脂肪含量对雪花牛排在高氧气调包装贮藏期间肉色稳定性的影响

为探究雪花牛排在高氧气调包装贮藏期间的肉色稳定性,该实验选用两种不同脂肪含量(A1和A3等级)的雪花牛排,进行高氧气调包装(80％O2+20％CO2).在每个时间点(0、5和10 d),测定其各个指标的变化.结果表明,随着贮藏时间的延长两种等级的牛排脂质氧化程度均逐渐增大,肌红蛋白还原力逐渐减弱,使高铁肌红蛋白比例显著...     

微生物亚硝化抑制剂对风干肠理化性质及安全品质的影响

为降低风干肠中生物胺（BAs）、N-亚硝胺（NAs）含量和亚硝酸盐残留量,提高产品的安全品质,设计4组风干肠：1)MNI组：添加0.05%微生物亚硝化抑制剂;2)MNIP组：添加0.05%MNI的同时接入PRO-MIX5商业发酵剂（木糖葡萄球菌、清酒乳杆菌、类植物乳杆菌）;3)FBFAP组：加入外源添加物的同时接入PRO-MIX5商业发酵剂;4)CK组：空白对照组。将灌肠后的4组样品,在30℃恒温、恒湿培养箱中发酵,当pH值降到5.4时终止发酵,进入20 d的风干成熟过程（14～16℃）。测定4组样品在发酵过程中的pH值变化,成熟过程（1,5,10,15,20 d）中的pH值、水分含量、aw、色差、硫代巴比妥酸反应物（TBARs）值和生物胺（BAs）的变化,以及4组风干肠成品的N-亚硝胺含量和亚硝酸盐残留量。结果表明：在发酵阶段,MNIP组和MNI组的pH值分别在12.5 h和15 h快速降到5.4,FBFAP组和CK组则发酵到21 h和22 h才达到要求的pH范围;MNIP组和MNI组样品在风干成熟的过程中pH值始终显著低于FBFAP组和CK组（P<0.05）,两组风干肠成品的...     

Physicochemical Properties of Wheat Flour Dough Modified by Microbial Transglutaminase

ABSTRACT: In this study, microbial transglutaminase (MTGase) was employed to modify viscoelasticity of wheat flour dough. Three flours, namely In-, Mid-, and Out-flour derived from different parts of wheat kernel, were used. When adding 16 ppm MTGase, the maximum resistance to extension (R_max) of In-(58%), Mid-(56%), and Out-flour(52%) doughs, prepared at specific water levels indicated in parentheses, is increased by 51%, 35%, and 77%, respectively. The extensibility (E) of these 3 doughs is reduced by 16%, 11%, and 6%; the stickiness is also lowered by 12%, 5%, and 22%, respectively. SDS-PAGE analysis indicates that crosslinks occur within wheat gluten of MTGase-treated dough.     

Changes in Biogenic Amines in Herring Stored under Modified Atmosphere and Vacuum Pack

ABSTRACT: Changes in 10 biogenic amines during the storage of herring in ice, in boxes without ice, in a modified atmosphere, and in vacuum packaging were investigated. The highest level of histamine was obtained from herring stored in boxes without ice, followed by herring stored in VP, ice, and MAP. Putrescine and cadaverine contents increased during the storage of herring held in ice, reaching levels of 4.0 mg and 23.7 mg/100g muscles at 16 d of storage, respectively. No significant differences were found in histamine concentrations within the treatments during the early stages of the storage period. However, there was a significant difference (P < 0.05) towards the end of the storage period in all treatments except between VP and ice.     

普通法焦糖色存储特性的研究

焦糖色在食用色素领域占有重要地位,因为普通法焦糖色具有高安全性,正日渐成为当下研究的热点。本文以普通法焦糖色为对象,探究了保温时间、样品浓度、热处理等因素对其理化性质的影响,试验结果显示:保温时间越长,p H越低且下降幅度越小,并最终趋于平衡;色率随保温时间的延长呈先增后减的趋势,120 min后基本稳定;红色指数、黄色指数随保温时间的延长呈先减后增的趋势,120 min后保持稳定;色率、红色指数、黄色指数的热处理前后变化基本遵循随保温时间延长变化值增加的趋势,保温超过90 min,变化值接近;样品制备终止后,保温促进物质的后续反应,促使物质稳定,利于各指标的稳定;样品浓度影响焦糖色的稳定性,高浓度焦糖色抑制物质的传递,因此稳定性更高。     

Microbial and Physicochemical Characterization of the Horse Meat in Fermented Sausage

In this study, 150 lactic acid bacterial strains, originating from horse meat, were subjected to a step-by-step screening and characterization to search for potential protective cultures to be used in the meat industry. Strains were first tested for their homofermentation and salt tolerance. Second, the antibacterial capacities towards Listeria monocytogenes were determined in an agar spot test. In total, 50% of the tested strains were inhibitory towards Listeria monocytogenes. However, only 12 strains produced a bacteriocin. Finally, three strains with strong bacteriocin activity were competitively evaluated by comparing their growth rate, acidifying character and lactic acid production at 15°C under anaerobic conditions in a liquid broth. All three strains had a fast growth rate with rapid acidification caused by the production of high levels of lactic acid. Based on this Lactobacillus sakei was used as starter culture for producing sausage horse meat. In this study, fermentations were followed analyzing the microbiological and physicochemical aspects of this product. The sausages were characterized based on microbial activity of lactic acid bacteria that resulted in a product with a final pH of about 4.56. No Listeria monocytogenes, Salmonella spp. nor Sulfite reducing clostridia were ever isolated from the raw materials or the fermented sausages during the maturation, reflecting the safety of this product. The final water activity of the product was 0.85. Lactobacillus sakei was efficient in reducing amine production since this strain caused a quick pH drop during sausage fermentation.     

Analysis of Volatile Compounds from Strawberry Fruit Stored under Modified Atmosphere Packaging (MAP)

Volatile compounds were extracted from strawberries stored at 1°C for 10 days under modified atmosphere packaging (MAP) conditions in high barrier pouches flushed with either carbon dioxide, mixed gas, or air, and identified by gas chromatography/mass spectrometry. Canonical variate analysis based on 25 selected volatile compounds classified the samples according to treatment and/or quality level. Unpackaged samples, MAP samples treated with air or mixed gas kept in storage for 3 days, and strawberries evaluated at day 0 were all initially different from strawberries held in carbon dioxide. After 10 days storage, all MAP strawberries were classified close together and quality attribute scores were lower.     

微生物发酵法改性苹果渣膳食纤维理化特性分析

对采用绿色木霉发酵改性的苹果渣膳食纤维的理化特性进行研究。结果表明,改性苹果渣膳食纤维显示较佳的理化性质,膨胀力为6.25mL/g,持水力为4.53g/g。改性苹果渣膳食纤维在pH 2.0条件下对NO₂^-吸附率可达98.8%,可以将NO₂^-浓度降低至3.5μmol/L,有效避免该物质对人体产生危害。吸附胆酸钠的测定结果表明,3g改性苹果渣膳食纤维对胆酸钠的吸附率可以达到72.8%,对降低血清胆固醇具有积极的意义。     

Assessment of Quality of Pears Stored in Laminated Modified Atmosphere Packages

Various aspects of modified atmosphere packaging for storage of pears in perm-selective polymeric film packages were investigated. The dynamics of respiration-permeation interaction was analyzed with a view to facilitate self establishment of dynamic equilibrium of gaseous composition within the package and external atmospheres at a desired storage condition. By combining different polymeric films, three types of laminated modified atmosphere packages (LF1, LF2, and LF3) were developed. The modified atmosphere packaged pears were found to have retained freshness and quality for a longer period of time. The shelf life of MA packaged pears could be extended approximately 0.75 to 1.5 times in comparison to unpacked pears. The performance of package type LF1 was found to be the best, whereas LF2 was found to be the second best.     

Sensory Evaluation of Ground Beef Stored in High-oxygen Modified Atmosphere Packaging

ABSTRACT: The quality of ground beef stored in high-oxygen modified atmosphere packaging (MAP) (80% O₂ and 20% CO₂) was evaluated and compared to controls stored in oxygen-impermeable chubs. Patties were formed from the stored ground meat at d 1, 6, and 10. Color, microbial load, thiobarbituric acid (TBA) number, and sensory acceptability were measured. Patties from both treatments bloomed to red with a* values > 16. Aerobic plate counts increased to 9 × 10⁵CFU/gby 10 d storage, but were not different (p < 0.05) between treatments. TBA number of high-oxygen samples increased to 2.1 after 10 d, compared to 0.8 for controls. The flavor of samples in high-oxygen were rated less desirable after 6 or 10 d.     

Stability of Anthocyanins in the Skin of Starkrimson Apples Stored Unpackaged, Under Heat Shrinkable Wrap and In-Package Modified Atmosphere

The concentration of cyanidin-3-galactoside, cyanidin-3-arabinoside, and an unidentified cyanidin arabinoside in the skin of Starkrimson apples stored unpackaged, under in-package modified atmosphere and in heat shrinkable wrap were determined at 7, 23, and 30 weeks storage. Carbon dioxide levels of higher than 73% in in-packaged modified atmosphere severely destablized the three anthocyanins. The unidentified cyanidin arabinoside was the most stable anthocyanin in the skin of Starkrimson apples. Cyanidin-3-galactoside was more stable in the skin of unpackaged apples than shrink-wrapped apples.     

香辛料对哈尔滨风干肠菌系及理化性质的影响

以添加混合香辛料的哈尔滨风干肠为研究对象,采用选择培养基对风干肠中的乳酸菌、葡萄球菌、微球菌及酵母菌进行选择性培养,并对风干肠发酵过程中的p H值和水分含量进行测定,研究风干肠中添加的混合香辛料对其加工过程中菌系和理化性质的影响。结果表明:香辛料可以调节风干肠中的乳酸菌、葡萄球菌、微球菌及酵母菌群的生长关系,显著加快风干肠p H值和水分含量的下降速率;混合香辛料的添加有效抑制了风干肠中菌落总数的增加,明显促进了乳酸菌、葡萄球菌、微球菌及酵母菌的生长。混合香辛料对哈尔滨风干肠的菌系有显著影响,菌系的变化进而改变了风干肠的理化性质。     

人工发酵剂对湘西腊肠微生物菌群和理化特性的影响

本文从动态角度探讨自然发酵、戊糖片球菌发酵、木糖葡萄球菌发酵和混合菌发酵腊肠在发酵过程中五种菌相(细菌总数、乳酸菌、葡萄球菌、酵母菌和肠细菌)和理化特性的阶段性变化。微生物数据显示,四组腊肠初始肠细菌数量约5.30 logCFU/g,而发酵结束,添加了戊糖片球菌腊肠组的肠细菌数量约1.00 logCFU/g,没有添加该菌腊肠组的肠细菌数量约3.30 logCFU/g,说明戊糖片球菌能有效抑制肠细菌的生长,保证了产品的安全性和稳定性;发酵初期,腊肠p H值迅速降5.30以下,到发酵中期,腊肠p H开始回升;在发酵过程中,戊糖片球菌腊肠组的TBARS(硫代巴比妥酸)值显著(p0.05)高于其他三组腊肠,而其它理化特性无显著差异。从数据分析可知,腊肠的发酵剂能有效改善其卫生质量,而对腊肠的p H值、AW和亚硝酸盐残留量没有显著影响。     

Physicochemical Properties,Microbial Profile,and Biogenic Amines Content of Barramundi (Lates calcarifer Bloch) Fillets Wrapped in Selected Packaging Films Under Modified Atmosphere Packaging

The purpose of this study was to investigate the effect of packaging film on physicochemical properties, microbial profile, and biogenic amines content of barramundi (Lates calcarifer Bloch) fillets packed in polyamide, polypropylene, and low-density polyethylene films and kept at 8°C more than 20 days under modified atmosphere packaging. Putrescine and cadaverine were the most abundant amines, whereas the concentration of histamine ranged from less than 0.5 (not detected) to 198.0, 264.3, and 308.5 mg/kg for polyamide, polypropylene, and polyethylene (low-density polyethylene) films, respectively. Among the three, the psychrotrophic bacteria count was initially 4.26 log colony forming units/g and exceeded the acceptable limit of 7 log colony forming units/g on the 16th day of storage for polyamide and on 12th day of storage for polypropylene and polyethylene. However, the total plate count, among the three packaging films, was initially 3.54 log colony forming units/g and exceeded the acceptable limit of 6 log colony forming units/g on the 12th day of storage. The histamine-forming bacteria count was significantly (p < 0.05) lower in barramundi fillets packaged with polyamide compared to polypropylene and polyethylene. The significant difference (p < 0.05) was observed between the concentration of amines in polyamide as compared with polypropylene and polyethylene. Among the three packaging materials, polyamide was found to be the best for prolonging the storage of barramundi fillets.     

高静压酯化木薯淀粉结构及其理化性质的研究

研究将淀粉的酯化改性在高静压的协同作用下进行。选择木薯淀粉为原料,压力水平300、450及600 MPa,以醋酸酐为酯化剂,合成高静压酯化木薯淀粉。借助偏光显微镜、傅里叶红外光谱仪、粘度计、可见光分光光度计等分析手段,对其结构及理化性质进行系统研究。结果表明,红外光谱显示在1700 cm-1左右形成酯键,随着压力的升高偏光十字并没有明显的变化,说明形成的酯键使淀粉颗粒的晶体结构更加稳定,即使在600 MPa的高压下,淀粉颗粒的结构也不会明显的破裂。高静压协同酯化木薯淀粉的稳定性降低,抗酸性增强,变性淀粉相对原木薯淀粉而言抗老化性明显。450 MPa较300、600 MPa压力水平的冷、热粘度差值最大,其差值为27.56 m Pa·s。以上说明变性淀粉可以在造纸、纺织和化工等领域拥有更广阔的应用前景。     

绿茶提取物添加及脂肪替代对低脂猪肉香肠品质及脂质氧化稳定性的影响

采用柯罗纳油或预乳化后的柯罗纳油取代50％的猪后背脂肪,并添加不同含量的绿茶提取物(100 mg/kg或1000 mg/kg)制作低动物脂肪猪肉香肠.对蒸煮后不同处理香肠的感官特性及脂肪氧化稳定性进行分析.结果表明直接采用植物油部分替代动物脂肪并不影响产品颜色(亮度和红度)、硬度和变形性,显著改善了产品的脂肪氧化稳定性...     

Effect of Carbon Dioxide Modified Atmosphere on the Compressibility of Stored Baked Goods

Whole wheat flour breads, white breads and biscuits were stored in flexible packages flushed with either air, 100% nitrogen or 100% carbon dioxide. Compressibility tests were performed during a storage time of 13 - 15 days for bread and 7 - 15 days for biscuits. Significantly lower regression coefficients (P < 0.01) were found for white and whole wheat breads and biscuits stored in carbon dioxide modified atmosphere than for the air stored samples. No significant differences were found between regression coefficients of air and nitrogen stored bread samples. Mold growth was inhibited on breads and biscuits by carbon dioxide atmosphere during 13 - 15 days of storage, but occured between the 5th and 7th day of storage on the air packaged samples.     

外源抑制物对风干肠风干过程中理化性质及安全品质的影响

为研究外源抑制物对风干肠在风干过程中理化性质和安全品质的影响,将实验室前期优选的复合抗氧化剂（combined antioxidant,CA）、复合香辛料（combined spice,CS）、发酵牛骨调味基料（fermented beef flavoring,FBF）以及FBF和CA以1∶1复配（FBFA）、CA和CS以1∶1复配（CSA）应用于风干肠加工过程中,测定风干1、3、6、9、12 d时样品水分含量、水分活度（water activity,aw）、红度值（a*）、亮度值（L*）、pH值、硫代巴比妥酸反应物（thiobarbituric acid resctive substances,TBARs）值、亚硝酸盐残留量以及风干6、12 d生物胺含量和风干12 d时N-亚硝胺（N-nitrosoamines,NAs）含量。结果表明：在风干肠风干过程中添加5 种外源抑制物,产品水分含量与对照组差异不显著,但aw降低（0.80～0.81）;亚硝酸盐残留量为3.77～5.65 mg/kg,产品品质和安全性均显著提高。通过比较5 组外源抑制物可知,FBFA更能增强风干肠的a*和L*,降低TBARs值和亚硝酸盐残留量,控制组胺和NAs的形成,对风干肠的色泽和安全品质等均具有较好的改善作用。此外,CSA可以较好地抑制组胺和酪胺的形成,控制脂肪氧化和阻断NAs的形成。FBFA和CSA对风干肠的品质和安全性均具有显著增效作用。