不同包装条件下精酥油的品质变化研究

对实验室制作的新鲜精酥油,采用真空、薄膜和普通塑料进行包装,并分别置于4℃和室温下进行贮存,依据相关检测方法及标准,定期测定水分含量、酸价、过氧化值、菌落总数及感官指标,研究精酥油在不同贮存条件下的品质变化。结果表明,在4℃冷藏条件下,真空包装相对于其他两种包装可以更好保持精酥油的水分含量;真空包装能够有效的抑制精酥油在贮存期间内的酸价增加,其次是薄膜包装和普通塑料包装;薄膜包装在抗氧化方面与真空包装效果相差不大,并且在4℃冷藏条件下相较于真空包装可以更好的防止精酥油的氧化;相比于其他两种包装,精酥油在薄膜包装下的菌落总数较低;依据感官评定标准,室温下贮存的精酥油保质期只有61d,而4℃冷藏条件下的精酥油保质期超过76d。     

新鲜红肉采用气体置换包装

<正> 气体置换包装就是把食物包围在阻气性优良的材料内,使食物的生物氧化率降低,抑制嗜氧微生物生长,阻止酶促腐败——以延长食物的货架期.气体置换包装应用于新鲜红肉包装可分成二种技术:真空包装和充气包装.真空包装是抽出包装袋内的气体,尔后热封;充气包装是排除气体后充入特定的气体或混合气体再热封的包装.两种技术所采用的包装材料要求具有良好的阻气性,从而达到延长货架期的要求.一般鲜肉整个流通过程都采取冷藏措施,其货架期也很少超过5—6天,而采用真空包装的新鲜红肉货架期可延长至21—28天,充气包装的新鲜红肉延长至7—12天.     

冷冻贮藏过程中包装处理对脆肉鲩鱼片品质的影响

对脆肉鲩鱼片在4种包装处理(镀冰衣+真空包装、不镀冰衣+真空包装、镀冰衣+非真空包装、不镀冰衣+非真空包装)下冻藏(-18℃)8 w过程中,理化、质构和感官品质的变化进行了研究。不同包装处理对干耗和TBA值的变化有显著影响。不同包装条件下粘着性无显著差异,而硬度、咀嚼性和回复性因受包装处理方式不同而存在显著差异。随着冻藏时间的延长。包装的条件对脆肉鲩鱼片各感官指标影响较大。与镀冰衣相比较,真空包装能更有效地防止脆肉鲩鱼片冻藏过程中理化、质构及感官品质的劣化,若在鱼片冻藏过程中采用镀冰衣与真空包装相结合的方法则能更有效地防止品质的劣化。     

鲜肉的气调保藏

以真空包装或充气包装的方式,来改变包装内的气体状况,延长了鲜肉类的货架期。气调包装(MAP)是将食品装在具有高度气密性的包装袋中,通过改变袋中的气体环境,减缓氧化速度,抑制微生物的生长和阻止酶促腐败——达到延长货架期的目的。现已应用于鲜肉的气调包装可以分为两种基本的技术:真空包装和充气包装。真空     

热成型气调包装肉品市场的新星

<正> 包装最重要的功能,不单是使内容物得到妥当的保护,同时还以最吸引的方式展示出来。就新鲜肉类或肉制品而言,要保持产品新鲜,色泽美观吸引,延长货架期,真空包装和气调包装是理想的包装方法。 使用真空包装方法,肉类首先被冷却至4℃左右,然后将肉块放进卷材包装     

真空包装机械的技术发展

一、概述国外首先把真空技术应用于包装,使被包装的物品在贮存、运输和销售等过程均处在隔绝空气的状态,起到保护商品,方便运输贮存的目的。真空包装机械就是利用真空技术,实现物品与空气隔绝的机械。食品采用真空包装,可以有效地防止因脂类物品氧化和好氧性细菌繁殖引起的腐败,同时可以防止食品脱水、变样、发霉和变质。食品经真空包装后能保持原有     

中国气调保鲜包装机国内发展市场待检验

气调包装是一种新型食品保鲜技术,呆用保护性混合气体置换包装内的空气,利用各种保护性气体所起的不同作用,抑制引起食品变质的大多数微生物生长繁殖,并使活性食物（果蔬等植物性食品）呼吸速度降低,从而使食品保鲜并延长保鲜期。真空包装机能有效地防止食品腐败变质,还能能有效防止包装内容物质的交换,即可避免食品减重、失味,又可防止二次污染。此外也避免了加热杀菌时,由于气体的膨胀而使包装容器破裂。     

新型加工胚芽

<正> 谷类胚芽所以引人注目,是由于它含大量的蛋白质和谷类维生素,是一种营养价值很高的食品。除此之外它还含有大量的酶,因此不宜长期保存。通常将其焙烤至180℃以上,以便保存和食用。然而,经这种加热处理之后,酶可能失活,且胚芽中的脂肪也容易氧化,因而其保存性能仍不十分可靠。为了能长期保存这类焙烤胚芽,一般用真空包装法包装或在包装内填充惰性气体等。使用这种包装或因材料有气孔,或因包装材料密封不好等原因,导致胚芽腐败。此外,即使添加脱氧剂或氧化防止剂等,目前效果亦不佳。而且,这种密封包装在打开包装后,胚芽本身保存性能就差了,免不了造成迅速变质的现     

CO气调包装对冷却猪肉货架期及色泽的影响

冷却猪肉采用不同浓度CO气调包装和真空包装,(4±1)℃下贮藏,研究CO气调包装对其货架期和色泽的影响。结果表明,CO气调包装肉在贮藏到第25天时,TVB-N值已超过0.15mg/g,细菌总数超过106cfu/g,与真空包装相比,并不能显著地延长肉的货架期;CO气调包装肉在贮藏期中一直保持稳定的鲜红色,不同浓度CO气调包装对肉色无显著性差异,真空包装肉呈褐色或暗紫色。     

密封小包装内气体环境对大米贮藏效果的影响

研究了在密封小包装内填充N2、CO2、空气以及真空包装对大米储藏效果的影响,研究结果表明:包装内填充不同的气体以及真空包装对大米含水量变化没有影响;在高温条件下填充N2、CO2以及真空包装较填充空气有更好的品质保持效果,尤其是CO2作用显著,在高水分条件下效果更加明显。     

Quality and Stability of Precut Mangos and Carambolas Subjected to High-Pressure Processing

ABSTRACT: Mangos were sliced, vacuum-sealed, and processed at 300 MPa or 600 MPa for 1 min. Fresh mango flavor declined and off-flavor increased during storage at 3 °C, but color, texture, and other sensory attributes changed very little. After 9 wk, the microbial levels in the control were 2 and 3 log CFU/mL greater than the 300 and 600 MPa treatments, respectively. Pressure treatments also slightly reduced fresh mango flavor and increased off-flavor and sweetness. Carambolas were sliced, vacuum-sealed, and processed at 600 MPa for 2, 4, or 6 min; at 800 MPa for 1, 3, or 5 min; or not treated. Samples were stored at 3 °C for 2 and 4 wk and color was evaluated after air exposure. All the 800 MPa treatments reduced browning compared to the control, but the 600 MPa was less effective.     

Effects of different storage conditions on steroidal saponinsin yam (Dioscorea pseudojaponica Yamamoto) tubers

Effect of storage on steroidal saponins, furostanol and spirostanol glycosides, in yam (D. pseudojaponica Yamamoto) tubers was determined. Unpeeled and vacuum-sealed peeled tubers were stored at −18, 4, 17 and 25 °C from 5 to 80 days separately. Furostanol glycosides in unpeeled tubers could be converted by furostanol glycoside 26-O-β-glucosidase (F26G) to spirostanol glycosides after 4 °C storage for 35 days (chilling injury could be found), or 17 and 25 °C storage for 50 days. The conversion increased with storage times. Peeled tubers stored at 17 and 25 °C for 5 days could experience organoleptic injury, which would enlarge with increasing storage period. After 35 days of storage, large part of vacuum-sealed tubers transformed to juice with stench. In the early 20 days storage, saponins in these tubers were lost rapidly. F26G activity in decreasing order was 25 °C > 17 °C > 4 °C and could be inhibited under vacuum.     

Effect of modified atmosphere packaging on the quality of germinated parboiled brown rice

Germinated parboiled brown rice (GPBR) is a healthy Thai food. To extend the quality of GPBR cv. KDML 105 with 8.06% moisture content, the effects of three packaging conditions on the characteristics of GPBR were investigated. GPBR in laminated (nylon/LLDPE) bags was sealed as follows: vacuum-sealed, 40% N₂-sealed with 60% CO₂ (60% CO₂+40% N₂), or 100% N₂-sealed before storage under ambient conditions (30±2°C, 70±5% RH) for 15 months. GPBR in all the packages exhibited delayed fungal proliferation and very low aflatoxin B₁ contamination (<0.82 μg/kg). The 100% N₂-sealed package was the best treatment to preserve GPBR quality, as indicated by the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and free fatty acid content as well as the least rancidity and brownness. As observed through a scanning electron microscope, compared with vacuum-sealed packages and those sealed with 60% CO2+40% N₂, the lowest hardness texture and the least elongation of cooked rice in 100% N₂-sealed package were linked to a lesser compact GPBR endosperm ultrastructure.     

Fermentation characteristics of corn forage ensiled in mini-silos

To evaluate numerous experimental variables and their interactions involving different corn (Zea mays, L.) silage hybrids, scaled down mini-silos are necessary. Objectives of this study were to evaluate the influence of sample size on pH, NH3, and volatile fatty acid profile of 8 corn silage hybrids, selected to vary in fiber digestibility and ensiled in vacuum-sealed polyethylene bags for 90 d, and to assess the suitability of these mini-silos for detecting differences among corn silage samples. Hybrids were grown at the Cornell Teaching and Research Center located near Harford, NY, and harvested at a dry matter content of about 32% in the fall of 2002. Samples from 3 field replications of each hybrid were chipper-shredder chopped and vacuum-ensiled in bags with sample sizes of 50, 100, 200, 400, and 600 g. Increasing sample size resulted in decreased lactic acid, acetic acid, total acids, and NH3. Most of the difference among sample sizes occurred between the 50- and 100-g sample sizes. Lactic acid:acetic acid ratio (3.1 +/- 0.13) and pH (3.9 +/-0.08) did not vary among sample sizes. There was no detectable butyric acid in the samples. Fermentation characteristics suggested that all samples were well ensiled but that the fermentation profile of the 50-g samples differed the most from other sample sizes. Hybrids did vary in lactic acid, acetic acid, lactic acid:acetic acid, and pH. Differences among hybrids were also noted for dry matter and crude protein. Field-chopped corn hybrids that were ensiled using mini-silos had higher acids than corresponding field-chopped corn hybrids ensiled in Ag-bags, in part due to no effluent escaping from the mini-silos. It is possible to use vacuum-sealed plastic bags to ensile corn, with samples as small as 200 g, and to use these mini-silos to assess differences among corn silage samples. Caution should be used when extrapolating mini-silo data to field-scale ensiling.     

一种可循环利用卷烟包装箱的设计与试验

针对卷烟包装纸箱在循环利用过程中存在循环利用次数少、消耗大、易损坏等问题,研究设计了一种可多次循环利用的卷烟包装箱。通过试制与试验,确定了包装箱选用材质、结构尺寸与定型工艺;并对10个试制周转箱连续进行条烟装封箱试验,装封箱成功率为100%,循环装箱次数可达30次。试验结果表明,该卷烟包装箱具有可循环利用次数多、损耗小等优点,可用于卷烟装封箱工序中。     

基于工业机器人的纸卷自动包装系统设计

针对纸卷包装流程和包装机包装工序,选用ABB 4600系列6自由度多关节型工业机器人和真空吸盘夹手,根据放封头工序在ABB机器人软件中进行编程;在整个控制系统中,选用西门子PLC作为主站,工业机器人作为从站,通过PROFIBUS-DP协议与西门子纸卷包装DCS系统通信,实现了自动取放纸卷包装封头和整个纸卷包装过程的全自动化。     

填料塔液泛性能的研究现状与发展趋势

填料塔液泛问题一直以来都是填料塔研究中的核心问题,液泛性能直接决定了填料塔的操作性能。介绍了近年来有关填料塔液泛现象、液泛机理和液泛性能预测的研究现状和进展。提出了未来关于填料塔液泛问题的研究重点和方向,使得填料塔液泛现象能够在线实时监测和诊断,提高填料塔的综合操作性能,实现节能减排生产。     

活性包装在肉类保藏中的应用

活性包装是新型的食品包装体系,是一项具有挑战性的技术,对食品安全及货架期的延长有着重大的影响。活性包装能够抑制微生物的生长繁殖,提供更安全、可靠的食品。本文主要介绍了食品活性包装及其在肉制品保藏中的应用。     

鲫鱼在冷藏过程中的鲜度变化(英文)

本实验利用感官评价、化学(TVBN值和pH值)和微生物(细菌总数)指标的分析,研究了鲫鱼在真空包装和非真空包装两种条件下贮藏于3±1℃时新鲜度的变化。实验结果表明贮藏在真空包装条件下能够延缓鲫鱼的腐败变质,贮藏过程中感官评分呈下降趋势,表明在两种贮藏条件下鲫鱼的新鲜度随时间延长而降低。贮藏过程中TVBN值都有升高,而非真空包装组样品中细菌生长的速度要高于真空包装组。     

直接跌落式装箱机的设计

介绍了现有技术中移位跌落式装箱机及其存在的问题,在此基础上设计了一种新型直接跌落式装箱机,该装箱机改变了进桶方式,桶经过分道理排后直接进入装箱工位,利用其特殊的翻板装置和动力同步装置将桶准确地装入纸箱中。该装箱机减少了桶的移位动作,提高了装箱速度;去除了推桶机构和防倒桶机构,缩小了装箱机的体积,降低了制造成本。