香菇抗氧化成分提取及其在牛肉糜中作用研究

利用静止提取法、恒温回流法、超声波法及恒温水浴提取法对香菇抗氧化成分进行提取,采用测定吸光度值来计算自由基清除率,确定出提取香菇抗氧化成分的最佳方法是超声波法,通过响应面方法对提取工艺条件进行优化,并将香菇提取液应用于牛肉糜中,从pH值、硫代巴比妥酸反应物质(TBARs)、色度及高铁肌红蛋白含量(metMb)变化来评价香菇提取物对生牛肉糜抗氧化性能.结果表明:超声波法提取香菇抗氧化成分最佳工艺条件为料液比1:49.46,超声时间119.4min,超声功率421.62w,随着时间的延长,香菇提取物对牛肉糜有一定抗氧化作用.     

香辛料提取物对生肉糜的抗氧化作用

研究了迷迭香、肉桂、丁香提取物对生肉糜的抗氧化效果,测定了生肉糜在贮藏期间色差、pH、硫代巴比妥酸反应物值(TBARS)、高铁肌红蛋白(metMb)的变化,并与BHA进行比较,结果表明香辛料提取物能显著抑制肉糜中脂肪的氧化,增加肉糜鲜红的色泽,与0.02%BHA效果相当.     

玫瑰雪菊混合浓缩液在预调理牛肉片中的保鲜研究

以玫瑰和雪菊为原材料,采用超声波水提法制备天然玫瑰雪菊混合浓缩液,分别与山梨酸钾(1.0g/kg)和Vc(0.1mg/mL)进行抗氧化与防腐效果比较,并将混合浓缩液应用于预调理牛肉片的贮藏保鲜实验。结果表明:玫瑰雪菊混合浓缩液的DPPH·自由基清除率和羟基自由基清除率分别可以达到82.50±0.06%和80.26±0.03%,优于Vc推荐浓度。抑菌方面,玫瑰雪菊混合浓缩液的吸光度可以达到0.564±0.02,与山梨酸钾效果相近。经过混合浓缩液浸泡处理的预调理牛肉片的pH、TVB-N、TBARs、羰基含量和菌落总数都优于对照组。     

L-赖氨酸和-D-阿拉伯糖美拉德反应产物对肉馅抗氧化作用的研究

通过测定在4℃冷藏7 d期间的pH、硫代巴比妥酸值(TBARs值)、球蛋白沉淀试验以及感官评价等指标的变化,研究不同添加量的L-赖氨酸和D-阿拉伯糖美拉德反应产物(MRPs)对新鲜肉馅的保鲜效果和抗氧化作用。结果表明:与空白组相比,添加L-赖氨酸和D-阿拉伯糖MRPs的处理组具有一定抑制脂肪氧化的作用,能更长时间的保持肉馅的新鲜度,并且在感官上也具有良好的接受性。随着添加量的增加,其抗氧化效果越好。添加6%MRPs的处理组与添加0.02%BHA的肉馅抗氧化程度相近。     

酶法提取茶树菇多肽工艺及体外抗氧化研究

试验用酶法提取茶树菇多肽,考察不同料液比、加酶量(质量分数)、提取温度以及提取时间对茶树菇多肽提取量的影响。通过清除DPPH自由基、总还原力测定研究茶树菇多肽体外抗氧化作用,并与Vc和BHT的抗氧化作用进行比较。试验结果显示,茶树菇多肽提取工艺为料液比1:60,2.0%复合蛋白酶,提取温度45 ℃,提取时间3.0 h。在此工艺条件下,多肽提取量最高,达到93.17 mg/g。体外抗氧化试验结果显示,当茶树菇多肽浓度为1.5 mg/mL时,对DPPH自由基清除率为44.8%,D_(700 nm)达到0.55。说明茶树菇多肽对DPPH自由基有一定的清除率,有较好的总还原力。     

生姜乙醇提取物对气调包装冷却猪肉的护色效果

将不同浓度的生姜乙醇提取物溶液喷涂于肉的表面，测定贮藏期间TBARS值和metMb百分含量的变化，并进行感官颜色的评定，结果表明：生姜乙醇提取物具有良好的抗氧化性能，并且添加浓度为0．08g/ml时抗氧化效果最佳，其与VE及VE和VC混合物的协同抗氧化作用明显。     

橄榄渣提取物对马肉饼的抗氧化作用

为研究橄榄渣提取物对马肉饼的抗氧化作用,以橄榄渣提取物为研究对象,分别测定其总酚含量,DPPH自由基清除能力以及ABTS+·清除能力;将不同浓度(0.2%、0.4%、0.6%)橄榄渣提取物添加到马肉饼中,测定其在9 d冷藏(4℃)过程中色差、高铁肌红蛋白含量、过氧化值、硫代巴比妥酸(TBARs)值和羰基含量的变化。结果表明:橄榄渣提取物的总酚含量为(70.82±7.34)mg GAE/g DW。随着橄榄渣提取物浓度的升高,橄榄渣提取物的DPPH、ABTS+自由基清除率逐渐升高。与对照组相比,橄榄渣提取物的添加使马肉饼中高铁肌红蛋白的含量降低、红度(a*)值升高,过氧化值、TBARs值和羰基含量显著降低(p<0.05)。并且提取物的添加量越高,上述作用越明显。因此,橄榄渣提取物有助于改善马肉饼贮藏过程中颜色的褪变,并延缓脂质和蛋白氧化,可以作为马肉饼贮藏过程中的潜在天然抗氧化剂。     

食盐添加量对草鱼腌制效果的影响

以南疆河坝草鱼为原料,分别添加质量分数为3%、5%、7%、9%的食盐进行干腌处理,以盐溶性蛋白含量、水分含量、水分活度(water activity,a_w)、含盐量、硫代巴比妥酸反应物(thiobarbituric acid reactive substance,TBARs)值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、pH值和质量变化率等指标的变化结合感官评价,研究不同食盐添加量对草鱼腌制过程中鱼肉品质的影响。结果表明:鱼肉的含盐量、质量变化率和TBARs值与食盐添加量呈正相关;鱼肉的水分含量、盐溶性蛋白含量、TVB-N含量、a_w和pH值与食盐添加量呈负相关。综合各项相关指标,确定草鱼腌制的适宜食盐添加量为5%。     

食用菌添加对自贡冷吃牛肉品质与风味影响研究

为探究茶树菇、香菇、杏鲍菇、蟹味菇的添加对冷吃牛肉的感官特性及风味物质的影响,在传统冷吃牛肉制作工艺基础上,分别添加茶树菇、香菇、杏鲍菇、蟹味菇到冷吃牛肉中,通过感官评价得出香菇为最优食用菌。通过正交试验优化加工工艺关键因素,最终确定最佳食盐添加量为5 g/500 g,味精添加量为3 g/500 g,牛肉与香菇的添加比例为5∶5。在此条件下,牛肉的氨基酸态氮含量和pH值较常规冷吃牛肉产品有所提高。通过顶空固相微萃取和GC-MS检测改进冷吃牛肉的风味物质组成,最优工艺下的冷吃牛肉共检测出51种风味物质,相比常规冷吃牛肉产品增加了3种香菇特征性风味物质,同时具有特征风味的醚类物质相对含量达到11.49%。     

文摘

本文介绍了维生素E(V_E),维生素C(V_C)和其混合物(V_E+V_C)对生牛肉糜中色素和脂类稳定性的影响。试验是在生牛肉糜4℃裸露光照七天过程中进行的,而色素和脂类的氧化可最大限度地得到控制。经过V_E处理后,色素和脂类的氧化可减缓,经V_C处理后,氧化可降低,经V_E+V_C处理后可使氧化降到最低。     

发酵牛肉调味基料在牛肉饼中的应用效果

冷冻牛骨肉末经热-压浸提、酶解、发酵和美拉德反应后制成发酵牛肉调味基料（fermented beef flavoring,FBF）,以新鲜牛前肩肉为原料,加入不同比例腌制剂制成牛肉饼,分别为阴性对照（negative control,NC）组（既不添加NaNO2又不添加FBF）、阳性对照（positive control,PC）组（添加不同比例的NaNO2）及实验组。对牛肉饼进行感官评价后于20 ℃条件下贮藏,测定贮藏期间牛肉饼的红度值（a*）、pH值、硫代巴比妥酸反应物（thiobarbituric acid reactive substance,TBARs）值及亚硝酸盐残留量。结果表明：与NC组相比,PC组和实验组牛肉饼色泽红润,口感香嫩,风味得到明显改善;只添加FBF的实验组牛肉饼a*较高,TBARs值和亚硝酸盐残留量较低;同时添加NaNO2和FBF的牛肉饼口感、色泽及风味等品质均有所提高,且20 g/kg FBF和0.05 g/kg NaNO2复配制成的牛肉饼品质最好。     

Color of fresh, frozen and cooked ground beef patties manufactured with mechanically recovered neck bone lean

Mechanical systems that recover lean tissue from beef vertebrae without grinding bone material are in use in major packing plants across the country. Our objective was to determine the effects of mechanically recovered neck bone lean (MRNL) on color stability of fresh, frozen and cooked ground beef patties. Ground beef patties at two fat levels (10 and 20%) and four MRNL levels (0, 15, 30 and 45%) were analyzed for percentage surface metmyoglobin (metMb) and HunterLab L^* and a^* values over 12 days of fresh display and 18 weeks of frozen storage. Data were collected for three replications of the experiment. Mechanically recovered neck bone lean caused an increase in surface metMb up to 7 days of retail display; however, patties made with higher levels of MRNL showed a rapid decrease in surface metMb from days 8 to 12. Both the increase and decrease in surface metMb may be due to microbial effects, which were greater at increased levels of MRNL. Patties made with 30 and 45% MRNL showed greater (p < 0.05) surface metMb by 18 weeks of frozen storage than controls; however, patties with 15% MRNL were not different (p > 0.05) than controls. HunterLab L^* values for cooked patties decreased in a linear fashion (p < 0.01, R² = 0.70) as MRNL level increased.     

Utilization of image processing to quantitate surface metmyoglobin on fresh beef

Ground beef patties were manufactured with various combinations of ascorbic acid and mechanically recovered neck bone lean (MRNL) to study the use of image processing in predicting percentage surface metmyoglobin (metMb) on fresh beef. Ascorbic acid and MRNL cause various color phenomena that resulted in a wide range of variation in surface color. Patties were also stored over six days of retail display to cause further color changes. Surface color was assessed by several different accepted methods. A prediction equation for percentage surface metMb included mean values for hue, saturation and intensity. Root mean square error, R-square and Mallow's Cp statistic were used as selection criteria for choosing the best predictive model. Image processing hue, saturation and intensity accounted for 93% of the variation in percentage surface metMb. Since hue, saturation and intensity each contribute to overall color profile it is logical that these parameters are good predictors. These data indicate that image processing is capable of objectively measuring percentage surface metMb.     

Effect of natural antioxidants on oxidative stability of cooked, refrigerated beef and pork

ABSTRACT:  The effect of grape seed extract (GS; 0.01% and 0.02%), oleoresin rosemary (OR; 0.02%) and water-soluble oregano extract (WS; 0.02%) on oxidative and color stability of cooked beef and pork patties stored at 4 °C for 8 d was determined. Fresh beef or pork lean and trim were ground, mixed (30% fat), and divided into 5 portions. Antioxidants mixed with salt (2%) were added. Patties were formed, cooked to an internal temperature of 71 °C, overwrapped in PVC, and stored at 4 °C. Lipid oxidation, assessed using thiobarbituric acid reactive substances (TBARS) and sensory evaluation, instrumental and visual color, and pH were determined after 0, 2, 4, 6, and 8 d. Based on TBARS values and off-odors associated with lipid oxidation such as rancidity, wet cardboard (for beef patties), and grassy (for beef and pork patties), grape seed extract resulted in the best antioxidant activity in both meat species. It did not change instrumental color measures of redness, yellowness, or color intensity, and appeared to reduce visual green discoloration in beef patties. The higher GS concentration (0.02%) exhibited more antioxidant activity than the lower concentration (0.01%). Therefore, grape seed extract at 0.02% has the potential to reduce oxidative rancidity and improve shelf life of refrigerated cooked beef and pork patties.     

Effects of pyruvate on lipid oxidation and ground beef color

Our overall objective was to better understand the effects of added pyruvate on enhanced beef color stability. The 2 possible mechanisms assessed were the role of pyruvate in lipid oxidation and direct interaction between pyruvate and beef myoglobin. Microsomes were incubated with pyruvate at pH 5.6, 25 °C, and lipid oxidation was measured hourly for 3 h. Bovine oxymyoglobin at pH 5.6 was incubated with pyruvate and used to quantify both redox stability (metmyoglobin formation) and pyruvate-myoglobin adduction using mass spectrometry analysis. Surface color and lipid oxidation were measured on ground beef patties stored for 6 d in polyvinyl chloride over-wrap (PVC) or high oxygen. Addition of pyruvate to microsomes decreased lipid oxidation compared with controls (P < 0.05). Conversely, no effect on myoglobin was observed (no changes in redox stability and no peaks corresponding to pyruvate were observed; P > 0.05). However, pyruvate increased color stability and decreased lipid oxidation of ground beef patties packaged in PVC and high oxygen. Pyruvate decreased nitric oxide metmyoglobin-reducing capacity and oxygen consumption of patties compared with controls (P < 0.05). This research suggests that pyruvate may improve beef color stability primarily through its antioxidant effect on lipids. Practical Application: Discoloration of meat often results in significant revenue loss. This study suggests that pyruvate can improve the color stability of patties packaged in high oxygen and PVC primarily through its antioxidant effect on lipids.     

没食子酸对猪肉糜脂肪和蛋白氧化的抑制作用及对肉糜品质特性的影响

为研究没食子酸对冷藏（4 ℃,9 d）猪肉糜脂肪和蛋白氧化的抑制作用及对肉糜品质的影响,将没食子酸添加到猪肉糜中（0、0.05、0.10、0.20 g/kg）,添加0.20 g/kg叔丁基羟基茴香醚（butylated hydroxyanisole,BHA）作为对照组,对肉糜的硫代巴比妥酸（thiobarbituric acid reactive substances,TBARs）值、总巯基含量、羰基含量、表面疏水性、色泽及蒸煮损失进行分析。结果表明：空白组猪肉糜的TBARs值显著增加,蛋白质总巯基含量降低,羰基含量增加,表面疏水性升高,红度值降低,蒸煮损失增加;没食子酸的添加降低了TBARs值的增加幅度,抑制了羰基化合物的生成和表面疏水性的增加,并且随着贮藏时间的增加,能够减少总疏基含量的损失,降低脂肪氧化和蛋白氧化的程度,没食子酸还有利于猪肉糜红度的保持,但对蒸煮损失无改善作用。因此,没食子酸可作为天然抗氧化剂应用于肉及肉制品中。     

Antioxidant activity in different parts of roselle (Hibiscus sabdariffa L.) extracts and potential exploitation of the seeds

The calyx of the roselle plant has long been recognised as a source of antioxidants. The objective of this study was to evaluate antioxidant activity, free radical-scavenging and total phenolic content in other parts of the roselle plant. Roselle seed extracts were found to have the highest antioxidant activity and strongest radical-scavenging activity of all plants tested. Methanol extracts showed a positive correlation between phenolic content and antioxidant activity, as measured by β-carotene bleaching assay and DPPH radical-scavenging activity. The antioxidant efficacy of roselle seeds in a whole food system was investigated by testing the effect on lipid oxidation in cooked beef patties stored at 4 °C for 14 days. Results showed that patties treated with roselle seeds had reduced lipid oxidation compared to patties treated with BHT. This study suggests that roselle seeds have the potential to be used as food antioxidants.     

大叶紫薇叶提取物抗氧化性能的研究

采用不同溶剂对大叶紫薇叶进行浸泡提取,计算提取率,并用FolinCiocalteu方法测定总酚含量;采用DPPH分析法和FRAP分析法评估了不同溶剂提取物的抗氧化活性,选出抗氧化活性最高的提取物添加到猪肉中,于4℃光照下贮存12d,通过测定贮存期间猪肉的TBARS值、pH值和亨特L、a、b值,评估了提取物抗脂质氧化、防腐保鲜和护色作用,并与BHT、VE、茶多酚比较。结果表明,不同溶剂提取物显示出不同的抗氧化活性,其中甲醇提取物抗氧化活性最高(高于BHT),其提取率和总酚含量也最高。大叶紫薇叶甲醇提取物在生猪肉中具有明显的抗脂质氧化和防腐保鲜的作用,且随着提取物含量的增大,抗氧化的效果增强,有明显的量效关系。     

Mechanically Recovered Neck Bone Lean and Ascorbic Acid Improve Color Stability of Ground Beef Patties

Ground beef patties at two ascorbic acid (Asc) levels (0 and 1,000 ppm) and three mechanically recovered neck bone lean (MRNL) levels (0, 15 and 30%) were analyzed for percentage surface metmyoglobin (metMb) and HunterLab L* and a* values over 6 days of retail display. Data were collected for two replications. Patties made with Asc had less (P < 0.01) surface metMb than patties made without Asc on days 1-4 of retail display. Ascorbic acid and MRNL acted synergistically to improve surface color. Patties made with Asc showed a linear decrease (P < 0.05) in surface metMb as MRNL level increased from 0 to 30%. Patties made without Asc showed no change in surface metMb as MRNL level increased.