不同气调包装对熟制蟹肉蟹黄贮藏品质的影响

熟制蟹肉蟹黄由于蛋白质和脂肪含量较高,暴露在空气中极易被氧化,腐败变质,使货架期大大缩短,严重限制了产品生产和销售规模。本文以熟制蟹肉蟹黄为研究对象,探讨不同气调包装方式（空气,60% CO₂+40% N₂和40% CO₂+60% N₂）在4℃贮藏条件下对其品质的影响,分析风味物质变化规律和货架期,最后确定产品最优气调包装方式。研究结果显示,与空气组比较,气调包装组的菌落总数、pH、挥发性盐基氮及丙二醛含量明显降低,且40% CO₂+60% N₂组效果最佳;40% CO₂+60% N₂组样品挥发性风味物质随时间变化损失较少,呈味核苷酸腺苷酸（AMP）含量显著减少,肌苷酸（IMP）、肌苷（HxR）及次黄嘌呤（Hx）显著增加（P<0.05）,感官评价得分最高,货架期可达到28 d左右,比空气包装组延长了8 d。因此在4℃贮藏条件下采用40% CO₂+60% N₂气调包装能有效提高熟制蟹肉蟹黄的风味品质和货架期限,是一种较好的冷藏保鲜方式。     

不同包装方式对香酥虾球品质的影响

为研究不同包装方式对香酥虾球（crispy shrimp balls）贮藏过程中品质的影响,以聚乙烯尼龙（PE/PA）作为包装材料,采用普通热封包装、气调包装（100% N₂、70% N₂+30% CO₂、50% N₂+50% CO₂、30% N₂+70% CO₂、100% CO₂）和真空包装7种包装方式,测定不同贮藏时间下香酥虾球的感官评分、脂质、蛋白质和微生物指标的变化,确定香酥虾球的最佳包装方式,同时,采用电子鼻/舌和气相色谱-质谱联用技术（GC-MS）对最佳包装方式下香酥虾球贮藏过程中的风味品质变化进行研究。结果表明,在贮藏过程中,30% N₂+70% CO₂气调包装组和100% CO₂气调包装组的过氧化值、羰基价、丙二醛含量、蛋白质羰基含量和菌落总数均低于其他组,感官评分和蛋白质巯基含量则均高于其他组（P<0.05）。随着CO₂浓度增加,香酥虾球的品质劣变速率降低,但100% CO₂气调包装组在贮藏30 d后存在塌瘪现象。因此,最佳包装方式为30% N₂+70% CO₂的气调包装。在最佳包装方式下（30% N₂+70% CO₂气调包装）,香酥虾球贮藏过程中的风味成分变化明显,贮藏30 d后香酥虾球中的醇类、醛类、含氮硫类及含氧类的挥发性种类及含量总量显著（P<0.05）增加。新鲜和贮藏30 d香酥虾球的挥发性风味物质分别有39种和57种,新鲜香酥虾球中甲酸乙烯酯、环丁醇、3,4-癸二烯和3,3-二苯基-5-甲基吡唑含量较高,贮藏30 d后香酥虾球中甲酸乙烯酯、2-异氰基-环己醇（反式）、3-环己基丙醇、（E,E）-2,4-十二烷醛、柠檬醛、2-异氰基-2,4,4-三甲基戊烷和2,3-环氧丁烷含量较高。本研究表明30% N₂+70% CO₂的气调包装可以有效减缓香酥虾球的品质劣变。     

CO2冷海水预处理结合气调包装对南美白对虾品质的影响

研究CO₂冷海水处理结合气调包装对南美白对虾的保鲜效果。新鲜南美白对虾经饱和CO₂冷海水处理,采用不同气调包装（QT1,100% CO₂;QT2,40% CO₂+60% N₂;QT3,85% CO₂+5% O₂+10% N₂;QT4,40% CO₂+30% O₂+30% N₂）后于4℃冷藏,以普通空气包装（CK1）和真空包装（CK2）为对照,比较了贮藏过程中菌落总数、pH、挥发性盐基氮、多酚氧化酶活性、质构等指标的变化。结果表明,随贮藏时间的延长,菌落总数、pH、挥发性盐基氮均呈上升趋势,且显示较好的正相关性,多酚氧化酶活性明显下降,剪切力逐渐下降。QT1、QT2和QT3均可抑制贮藏期间菌落总数增加,减缓TVB-N上升速度,同时QT2和QT3可明显抑制多酚氧化酶活性,显示出良好的防褐变效果,在CO₂冷海水预处理的基础上进一步延长2~3 d的货架期。     

气调包装狮子头冷藏过程中微生物变化及菌群结构分析

以狮子头为研究对象,设置对照组和气调包装组（100% N₂、30% CO₂+70% N₂、40% CO₂+60% N₂）,研究其在4 ℃贮藏过程中,包装顶空气体组成及狮子头微生物数量的变化,并通过高通量测序技术分析腐败时期气调包装狮子头的菌群结构。结果表明:与对照组相比,30% CO₂+70% N₂和40% CO₂+60% N₂气调包装组能够抑制狮子头贮藏过程中菌落总数、假单胞菌属、肠杆菌属的生长繁殖。贮藏15 d时,30% CO₂+70% N₂组的菌落总数显著高于40% CO₂+60% N₂组（P<0.05）。因此40% CO₂+60% N₂组的抑菌效果优于30% CO₂+70% N₂组。腐败时期,三个气调包装处理组的菌群结构主要由芽孢杆菌属（Bacillus spp.）、假单胞菌属（Pseudomonas spp.）、链球菌属（Streptococcus spp.）、不动杆菌属（Acinetobaceter spp.）、热杀索丝菌属（Brochothrix spp.）、肠杆菌属（Enterobacter spp.）、乳酸菌属（Lactobacillus spp.）以及嗜冷杆菌属（Psychrobacter spp.）组成。本研究可为延长气调包装狮子头的货架期提供参考。     

酸性电解水冰衣对单冻虾仁品质的影响

以单冻南美白对虾虾仁为研究对象,重点评价酸性电解水镀冰衣对于虾仁的抑菌效果以及对单冻虾仁贮藏品质的影响。结果表明:1)-18℃冻藏下,酸性电解水冰衣可显著降低单冻虾仁中的细菌总数和金黄色葡萄球菌含量。2)经80 d冻藏后,传统蒸馏水镀冰衣的生、熟虾仁TVBN含量分别为18.96 mg/100 g和13.86 mg/100 g,而酸性电解水镀冰衣的生、熟虾仁TVBN含量仅为11.25 mg/100 g和8.52 mg/100 g,保鲜效果显著。3)酸性电解水冰衣对单冻虾仁的明度、质构特性及挥发性风味物质均未产生显著性影响。4)酸性电解水冰衣通过缓慢释放的有效氯,协同其高氧化-还原作用,可有效延缓虾仁中微生物生长,进而减少微生物产生的酶类对肌肉纤维的分解作用。本研究结果为单冻虾仁产品新型镀冰衣技术的研发提供一定的理论依据和技术支持。     

气调包装结合电子束辐照对蚌肉的保鲜效果

为探究气调包装结合电子束辐照对蚌肉的保鲜效果,分别设置气调比例为A组:100%CO₂、B组:70%CO₂+30%N2、C组:50%CO₂+50%N2、D组:30%CO₂+70%N2和E组:50%CO₂+30%N₂₊20%O₂,气调包装后使用5 kGy电子束辐照处理,同时设置2个对照组,处理后蚌肉进行冰藏实验。研究结果表明:气调包装结合电子束辐照能较大程度抑制蚌肉冰藏中微生物的增长,减少挥发性盐基氮(TVBN)的产生,同时气调包装能有效减缓由于电子束辐照引起的脂肪氧化,降低蚌肉中TBA值。各气调包装组结合电子束辐照比对照1组分别延长了冰藏蚌肉货架期17、17、15、13和16 d。在CO₂含量高于50%时,对蚌肉的保鲜效果相差不大(p>0.05),且20%O2的存在,可提高蚌肉的色泽度,改善感官品质。综合考虑,50%CO₂+30%N₂₊20%O₂气调包装结合电子束对蚌肉的保鲜效果较优。     

不同贮藏温度下不同充气包装处理对鲜食枸杞贮藏品质的影响

为了研究鲜食枸杞最佳冷藏温度及充气包装条件,以新鲜、无腐烂的红枸杞为试材,采用CO₂:O₂:N₂分压比例分别为3:15:82、7:25:68、11:35:54的充气包装,在冷库中置于0、1、2℃贮藏24 d,分别对贮藏期间枸杞果实可滴定酸、还原糖、可溶性固形物、色差、腐烂率进行测定。结果表明,贮藏过程中0、1℃条件下7% CO₂+25% O₂+68% N₂气体浓度可有效维持枸杞果实中较高的还原糖、可滴定酸、可溶性固形物的含量,有效抑制果实腐烂率的下降,不同贮藏温度和不同充气包装对果实色泽没有显著影响(p>0.05)。由此表明,0、1℃条件下7% CO₂+25% O₂+68% N₂包装可有效延长鲜食枸杞贮藏期,保持果实品质。     

不同气调包装对薄荷贮藏品质的影响及薄荷保鲜呼吸速率模型的建立

为了提高薄荷采后贮藏时间和预测薄荷采后的呼吸速率,通过失重率、相对电导率、色差、感官评分、维生素C含量、总叶绿素含量和菌落总数指标的测定,从包装材料为聚乙烯包装(PE)、邻苯基苯酚复合聚乙烯包装(OPP1.8/PE3.5、OPP1.8/PE4.5、OPP2.3/PE4.5)、高密度聚乙烯包装(HDPE),O₂浓度为3%～7%,CO₂浓度为5%～15%中筛选薄荷的气调包装条件,并以O₂、CO₂和包装材料为因素开展响应面优化试验,优化薄荷采后保鲜的最优气体比例及包装材料,在此基础上研究薄荷挥发性化合物和表面真菌多样性。使用密闭空间系统法测量薄荷在最优包装材料内O₂和CO₂的比例。在此基础上,再采用渗透系统法得到模型方程,并对其进行数值模拟。运用Matlab软件对处于平衡点时的呼吸速率进行计算,利用二次多项式模型对结果进行回归分析。利用高通量测序对最优、最差和对照处理组的薄荷进行测序和分析,比较其优势菌群的占比变化。结果表明：最优气调比例及包装材料为3.5%O<...     

鲜切菠菜和香菜专用自发气调包袋的研制

为满足鲜切菠菜和香菜包装的需求,本文采用不同透气率和不同面积的气调窗与包装袋相结合进行试验,分别研制出鲜切菠菜和香菜最适宜的气调包装(MAP)袋。结果表明:鲜切菠菜和香菜都适宜选用O₂和CO₂透过速率分别为4×105和1.6×106 cm3/m2·d·atm的气调窗,所需要气调窗的面积均为5~7.5 cm2/kg;综合计算气调窗和薄膜的透气量可知,适于鲜切菠菜和香菜包装袋的O₂和CO₂的透过量应分别为3.17×103~3.74×103和1.42×104~1.65×104 cm3/kg·d·atm,袋内气体稳定后,鲜切菠菜的O₂和CO₂分别为7.34%~8.30%和5.31%~5.49%,鲜切香菜的O₂和CO₂分别为3.96%~7.16%和4.89%~6.52%,在4 ℃条件下此类型的包装袋均可延长货架期6 d以上。研制的自发气调包装袋可使鲜切菠菜和香菜处于适宜的气体状态,很好地避免包装袋内由于无氧呼吸产生的异味问题,且保留原有的鲜切产品气味,延长其货架期,为鲜切企业提供有力的技术支持。     

气调贮藏对“徐香”猕猴桃采后保鲜效果影响

为研究不同气调贮藏条件对猕猴桃采后保鲜效果的影响,以"徐香"猕猴桃为试材,分别用2% O₂+3% CO₂、2% O₂+5% CO₂、5% O₂+3% CO₂、5% O₂+5% CO₂四种不同气体成分结0℃贮藏猕猴桃,并测定贮藏期间猕猴桃果实的硬度、可溶性固形物含量、维生素C含量、总酚含量、丙二醛(MDA)含量、过氧化物酶(POD)活性和多酚氧化酶(PPO)活性等指标。结果表明:气调贮藏能够有效保持果实的硬度,延缓可溶性固形物含量、V_C含量、总酚含量的下降,抑制MDA含量的上升以及PPO活性的增加,并保持较高的POD活性,有效延长了猕猴桃果实的贮藏期。综上,2% O₂+5% CO₂的气调条件对猕猴桃的保鲜效果最好,能够较好地保持果实品质,提高抗氧化物质含量,延缓果实的衰老速度。     

气调包装协同高功率脉冲微波对河蟹肉储藏期品质影响研究

为研究气调包装协同高功率脉冲微波对河蟹肉的保质效果,设置不同气体类型和组成比例(100％CO2、80％CO2+20％N2、50％CO2+50％N2、20％CO2+80％N2)以及协同高功率脉冲微波(作用频率200 Hz、时间6 min)处理,测定处理后河蟹肉在25℃贮藏期间菌落总数、挥发性盐基氮(total volat...     

不同贮藏条件下牛肉的理化性质及感官品质的对比分析

为分析牛肉在不同包装方式与贮藏温度下理化性质及感官品质的变化,该试验将牛肉背最长肌分别采用空气包装(air-packaging,AP)、真空包装(vacuum packaging,VP)和气调包装(modified atmosphere packaging,MAP),其中MAP包括两种气体比例:MAP1为78.8％O2...     

Centralised bulk pre-packaging of fresh pork retail cuts in various gas atmospheres

A centralised bulk pre-packaging technique (laboratory method), utilising various gas mixtures (c. 100% CO₂; c. 75% CO₂:25% N₂; c. 80% O₂: 20% CO₂ and c. 25% CO₂:50% N₂:25% O₂), was evaluated in terms of quality attributes such as microbiology, colour, odour and consumer acceptability. According to the bacterial counts recorded, all four packaging treatments were successful in prolonging the storage life (21 days c. 0°C) of centralised bulk pre-packaged pork retail cuts, while still ensuring a subsequent shelf life of at least 3 days (c. 0°C). The gas mixture comprising c. 25% CO₂:50% N₂:25% O₂ was the most successful treatment in terms of acceptability and colour scores.     

Beef shelf life in low O(2) and high CO(2) atmospheres containing different low CO concentrations

The use of atmospheres with low concentrations of CO (0.1 to 1%), in combination with O₂ (24%), high CO₂ (50%) and N₂ (25 to 25.9%), for preserving chilled beef steaks was investigated. The atmosphere used as reference contained 70% O₂+20% CO₂+10% N₂. Bacterial counts showed that all atmospheres containing CO greatly reduced total aerobic population numbers, including Brochothrix thermosphacta. Lactic acid bacteria, however, were not affected. CO concentrations of 0.5–0.75% were able to extend shelf life by 5–10 days at 1±1°C, as demonstrated by delayed metmyoglobin formation (less than 40% of total myoglobin after 29 days of storage), stabilisation of red colour (no change of CIE a* and hue angle after 23 days), maintenance of fresh meat odour (no variation of sensory score after 24 days) and significant (P<0.01) slowing of oxidative reactions (TBARS).     

The display life of retail-packaged beef steaks after their storage in master packs under various atmospheres

Beef strip loins were divided into four portions. One portion of each loin was vacuum-packaged and then stored at −1·5°C. The other portions were each divided into three steaks, which were retail-packaged. The retail packs were master-packaged under atmospheres of N₂, CO₂, or O₂ + CO₂ (2 : 1, v/v) and then stored at 2°C. Product was assessed after storage times of up to 60 days. At each assessment, a vacuum pack and a master pack of each type, each containing product from the same loin, were withdrawn from storage. The vacuum-packaged product was cut into three steaks, which were retail-packaged. The newly prepared retail packs and those from the master packs were displayed in a retail cabinet, at air temperatures that averaged between 3 and 5·7°C, and were assessed twice daily until the product was judged to be unacceptable. When first assessed, steaks cut from vacuum-packaged product were generally considered desirable, with little metmyoglobin in the surface pigment, although the edges of same steaks were discoloured. Steaks stored under N₂ or CO₂ for 4 days or less were only slightly desirable at best, with metmyoglobin forming relatively large fractions of the surface pigment. However, after storage under N₂ or CO₂ for 6 days or more, metmyoglobin fractions were low, and the steaks bloomed to a desirable red colour. Steaks stored under O₂ + CO₂ had lower metmyoglobin fractions, and were desirable after storage for up to 8 days. However, the fractions of metmyoglobin increased, and steaks were judged to be less desirable after longer storage times. Steaks stored under O₂ + CO₂ for 20 days were unacceptable. After storage, the numbers of bacteria on steaks from vacuum packs and N₂, CO₂, and O₂ + CO₂ atmospheres were, respectively, <10⁴, <10⁶, <10⁵, and <10⁴ CFU/cm². The flora from steaks stored under CO₂ were composed wholly of lactic acid bacteria. Other flora were dominated by lactic acid bacteria, but contained fractions of enterobacteria and/or Brochothrix thermosphacta.

The appearance of product from vacuum packs generally was unacceptable after 72 h of display. The display life of steaks stored under N₂ or CO₂ was shorter than that of the product from vacuum packs when product was stored for 2 days or less, or 46 days or more. After other storage times, the product from vacuum packs or master packs with N₂ or CO₂ atmospheres had a similar display life. The display life of product stored under O₂ + CO₂ was similar to that of product from vacuum packs or CO₂ or O₂ + CO₂ was similar to that of product from vacuum packs after storage times of 8 days or less but was shorter after storage times of 12 or 16 days. The flora on displayed product from vacuum packs or CO₂ or O₂ + CO₂. atmospheres did not attain the maximum number of 10⁷ CFU/cm². and the product did not develop off-odours of microbial origin. However, numbers of 10⁷ CFU/cm² were approached or attained during display of product stored under N₂ for 28 days or longer, and some of that product developed moderate off-odours. It then appears that, under temperature regimes that are common in commercial practice, retail-packaged strip-loin steaks with a display life of 2 days or longer can be obtained from master packs after storage periods of up to about 2, 4, or 7 weeks, respectively, with master-pack atmospheres of O₂ + COPin2 (2 : 1, v/v), N₂, or CO₂.     

Effect of carbon monoxide and high oxygen modified atmosphere packaging and phosphate enhanced, case-ready pork chops

The objective of this study was to evaluate the effects of CO-MAP compared to traditional high oxygen MAP (HiOx-MAP) packaging and enhanced with different phosphate on enhanced pork quality. Pork loins were enhanced to 10.5% over initial weight to contain 0.3% salt and 0.4% phosphate (either sodium tripolyphosphate [STP] or a blend of STP and sodium hexametaphosphate) on a finished weight basis. Chops were cut, packaged in atmospheres containing 0.4% CO/30.0% CO₂/69.6% N₂ (CO-MAP) or 80% O₂/20% CO₂ (HiOx-MAP), aged in the dark, then placed in a lighted retail display case for 48 h. Chops packaged in CO-MAP were redder (higher Minolta a^* values) and darker (lower Minolta b^* values) than chops packaged in HiOx-MAP. Based on sensory scores, the CO-MAP chops were pinker than the HiOx chops after cooking. CO-MAP chops also experienced less purge loss than chops in HiOx-MAP. Results indicate that CO-MAP had no effect on flavor or consumer acceptability and only minimal effects on other characteristics.     

Colour changes and consumer acceptability of bulk packaged pork retail cuts stored under O(2), CO(2) and N(2)

A centralised bulk packaging technique, utilising various gas mixtures, c. 100% CO₂ + oxygen scavenger, c. 80% O₂:20% CO₂ and c. 25% CO₂:50% N₂:25% O₂, was evaluated in terms of consumer acceptability and colour. The inclusion of an oxygen scavenger ensured that pork retail chops bulk packaged in a 100% CO₂ were as acceptable after 0, and 14 days bulk storage and subsequent retail display than chops stored in oxygen-enriched atmospheres. The study also indicated that a saturation level of 10 and higher indicated that the appearance of the pork chop was acceptable to the consumer panel. From the results of this study it is apparent that consumers find pork retail packs, bulk packaged in oxygen depleted atmospheres, as acceptable as pork chops stored in oxygen enriched atmospheres.