板栗及其膨化制品的挥发性香气成分分析

采用顶空固相微萃取结合气相色谱-质谱联用技术对生板栗粉、煮板栗和3种膨化板栗制品的挥发性香气成分进行分离鉴定。共鉴定出68种挥发性物质,初步认定吡嗪类物质中的甲基吡嗪、2,3-二甲基吡嗪、2-乙基-6-甲基吡嗪、2,6-二甲基吡嗪;呋喃类物质中的2-戊基呋喃、γ-丁内酯、2-糠醇、2,5-二氢-3,5-二甲基-2-呋喃酮和γ-辛内酯及芳香族类物质中的苯甲醛是板栗的特征风味物质。煮制可提升板栗的香气。膨化板栗片的膨化加工方式对其香气成分影响显著,挤压膨化板栗片的香气物质组成和煮板栗比较相似,微波膨化板栗片中易产生具有枯焦气息的2,4-二叔丁基苯酚,油炸膨化板栗片的挥发性成分最复杂,醛类物质较多。     

加热卷烟气溶胶中香气成分的GC-MS/MS同时测定和比较

采用超声萃取结合GC-MS/MS定量检测,建立了同时测定加热卷烟气溶胶中112种香气成分的方法,对典型加热卷烟气溶胶中香气成分进行了比较。结果表明：112种香气物质的线性相关系数均＞0.99,检出限为0.005～0.160 mg/L,回收率为75.2%～128.0%,精密度＜8.9%;28种加热卷烟气溶胶中含量较高的香气成分有5-羟甲基糠醛、茄尼酮、麦芽酚、糠醇、β-石竹烯、乙酸己酯、乙酸异丁酯、α-当归内酯、2-甲基吡嗪等;不同样品中差异性香味成分主要有L-薄荷醇、乙基麦芽酚、芳樟醇、香兰素、甲基环戊烯醇酮、3-羟基-2-丁酮、乙酸己酯、紫苏葶、WS-23等,这些差异性成分是不同风味的物质来源。     

3种山茶属花香气成分的HS-SPME/GC-MS分析

采用顶空固相微萃取-气相色谱/质谱联用技术对山茶属中山茶花、油茶花、茶树花3种茶花香气成分进行分析。结果表明：3种山茶属花的香气组分及相对含量具有显著性差异;从山茶花、油茶花、茶树花中分别检测出26、36、48种香气成分,各占其总香气成分的94.53%、96.43%和98.76%。其中共有的香气成分为1-己醇、苯乙酮、芳樟醇、(反)茴香烯、去氢土臭素、吉马烯D、对羟甲酚、δ-杜松烯,但各自的相对含量差别较大;另外,各种茶花均具有自己独特的香气成分,山茶花的特有香气成分主要有丁香酚、醋酸癸酯等;油茶花特有香气成分主要为3-甲基-二氢-2(3H)呋喃酮、月桂烯等;茶树花的主要香气成分为有6,10,14-三甲基-2-十五烷酮、柠檬醛等。     

枣花及枣花蜜香气成分分析

为鉴定枣花中主要香味化合物,比较不同开花时期的枣花香气成分的变化,以及枣花与枣花蜜香气成分的关联。采用顶空固相微萃取提取样品中的挥发性物质并优化提取条件,采用气相色谱-质谱-嗅觉（gas chromatography-mass spectrometry-olfactometry,GC-MS-O）法对提取的挥发物进行分析鉴定。GC-MS-O鉴定枣花的主要香气成分为2-甲基丁酸乙酯、异戊酸乙酯、（E）-2-甲基-2-丁烯酸乙酯、3-己烯醇乙酯、α-罗勒烯、4,8-二甲基-1,3,7-壬三烯、4-甲基-戊酸乙酯、苯甲酸乙酯、α-法尼烯、月桂酸甲酯和2-甲基-环丁酮。这些成分呈现的枣花气味类型主要有果香味、花香味、酸味和青草味。枣花与枣花蜜共有香气物质为（E）-3-己烯-1-醇、异辛醇、芳樟醇、苯甲醇、乙酸、正己酸、正辛酸、壬酸、月桂酸、肉豆蔻酸、棕榈酸、2,6-二甲基-1,3,5,7-辛四烯、苯酚、水杨酸甲酯、甲氧基苯基-肟、萘和3-氰基吡啶。以上共有成分是枣花蜜具有枣花气味特征的主要原因。     

GC-MS结合ROAV分析评价加工工艺对藤茶香气成分的影响

目的：探讨加工工艺对藤茶特征香气成分的影响。方法：分别采用传统加工工艺、红茶加工工艺、绿茶加工工艺、黑茶加工工艺制备4种不同的藤茶样品,以自然干燥的显齿蛇葡萄叶为对照,通过顶空固相微萃取和气相色谱—质谱联用技术结合相对气味活度值（ROAV）分析不同样品的关键风味化合物。结果：从4种藤茶样品及对照样品中共检出37种挥发性风味化合物,其中,1-辛烯-3-醇、苯甲醇、β-紫罗兰酮、苯乙醛、反式-2-己烯醛、二氢猕猴桃内酯、水杨酸甲酯7种物质为4种样品的共有组分;ROAV值显示,1-辛烯-3-醇和β-紫罗兰酮为共有关键香气组分,其中β-紫罗兰酮的贡献度最大;藤茶制作工艺条件不同,其关键香气成分存在差异,红茶工艺组藤茶关键性香气成分中出现了红茶的标志性香气成分芳樟醇及反式-2-壬烯醛。结论：红茶工艺和绿茶工艺加工的藤茶与传统工艺的在香气表现水平上相差不大,而黑茶工艺加工的香气表现稍逊;发酵工序可考虑作为藤茶制作的优选关键工序之一。     

文冠果茶与文冠果金花散茶的香气分析

目的分析文冠果茶与文冠果金花散茶的香气成分。方法采用同时蒸馏萃取法(simultaneous distillationandextraction,SDE)提取香气物质,用气相色谱-质谱(gaschromatography-massspectrometry,GC-MS)测定各香气成分,并分析各成分的相对含量及其差异。结果 2者香气物质丰富,分别有123和118种;文冠果茶中以醇类、醛类和酮类为主要香气成分,其相对含量达到了总香气物质的84.65%,其中含量较高的组分是α-松油醇、反,反-2, 4庚二烯醛、香叶基丙酮及6-甲基-5-庚烯-2-酮等;文冠果金花散茶以醛类和酮类为主要香气物质,其相对含量达到了总香气物质的51.98%,其次是醇类和酸类,且醇类明显减少,而醛类和酸类明显增加,其含量最高的组分是反,反-2, 4庚二烯醛等烯醛类物质,对菌花香有积极作用。结论工艺的差异会形成不同风味的文冠果茶。     

基于顶空固相微萃取法-气相色谱-质谱法和相对气味活度值分析13种凤凰单丛茶香气成分

目的 探究13种凤凰单丛茶香气成分及各香气成分对总体风味的贡献。方法 采用顶空固相微萃取法(headspace solid phase microextraction, HS-SPME)和气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)对13种单丛茶进行香气成分分析, 并结合相对气味活度值(relative odor activity value, ROAV)筛选各单丛茶关键香气成分。结果 在13种单丛茶样品中检出香气成分179种, 新检出成分88种, 共有香气成分53种。同时, 根据挥发性成分的ROAV值, 共检出17种关键香气成分, 对总体香气的贡献率由大到小依次为1-辛烯-3-醇、癸醛、β-环柠檬醛、异丁醛、β-紫罗兰酮、法尼醇、香叶醇、α-法尼烯、异戊醇、顺-1,5-辛二烯-3-醇、顺-3-己烯醇、庚醛、脱氢芳樟醇、反-3-戊烯-2-酮、2-癸酮、2-庚烯醛、6-甲基-5-庚基-2-酮; 另外, 检出16种重要修饰成分, 共有关键香气5种, 分别为1-辛烯-3-醇、法尼醇、β-环柠檬醛、癸醛和β-紫罗兰酮。结论 各关键香气成分在不同单丛茶中含量及贡献度存在明显差异。     

湖南茯砖茶香气成分的SPME-GC-TOF-MS分析

采用单因素对比试验方法确定固相微萃取湖南茯砖茶中香气成分的优化条件,并结合气相色谱-飞行时间-质谱法鉴定湖南茯砖茶香气组分。结果表明：固相微萃取与气相色谱-飞行时间-质谱联用分析湖南茯砖茶香气成分的最佳条件为DVB/CAR/PDMS萃取头（50/30 μm）、萃取温度80 ℃和萃取时间60 min。气相色谱-飞行时间-质谱法从3 个茯砖茶中共分离鉴定出93 种香气成分,占检出挥发性成分总量的90%以上,主要由酮类、醛类、碳氢类、杂氧类、醇类、酸类、酯类、含氮类8 类化合物构成。在鉴定出的香气化合物中共有香气组分50 个,其中含量较高的组分有反,反-2,4-庚二烯醛、甲基庚烯酮、2-戊基呋喃、香叶基丙酮、3,5-辛二烯-2-酮（E,E）、6-甲基-3,5-庚二烯-2-酮等。     

GC-MS-O结合OAV鉴定花生油特征香气成分

该研究利用气相色谱-质谱联用（GC-MS）、气相色谱-嗅闻（GC-O）、气味活性值（OAV）和香气重组对花生油的特征香气成分进行评价分析。得到顶空固相微萃取最优条件为DVB/CAR/PDMS萃取头、萃取温度50℃、萃取时间60 min。在此条件上,在花生油中共检测出89种挥发性化合物,包括吡嗪、呋喃、醛、酚、吡咯、吡啶、酮、醇、酸、酯类等化合物。其中GC-O确定的香气活性化合物32种,结合OAV分析得到特征香气成分27种。热榨花生油和冷榨花生油中的特征香气成分分别有22、8种,共有成分为己醛、乙酸和苯甲醛。热榨花生油的特征香气成分主要为2,6-二甲基吡嗪、2,3-二甲基吡嗪、2-乙基-6-甲基吡嗪、2-乙基-5-甲基吡嗪、2,3,5-三甲基吡嗪、3-乙基-2,5-二甲基吡嗪、2-乙基-3,5-二甲基吡嗪、苯甲醛、乙酰基吡嗪、2,4-癸二烯醛、麦芽酚、甲基环戊烯醇酮、2-乙酰基吡咯、吡咯-2-甲醛、2-甲氧基-4-乙烯基苯酚。冷榨花生油特征香气成分主要为己醛、D-柠檬烯等物质。结果预期对评价花生油的品质及优化其加工工艺具有重要意义。     

重庆针形名优绿茶香气特征及成分分析

为探究重庆针形名优绿茶香气品质特征及成分组成,收集重庆市38个针形名优绿茶样品,采用感官审评及顶空固相微萃取联用气相色谱-质谱技术对其香气特征及含量进行分析。结果表明,重庆针形名优绿茶主要表现为清香型或栗香型。共检测出香气成分40种,包括醇类11种,酯类6种,醛类4种,酮类5种,碳氢化合物类10种,芳烃2种,杂环及含硫化合物各1种。香叶醇、苯甲醇、苯乙醇、β-芳樟醇、顺-茉莉酮、吲哚、橄榄醇、橙花叔醇、顺-已酸-3-己烯酯、2-甲基戊酸甲酯、水杨酸甲酯、β-杜松烯、顺-β-法尼烯等香气物质对构成重庆针形名优绿茶特征香气品质具有重要作用。酯类在清香型绿茶中含量显著高于栗香型绿茶。通过主成分分析,清香型与栗香型绿茶主要贡献香气成分有明显差异,清香型绿茶差异成分有反,反-3,5-辛二烯-2-酮、柠檬烯、反-戊酸-2-己烯酯、香叶基丙酮、橙花叔醇、氧化芳樟醇Ⅰ(呋喃型)、β-芳樟醇、顺-茉莉酮、6,10,14-三甲基-十烷-2-酮,主要为呈现花香和果香类物质;栗香型绿茶差异成分主要有环氧芳樟醇Ⅱ、4,8-二甲基-1,3,7-壬三烯、壬醛、二甲硫,主要为呈现甜香和鲜味类物质。产地聚类分析表明,地...     

即烹扇贝冷冻预制菜的质构特性及营养品质评价分析

目的 探讨即烹扇贝冷冻预制菜的质构特性和营养价值。方法 采用不同熟化方式对3种扇贝冷冻预制菜(蒸蒜蓉扇贝、香煎扇贝、烤扇贝)进行处理, 分析熟化后的质构、色差、微观结构、基本营养成分、氨基酸及脂肪酸组成与生扇贝及煮扇贝的差异, 采用相关性分析及主成分分析综合评价扇贝预制菜品质。结果 扇贝冷冻预制菜熟化后硬度、弹性和咀嚼性均显著性增加, 但蒸蒜蓉扇贝和烤扇贝的质构指标均低于煮扇贝和香煎扇贝, 后者肌肉纤维排列更紧密;香煎扇贝、烤扇贝和蒸蒜蓉扇贝的白度值均显著低于煮扇贝和生扇贝; 熟化后扇贝均具有高蛋白低脂肪的特点, 蛋白质含量为20.68~29.79 g/100 g, 粗脂肪含量为0.50~2.26 g/100 g; 氨基酸组成合理, 脂肪酸组成丰富, 必需氨基酸含量在22.05~31.07 g/100g, 烤扇贝具有较高的二十碳五烯酸和二十二碳六烯酸含量; 主成分分析营养价值由高到低为香煎扇贝>烤扇贝>蒜蓉扇贝>煮扇贝>生扇贝。结论 即烹扇贝冷冻预制菜熟化后营养全面, 香煎扇贝质构及营养价值综合评价较高, 本研究为后续开发扇贝产品提供了理论数据。     

Influence of different methods of cooking of hunchback salmon on contents of polyunsaturatedfatty acids

Composition and contents of fatty acids in hunchback, fresh, boiled, fried, roasted and boiled in a small amount of water were determined. It was found, that absolute contents of essential polyunsaturated fatty acids--eicosapentaenoic (EPA) and docosahexaenoic (DHA) decreased significantly only in the process of frying. Sum ratio of omega3/omega6 acids was dietetically more favorable in the roasted and fried fish.     

Effect of local processing methods (boiling,frying and roasting) on the amino acid composition of four marine fishes commonly consumed in Nigeria

The effects of different processing methods on the amino acid contents of four marine fishes commonly consumed in Nigeria: Clupea harengus, Scomber scombrus, Trachurus trachurus and Urophycis tenuis were investigated. The samples were boiled, roasted over hot charcoal, or fried in any of four different oil types (palm oil, soybean oil, vegetable oil and groundnut oil). The total amino acids for all the fish samples ranged from 76.72 to 98.01 g/100 g protein and the total essential amino acids from 28.95 to 44.73 g/100 g protein. Frying reduced the total amino acid contents, with the lowest values obtained in samples fried in palm oil. Boiling and roasting increased the total amino acid contents, with the values higher in roasted than boiled samples. The percentage of essential amino acids reduced with processing in almost all samples, but the reduction was more pronounced in the fried samples. The raw, boiled and roasted samples had amino acid scores greater than 100%, while for the fried samples, the limiting amino acids were either leucine or threonine. The results showed that roasting and boiling had more desirable effects on the amino acid content of the fish samples.     

Organic acids in two Portuguese chestnut (Castanea sativa Miller) varieties

The organic acids composition of two different chestnut (Castanea sativa Miller) varieties (Judia and Longal) were determined by HPLC/UV. In order to check the influence of the processing over these compounds, samples treated in three distinct manners (roasted, boiled and fried) were also analysed. The results showed that chestnut is characterized by the presence of seven organic acids: oxalic, cis-aconitic, citric, ascorbic, malic, quinic and fumaric acids. The organic acid quantitative profile allows the distinction of the two varieties. Longal variety samples presented higher organic acids contents than those from Judia variety. The contents of the pair malic plus quinic acids may be useful for the discrimination of the two varieties. Roasting, boiling and frying procedures lead to significant reduction of total organic acids contents.     

Determination of acrylamide in roasted chestnuts and chestnut-based foods by isotope dilution HPLC-MS/MS

A collaboratively trial tested isotope dilution liquid chromatographic method with positive electrospray ionisation tandem mass spectrometry for the analysis of acrylamide in bakery ware and potato products has been extended to the determination of acrylamide in roasted chestnuts and chestnut-based foods. As chestnuts have a similar composition to potatoes, considerable amounts of acrylamide can be expected, especially in roasted chestnut products. This paper presents the concentrations of acrylamide in 31 different chestnut samples (fresh, roasted, flour, cooked, glazed) that were collected in nine European countries during 2005/2006. The influence of the roasting time on the acrylamide content was also experimentally investigated. A test portion was extracted after homogenisation with water and isotopically labelled acrylamide was added. The extract was centrifuged and the supernatant was cleaned-up in two consecutive solid phase extraction steps. The final extract was analysed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). An HPLC column based on graphitised carbon was applied for chromatographic separation. Acrylamide concentrations in purchased roasted chestnuts were in the range of <8–1278 μg/kg whereas only low amounts (<4–159 μg/kg) were found in chestnut products. However, the median acrylamide content of the commercial roasted chestnut samples was 90 μg/kg. The influence of the roasting time on the acrylamide content in roasted chestnuts was evaluated too. As with roasted and fried potato products, the roasting time has a significant influence on the acrylamide formation. Therefore, the consumers might be exposed to significant amounts of acrylamide by eating roasted chestnuts, especially when a batch remains in the roasting vessel for too long time.     

The effects of various Chinese processing methods on the nutritional and safety properties of four kinds of meats

Chinese processed meat products are popular in the world, while different processing methods produce meats of different quality and safety. The aim of this work was to compare and evaluate the effects of seven Chinese processing methods (steaming, boiling, braising, pan-frying, frying, roasting and drying) on the nutritional and safety properties of four kinds of meats (beef, pork, chicken, duck). Comparing with the unprocessed raw meat, four kinds of meats treated with thermal processing displayed increased L^⁎ values, generally enhanced texture properties, decreased moisture contents, and increased protein contents. Among all the processing meats, the wet thermal processed meats exhibited relatively high total amino acid contents. Fatty acid contents showed the lowest value in boiled meats but relatively high values in fried, pan-fried and dried meats. For safety properties, thermal processing methods of pan-frying, frying and roasting caused mass formation of trans fatty acids and polycyclic aromatic hydrocarbons (PAHs). The highest PAHs contents were detected as 49.70 μg/kg in pan-fried beef, 18.18 μg/kg in fried pork, 11.02 μg/kg in roasted chicken and 15.24 μg/kg in fried duck, which were 14.34 times, 4.74 times, 7.50 times and 8.35 times of their corresponding blank control groups. When nutritional and safety properties are pursued, steaming and boiling are recommended for all the four kinds of meats. Besides, braising is also suitable for pork, while drying could also be used for chicken and duck.     

OIL CONTENT IN FRIED PROCESSED SWEETPOTATO PRODUCTS

Ninety-four different sweetpotato cultivars with various dry matter contents were used to process crisps and the end product was analyzed to determine the oil content. A linear relationship between dry matter content in raw sweetpotato storage roots and the level of oil uptake in crisps was determined. Sweetpotato storage roots with 23–25% (fwb) dry matter content gave crisps containing between 21% and 32% of oil, while the fat contents of crisps from potatoes having a similar dry matter content were 36% and more. Consequently, storage roots from Kemb 10 sweetpotato cultivar having a high dry matter content of 32.9% (fwb), either in boiled and mashed, raw and grated, or flour form, were used to partially substitute wheat flour in processing fried products. It has been found that boiled and mashed sweetpotato lessens oil uptake in mixtures of fried products such as "mandazis" (doughnuts).     

响应面法优化小龙虾烤箱辅助烤制工艺

以小龙虾为研究对象,探讨烤箱烤制小龙虾的加工工艺,以腌制时间、腌制液盐含量、烤制温度和烤制时间为单因素影响因子,小龙虾的感官评分和弹性为响应值,进行响应面优化分析。然后对烤制小龙虾的营养成分和风味特征进行测定和分析,并以鲜虾和水煮虾作为对照。结果表明：经优化后的小龙虾腌制时间为30 min、腌制液盐含量12 g/100 mL、烤制温度180℃、烤制时间20 min,在此工艺条件下小龙虾的感官评分为9.08分、弹性为3.88 mm,与预测值接近,表明该烤制工艺合理有效;烤制处理条件下单不饱和脂肪酸和多不饱和脂肪酸总含量显著高于鲜虾和水煮虾;烤制之后的小龙虾必需氨基酸和风味氨基酸含量较鲜虾和水煮虾差异明显,主要表现在天冬氨酸、甘氨酸、精氨酸和亮氨酸的损失,其中精氨酸损失最大;电子舌传感器上的烤虾响应值鲜度、咸味和甜味均显著高于鲜虾和水煮虾。适当的烤制有利于虾肉营养物质的保存和鲜香味的挥发,同时有利于产品营养与风味的提高。     

The effect of post-mortem ageing and heating on water retention in bovine muscles

The muscles semitendinosus (ST) and psoas major (PM) were removed from chilled young bull carcasses 24 h after slaughter and stored at 4 °C. At the 1st, 6th and 12th day of post-mortem ageing the chemical composition (moisture, fat, protein, collagen) and contents of free, immobilized and unfreezable water in the muscles were estimated. The muscle steaks were boiled at 100 °C, roasted at 170 °C or fried at 160 °C to an internal temperature of 75 °C, and the amounts of total, free, immobilized, and unfreezable water in heated muscles were evaluated. The unfreezable water was estimated by DSC. In the raw muscles immobilized water constituted 74–75%, free water 16.6–17.6% and unfreezable water 7–8% of the total water. Independent of time of ageing, PM muscle contained significantly more free water than ST muscle. During post-mortem ageing, changes in free, immobilized and unfreezable water in muscles were not significant. The level of free water was highest in boiled and least in fried meat, however the amount of immobilized water was highest in fried and lowest in boiled meat. The amount of unfreezable water in muscles heated after 12 days of post-mortem ageing decreased.