水浴复热时间对猪肉糜制品挥发性风味的影响

利用动态顶空-气相色谱-质谱联用结合嗅闻技术对不同水浴复热时间（0、5、20、35、65?min）处理猪肉糜制品挥发性风味物质含量进行分析。结果表明,不同复热时间样品共鉴定出54?种风味物质,共有物质36?种;复热前期（5～20?min）以醛类物质为主,复热后期（35～65?min）酸类物质含量大幅升高;戊醛、己醛、辛醛、（E,E）-2,4-癸二烯醛含量随复热时间延长呈先升后降趋势,1-辛烯-3-醇和2-戊基呋喃受复热时间影响不显著（P＞0.05）;基于风味活性值分析和主成分分析,复热显著改变猪肉糜制品风味;以戊醛、己醛、辛醛和（E,E）-2,4-癸二烯醛为过熟味（warmed-off flavor,WOF）评价指标,随复热时间延长,WOF对猪肉糜制品总体复热风味的贡献略降。因此,脂质氧化是猪肉糜制品复热风味形成的主要途径,较短时间复热更易促进WOF产生。     

关键工艺点对四喜丸子软罐头高温蒸煮异味形成的影响

本研究利用电子鼻和顶空固相微萃取结合气质联用技术,探究四喜丸子软罐头加工关键工艺点的挥发性风味特征及变化规律,以确定其高温蒸煮异味（Warmed-over flavor, WOF）的形成机制。结果表明,高压蒸汽灭菌后的样品与其他组的风味轮廓存在显著性差异（P<0.05）;蒸制后的四喜丸子风味较好,而高压蒸汽灭菌后的样品产生显著的WOF异味（以亚麻籽油味和罐头味为主）（P<0.05）。此外,气味活度值分析结果表明,WOF关键异味分子为正己醛和庚醛;热加工过程中,这两种物质含量显著上升（P<0.05）,POV值显著下降（P<0.05）,TBARS值显著升高（P<0.05）,热处理促进四喜丸子中脂质的氧化降解。因此,本研究为四喜丸子软罐头工业化产品的异味形成和品质提升提供理论依据和技术支持。     

微波复热时间对预制猪肉饼过熟味、脂肪氧化和水分分布特性的影响

以预制猪肉饼为模型,研究微波复热时间(0、30、60、90、120、180 s)对其复热过熟味(warmed-over flavor,WOF)、脂肪氧化和水分分布特性的影响。结果表明,采用固相微萃取-气相色谱-质谱联用仪从不同处理组样品中共鉴定出25种挥发性风味物质,以醛类物质为主;在较短复热时间(30 s)下,预制猪肉饼中脂肪氧化加速,促进WOF关键风味因子产生,不同状态水弛豫时间和比例变化不显著(P0.05);微波复热时间持续延长(120～180 s),WOF关键风味因子含量下降,水分质量分数显著下降(P0.05),不易流动水弛豫时间T_(21)和自由水弛豫时间T_(22)向较短时间移动。主成分分析结果表明,适度微波复热(60～90 s)可以降低预制猪肉饼复热WOF关键风味因子含量,较好地保持预制猪肉饼的风味品质。     

熟制、高压灭菌和复热对粉蒸肉挥发性风味物质的影响

采用固相微萃取-气相色谱-质谱-嗅闻仪联用测定加热、高压灭菌、复热后粉蒸肉中的挥发性化合物的种类及含量。结果表明,共测定出40 种挥发性化合物,其中18 种在所有组中均有检出。高压处理后样品中挥发性物质含量（C组2 026.40 μg/kg;D组1 978.77 μg/kg）显著高于未经处理组（A组705.00 μg/kg,B组1 038.53 μg/kg）,但微波复热组除外（E组989.12 μg/kg）。气味活度值分析显示己酸乙酯和醛类物质可能是导致“过熟味”、“罐头味”等不良风味产生的主要原因。主成分分析（principal component analysis,PCA）显示各组间分离良好,除微波组外其他组在PC1上贡献差异较小,但在PC2上差异较大;微波组在PC1上贡献低于其他组,在PC2上与高压灭菌组差异不大。总体来看控制醛类物质以及己酸乙酯有助于抑制粉蒸肉高温灭菌及复热产生的不良风味,微波复热对产品风味的不良影响较小。     

帕累托图结合双标图研究复热条件下鸡肉汤挥发性物质

以冷冻调理炖煮鸡肉汤为对象,利用帕累托图和主成分双标图研究85 ℃水浴和沸水蒸汽2 种复热方式与（65±5） ℃和（75±5） ℃ 2 种复热中心温度对鸡肉汤总体挥发性物质和特征挥发性物质的影响。结果表明：冷冻调理炖煮鸡肉汤经复热后检出气味阈值化合物47 种,未报道气味阈值化合物5 种;气味累积贡献率结果表明,1-辛烯-3-酮、正己醛、苯乙醛、（Z）-罗勒烯、壬醛、芳樟醇、（E）-柠檬醛、（E）-罗勒烯、（Z）-柠檬醛、月桂烯、乙酸丁酯、桉叶油醇和姜烯13 种化合物为调理鸡肉汤的特征风味物质,气味累积贡献率接近100%;复热中心温度和复热方法显著影响1-辛烯-3-酮、苯乙醛和乙酸丁酯的形成,3 种化合物的气味贡献率分别为41.6%、13.4%和1.1%;复热中心温度为（65±5） ℃时促进了亚油酸降解反应,形成更多1-辛烯-3-酮,（75±5） ℃时则促进美拉德反应后期阶段醛胺缩合等反应,导致1-辛烯-3-酮含量降低;复热能够促进鸡肉汤中部分氨基酸与还原糖之间的美拉德反应,促进Strecker降解醛——苯乙醛的生成;长时间的复热会使鸡肉汤累积更多脂质氧化产物,从而促进苯乙醛的生成;双标图结果表明,复热处理对鸡肉汤总体挥发性物质影响显著,水浴复热后总体挥发性物质种类和含量与对照组相似度较高,85 ℃水浴复热至中心温度（65±5） ℃时,鸡肉汤中总体挥发性物质和特征挥发性物质种类和含量与对照组相似度最高,冷冻调理炖煮鸡肉汤经较低传热速率和较低中心温度复热后能够最大程度保持复热前的总体风味。     

控制热氧化冷榨芝麻油的脂肪酸组成及挥发性

本文采用气相色谱（GC）和固相微萃取-气相色谱-质谱联用（SPME-GC-MS）方法分析了控制热氧化前后冷榨芝麻油的脂肪酸组成和挥发性成分的变化情况。通过相对气味活度值（ROAV）评价各风味物质对芝麻油整体香气的贡献,并结合聚类分析确定控制热氧化后冷榨芝麻油中的关键风味物质。结果显示,样品中的脂肪酸主要有7种,包括3种饱和脂肪酸和4种不饱和脂肪酸,热氧化后冷榨芝麻油中的亚油酸及总不饱和脂肪酸的含量显著降低;柠檬烯和罗勒烯等烃类是冷榨芝麻油中的主要挥发性成分,其含量占风味物质总量的74.6%;热氧化后样品中的挥发性成分增加了10种,总峰面积是冷榨芝麻油风味物质总峰面积的2.68倍,3-甲基丁醛、癸醛、(E,E)-2,4-壬二烯醛、(E,E)-2,4-癸二烯醛等醛类含量高达67.9%,是热氧化样品的主要挥发性成分,其中亚油酸的氧化产物(E,E)-2,4-癸二烯醛是热氧化冷榨芝麻油中最重要的风味物质。     

鱼糜制品加热过程中过熟味的特征风味成分解析

为探究鱼糜制品在二段式制备过程中及水浴复热方式中过熟味(Warmed-over flavor,WOF)形成过程及变化趋势,采用采用(40℃加热60 min预煮)不同二段式水浴温度(85、90、100℃加热30 min)、不同二段式水浴时间(90℃加热5、10、15、20、25、35、40、45 min)制备鱼糜凝胶;对(40℃加热60 min+90℃加热30 min)制备的鱼糜凝胶采用不同复热水浴温度(60,70,80,90,100℃加热30 min)、不同复热水浴时间(90℃加热2.5、5、7.5、10、15 min)进行处理,并对水浴加热前后的鱼糜凝胶进行感官、电子鼻和气质联用(gas chromatography-mass spectrometry,GC-MS)评价。结果表明:不同水浴加热方式下鱼糜凝胶共检测到74种挥发性物质,其中醛类15种、酮类6种、醇类15种、酯类10种、酚类4种、酸类2种、烃类7种、其他化合物15种;结合OAV值及感官评价显示鱼糜凝胶WOF关键因子为己醛、壬醛、辛醛、1-辛烯-3-醇、庚醛、(E)-2-壬烯醛、(E,Z)-2,6-壬二烯醛、香叶基丙酮以及(E)-2-辛烯-1-醇、苯乙酮、苯乙烯等,且WOF表现为类似"酸败气味"、"陈腐气味"的异味。在二段式加热条件下(预煮40℃,60 min;鱼糕化90℃,30 min)制备的鱼糜凝胶在复热条件80℃加热30 min开始产生WOF,并随温度升高,WOF愈浓。本研究为鱼糜制品在二段式制备及后续熟化加工中WOF控制策略提供了理论参考。     

牡蛎蒸煮过程中的品质变化

为系统研究牡蛎在蒸煮过程中的品质变化,本实验对蒸煮过程中（2、4、6、8、10 min）牡蛎基本成分、烹饪损失率进行测定,采用质构剖面分析法分析牡蛎的质构特性,并通过顶空固相微萃取-气相色谱-质谱测定挥发性成分含量,同时进行电子舌、电子鼻以及感官分析。结果表明,蒸煮过程中,牡蛎的水分和粗脂肪含量明显减少,总糖和粗蛋白含量明显增加,风味、口感和形态等发生明显变化,基于感官品质结合中心温度将蒸煮程度分为6 级。质构剖面分析结果显示,蒸煮至4 min时牡蛎腹部组织和闭壳肌的硬度、弹性等显著增强（P＜0.05）。从蒸煮牡蛎中共检测出8 类48 种挥发性风味物质,其中,醛、酮类物质总量在蒸煮过程中先增后减,酯、醚类物质总量明显减少;经气味活性值分析和主成分分析可以确定二甲基硫醚、(E,Z)-2,6-壬二烯醛、(E,E)-2,4-庚二烯醛、(E,E)-2,4-癸二烯醛和E-2-壬烯醛为蒸煮牡蛎中的关键风味物质;经滋味活性值分析发现,甜菜碱、可溶性糖、游离氨基酸、呈味核苷酸对蒸煮牡蛎的呈味有显著贡献,且其含量在蒸煮过程中发生显著变化（P＜0.05）。综上,本实验可为牡蛎蒸煮过程中品质的控制提供一定参考。     

不同工艺核桃油挥发性物质比对及关键香气成分表征

以有机溶剂浸提法和压榨法（冷榨和不同烘烤处理的热榨）制备的核桃油为研究对象，通过顶空-气相色谱-质谱联用仪测定其挥发性物质构成，结合相对气味活度值（relative odor activity value，ROAV）、主成分分析（principal component analysis，PCA）和聚类热图的计算分析明确核桃油中的关键香气成分构成差异，以期为核桃油风味品质控制提供理论依据。结果表明不同工艺核桃油样品的挥发性物质构成存在显著差异性（P＜0.05），11?个核桃油样品中共鉴定出92?种挥发性物质，主要包括醛类、烃类、醇类和含氧杂环类，其中压榨核桃油中反-2-庚烯醛（21.00%～28.61%）、正己醛（15.09%～20.72%）和顺-2-辛烯（9.77%～16.28%）相对含量较高，而有机溶剂浸提核桃油中正己醛（35.79%）、反-2-庚烯醛（13.46%）和戊醛（11.79%）相对含量较高。结合ROAV计算和PCA确定壬醛（油脂、柑橘和青草味）、反-2-壬醛（黄瓜、油脂、青草味）、反,反-2,4-癸二烯醛（油炸、蜡、油脂味）和1-辛烯-3-醇（蘑菇味）是核桃油中的关键香气成分。通过挥发性物质聚类热图分析发现不同工艺核桃油样品之间色差较大，表明基于挥发性物质进行不同工艺制备核桃油的区分判别具有可行性。     

即食秋刀鱼加工过程中挥发性成分变化规律

目的：采用顶空固相微萃取法结合气相色谱质谱联用技术（HS-SPME-GC-MS）分离鉴定不同加工阶段秋刀鱼（Cololabis saira）的挥发性成分。方法：用气味阈值计算相对气味活度值（ROAV）,确定样品的关键风味物质;利用主成分和变量投影重要性分析值（VIP）分析不同阶段的特征风味及化合物。结果：秋刀鱼样品中共检出63种挥发性成分,醛类是主要的风味物质。6个关键风味化合物分别为（E,Z）-2,6-壬二烯醛、辛醛、3-甲硫基丙醛、（Z）-4-庚烯醛、（E,E）-2,6壬二烯醛和1-辛烯-3醇。结论：腌制前的秋刀鱼香气特征为蘑菇香,腌制后样品的香气特征为鱼香和果香,油炸处理的秋刀鱼风味物质最为丰富,香气特征是油脂香和肉香。     

Effectiveness of oxygen barrier oven bags in low temperature cooking on reduction of warmed-over flavor in beef roasts

A 3 × 3 × 2 factorial was utilized to determine if roast size (small, medium, large), cooking method (open-pan, oven bag, vacuum bag), and heating process (fresh, reheated) prevented warmed-over flavor (WOF) in beef clod roasts. Fresh vacuum bag and reheated open-pan roasts had higher cardboardy flavor scores compared with fresh open-pan roast scores. Reheated roasts in oven and vacuum bags did not differ from fresh roasts for cardboardy flavor. Brothy and fat intensity were increased in reheated roasts in oven and vacuum bags compared with fresh roasts in oven and vacuum bags. Differences in TBARS were found in the interaction of heating process and roast size with the fresh and reheated large, and reheated medium roasts having the lowest values. Based on TBARS data, to prevent WOF in reheated beef roasts, a larger size roast in a cooking bag is the most effective method.     

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.     

Antioxidant Properties of Natural Plant Extracts Containing Polyphenolic Compounds in Cooked Ground Beef

Thiobarbituric acid‐reactive substances (TBARS) values, hexanal content, and sensory analysis were used to evaluate the effectiveness of selected natural antioxidants to reduce warmed‐over flavor (WOF) development in cooked ground beef. The control without added antioxidant showed the highest TBARS value, hexanal content, and WOF scores. Grape seed extract (ActiVin^TM) and pine bark extract (Pycnogenol®) significantly improved the oxidative stability of cooked beef. Compared to the control, ActiVin^TM, Pycnogenol®, and oleoresin rosemary reduced the hexanal content by 97%, 94% and 73% after 3 d of refrigerated storage, respectively. WOF scores showed a similar pattern as TBARS values and hexanal contents. TBARS values, WOF scores, and hexanal contents were all well correlated.     

Modified Extraction Method for Determining 2-Thiobarbituric Acid Values in Meat with Increased Specificity and Simplicity

ABSTRACT: Monitoring the development of warmed-over flavor (WOF) is critical for the quality control of meat products. This study was to modify the acid-extraction method for analyzing thiobarbituric acid-reactive substances (TBARS) as an indicator of WOF in cooked meats. After centrifuging the extract of cooked beef, the supernatant of the extract was reacted with 80 mM TBA solution at 40 °C. The reaction between TBA and malonaldehyde was completed within 90 min, and interfering agents such as sucrose did not form any detectable color interference. The TBARS values in cooked beef samples after storage at 4 °C for zero and 7 d were 2.1 and 10.8 mg/kg, respectively. The recovery rate was between 92 and 102%. This method could be used to measure TBARS in cooked beef.     

LIPID OXIDATION IN MUTTON: SPECIES-RELATED AND WARMED-OVER FLAVORS

Effects of lipid oxidation in cooked mutton on species-related flavor and warmed-over flavor (WOF) intensities were studied using various additive treatments and post-cooking storage (versus no additive/no storage) as means to produce samples of varied lipid oxidation. Ground mutton was treated with 200 ppm sodium nitrite, 0.5% sodium tripolyphosphate, 0.05% sodium ascorbate, 3% sodium lactate, 0.002% propyl gallate, or water only (control), cooked to 74C, and aerobically stored at 4C for 0, 2, or 4 days. Nitrite-treated samples showed the least lipid oxidation as determined by the 2-thiobarbituric acid reactive substances (TBARS) and had more intense species-related (muttony) flavor than all other treated samples. Some samples exhibited high TBARS after 4 days but were still rated "slight" for WOF intensity, probably due to the strong species-related flavor that could have made WOF less perceivable. Accordingly, correlations, although statistically significant, were low between TBARS and WOF intensity or between species flavor intensity and WOF intensity.     

Reduction of Warmed-Over Flavor Volatiles from Freeze-Dried Lean by Supercritical CO2 Extraction

Supercritical carbon dioxide (SC-CO₂) was used to extract warmed-over flavor (WOF) volatiles from cooked, freeze-dried beef at 40°C and pressures of 10.3 MPa or 30 MPa after 2 days storage. WOF markers, hexanal, heptanal, octanal, nonanal, and 2,3-octanedione, were identified in the volatiles profile of precooked beef by dynamic headspace extraction and gas chromatography-mass spectrometry before and after CO₂ extraction. TBARS and levels of WOF markers increased over 2 days storage. There was a reduction in WOF markers at both extraction pressures. The higher pressure led to greater reduction of WOF markers (e.g., hexanal: 73.5%) than the lower pressure (e.g., hexanal: 60.3%), notably for heptanal and nonanal. SC-CO₂ may be applicable for reducing WOF volatiles from precooked meats.     

不同烹煮方式对米饭食味品质的影响

以4种市售大米为研究对象,利用质构仪、气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)及感官评价等检测和评价手段,对不同烹煮方式的米饭进行基本蒸煮品质、质构特性以及风味物质等食味品质的评价,并探究其与感官评价的相关性。旨在探究不同大米品种(粳米和籼米),以及不同蒸煮工艺(高压烹煮、电饭锅烹煮、微波烹煮和电蒸锅烹煮)对米饭食味品质的影响,寻找一种能够综合评价米饭食味品质的方法,为米饭的制作及米饭食味品质的改善提供理论参考。结果表明:经高压烹煮后的米饭吸水率、膨胀率、碘蓝值均高于其他方式,且米饭硬度小,弹性和黏性较大,感官品质评价最优,而微波烹煮米饭食味品质最差。米饭膨胀率与感官评价中米饭的滋味和形态呈显著正相关(P0.05,P0.01),硬度与口感呈极显著负相关(P0.01),弹性与米饭形态呈极显著正相关(P0.01)。此外,米饭风味物质分析表明经高压烹煮和电饭锅烹煮的米饭,醛、醇、酮等主要的米饭风味物质含量和种类均高于其他烹煮方式,且因品种不同大米的香气有所差异。     

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。     

Effect of γ-Oryzanol on the Flavor and Oxidative Stability of Refrigerated Cooked Beef

ABSTRACT: γ-Oryzanol and α-tocopherol were added to beef patties as natural antioxidants. Beef patties containing 100 ppm γ-oryzanol had higher oxidative stability ( P <0.05) during storage at 4 °C than did beef patties with other antioxidants and without antioxidant. Thiobarbituric acid-reactive substances (TBARS) values, warmed over flavor (WOF) scores, C-7 oxidized cholesterol derivatives (OCDs), and concentrations of both hydroperoxide and hexanal in the cooked beef containing γ-oryzanol were significantly lower than those of other treatments ( P < 0.05). All variables had similar trends during the refrigerated storage. Significant correlations were found between TBARS and C-7 OCDs, TBARS and WOF, hydroperoxide and hexanal, and hexanal and WOF ( P < 0.05).