many packaged foods. When trace metals are present in packaged foods, they can initiate degradation of nutritional compounds such as unsaturated fatty acids, carotenoids, antioxidants, phytosterols, and many vitamins. These reactions occur at metal concentrations naturally occurring in foods (often in the low parts per billion range) therefore complete metal removal is not a practical solution to inhibit these reactions. Chelators such as EDTA can be added to inhibit metal‐promoted oxidation, however there is significant consumer and industry demand to eliminate EDTA from product formulations. Other natural chelators such as citric acid are ineffective in many foods and in some cases can actually increase oxidation rates by increasing metal solubility. An alternate approached to control transition metal reactivity is to utilize active packaging technologies. However, current approaches to antioxidant active packaging can impact packaging film mechanical properties and often exhibit low antioxidant activity. This review article surveys and critically reviews advances in the control of lipid oxidation, paying particular attention to novel advances in both food product formulation (e. g. additives, food microstructure) as well as food packaging. We introduce a new concept of active packaging in which metal ion chelation by non‐migratory active packaging materials may enable removal of synthetic food additives from product formulations while maintaining product quality and shelf‐life.     

阻隔性包装材料的发展趋势

当今市场对包装材料的要求是：贮存期限长,原材料耗量少,加工方式多样化,还要对包装品提供最好的保护,免受外界的影响,原材料生产商和加工厂商为适应市场要求,专门设计,开发了一系列新的阻隔性材料,本文择要介绍这方面的情况。     

Design of Polymeric Films for Antioxidant Active Food Packaging

Antioxidant active food packaging can extend the shelf life of foods by retarding the rate of oxidation reactions of food components. Although significant advances in the design and development of polymeric packaging films loaded with antioxidants have been achieved over the last several decades, few of these films have successfully been translated from the laboratory to commercial applications. This article presents a snapshot of the latest advances in the design and applications of polymeric films for antioxidant active food packaging. It is hoped that this article will offer insights into the optimisation of the performance of polymeric films for food packaging purposes and will facilitate the translation of those polymeric films from the laboratory to commercial applications in the food industry.