高氧气调包装对鲜切莴苣呼吸和酶活性的影响

以空气包装的鲜切莴苣为对照,研究了60%O2﹢20%CO2﹢20%N2和100%O2高氧气调包装的鲜切莴苣在4℃贮藏14d期间呼吸强度和酶活性的变化。结果表明:高氧气调包装对鲜切莴苣呼吸和酶活性影响显著,60%O2﹢20%CO2﹢20%N2和100%O2高氧气调包装显著抑制鲜切莴苣的呼吸,且100%O2气调包装的抑制效果优于60%O2﹢20%CO2﹢20%N2气调包装;60%O2﹢20%CO2﹢20%N2和100%O2高氧气调包装促进SOD酶活性的上升、抑制O2-.生成量的增加和PPO、PAL酶活性的上升。     

气调保藏对苏姜猪肉货架期的影响

为提高苏姜猪肉的贮藏品质和延长其货架期,在温度为0～4℃冷藏条件下,设4个气调处理组:真空组、CO气调组(39.5%O2+60%CO2+0.5%CO)、高氧气调组(70%O2+30%CO2)和低氧气调组(45%O2+20%CO2+35%N2),探讨不同气体组分对苏姜猪肉的贮藏效果。结果显示:在15d的贮藏期内,CO气调组较真空组可延长7～9d,挥发性盐基氮、TBARS、pH、乳酸菌总数、细菌总数都较低,肉色稳定无任何异味。     

不同包装方式对冷鲜猪肉的保鲜效果

研究了普通托盘包装、真空包装、高氧气调包装(70%O2+30%CO2)和一氧化碳气调包装(0.4%CO+30%CO2+69.6%N2)对冷鲜猪肉的保鲜效果。通过对不同包装方式下冷鲜猪肉在贮藏期的色泽、汁液流失、挥发性盐基氮和微生物的分析,发现真空包装、高氧气调包装和一氧化碳气调包装均显著抑制了冷却肉中微生物的生长,提高了贮藏期间的色泽品质,但是真空包装汁液流失严重,且抑菌效果不如2种气调包装;高氧气调包装虽然有较好的护色效果和抑菌效果,但易使肉后期色泽变暗;一氧化碳包装既能维持贮藏期内较好的肉色,又能起到较好的抑菌效果,对冷却猪肉具有较理想的保鲜效果。     

气调包装中氧气含量对冷鲜猪肉品质的影响

为研究气调包装中氧气含量对冷鲜猪肉贮藏期间品质的影响,采用高阻隔性包装材料及两种不同气体比例(80%O2+20%CO2和50%O2+20%CO2+30%N2)对冷鲜猪肉进行气调包装,以托盘包装为对照,对冷鲜猪肉贮藏期间的菌落总数、色差、保水性、剪切力及包装内气体组成等指标进行检测分析。结果表明:气调包装组能够维持贮藏过程中包装盒内气体成分基本恒定;与托盘包装相比,50%O2气调包装可延长冷鲜猪肉货架期6 d,80%O2气调包装冷鲜猪肉货架期更长;气调包装组冷鲜肉红度值a*、黄度值b*显著高于(P0.05)托盘包装组;气调包装冷鲜猪肉保水性比托盘包装差,而两气调包装组之间无显著差异(P0.05);贮藏过程中气调包装组剪切力值大于托盘包装组(P0.05),80%O2气调包装组剪切力值小于50%O2气调包装组(P0.05);结论:气调包装会对冷鲜猪肉保水性、嫩度等品质造成一些不良影响,但可显著延长其货架期,采用80%O2比50%O2保鲜效果更好。     

包装方式对鲜鱼肉品质的影响

以新鲜宰杀的草鱼为原料,采用高阻隔性材料A和低阻隔性材料B 2种包装材料分别进行普通包装、真空包装和不同比例CO2、O2混合气体充气包装,研究了包装工艺对包装鲜鱼肉在贮藏过程中品质的影响。结果表明:不同包装方式对贮藏期间鲜鱼肉品质变化的影响显著,在充气包装中,O2含量越高,TVB-N值的增速越大。采用高阻隔性材料包装鲜鱼肉,其TVB-N值的增速为80%O2+20%CO2包装>普通包装>50%O2+50%CO2包装>真空包装,而采用低阻隔性材料包装其TVB-N值的增速却为普通包装>80%O2+20%CO2包装>真空包装;鲜鱼TBA增加量随贮藏时间呈逐渐上升,其变化速度基本随着包装中氧气含量的增加而增加。     

生物保鲜剂结合气调包装对冷却猪肉品质的影响

以空气包装组为对照,在4℃冷藏条件下,研究了单一保鲜剂(ε-聚赖氨酸)和复合保鲜剂(ε-聚赖氨酸、壳聚糖、茶多酚)分别结合气调包装对冷却猪肉品质的影响。通过测定样品的菌落总数、理化等指标,评价两种保鲜方法结合使用的保鲜效果。结果表明:对照组货架期约为6d,经过ε-PL和复合保鲜剂浸泡处理的冷却猪肉货架期分别为10d和16d。生物保鲜剂结合气调包装能显著延长冷却猪肉货架期,其中,真空包装组比气调组的保鲜效果差;80%CO2+20%O2包装组抑菌以及延缓TVB-N上升的效果最佳,复合保鲜剂组在第20d时还没有超出鲜度标准,但对冷却猪肉色泽有一定的负面影响,且保水性较差;20%CO2+80%O2的抑菌效果在气调组中最差,但对猪肉的色泽有很好的保护作用,复合保鲜剂组保质期约19d;50%CO2+50%O2在抑菌效果、色泽保护以及保水性方面都有很好的效果。     

低温结合气调包装处理对鲜切胡萝卜品质的影响

该研究以鲜切胡萝卜为对象,采用低温结合气调包装对鲜切胡萝卜进行处理,研究不同保鲜方式对鲜切胡萝卜品质的影响。鲜切胡萝卜经气调(气体组成分别为5%O2+5%CO2+90%N 2、5%O2+10%CO2+85%N 2、10%O2+5%CO2+85%N 2)包装后,(4±1)℃下在保鲜盒中贮藏,每3 d测定感官品质、失重率、可溶性固形物含量、抗坏血酸含量、胡萝卜素含量、菌落总数、丙二醛(malondialdehyde,MDA)含量和以及超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性等指标。结果表明,低温结合5%O2+10%CO2+85%N 2气调包装处理组有效地保持了鲜切胡萝卜的品质,减少了水分的流失,延缓了营养物质可溶性固形物、胡萝卜素以及抗坏血酸含量的下降,抑制了MDA含量的增加,提高了抗氧化酶活性,同时延缓了菌落总数的增加。在贮藏15 d后,仍有商品价值和食用价值。结果表明,低温结合5%O2+10%CO2+85%N2气调包装处理可以维持鲜切胡萝卜贮藏品质并延缓采后衰老过程。     

荷叶精油与气调包装协同对鲜肉的抑菌活性研究

研究荷叶精油与气调包装复合对散装鲜肉的抑菌活性。用不同浓度的荷叶精油与高氧气调包装(80%O2,20%CO2)和低氧气调包装(50%CO2,20%O2,30%N2)复合对接种到肉样中的大肠杆菌、金黄色葡萄球菌和沙门氏菌进行抑菌试验,分别对包装后肉样的感官指标、pH值和菌落总数进行测定。结果表明2.0%荷叶精油结合气调包装,可以达到理想的抑菌效果,能延长鲜肉的保质期至7d;低氧气调包装对不同菌种的抑菌效果略优于高氧气调包装,但不能保持鲜亮的颜色。     

高氧气调包装鲜切洋葱的研究

本研究对比三种气体比例包装(空气包装、5%O2+10%CO2+85%N2、80%O2+20%CO2)并结合使用三种不同浓度(0.5%、1%、1.5%)的柠檬酸溶液浸泡处理鲜切洋葱研究贮藏期间对品质和安全性的影响。通过测定其贮藏期间的硬度、多酚氧化酶活性、细菌总数等的变化来比较保鲜的效果。结果表明:(80%O2+20%N2)气调包装并采用1.5%柠檬酸溶液浸泡处理,对鲜切洋葱的保鲜效果较好,在4℃下贮藏17d仍能保持较好的品质。     

高O_2结合高CO_2气调包装对绿芦笋抗氧化活性的影响

以空气为对照,研究不同体积分数的高氧(60%O_2+20%CO_2+20%N2、80%O_2+20%CO_2、100%O_2)气调包装对绿芦笋嫩茎在(3±1)℃贮藏期间Vc、总酚、总黄酮含量及1,1-二苯基-2-三硝基苯肼(DPPH)、羟基(·OH)自由基清除能力的变化规律,以探究高氧气调包装对绿芦笋抗氧化活性的影响。结果表明:高氧气调包装对绿芦笋抗氧化活性有显著影响,60%O_2、80%O_2结合20%CO_2气调包装处理能有效抑制绿芦笋嫩茎低温贮藏期间总酚、总黄酮含量和DPPH自由基清除能力的下降,这种抑制作用在贮藏14 d后尤为显著;高氧气调包装处理能有效抑制Vc含量和·OH自由基清除能力的下降,抑制能力强弱顺序依次为60%O_2、80%O_2和100%O_2。由此表明,60%O_2、80%O_2结合20%CO_2气调包装处理对绿芦笋抗氧化活性的保持效果要优于100%O_2处理。     

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。     

Effect of modified atmosphere packaging and irradiation in combination on content of nitrosamines in cooked pork sausage

The effect of modified atmosphere packaging and irradiation in combination on nitrosodimethylamine (NDMA) and nitrosopyrrolidine (NPYR) levels in pork sausage was studied. Emulsion-type cooked pork sausage was manufactured and packaged in aerobic, CO2 (100%), N2 (100%), and CO2/N2 (25%/75%) environments, respectively, and irradiated at 0, 5, 10, and 20 kGy with gamma irradiation. The nitrosamine contents were significantly reduced by irradiation, and the reduction of nitrosamines was more extensive with modified atmosphere packaging than with aerobic packaging. The correlation coefficient between irradiation dose and nitrosamine content indicated that irradiation can reduce the levels of nitrosamines. The combination of irradiation and modified atmosphere packaging is effective in enhancing the chemical safety of sausage by reducing nitrosamines, if present, as well as enhancing the microbial safety of cooked pork sausage.     

Use of carbon monoxide combined with carbon dioxide for modified atmosphere packaging of pre- and postrigor fresh pork sausage to improve shelf life

Fresh pre- and postrigor pork sausage patties were manufactured in the Iowa State University Meat Laboratory and packaged either in modified atmosphere (MAP) with 0.4% carbon monoxide (CO) and 99.6% carbon dioxide (CO2) or on foam trays overwrapped with oxygen-permeable film (OW). Packages were stored at 2 to 40C under fluorescent lights for up to 31 days. Aerobic, anaerobic, and psychrotrophic plate counts, raw and cooked color, purge, and lipid oxidation were measured during storage. Results indicated that both pork sausage products in MAP had lower aerobic and psychrotrophic counts and less lipid oxidation throughout storage (P < 0.05). Raw color of both products in MAP was redder than the OW patties (P < 0.05), but the prerigor pork sausage in MAP benefited more from the CO atmosphere in terms of raw color than the postrigor pork sausage in MAP. Cooked color of the prerigor pork sausage in MAP was significantly redder than cooked color of the postrigor pork sausage. Both pork sausage products in MAP were also lighter (L* value) than the OW patties for raw and cooked color. Therefore, the combination of CO and CO2 in MAP was beneficial in extending the shelf life of pre-and postrigor fresh pork sausage by reducing aerobic and psychrotrophic microbial growth and improving oxidative stability and color, compared to conventional OW packaging. However, increased purge, increased anaerobic growth, and changes in cooking behavior were also observed for the products in MAP during storage (P < 0.05).     

大蒜提取物与有氧气调包装复合对冷却肉的保鲜研究

将大蒜提取物与气调包装复合对冷却肉进行保鲜试验。用不同浓度的大蒜提取物与低氧气调包装(50%CO_2、40%O_2、10%N_2)复合进行试验,分别测定硫代巴比妥酸反应物质(thiobarbituric acid-reactive sub- stances,TBARS)、pH值、α*值(红度值)、细菌总数对冷却肉进行测定,得出2%的大蒜提取物可以达到理想的抑菌效果,但是低氧气调包装不能使肉色保持鲜亮颜色,所以用2%大蒜提取物与高氯气调包装、抗氧化剂复合对冷却肉保鲜,得出最佳的保鲜配方:2%大蒜提取液+250mg/kg Nisin(乳酸链球菌素)+1%乳酸+0.05%Ve溶液+高氧MAP(modified atmosphere packaging)(20%CO_2、80%O_2),可以使冷却肉在保存至21 d时仍保持鲜红的颜色,贷架期大大延长。     

Nonproteolytic Clostridium botulinum toxigenesis in cooked turkey stored under modified atmospheres

The ability of nonproteolytic Clostridium botulinum type B spores to grow and produce toxin in cooked, uncured turkey packaged under modified atmospheres was investigated at refrigeration and mild to moderate abuse temperatures. Cook-in-bag turkey breast was carved into small chunks, surface-inoculated with a mixture of nonproteolytic C. botulinum type B spores, packaged in O2-impermeable bags under two modified atmospheres (100% N2 and 30% CO2:70% N2), and stored at 4, 10, and 15 degrees C. Samples were analyzed for botulinal toxin and indigenous microorganisms, as well as subjected to sensory evaluation, on days 0, 7, 14, 28, 42, and 60. Given sufficient incubation time, nonproteolytic C. botulinum type B grew and produced toxin in all temperature and modified atmosphere treatment combinations. At moderate temperature abuse (15 degrees C), toxin was detected by day 7, independent of packaging atmosphere. At mild temperature abuse (10 degrees C), toxin was detected by day 14, also independent of packaging atmosphere. At refrigeration temperature (4 degrees C), toxin was detected by day 14 in product packaged under 100% N2 and by day 28 in product packaged under 30% CO2:70% N2. Reduced storage temperature significantly delayed toxin production and extended the period of sensory acceptability of cooked turkey, but even strict refrigeration did not prevent growth and toxigenesis by nonproteolytic C. botulinum. At all three storage temperatures, toxin detection preceded or coincided with development of sensory characteristics of spoilage, demonstrating the potential for consumption of toxic product when spoilage-signaling sensory cues are absent.     

高氧气调包装对绿芦笋木质化的影响

以空气包装为对照,研究了60% O2+20% CO2+20% N2、80% O2+20% CO2 和100% O2 高氧气调包装的绿芦笋在(4 ± 1)℃贮藏28d 期间失重率、叶绿素含量、木质素含量、苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)活性的变化。结果表明：高氧气调包装可以减缓绿芦笋的失重,抑制叶绿素的降解、木质素含量的上升,抑制PAL和POD 酶活性的上升。80% O2+20% CO2 气调包装贮藏条件下绿芦笋失重较小、色泽保持良好、木质化程度较低。该条件可较好地延长绿芦笋货架期并保持其良好的品质。     

Study of the shelf life of a dry fermented sausage "salchichon" made from raw material enriched in monounsaturated and polyunsaturated fatty acids and stored under modified atmospheres

The microbiological, physico-chemical and sensory properties of salchichon with high unsaturated fat content, packed under vacuum and 20/80% CO(2)/N(2) modified atmosphere, were evaluated to determine its quality changes during storage under refrigeration. These sausages were manufactured with pork meat and pork backfat obtained from pigs fed with three different diets (control diet-CO, high oleic diet-HO and high linoleic diet-HL). In general, few significant differences were found in counts of different groups of microorganism between the three types of sausages and no difference between the packaging methods. A reduction in pH values was observed during storage and no great differences were determined by storage period on water activity (a(w)). Both parameters (pH and a(w)) presented similar results to those found in different Spanish sausages and other European dry fermented products. The sensory results denoted that sensory quality gradually decreased during storage under both packaging conditions (vacuum and 20/80% CO(2)/N(2)), so it is not advisable to store longer than 150days. On the other hand, fermented sausages with high content of unsaturated fatty acids had similar sensory properties to those of conventional sausages, and even a comparable sensory stability. In conclusion, the results showed healthier salchichons (HO and HL) similar to the traditional (CO) one could be manufactured and stored under refrigeration after slicing for a reasonable period, but the advantage of the gas mixture packaging (20/80% CO(2)/N(2)) versus vacuum packaging was not clear.     

高氧气调包装对鲜切莴苣抗氧化活性的影响

研究60% O2＋20% CO2＋20% N2和100% O2高氧气调包装的鲜切莴苣在4℃贮藏14d期间抗氧化能力的变化,以空气包装的鲜切莴苣为对照。结果表明：高氧气调包装对鲜切莴苣的抗氧化活性有明显影响,60% O2＋20% CO2＋20% N2和100% O2高氧气调包装抑制了VC及其对DPPH自由基清除率的下降,促进类胡萝卜素及其对DPPH自由基清除率的下降,促进了多酚及其对DPPH自由基清除率的上升,从而抑制了鲜切莴苣抗氧化活性的下降。统计分析表明,VC与DPPH自由基清除能力间呈显著的线性正相关关系,相关系数为0.8745,说明高氧气调包装抑制鲜切莴苣抗氧化活性的下降与其抑制VC含量的下降有关。     

Chitosan inhibits premature browning in ground beef

Our objective was to evaluate the effect of chitosan on premature browning in refrigerated ground beef patties stored in different packaging systems. Ground beef patties (15% fat) with chitosan (1% w/w) or without chitosan (control) were individually packaged either in vacuum (VP), aerobic packaging (AP), carbon monoxide modified atmosphere packaging (LO-OX; 0.4% CO+19.6% CO(2)+80% N(2)), or high-oxygen modified atmosphere packaging (HI-OX; 80% O(2)+20% CO(2)), and stored for 0, 1, or 3 days at 1°C. At the conclusion of storage, raw surface redness was evaluated, patties were cooked to internal end-point temperatures of either 66°C or 71°C, and internal cooked color was measured. The incorporation of chitosan increased (P<0.05) the interior redness of patties stored in AP, VP, and LO-OX, but not in HI-OX. The results of the present study suggest that the incorporation of 1% chitosan minimizes premature browning in ground beef patties stored under AP, VP, and LO-OX.     

Effects of dietary soybean oil on lipid and protein oxidation in pork patties during chill storage

The effect of dietary soybean oil on lipid and protein oxidation in low and high fat pork patties made from quadriceps femoris during chill storage in a high oxygen atmosphere packaging (80% O(2)/20% CO(2)) in the dark for 7 days was investigated. Pigs were fed either a standard diet or a diet added 2% soybean oil. After slaughter high fat pork patties were prepared for both feeding regimes by addition of back fat from pigs fed the same diet whereas low fat pork patties were prepared without addition of back fat. The 2% soybean diet increased the amount of unsaturated fat in the pork. Secondary lipid oxidation products determined as thiobarbituric acid reactive substances (TBARS) were found to increase in the pork patties with increased unsaturated fat. Increased unsaturated fat in the pork patties had no effect on protein oxidation determined as free protein thiol content and protein carbonyl content. A small, but significant increase in protein oxidation was found in the high fat pork patties independent on dietary fat. In conclusion, protein oxidation is unaffected by dietary fat in pork patties during chill storage for periods normally used in retail trade, and lipid and protein oxidation are not coupled under these conditions.