Antimicrobial Properties of Raisins in Beef Jerky Preservation

: Fruits and vegetables may contain components that exert antimicrobial effects. In this study, beef jerky formulated with 15% raisins produced conditions inhibitory to pathogenic bacteria by decreasing pH to 5.4 and a_w to 0.64. Storage of vacuum‐packaged raisin‐beef‐jerky (10‐wk; 30 °C) resulted in a further decrease to pH 4.5 and a_w to 0.62. The antioxidant potential was increased by over 600%. The product received favorable sensory ratings for appearance, texture, and flavor, comparable to the non‐raisin control. Raisins in ready‐to‐eat meats such as jerky produce a lower fat, higher fiber product with antimicrobial capability and increased antioxidant potential, thereby providing a potentially safer, healthier alternative to traditional meat snacks.     

牛肉干中添加绿茶提取物对其色泽和氧化稳定性的影响

本实验在牛肉干中添加亚硝酸盐和绿茶提取物,主要对牛肉干色泽和氧化稳定性的影响进行了研究。添加调味料时随机分成对照组(无添加)和三个实验组(A:添加120×10-6亚硝酸盐;B:添加4%的绿茶水提物;C:2%的绿茶水提物和60×10-6亚硝酸盐)。结果表明:试验组的TBARS值显著低于对照组(p<0.05),各实验组间,4%绿茶提取物添加组的TBARS值最低。添加绿茶实验组可显著抑制牛肉干的氧化,稳定牛肉干的色泽。     

陈皮对烘烤牛肉干中杂环胺含量的影响

探讨陈皮对烘烤牛肉干中杂环胺生成及牛肉干质量损失率、色差、感官指标的影响.陈皮的总酚物质含量及抗氧化能力分别通过福林-酚法及DPPH法测定,牛肉干中杂环胺含量利用高压液相色谱法测定.在没有经过陈皮水提物腌制处理牛肉干中检测出2-氨基-3,8-二甲基咪唑并[4,5-F]喹喔啉(MeIQx)、2-氨基-3,4,8-三甲基咪唑并[4,5-用喹喔啉(4,8DiMeIQx)、9H-吡啶并[3,4-B]吲哚(Norharman)、1-甲基-9H-吡啶并[3,4-B]吲哚(Harman)和2-氨基-1-甲基-6-苯基-咪唑并[4,5-B]吡啶(PhIP),总含量为44.01ng/g.160mg/mL的陈皮水提物可显著降低MeIQx(34.3％),PhIP(96.5％),但是显著增加了Norharman(32.4％);且陈皮提取液浓度越高、腌制时间越长,其对牛肉干中杂环胺含量的影响越大;陈皮腌制处理对牛肉干质量损失率没有显著影响,而色泽随着陈皮浓度的升高而明显变淡;感官评价表明经过陈皮腌制的牛肉干在颜色及风味感官品质上无不良影响.因此,陈皮提取物腌制是一种较好的抑制烘烤牛肉干中杂环胺的方法.     

藏式风干牦牛肉模拟加工过程中理化特性与挥发性风味物质的变化

本试验研究了牦牛背最长肌在模拟藏式风干肉加工过程中先在-20℃冻结6 h,后在40℃风干20 h、60℃风干10 h或80℃风干5 h条件下风干肉的水分活度（water activity,Aw）、pH、色差值、硫代巴比妥酸值（Thiobarbituric acid value,TBA）以及挥发性风味物质的变化。结果表明,随着风干温度升高,Aw的下降速率增加。pH先升高后下降,升高速率60℃ > 40℃ > 80℃。L^*值先下降,经过3次冻结-风干后升高,其升高速率60℃ > 80℃ > 40℃;a^*值和b^*值呈显著下降的趋势（P<0.05）,下降速率40℃ > 80℃ > 60℃。TBA值显著性增加（P<0.05）,增加速率60℃ > 40℃ > 80℃。藏式风干牦牛肉中共检出7类挥发性风味物质,通过主成分分析得到三个主成分,累计贡献率达到76.117%,PC1 38.565%,由酸类、醛类、醇类、烯烃类以及含硫化合物组成;PC2 22.198%,由酸类和酮类组成;PC3 15.354%,由杂环类组成。不同风干温度时间点的挥发性风味物质在PC1、PC2、PC3上的得分是具有差别的,40℃风干至12 h时在PC1和PC2上的得分最高;60℃在风干至第8 h时在PC1上的得分最高;80℃在风干3 h时在PC1中得分最高。综上,不同风干温度下的藏式冻结-风干对牦牛肉的理化性质与挥发性风味物质的变化有不同的影响。     

添加复合发酵剂对发酵猪肉干食品安全性的影响

以清酒乳酸杆菌（Lactobacillus sakei）和木糖葡萄球菌（Staphylococcus xylosus）为复合发酵剂发酵猪肉干,研究复合发酵剂对发酵猪肉干腐败微生物生长增殖、组胺积累、亚硝酸盐残留、脂质氧化及挥发性氨基氮（TVB-N）生成的影响。结果表明:接种复合发酵剂显著（p<0.05）抑制发酵过程中大肠杆菌、李斯特菌、假单胞菌和金黄色葡萄球菌等腐败微生物的生长增殖;发酵结束时,添加复合发酵剂和自然发酵组的组胺含量分别为0.32和8.85 mg/kg,亚硝酸钠残留量分别为8.95和45.6 mg/kg,硫代巴比妥酸（TBA）值分别为0.67和1.54 mg MDA/kg,TVB-N含量分别为1.23和5.25 mg/100 g。添加复合发酵剂组的组织状态、风味和色泽等感官评分均高于自然发酵组,获得了优良的感官特性。      

卡拉胶/魔芋胶和钾盐对猪肉脯及猪肉糜质构特性的影响

亲水性胶体对肉糜制品的品质有重要影响。通过测定猪肉糜的失水率、质构特征以及猪肉脯的水分活度、质构特征,研究卡拉胶和魔芋胶的复配胶体以及K+对猪肉糜和猪肉脯质构特性的影响。结果表明,适宜比例的卡拉胶、魔芋胶复配胶体及0.1%K+能够改善猪肉糜及猪肉脯的质构特性。在猪肉糜中添加0.24%卡拉胶/0.16%的魔芋胶的复配胶与0.1%KCl所制得的猪肉脯质构特性较佳。     

不同干燥温度对牛肉脯水分分布迁移规律的影响

借助低场核磁共振技术及其核磁共振成像技术,探讨不同热风干燥温度（50～70 ℃）在干燥时间（120～180 min）范围内牛肉脯的水分状态、水分质量分数与水分分布情况。3种干燥温度下平均干燥速率分别为 0.226 5、0.277 9、0.353 9 g/（g·min）;牛肉脯的干燥效果主要取决于其不易流动水的含量,通过在热风干燥过程中提高温度,可以明显提高肉脯的干燥速率,结合水、不易流动水和自由水的迁移也会加快;干燥过程中不易流动水在自由水和结合水之后发生变化,不同热风温度条件下的峰面积、峰比例变化趋势较为一致,温度越高曲线变化愈明显;牛肉脯水分含量与峰面积之间呈现良好的线性关系,其中70℃干燥的线性回归方程为 y=323.34x- 6 092.77（R²=0.975 0）;纵向弛豫时间T1加权成像图表明牛肉脯70 ℃热风干燥过程中氢质子密度分布相对均匀,干燥品质较高。比较3种干燥温度的差异,这可为今后肉脯品质提升、产品研发和节约能源提供理论依据。     

The physicochemical and microbiological characteristics of pork jerky in comparison to beef jerky

This study was carried out to compare the physicochemical and microbiological characteristics of beef and pork jerky, prepared from whole muscle of beef semimembranosus (BSM), pork semimembranosus (PSM), pork longissimus dorsi (PLD), and pork psoas major (PPM). The BSM and PSM jerky had higher moisture content, and PPM jerky had lower water activity than other jerky samples during 30 days of storage at 25 °C (P < 0.05). Pork jerky samples had higher lightness value than beef jerky, while PSM jerky had higher pH value than other jerky samples (P < 0.05). The shear force and TBARS values of PPM jerky were higher than those of other jerky samples (P < 0.05). Saturated fatty acid (SFA, %) was significantly higher in the BSM jerky than others, while unsaturated fatty acid (UFA, %) was significantly higher in the PSM and PLD than BSM and PPM jerky samples (P < 0.05). The PPM jerky showed a significant increase in UFA (%) during storage, and a significantly decrease in microbial count after storage of 30 days (P < 0.05).     

响应面法优化牛肉干发酵工艺的研究

采用响应面法对牛肉干发酵工艺条件进行优化。应用Box-Behnken实验设计,以感官评分为响应值,研究了发酵温度、发酵时间和食盐添加量三个因素对发酵牛肉干品质的影响,最终确定最佳工艺参数为:发酵温度16℃,发酵时间68h,食盐添加量为1.65%。通过验证实验得到该条件下加工的发酵牛肉干感官评分为90.35,与模型预测值89.01基本相符。     

Safety Study of Milled Beef and Slices Beef Jerky Viewed from Cadmium and Plumbum Heavy Metals Contamination

Heavy metals Plumbum (Pb) and Cadmium (Cd) are chemical contamination that may contaminate during pre-harvest, processing as well as the contribution of environmental factors. The results showed an average content of Pb highest milled beef jerky products from trader C is 2.0177 ppm, while the highest Pb content of beef jerky slices of trader B 2.6680 ppm. The highest average cadmium content of beef jerky products milled from 4 traders coming from trader D is 0.8841 ppm, while the highest Cd content of beef jerky slices of trader B 0.3101 ppm.