鸡蛋不同保存方法品质变化规律的研究

选用具有抑菌作用的保鲜剂壳聚糖和苯甲酸钠对产后12h内的褐壳鸡蛋进行涂膜处理,研究其在夏季的保鲜效果。将鸡蛋的感官评价、品质变化及部分微生物变化作为衡量鸡蛋新鲜度变化的各种指标,结果表明,保存32d,对照组蛋壳表面的菌落总数超过鲜蛋卫生标准和绿色鸡蛋标准,但对照组和壳聚糖组的蛋内容物中菌落总数、大肠杆菌、沙门氏菌均未检出;保存28d时,对照组的哈氏单位仪器全部检测不出来,壳聚糖处理组在40d全部检测不出来,降为次鲜蛋。此外,蛋的失重率、蛋黄指数和气室高度及其它一些检测指标均好于对照组。     

木醋液复合保鲜膜对鸡蛋保鲜的影响

文章研究了木醋液、壳聚糖、海藻酸钠以及蔗糖酯4种复合保鲜剂对鲜鸡蛋保鲜效果的影响,以鸡蛋感官品质、哈夫单位、蛋黄指数、失重率、p H值、菌落总数为评价指标,通过单因素试验及响应面试验,得出木醋液复合保鲜膜最佳配方工艺为：1.0%木醋液、1.0%壳聚糖、1.5%海藻酸钠、1.5%蔗糖酯,其余为纯净水。在此条件下涂膜鲜鸡蛋后,36℃贮藏25 d,鸡蛋哈夫单位为65.74,蛋黄指数为0.31,失重率为2.67%,p H值为8.8,菌落总数为3.5×102 cfu/mL。以上指标与对照组相比,涂膜组鸡蛋的鲜度指标显著优于对照组。结果表明木醋液复合保鲜膜有效延长了鸡蛋的贮藏期。     

丁香油-壳聚糖复合膜涂膜处理对鲜切甜瓜品质的影响

目的:研究丁香油-壳聚糖复合膜涂膜处理对鲜切甜瓜菌落总数和品质的影响。方法:以未涂膜处理作为对照组,具有广谱抑菌作用的ε-聚赖氨酸涂膜处理作为阳性对照组,评价丁香油-壳聚糖复合膜涂膜处理在4 ℃贮藏5 d对鲜切甜瓜菌落总数、失重率、硬度、电导率、色度、pH、可溶性固形物含量和V_C含量的影响。结果:ε-聚赖氨酸和丁香油-壳聚糖复合膜涂膜处理均能延缓鲜切甜瓜品质劣变。与阳性对照组相比,丁香油-壳聚糖复合膜涂膜处理组的菌落总数降低了一个数量级,以5.0 lg (CFU/g)为货架期菌落总数的阈值,复合膜组的货架期比对照组和阳性对照组分别延长了2.1和1.5 d;并且复合膜涂膜处理降低果肉细胞损伤程度,降低产品失重率18.18%,维持鲜切甜瓜原有的橘红色,提高鲜切甜瓜的硬度19.65%,提高鲜切甜瓜可溶性固形物含量8.18%。结论:丁香油-壳聚糖复合膜涂膜处理降低鲜切甜瓜表面菌落总数,并延缓其品质劣变。     

植物精油与壳聚糖复配涂膜保鲜剂对鸡蛋的保鲜效果研究

探讨了一种新型、安全的涂膜保鲜剂的配制,并对鸡蛋保鲜效果进行了研究。选取植物精油和壳聚糖为涂膜保鲜剂中的抑菌物质,以沙门氏菌抑菌率为指标,确定了最佳的复合抑菌物质浓度组合为:桉叶精油0.8mg/m L、连翘精油1.1mg/m L、壳聚糖15mg/m L;同时确定以0.20%的明胶作为成膜剂,配制出鸡蛋的涂膜保鲜剂。通过测定涂膜处理组和未涂膜对照组的鸡蛋在高温(37℃)条件下的贮藏过程中失重率、哈夫单位、蛋白系数、蛋黄指数、pH、游离脂肪酸和菌落总数等指标的变化。结果表明经过涂膜保鲜剂处理后的鸡蛋在贮藏过程中的品质远优于未涂膜的鸡蛋;且在37℃下贮藏,经涂膜保鲜剂处理的鸡蛋保鲜期至少延长了1周。      

植物精油与壳聚糖复配涂膜保鲜剂对鸡蛋的保鲜效果研究

探讨了一种新型、安全的涂膜保鲜剂的配制,并对鸡蛋保鲜效果进行了研究。选取植物精油和壳聚糖为涂膜保鲜剂中的抑菌物质,以沙门氏菌抑菌率为指标,确定了最佳的复合抑菌物质浓度组合为:桉叶精油0.8mg/m L、连翘精油1.1mg/m L、壳聚糖15mg/m L;同时确定以0.20%的明胶作为成膜剂,配制出鸡蛋的涂膜保鲜剂。通过测定涂膜处理组和未涂膜对照组的鸡蛋在高温(37℃)条件下的贮藏过程中失重率、哈夫单位、蛋白系数、蛋黄指数、pH、游离脂肪酸和菌落总数等指标的变化。结果表明经过涂膜保鲜剂处理后的鸡蛋在贮藏过程中的品质远优于未涂膜的鸡蛋;且在37℃下贮藏,经涂膜保鲜剂处理的鸡蛋保鲜期至少延长了1周。     

天然食品防腐剂对泡菜常温流通中菌落总数和pH的影响

为研究天然食品防腐剂应用于泡菜的防腐保鲜,实验选取乳酸链球菌素、茶多酚、壳聚糖三种天然食品添加剂对泡菜进行浸泡处理,在常温贮藏7天过程中测定菌落总数和pH的变化。研究结果表明:乳酸链球菌素控制菌落总数和pH所需的浓度分别为0.17,0.28g/kg,水溶性壳聚糖控制菌落总数和pH所需的浓度分别为0.11,0.33g/kg,茶多酚控制菌落总数和pH所需浓度分别为0.62,0.16g/kg。乳酸链球菌素和水溶性壳聚糖控制泡菜中微生物的能力强于控制产酸,茶多酚控制产酸能力强于控制微生物。水溶性壳聚糖控制微生物总数效果最好,茶多酚控制乳酸菌等产酸菌最强。     

鸡蛋壳暗斑对鸡蛋贮藏性能的影响

文章探讨了鸡蛋壳具有0%,10%,30%,60%的暗斑覆盖率对贮藏中鸡蛋失重率、相对密度、蛋黄指数、蛋清pH值、哈夫单位等新鲜度指标及菌落总数、大肠菌群、霉菌、沙门氏菌等微生物的影响。结果表明,在鸡蛋存放期间,暗斑鸡蛋新鲜度指标的变化速度以及菌落总数、霉菌等微生物的增长速度均较无斑鸡蛋快,且随着鸡蛋壳暗斑覆盖率的增加,鸡蛋新鲜度下降越快,菌落总数、霉菌等微生物的增长也越快。鸡蛋壳暗斑的存在对鸡蛋品质具有不良影响,可使鸡蛋贮藏期缩短。     

冷却肉涂膜保鲜的初探

考察了冷却肉经壳聚糖涂膜后,在0～8℃贮藏过程中菌落总数的变化,实验结果表明:1%HAc+1g壳聚糖组成的涂膜液、0.5%HAc+1g壳聚糖组成的涂膜液具有明显抑制微生物生长、延长冷却肉保鲜期的作用。此外,还探讨了由复合保鲜剂组成的涂膜液对冷却肉贮藏过程中菌落总数的影响。     

白藜芦醇和壳聚糖复合生物保鲜剂对冷藏鱿鱼品质的影响

为了降低鱿鱼中甲醛含量和改善鱿鱼的贮藏品质,研究了白藜芦醇和壳聚糖对鱿鱼品质和货架期的影响。实验分为对照组、白藜芦醇组(0.2%)、壳聚糖组(1.0%)、白藜芦醇(0.2%+壳聚糖1.0%)组。鱿鱼在(0±0.5) ℃贮藏20 d。以挥发性盐基氮(TVB-N)、硫代巴比妥酸值(TBA)、硬度、弹性、甲醛含量的变化、菌落总数(TVC)和感官评分作为评价指标,研究其对鱿鱼的保鲜效果。结果表明:相对对照组,白藜芦醇+壳聚糖显著(p<0.05)降低菌落总数、TVB-N、TBA值和甲醛含量,使硬度和弹性下降程度变缓,显著提高感官评分。白藜芦醇+壳聚糖能够改善鱿鱼的品质,抑制微生物的增殖,并减缓脂肪氧化,延长鱿鱼的货架期,可以用于鱿鱼的保鲜。     

含牛至精油的壳聚糖涂层对烤鸭保鲜效果的影响

研究不同浓度牛至精油-壳聚糖可食性涂层结合气调包装对冷藏烤鸭品质的影响。试验以气调包装（modified atmosphere packaging,MAP）（30%CO2-MAP）的烤鸭片为对照组1和仅涂有壳聚糖涂层的烤鸭片作为对照组2,测定添加不同浓度牛至精油（0.05%、0.10%、0.15%、0.30%）的壳聚糖涂层烤鸭中肉色、菌落总数、脂肪氧化和感官评分随贮藏时间的变化情况。添加精油处理对烤鸭肉色无显著影响（P＞0.05）,但随着精油浓度的增加,烤鸭的菌落总数和脂肪氧化值显著降低（P＜0.05）,这与牛至精油中的主要成分烯烃类和酚类物质有关。且由于精油本身具有强烈气味,浓度过高会影响烤鸭风味,进而影响消费者对烤鸭的可接受程度。因此,结合肉色、菌落总数、脂肪氧化值和感官指标的结果,最终优选出适合30%CO2-MAP条件下烤鸭的牛至精油浓度为0.15%。     

Some changes in composition and properties of the hen's egg on incubation

The effects of incubation on fertile and infertile eggs were examined. The examination included chemical, bacteriological, physical and organoleptic tests for changes which had taken place. Isovaleric acid was identified in all incubated eggs and also in certain fresh eggs. Additional unidentified compounds were detected in the incubated samples. Upon storage at 1 ºC, it was observed that the level of isovaleric acid in the eggs dropped significantly, irrespective of the length of incubation. No significant increase in bacterial population was observed in the eggs during incubation. Physically and organoleptically the changes during incubation were similar to those observed during extended ageing of fresh eggs.     

Functional and sensory properties of hen eggs with modified fatty acid compositions

Foaming, emulsifying, gelling, and sensory properties of fresh and stored hen eggs fed with a diet supplemented with flax oil (FO), rapeseed oil (RO), fish oil (FISH), and by-product from black currant processing (BC) were investigated. With these diets, the ω6/ω3 fatty acid ratio of eggs varied from 1.5 to 5.8, while the ratio for eggs in the control group was 6.2. Compared to eggs in the control group, FO supplementation in the feed had statistically significant influences on the foaming properties of the fresh eggs. Eggs stored for 21 days lost part of their foaming properties in FISH oil supplemented group, but the foaming properties in all test groups were technically acceptable. The emulsifying properties of eggs in FO and FISH supplemented feeding groups were statistically different compared to control group. In boiled eggs, flax oil and fish oil supplementation induced off flavours in eggs, but no changes between the control group and test groups were found in the sensory properties of mayonnaise preparations. These results suggest that the egg processing industry may produce egg-based products using oil-supplemented eggs without major problems in functional or sensory properties.     

Rheological Properties of Fresh and Frozen Chum Salmon Eggs With and Without Treatment by Cryoprotectants

Chum salmon eggs from six batches of ovaries were subjected to flat plate compression loading to determine the membrane strength. The intact eggs withstood compression forces of between 0.47 to 1.22 newtons. The membrane rupture energy ranged from 2.36 to 7.99 (x 10^-4) joules. After freezing fresh eggs at -10°C for 7 days, the average membrane rupture energy upon thawing was 46% less than that for fresh eggs. The apparent viscosities of fresh and frozen-thawed yolk of chum eggs were similar, and it may be concluded that yolk proteins were not cryodamaged. Sodium chloride was found to be the most effective cryoprotective agent for the prevention of membrane cryodamage.     

EGG QUALITY AS AFFECTED BY STORAGE AND HANDLING METHODS

The quality and shelf-life of fresh eggs were studied under simulated climatic conditions as found in Kuwait. Three groups of eggs (unwashed, washed, and washed and oil treated) were used. The treated eggs were stored at 5°, 25°, 37° and 42°C. Internal and external quality and sensory evaluation of the eggs stored up to 75 days were determined. The quality of the unwashed and washed eggs stored at 37°C and 42°C deteriorated rapidly while the wash and oil treatment extended shelf-life but decreased in quality to C over a period of time. The percent weight loss in the oil treated eggs at all temperatures was about 0.6% while the washed and unwashed lost more depending upon the temperature and storage time. All parameters studied for interior quality showed that oil treated eggs were significantly better than untreated eggs even at 42°C. Sensory evaluation on boiled eggs indicated that changes in flavor and overall quality for untreated eggs stored at high temperatures were obvious while little change in texture was observed. It was concluded that under Kuwaiti conditions eggs should be oil treated directly after collection and stored at or below 25°C so that the quality and shelf-life can be extended significantly.     

充气鲜蛋贮存运输箱的研制

养禽业的发展和人们对鲜蛋及其制品需求增加，其鲜蛋的贮存，包装和运输问题显得十分突出。根据蛋类贮存保鲜的特性以及运输条件的要 ，成功地研制出充气蛋类贮存运输箱。通过充气蛋类贮存运输箱，鲜蛋进行自由落体振动试验和运输振动试验。其结果表明，充气蛋类贮存运输箱能较好地解决鲜蛋贮存运输过程中破损率和散黄率较高的问题，并延长其保鲜期。有较好的推广使用价值。     

Consumer Acceptance of Ozone-Treated Whole Shell Eggs

ABSTRACT: Ozone-based processing is a novel technology with potentially fewer adverse effects than in-shell thermal pasteurization of eggs. There are no consumer acceptance studies published on ozone-treated eggs. This study examines consumers’ ability to detect changes between ozone-treated, thermal-treated, and fresh untreated eggs. Consumers (n = 111) evaluated visual attributes of uncooked eggs and a separate group of consumers (n = 132) evaluated acceptability of cooked eggs. Consumers evaluated attribute intensity of the eggs. The yolks and albumens of the thermal-treated and ozone-treated eggs were perceived to be significantly cloudier than the untreated control, while the ozone-treated eggs were more similar to control (P < 0.05). The yolks of ozone-treated eggs were perceived to have significantly lower heights and greater spreads than the others (P < 0.05). Despite these perceptions, overall visual appeal of ozone-treated eggs was not significantly different from control eggs. A separate set of consumers used hedonic scales to evaluate overall liking, appearance, aroma, flavor, and texture of cooked eggs. Just-about-right (JAR) scales were used to rate the color, moistness, and texture. There were no differences on any attribute scores between the treatments, except thermal-treated and ozone-treated were perceived as less moist than the control. There were no adverse effects on consumer acceptance of eggs, treated with ozone, with acceptance the same as an untreated control. These findings are useful as ozone pasteurization can enhance the safety of fresh shell eggs to meet the goals of the U.S. Egg Safety Action Plan. Practical Application: The U.S. Egg Safety Action Plan requires all shell eggs to be pasteurized to prevent foodborne illness. Heat pasteurization partially cooks the egg, so an alternative process uses ozone with less heat. This study shows the ozone pasteurization has no detectable sensory defects.     

分段碱调“无金属添加”水晶鸡皮蛋的控制技术

以鲜鸡蛋为原料腌制鸡蛋皮蛋,使用不同阶段改变料液中碱的浓度的控制技术,实现全过程“无金属添加”,并分析腌制过程中料液碱浓度、鸡皮蛋流变性、色差、质构特性等随着时间的变化,优化鸡皮蛋加工工艺,达到鸡皮蛋外观色浅透明度高的感官效果。结果表明:料液碱浓度越高,相对蛋清碱浓度变化越大,第一阶段料液碱浓度为3%、4%、5%时鸡皮蛋结构凝胶速度最快;鸡皮蛋颜色变化、质构特性与料液碱浓度关系显著,白度值在料液碱浓度4%更换为1%后腌制30 d时达到峰值,感官接受度最好,碱浓度对鸡皮蛋硬度影响较大,内聚性、粘性等无明显差异。结论:无金属添加水晶鸡皮蛋腌制最佳工艺为:鸡蛋以浓度为4%的NaOH溶液腌制14 d后,更换料液浓度为1%的NaOH溶液再次腌制25 d。     

电感耦合等离子发射光谱法测定铅法皮蛋中的多种无机元素含量

采用电感耦合等离子发射光谱法(ICP-AES)对鲜鸭蛋和铅法皮蛋蛋壳、蛋白、蛋黄中的Pb、Cu、Mg、Zn、Ca、Fe 等20 种无机元素进行分析测定。该方法的加标回收率为84.4%～112.2%,相对标准偏差小于7%,20 种元素的方法检测限在0.4～10g/L 之间。结果表明：铅法皮蛋可食部分中富含多种人体所必需的无机元素,且其蛋黄中的大部分有机元素含量皆高于蛋白。鲜鸭蛋经加工成皮蛋后,Cu、Fe、Al、Pb、Mn 等元素在各部位含量明显升高,其中有害元素Pb 的含量大大提高,且由外到内其Pb 的含量增幅呈逐渐减少的趋势。实验同时说明：ICP-AES 法是一种快速、准确、灵敏测定皮蛋中无机元素的有效方法。