迷迭香提取物对大黄鱼货架期的影响

研究了迷迭香提取物作为生物保鲜剂对大黄鱼4℃贮藏过程中其品质变化和货架期的影响。实验将碎冰处死的整条大黄鱼分别置于4℃的迷迭香溶液（0、0.1%、0.2%、0.3%）中浸泡60min,沥干后所有样品采用蒸煮袋包装于4℃的冰箱中贮藏。通过测定鱼体贮藏过程中的菌落总数、pH、TVB-N、TBA、K值、感官评分等鲜度指标的变化规律,探讨了迷迭香提取物对大黄鱼低温贮藏过程中货架期的影响。结果表明,经过迷迭香提取物处理的大黄鱼细菌总数、TVB-N、TBA、K值在储藏期20d内显著低于对照组（p<0.05）,且具有较好的感官评分;其中迷迭香浓度为0.2%时,保鲜效果最佳,能够抑制大黄鱼低温贮藏过程中的微生物繁殖,有效减缓蛋白质的降解及脂肪的氧化,有效延长大黄鱼的货架期。      

迷迭香-鱼精蛋白复合保鲜剂对冷藏白鲢鱼丸的保鲜效果研究

为了探讨迷迭香-鱼精蛋白复合保鲜剂对白鲢鱼丸4℃冷藏条件下的保鲜效果,本研究采用三种不同复合比例处理鱼丸,在贮藏期间定期测定其细菌总数、p H、TVB-N值、弹性、硬度、白度、水分分布、凝胶强度的变化并进行感官评定。结果表明:与对照组相比,各处理组都有抑制微生物生长繁殖的作用,可降低TVB-N值,同时弹性、硬度、凝胶强度及水分分布等指标均优于对照组,但对白度影响不大,其中处理组C（0.1 g/kg迷迭香+0.3 g/kg鱼精蛋白）保鲜效果最为显著。这表明迷迭香-鱼精蛋白复合保鲜剂在不影响白鲢鱼丸感官品质的情况下可以有效改善其贮藏品质,延长其货架期。      

Improvement of active chitosan film properties with rosemary essential oil for food packaging

Rosemary essential oil (REO) was used to develop an active film from chitosan. The effects of REO concentration (0.5, 1.0 and 1.5% v/v) on film properties were studied by measuring the physical, mechanical and optical properties of the REO‐loaded films. Scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy were used to study microstructure and the interaction of the chitosan‐based films. The solubility and water gain of the chitosan film decreased about 25% and 85%, respectively, by REO incorporation, up to 1.5% v/v, because of the interaction between hydrophilic groups of chitosan and REO as confirmed by FTIR. It was determined that REO improved the transparency of the films from 4.97 in neat chitosan up to 7.61; moreover, it reduced the films’ light transmission in UV light more than 25%. Films containing REO showed more antibacterial activity and total phenol content. The films containing REO showed potential to be used as active film in food preservation.     

微胶囊化姜黄油对冷藏鲢鱼鱼丸的保鲜效果

以鲢鱼鱼丸为研究对象,将姜黄油及微胶囊化姜黄油添加到鱼丸中,测定分析其在冷藏过程中微生物、理化和感官等品质指标的变化,评价微胶囊化姜黄油对鲢鱼鱼丸的保鲜效果。结果表明:4℃下空白组鱼丸在贮藏5 d后菌落总数(TVC)达到6.2×104 cfu/g,超过国家规定的卫生标准;而添加0.1%微胶囊化姜黄油的鱼丸样品细菌生长受到明显抑制,可使鱼丸货架期延长8 d(TVC值为5.9×104 cfu/g)。微胶囊化姜黄油还可以有效地减缓脂肪氧化,提高了鱼丸的白度,而对弹性影响不大。该生物保鲜剂在鱼糜制品保鲜中具有明显效果,使产品在较长时间内保持良好的食用品质。      

Agar hydrogel with silver nanoparticles to prolong the shelf life of Fior di Latte cheese

The objective of this work was to evaluate the effectiveness of an antimicrobial packaging system containing active nanoparticles on the quality deterioration of Fior di Latte cheese. To this aim, 3 concentrations of silver montmorillonite embedded in agar were used. The cell loads of spoilage and useful microorganisms were monitored during a refrigerated storage period. Moreover, cheese sensory quality (i.e., odor, color, consistency, and overall quality) was evaluated by means of a panel test. Results showed that the active packaging system markedly increased the shelf life of Fior di Latte cheese, due to the ability of silver cations to control microbial proliferation, without affecting the functional dairy microbiota and the sensory characteristics of the product. The active packaging system developed in this work could be used to prolong the shelf life of Fior di Latte and boost its distribution beyond local market borders.     

迷迭香提取物对白鲢鱼肉腥味的影响及其脱腥条件优化

选用迷迭香提取物对白鲢鱼肉进行浸泡脱腥处理,以硫代巴比妥酸(thiobarbituric acid,TBA)值、三甲胺(trimethylamine,TMA)值和感官腥味值作为评价指标,在单因素试验的基础上运用响应面模型优化脱腥条件,通过顶空固相微萃取-气相色谱-质谱联用技术评价脱腥前后鱼肉挥发性成分的变化.结果表明,...     

鲢鱼骨中油脂提取方法的研究

目的 研究鲢鱼骨中鱼油的提取最佳工艺。方法 对比高温蒸煮、热风干燥、冷冻干燥不同处理方式, 将鲢鱼骨粉碎后, 以提取率为指标, 分别研究索氏提取、稀碱水解、酶法水解三种鱼油的提取方式, 并对稀碱水解法进行正交实验方案设计。结果 综合考虑, 采用稀碱水解法提取具有较高的应用价值。稀碱水解法的最优条件为温度85 ℃、pH10.0、料液比1:2、时间40 min, 鲢鱼骨油提取率为39.83%。结论 采用热风干燥法对鱼骨进行前处理, 稀碱水解法提取鲢鱼骨中脂肪提取率最高。     

Effects of chitosan coating on quality and shelf life of silver carp during frozen storage

The effects of chitosan coating on quality and shelf life of silver carp during frozen storage were investigated. Fish samples were treated with aqueous solution of 2% chitosan, and then stored at −3 °C for 30 days. The control and the treated fish samples were analyzed periodically for microbiological (total viable count), chemical (pH, TBA, TVB-N, K-value), and sensory characteristics. The results indicated that the effect of chitosan coating on fish samples was to retain their good quality characteristics and extend the shelf life during frozen storage, which was supported by the results of microbiological, chemical, and sensory evaluation analyses.     

Effects of chitosan coating and storage position on quality and shelf life of eggs

Effects of chitosan coating and storage positions (small-end down, small-end up or horizontal) on internal quality and shelf life of eggs were evaluated during 5 weeks of storage at 25 °C. Compared with noncoated eggs, all chitosan-coated eggs, irrespective of storage positions, had significantly lesser weight loss, higher Haugh units and higher yolk index throughout the storage. Chitosan coating, irrespective of storage positions, extended the egg shelf life by at least 3 weeks at 25 °C compared with noncoated eggs. Noncoated and chitosan-coated eggs placed small-end down tentatively showed better quality than eggs placed small-end up after 3 and 4 weeks of storage. After 5 weeks of storage, storage positions did not significantly affect quality of noncoated and chitosan-coated eggs. There were no notable differences in total amino acid content of the albumen and fatty acid composition of the yolk between noncoated and chitosan-coated eggs after 5 weeks of storage.     

棕榈油品质对饼干保质期的影响

本文通过饼干的虐待储藏实验及风味品评实验，研究了棕榈油不同色泽及抗氧化剂TBHQ含量对饼干保质期的影响，并提出了饼干保质期达到12个月所要求的棕榈油质量指标。     

Influence of cold chain interruptions on the shelf life of fresh pork and poultry

In this study, the influence of fluctuations of the cold chain on the growth of Pseudomonas spp. on fresh pork and poultry and, therefore, their shelf life was evaluated. Thus, four storage trials were examined. In each trial, shelf life at the control scenario (4 °C, constant) was compared with shelf life at two dynamic scenarios including temperature shifts from 4 to 7 and to 15 °C, respectively. Overall, fresh pork and fresh poultry showed similar spoilage patterns at dynamic temperature conditions with remarkable reductions in the shelf life when short temperature upshifts occurred at the beginning of the storage. Reductions were up to 2 days (up to over 30%), although the storage time with an abusive temperature was <5% of the total storage time. As expected, scenarios with shifts to 15 °C led to higher shelf life reductions than scenarios with shifts to 7 °C for both meat types.     

Effect of a gelatin coating on the shelf life of fresh meat

ABSTRACT:  The end of shelf life for fresh meat is determined by unacceptable aroma, appearance, and color, which appear before unacceptable microbial counts. Addition of a bovine gelatin coating to fresh meat may extend its shelf life. This study utilized a 20% bovine gelatin solution that was spray-coated onto beef tenderloins, pork loins, salmon fillets, and chicken breasts which were packaged in an 80% O₂ and 20% CO₂ modified atmosphere and stored under fluorescent light at 4 °C for 2 wk. All of the gelatin-coated fresh meat products showed a reduction in purge. The gelatin reduced purge by acting as a barrier to water loss. There was a reduction in color deterioration for gelatin-coated beef, a slight reduction of color deterioration for gelatin-coated pork, and no reduction in color deterioration for salmon and chicken. The gelatin coat reduced color deterioration by acting as a barrier to oxygen, but also had a negative effect on color due to its own color deterioration. No change in lipid oxidation was seen with any of the gelatin-coated meat products. The gelatin coat was not an effective barrier for lipid oxidation at refrigeration temperatures. Sensory analysis of beef tenderloins confirmed that color deterioration was reduced, and flavor was not affected by the application of a gelatin coat. The gelatin coat was equally effective during light and dark storage. It was more effective on vacuum packaged products than on modified atmosphere packaged products.     

天然抗氧化剂对冷榨火麻油保质期的影响研究

茶多酚、槲皮素、二氢杨梅素、迷迭香、过路黄5种天然抗氧化剂添加于火麻油中,研究其种类与不同添加量对火麻油保质期的影响。结果显示：二氢杨梅素的抗氧化效果最好,添加0.02%的二氢杨梅素火麻油冷藏保质期达到13个月,添加0.04%剂量达到17个月,添加0.05%剂量可达25个月。     

鲢鱼内脏油提取方法的比较研究

为建立鲢鱼内脏油的最佳提取方法及工艺,充分利用鲢鱼资源,以鲢鱼内脏为原材料,分别采用淡碱水解法-钾法和酶解法进行鱼油提取,以鱼油提取率和理化性质进行比较研究。结果表明,钾法提取鲢鱼内脏油的最佳工艺条件为液固比1.5∶1（mL/g）、硝酸钾用量5%、温度70℃、pH7.5、水解时间40min和盐析时间15min,鱼油提取率为87.49%;酶解法提取的最佳工艺条件为pH7、温度50℃、酶解时间2.5h、酶添加量1.5%和液固比1.5∶1,鱼油提取率为90.33%。钾法与酶解法提取的鱼油理化指标分别为:酸值14.58、9.23mg KOH/g,过氧化值3.82、3.47mmol/kg,碘值123.93、127.48g I2/100g,水分及挥发物0.48%、0.32%,不溶性杂质0.13%、0.34%。除不溶性杂质外,其他指标酶解法均优于钾法。酶解法是鲢鱼内脏油提取的较好方法。      

奇亚籽油储藏稳定性研究及货架期预测

为研究奇亚籽油储藏稳定性,以液压法制备的奇亚籽油为原料,探讨储藏温度、氧气和光照条件对奇亚籽油过氧化值、酸价、K₂₃₂、K₂₆₈和TBA的影响,并应用一级动力学模型结合Arrhenius方程建立过氧化值、酸价两个氧化指标随储藏温度、储藏时间变化的货架期预测模型,预测奇亚籽油货架期。结果表明：奇亚籽油的氧化稳定性受光照、氧气和温度的影响,在避光、密封、低温的储藏条件下能有效降低过氧化值、酸价等的增长速率,延长储藏时间;通过模型推算得出密封、避光条件下奇亚籽油在25℃条件下的货架期为94 d。     

Development of active chitosan films incorporating potassium sorbate or vanillin to extend the shelf life of butter cake

Active film from chitosan was developed by adding potassium sorbate or vanillin as antimicrobial agents. The addition of potassium sorbate in the film's formula resulted in less transparency, lower strength, water permeability, while increased flexibility and oxygen permeability. Addition of vanillin in film resulted in more yellow of film colour, lower film's strength and permeability. After that, all films were used to wrap around butter cake. The inhibitory effect of film against mould was studied using commercial stretch film as control. Mould was observed on cake wrapped by stretch film and chitosan film on day 4 and 7, respectively, while mould was not observed on cake wrapped by chitosan film containing potassium sorbate or vanillin during 8‐day storage which agreed with the amount of mould enumeration on PDA. The quality of cake during storage at room temperature was also studied. Cake wrapped with film containing vanillin became more yellow. The sensory of all cake treatments were acceptable.