Odorants Contributing to Warmed-Over Flavor (WOF) of Refrigerated Cooked Beef

A systematic study was performed to determine the odorants contributing to the warmed-over flavor (WOF) of cooked beef patties. The most potent odorants of the freshly cooked patties and of the cooked, refrigerated and reheated patties showing WOF were screened by dilution experiments. Eleven odorants were selected for quantification by stable isotope dilution assays. Three aroma models were prepared on the basis of the results. A sensory comparison of the models indicated that WOF was the result of a combination of a loss of desirable odorants, e.g. 4-hy-droxy-2,5-dimethyl-3(2H)-furanone and 3-hydroxy-4,5-dimethyl-2(5H)-furanone, along with an increase in lipid peroxidation products, in particular n-hexanal and trans-4,5-epoxy-(E)-2-decenal.     

Improving the Sensory and Oxidative Stability of Cooked and Chill‐Stored Lamb Using Dietary Rosemary Diterpenes

Two dietary rosemary extracts (DREs) containing diterpenes (carnosic acid and carnosol at 1:1 and 2:1 w:w) were tested in fattening lambs to stabilize the sensory quality of cooked and chill‐stored patties. A total of 63 lambs were fed freely for 80 ± 5 d with a basal diet supplemented or not with DRE. Minced leg meat from each lamb was used to make patty batches. The patties were cooked at 72 ºC for 2 min, aerobically packed, kept at 2 ºC for up to 4 d and then reheated. Sensory traits (color, odor, flavor, and texture), CIELab color, and lipid oxidation (assessed as TBARS) were determined. In a first experiment, the lamb diet was supplemented with 600 mg of 1:1‐DRE or 2:1‐DRE kg^?1 feed. The 1:1‐DRE diet delayed discoloration, flavor deterioration, and rancidity, while the 2:1‐DRE diet was ineffective in this respect. In a second experiment, 4 supplementation levels of 1:1‐DRE (0, 200, 400, and 600 mg kg^?1 feed) were compared. Flavor deterioration was delayed when the lamb diet was supplemented with at least 400 mg 1:1‐DRE kg^?1 feed. The effects of the diet on the odor, flavor, and color were corroborated by differences in TBARS and CIELab. The results obtained suggest that rosemary diterpenes and/or their active secondary compounds deposited in muscle can act as endogenous antioxidants in cooked lamb. The carnosol intake seems crucial in the antioxidant actions achieved through DRE. The use of rosemary antioxidants in animal feeding would allow meat‐based dishes to be preserved longer without adding preservatives.     

Stability of α-, γ-, or δ-Tocopherol during Soybean Oil Oxidation

ABSTRACT:  The decomposition of α-, γ-, or δ-tocopherol in soybean oil during 24 d of storage at 50 °C was determined by high performance liquid chromatography (HPLC). The initial contents of α-, γ-, and δ-tocopherol in soybean oil were 53, 750, and 268 ppm, respectively. The degradation rates of α-, γ-, and δ-tocopherol for the first 10 d were 5.6%, 1.2, and 0.5% per day, respectively. The α-tocopherol was completely destroyed in 16 d. The destructions of γ- and δ-tocopherol were 28% and 17% after 24 d. The induction period of soybean oil determined by headspace oxygen, conjugated diene, and peroxide value was 8 d. As the degradations of α-, γ-, and δ-tocopherol increased, the headspace oxygen disappearance, conjugated diene formation, and peroxide value of soybean oil increased. The correlation coefficient between the degradation of tocopherols and the oxidation of soybean oil was about 0.95. The degradation of tocopherols in soybean oil during storage was due to the oxidation.     

Effect of Cooking Method and Ethanolic Tocopherol on Oxidative Stability and Quality of Beef Patties During Refrigerated Storage (Oxidative Stability of Cooked Patties)

ABSTRACT: Incorporation of δ-tocopherol using an ethanolic carrier to control lipid oxidation in impingement and ohmic cooked beef patties was evaluated, and quality characteristics were determined. Ethanolic δ-tocopherol delayed oxidative deterioration of cooked beef patties in both cooking methods. Ohmic cooked samples developed significantly higher ( P < 0.05) thiobarbituric acid-reactive substances (TBARS) than impingement-cooked samples. Formation of TBARS significantly ( P < 0.05) increased with storage time in both cooking treatments. Cooking method significantly ( P < 0.05) influenced color and textural attributes of beef patties. Samples cooked by ohmic heater were lighter, displaying significantly ( P < 0.05) larger L * color values. Additionally, ohmic samples were harder, chewier, and more cohesive ( P < 0.05) than samples cooked with an impingement oven. Exogenous addition of ethanolic tocopherol can delay lipid oxidation and improve quality of cooked meat products.     

不同形态硒与VE联用对H_2O_2诱导人脐静脉血管内皮细胞氧化应激损伤的保护作用

目的:研究不同形态硒化合物(有机硒:L-硒甲基硒代半胱氨酸;无机硒:亚硒酸钠)单独使用及其与VE联合使用后对H_2O_2诱导人脐静脉血管内皮细胞(human umbilical vein endothelial cells,HUVECs)产生氧化应激损伤的保护作用。方法:采用体外细胞培养方法,将HUVECs随机分为7组:对照组、H_2O_2组、L-硒甲基硒代半胱氨酸(L-Se-methylselenocysteine,L-Se MSC)组、亚硒酸钠(sodium selenite,SS)组、VE组、L-Se MSC+VE联用组、SS+VE联用组。经不同样品干预处理后,采用四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)法检测HUVECs存活率;检测各组细胞内脂质氧化终产物丙二醛(malondialdehyde,MDA)含量以及超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性的变化。结果:各处理组HUVECs存活率之间没有显著差异;与H_2O_2组比较,0.1 mg/L亚硒酸钠、10 mg/L VE处理能使HUVECs内MDA生成量显著减少,SOD和GSH-Px活性显著升高,并且亚硒酸钠和VE联合使用在细胞水平上具有显著的协同作用,而L-Se MSC组与对照组无显著差异。结论:亚硒酸钠和VE均可保护由H_2O_2诱导引起的HUVECs氧化损伤,提高HUVECs抗氧化能力,并且亚硒酸钠和VE联用具有明显的协同抗氧化作用。     

Effect of Aging Time on Volatile Compounds, Odor, and Flavor of Cooked Beef from Pirenaica and Friesian Bulls and Heifers

ABSTRACT: Volatile compounds, odor, and flavor produced by beef from bulls and heifers of the Pirenaica and Friesian breeds were studied during 7 d of aging. The Friesian breed beef had stronger fatty flavor and aftertaste than the Pirenaica, as well as differences in the content of several volatile compounds. Bull beef had stronger liver-like odor and flavor, and bloody flavor that were related to a higher 2-propanone content, while beef from heifers had stronger characteristic flavor. Aging of meat increased characteristic flavor and aftertaste. Ethanal showed a positive correlation with livery flavor and a negative correlation with the characteristic odor. The hexane seems to contribute to fatty flavor, 2-propanone was related to livery and bloody notes, and 2,2,4,6,6-pentamethylheptane to characteristic flavor.     

葡萄糖添加量和卤制时间对鸭肉熟制品中WOF(warmed-over flavor)异味调控效果的影响

鸭肉熟制品在冷藏后再次加热会产生WOF(warmed-over flavor)异味,为对异味进行抑制,在鸭肉加工的过程中添加还原性的葡萄糖和鸭肉中的蛋白质产生具有抗氧化性的美拉德反应产物,研究添加不同量的葡萄糖和不同的加工保持时间对WOF异味抑制效果的影响,采用气相色谱-质谱联用法测定鸭肉熟制品中己醛的相对含量,以己醛的相对含量作为衡量WOF异味程度的指标,并结合感官评价进行综合分析。结果表明:在鸭肉制品加工的过程中添加葡萄糖有抑制WOF异味的作用,且随着葡萄糖添加量的增加抑制作用效果增加,加工保持时间对WOF异味的抑制效果也会产生影响,随着保持时间的延长抑制效果增加。随着葡萄糖添加量的增加及保持时间的延长会对鸭肉熟制品的口感和色泽产生不良影响,因此在加工中需进行综合分析。     

葡萄糖添加量和保持时间对鸭肉熟制品中 WOF (Warmed-Over Flavor)异味调控效果的影响

鸭肉熟制品在冷藏后再次加热会产生 WOF(Warmed-Over Flavor)异味,为对异味进行抑制,在鸭肉加工的过程中添加还原性的葡萄糖和鸭肉中的蛋白质产生具有抗氧化性的美拉德反应产物,研究添加不同量的葡萄糖和不同的加工保持时间对 WOF 异味抑制效果的影响,采用气相色谱-质谱联用法测定鸭肉熟制品中己醛的相对百分含量,以己醛的相对百分含量作为衡量 WOF 异味程度的指标,并结合感官评价进行综合分析.结果表明:在鸭肉制品加工的过程中添加葡萄糖有抑制WOF 异味的作用,且随着葡萄糖添加量的增加抑制作用效果增加,加工保持时间对 WOF 异味的抑制效果也会产生影响,随着保持时间的延长抑制效果增加.随着葡萄糖添加量的增加及保持时间的延长会对鸭肉熟制品的口感和色泽产生不良影响,因此在加工中需进行综合分析     

Incorporation of Histidine and β-Alanine into the Macromolecular Fraction of Beef Soup Stock During Heating

Beef soup stock solution was heated at 95 °C, and the macromolecular fractions were obtained by dialysis. Amino-acid analysis indicated that histidine and β-alanine increased. The existence of β-alanine suggests incorporation of carnosine into the macromolecular fraction during beef extract production. To confirm the incorporation of carnosine, the macromolecular fraction was digested and the β-alanine-containing fraction was purified. This resulted in a tripeptide that consisted of glutamic acid, histidine, and β-alanine which was isolated. It was resistant to an aminopeptidase and a carboxypeptidase and released glutamic acid and carnosine when treated with γ-glutamyltranspeptidase. These results suggest that a portion of carnisone was incorporated into the macromolecular fraction and formed γ-glutamyl-β-alanyl-histidine.     

脂肪醛对“半胱氨酸-木糖”美拉德反应进程及肉香物质形成的影响

为研究脂肪醛对"半胱氨酸-木糖"美拉德反应进程及肉香物质形成的影响,设计"半胱氨酸-木糖"及"半胱氨酸-木糖"中分别添加己醛、反-2-庚烯醛、反,反-2,4-癸二烯醛的4个反应体系,在温度90℃、p H 5.5条件下反应5 h,液相色谱-蒸发光散射检测监测反应原料(半胱氨酸、木糖)和初期反应中间体(半胱氨酸的Amadori重排化合物(Cys-Amadori)、2-木糖化噻唑烷-4-羧酸)随反应时间的浓度变化,同时还监测反应液p H值及波长294、420 nm处紫外-可见吸光度随反应时间的变化,并且采用固相微萃取-气相色谱-质谱联机分析比较3 h反应产物的挥发性风味物质组成。添加3种脂肪醛后,形成的Cys-Amadori重排化合物、2-木糖化噻唑烷-4-羧酸中间体浓度均下降,表明均对"半胱氨酸-木糖"初期美拉德反应有抑制作用,且相比之下抑制强弱为反-2-庚烯醛反,反-2,4-癸二烯醛己醛。但添加己醛时,反应液于波长294、420 nm处的吸光度下降,表明中、末期美拉德反应也受到抑制;而加入反-2-庚烯醛、反,反-2,4-癸二烯醛时,反应液于波长294、420 nm处的吸光度却增加,表明中、末期美拉德反应被促进,且相比之下反,反-2,4-癸二烯醛的促进作用大于反-2-庚烯醛。另外,比较挥发性风味组成发现,加入反-2-庚烯醛、反,反-2,4-癸二烯醛的体系,含硫化合物的总量增多,检测到醛参与美拉德反应或醛自身受美拉德反应影响而形成的多种带烷基侧链的含硫化合物和呋喃化合物如2-己基噻吩和2-丙基呋喃。     

不同预冷方式对西式火腿风味及微生物安全的影响

基于作者前期的研究基础,本文将进一步探讨超声波辅助浸渍真空预冷(Immersionvacuumcoolingwithultrasonic assistance,IVCUA)对西式火腿挥发性风味组分和微生物数量变化的影响。通过与浸渍真空预冷(Immersion vacuum cooling,IVC)、真空预冷(Vacuum cooling,VC)和风冷(Air blast cooling,AB)等预冷方式作对比,并以预冷后西式火腿的电子鼻、GC-MS和微生物结果分析为评价指标。电子鼻分析结果表明,电子鼻能够较好地区分不同预冷方式处理组西式火腿挥发性风味物质的差异。GC-MS分析结果表明,相比于AB处理组西式火腿中检出的106种挥发性风味物质,VC、IVC和IVCUA处理组中分别检出66、70和77种,且损失的种类大部分为对风味贡献不大的醇和烃类。相比VC组和IVC组而言,IVCUA组在对风味贡献大的醛类、酮类、酯类等挥发性风味物质上有更小的损失。菌落总数和乳酸菌数量变化结果表明,IVCUA组具有较AB、VC和IVC组更低的菌落总数和乳酸菌数量,表明其具有更长的货架期。综上所述,IVCUA组作为一种创新的预冷方式对熟肉制品的预冷是可行的。     

氧化及未氧化脂肪对半胱氨酸-核糖体系热反应肉香味形成的影响

以鸡脂作脂肪原料,氧化脂肪用控制氧化工艺制备。通过固相微萃取/气-质联机对比分析半胱氨酸-核糖、半胱氨酸-核糖-氧化脂肪、半胱氨酸-核糖-未氧化脂肪、单纯氧化脂肪、未氧化脂肪等5种热反应产物的挥发性组成,发现氧化或未氧化脂肪均可调控Maillard反应对半胱氨酸-核糖体系的肉香味产生影响,表现为热反应产物的挥发性肉香成分含量增加,含硫化合物含量降低,出现Maillard反应与脂质降解相互作用成分及大量脂质降解成分。与未氧化脂肪相比,氧化脂肪对Maillard反应的调控作用更为显著。在半胱氨酸-核糖体系中加入氧化脂肪时,热反应产物挥发性组成更趋于较佳的肉香风味,具有浓郁、协调、特征肉香味突出的优点。     

Ligand and Flavor Binding Functional Properties of β-Lactoglobulin in the Molten Globule State Induced by High Pressure

ABSTRACT: β-lactoglobulin (β-LG) in the molten globule state induced by high hydrostatic pressure (HHP) at 500 MPa and 50 °C for 32 min exhibited a significant decrease in affinity for retinol and a significant increase in affinity for cis-parinaric acid (CPA) and 1-anilino-naphthalene-8-sulfonate (ANS) compared to native β-LG. The number of β-LG binding sites for retinol and CPA significantly decreased after HHP treatment. The HHP-induced molten globule state of β-LG exhibited less affinity for palmitic acid, capsaicin, or carvacrol ligands than native β-LG, and no detectable specific binding for α-ionone, β-ionone, cinnamaldehyde or vanillin flavors. HHP treatment resulted in changes in the hydrophobic calyx and surface hydrophobic sites of β-LG.     

Stability of α-Linolenic Acid and Secoisolariciresinol Diglucoside in Flaxseed-Fortified Macaroni

Research was conducted to determine the stability of secoisolariciresinol diglucoside (SDG) and α‐linolenic acid (ALA) in flaxseed‐fortified macaroni. Macaroni was fortified with whole ground flaxseed (GWF) at levels of 10% to 20% and then dried under low temperature (LT, 40°C), high temperature (HT, 70°C), or ultrahigh temperature (UHT, 90°C). Macaroni was also fortified with 15% ground hull (GHF) or steam‐treated whole ground flaxseed (GSWF) and dried under UHT. The dried macaroni was stored for 32 wk under ambient conditions. Approximately 80% to 95% of the SDG was recovered, indicating that SDG was stable during the 32‐wk storage period. Total lipid and ALA levels in all flaxseed macaroni treatments remained unchanged throughout the 32‐wk storage. This observation was consistent across the drying conditions and flaxseed addition levels. Conjugated diene (CD) values indicated that macaroni fortified with GWF did not oxidize significantly during the 32‐wk storage for the macaroni dried under HT or UHT. However, a significant increase (P <0.05) in CD values for macaroni containing 10% and 20% flaxseed and dried using LT was observed at the 32‐wk storage period. Headspace volatile concentrations did increase over the storage period for macaroni containing GWF, but the increase was not significant. Significant increases (P < 0.05) in oxidation were found by 24 wk in GHF‐ and GSWF‐fortified macaroni. GWF macaroni dried at UHT, HT, or LT could be used as a way to improve our dietary consumption of ALA and SDG. However, use of steam as a method to inactivate unwanted enzyme activity is not recommended.     

表儿茶素对牛肉汤营养成分和风味的影响

研究表儿茶素对牛肉汤中总糖、固形物、水溶蛋白、脂肪酸、氨基酸以及矿物元素等营养成分的影响,并结合电子鼻以及气相色谱-质谱联用技术分析表儿茶素对牛肉汤气味轮廓以及挥发性成分的影响。结果表明,表儿茶素降低了牛肉汤中总糖和蛋氨酸的含量,提高了固形物和不饱和脂肪酸的含量。电子鼻分析结果表明表儿茶素可显著影响牛肉汤的气味轮廓。通过气相色谱-质谱分析,在对照组和表儿茶素组牛肉汤中共检测出21?种挥发性化合物。与对照组相比,表儿茶素组牛肉汤中2,4-二叔丁基苯酚含量显著升高,己醛、壬醛、邻苯二甲酸二丁酯以及十六烷含量显著降低,且醛类和酯类化合物总量显著降低。本研究可为表儿茶素及富含表儿茶素的香辛料在肉汤中的合理应用提供理论支持。     

Effect of α-Tocopherol, β-Carotene, and Sodium Tripolyphosphate on Lipid Oxidation of Refrigerated, Cooked Ground Turkey and Ground Pork

ABSTRACT α-Tocopherol and β-carotene at 0.03% levels and sodium tripolyphosphate (STP) at 0.2% and 0.3% levels, alone and in combination, were added to ground turkey and ground pork. Hexanal was measured after cooking and storage at 4 °C for 2, 4, or 6 d. α-Tocopherol alone significantly reduced hexanal of stored, cooked, turkey but had no effect in pork. STP was more effective than α-tocopherol and a combination of α-tocopherol with STP resulted in enhanced antioxidant activity. Hexanal of pork with 0.03%α-tocopherol plus 0.3% STP did not increase significantly during storage, and that of turkey increased only slightly. β-Carotene and salt (1% NaCl) had no effect on hexanal.     

复合添加剂对鲟鱼籽酱(Huso dauricused × sturger schrenckii)挥发性成分的影响

采用固相微萃取-气相色谱-质谱联用分析技术,分别检测未经添加剂处理的鲟鱼籽酱、添加0.5‰山梨酸钾和0.2‰抗坏血酸的鲟鱼籽酱(A1组),添加0.5‰山梨酸钾、0.2‰抗坏血酸和0.2‰乳酸链球菌素(Nisin)的鲟鱼籽酱(A2组),添加0.5‰山梨酸钾、0.2‰抗坏血酸和0.2‰L-抗坏血酸棕榈酸酯的鲟鱼籽酱(A3组),在0℃冷藏时挥发性物质的变化,经NIST 05a.L和NIST 05.l谱库数据库检索,确定其挥发性成分。结果表明:初始鲟鱼籽酱检测出46种挥发性成分,醛类物质作为主要气味贡献组分,其中壬醛、己醛、辛醛和庚醛含量较高,另外,一定含量的D-柠檬烯、长叶烯和石竹烯可能赋予新鲜鲟鱼籽酱独特的柠檬香、木香等清新气味。3组复合添加剂的使用,都有利于防止在贮藏过程中鱼籽酱挥发性物质的流失,减少了酮类和醇类物质的变化。其中,A2组中,山梨酸钾、抗坏血酸和Nisin的添加促进了贮藏3个月后鱼籽酱中醛类物质的还原反应,导致醛类物质的大量减少,酯类物质的大量增加。最后,在贮藏期间醛类物质的变化,显示A1组和A3组复合防腐剂的处理促使鲟鱼籽酱具有更浓的腥味、青草味。     

蔗糖对绿茶饮料理化成分及其风味稳定性的影响

绿茶饮料的风味稳定性一直是制约高品质绿茶饮料货架期的技术瓶颈。为了提高绿茶饮料的风味稳定性,分析比较了绿茶加工过程中不同蔗糖添加量(0,1%,2%,4%和8%)对绿茶饮料灭菌(135℃,15 s)、贮藏(4,25,38℃;0~60 d)过程中感官品质以及理化成分的影响。结果表明,与对照(未加蔗糖处理)相比,添加蔗糖使绿茶饮料滋味更鲜爽甜醇,香气浓度增加;灭菌后,添加蔗糖使得绿茶饮料的香气和滋味品质提高,总儿茶素和表型儿茶素含量增加,非表型儿茶素下降;在不同贮藏条件下,相比对照,添加蔗糖后的绿茶饮料风味品质有明显改善,包括汤色亮度增加,香气和滋味增强,茶多酚、氨基酸、咖啡碱以及儿茶素含量均有所增加,在贮藏42 d内添加蔗糖对绿茶饮料风味品质稳定性的提高更为明显,且2%和4%蔗糖添加量对绿茶饮料的风味品质有更好的改善作用。研究结果表明在一定的贮藏条件下,绿茶加工过程中添加蔗糖可以较好地改善绿茶饮料的风味品质并保持其稳定性。     

沙棘添加对乳酸菌发酵牛乳风味和消费者接受度的影响

本研究目的是探究添加沙棘(5％,v/v)对发酵乳风味和消费者接受度的影响.选取本实验室前期从新疆老酸奶、西藏开菲尔颗粒等样品中筛选到的8株乳酸菌进行原味发酵乳和沙棘发酵乳的制备.通过电子鼻(Electronic-nose,E-nose)和电子舌(Electronic-tongue,E-tongue)技术,采用模糊数学综...     

氧化应激对牛肉肉色及其稳定性的影响研究进展

肉色作为衡量肉品质的关键指标一直是肉品产业关注的焦点。刚屠宰的牛胴体由于缺氧、缺血产生了大量活性氧,活性氧积累造成胴体氧化应激,进一步促进肌红蛋白的氧化,对肉色产生不利影响。但目前关于氧化应激对肉色及肉色稳定性的影响鲜有系统、深入总结。本文综述氧化应激通过调控脂质氧化、蛋白质氧化和降解以及线粒体的功能等途径对肉色及其稳定性的影响,以期为通过控制宰后氧化应激来保持牛肉良好的肉色提供理论依据。