Effect of different drying methods on the amino acids,α-dicarbonyls and volatile compounds of rape bee pollen

The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.

Evaluation of Protein Concentration, Amino Acid Profile and Antinutritional Compounds in Hempseed Meal from Dioecious and Monoecious Varieties

Hempseed meal from three dioecious and three monoecious varieties has been evaluated for content and quality of the protein and for the concentration of antinutritional compounds. Hemp seeds were obtained from plants grown in two experimental fields for two consecutive years (2011-2012). For all the varieties, hempseed meal resulted in a rich source of protein (34% mean content) with an amino acid profile extremely rich in arginine and slightly poor in lysine. Differences between dioecious and monoecious varieties were observed in the content of antinutritional compounds. They were more concentrated in monoecious varieties in comparison with those dioecious. The concentration of phytic acid in hempseed meal deserves attention in both groups, being 63 and 75.4 g·kg-1 of dry matter in dioecious and monocieous varieties, respectively. The results show that, besides the recognized value of hemp oil, also the hempseed cake could find application in animal feed as a substitute of other cakes (soybean, rapeseed). From this point of view, the dioecious varieties showing lower contents of antinutritional compounds with respect to the monoecious varieties would be preferred.

Influences of Ridge Width and Foliar Spraying of Amino Acids Compounds on Yield and Quality of Two Faba Bean Cultivars

A two-year study was carried out at the Agricultural Experiments and Research Station, Faculty of Agriculture, Cairo University, Giza, Egypt, during 2015/2016 and 2016/2017 seasons to evaluate seed yield and quality of two faba bean cultivars to different rates of amino acids compounds under narrow and wide ridges. Two faba bean cultivars Sakha 1 and Masr 3 were grown in two ridge widths 60 and 120 cm and received five rates of amino acids compounds (Power mix at rates 1.5 cm⋅L−1 “Pm1” and 3.0 cm⋅L−1 “Pm2”, Super mix at rates of 3.5 cm⋅L−1 “Sm1” and 7.0 cm⋅L−1 “Sm2”, as well as, water only “control treatment”). The treatments laid out in a split split plot distribution in randomized complete blocks design in three replications were used. Ridge width was randomly assigned to the main plots, faba bean cultivars were allocated in sub-plots and amino acids compounds were allocated in sub sub-plots. Shoot chemical composition and photosynthesis pigments, as well as, chemical composition in seed traits of faba bean were tested in the laboratories of Plant Physiology Section, Agricultural Botany Department, Faculty of Agriculture, Cairo University, Giza, Egypt. Wide ridge had higher nitrogen (N), phosphorus (P), potassium (K), total sugars and total free amino acids concentrations in faba bean shoot and seeds in addition to chlorophyll a (Chl a) and chlorophyll b (Chl b) in faba bean shoot, as well as, most seed yield attributes than those of the narrow one. Faba bean cultivar Sakha 1 had higher values of seed yield, yield attributes and quality than Masr 3 that achieved higher seed antioxidants. Also, amino acids compounds affected significantly all studied traits of faba bean plants. Pm2 recorded the highest values of chemical composition in faba bean shoot and seeds. Moreover, Pm2 gave the highest seed yield and yield attributes compared to others. The interaction between ridge width and faba bean cultivar was significant for total sugars and carotenoids concentrations in faba bean shoot and 100-seed weight, as well as, seed N content. Also, the interaction between ridge width and amino acids compound had significant effects on shoot and seed N, P, K concentrations, number of pods plant−1 and seed yield ha−1, as well as, total soluble phenols and total free amino acids concentrations. Moreover, the interaction between faba bean cultivar and amino acids compound had significant effects on shoot Chl a and b concentrations, number of seeds pod−1 and seed yield plant−1, as well as, seed N, total soluble phenols and total free amino acids concentrations. Wide ridge x faba bean cultivar x amino acids compound interaction had significant effects on photosynthesis pigments, number of seeds pod−1 and seed yield ha−1, as well as, seed N, total sugars, total soluble phenols and total free amino acids concentrations. High seed yield and quality were recorded by growing faba bean cultivar Sakha 1 in wide ridge with foliar spraying at rate of 3.0 cm⋅L−1 of power mix. On the other hand, growing faba bean cultivar Masr 3 in narrow ridge with foliar spraying at rate of 3.5 cm⋅L−1 of super mix had good antioxidants in faba bean seeds.

Influence of Fe_(2)O_(3) on Release Mechanism of NH_(3) and Other Nitrogen-Containing Compounds from Pyrolysis of Three Typical Amino Acids in Urban Sludge

To elucidate the effects of Fe_(2)O_(3) on nitrogen transformation during sludge pyrolysis,thermogravimetry coupled with mass spectrometry(TG-MS)was used to investigate the influences of Fe_(2)O_(3) on the pyrolysis characteristics and the release of important gaseous NO_(x) precursors such as HCN and NH_(3) during pyrolysis of three typical amino acids in urban sludge.The results show that after Fe_(2)O_(3) addition,the total weight loss rate of the three amino acids and the initial decomposition temperature of proline are reduced.The release amounts of NH_(3),HCN,CH_(3)CN,and HNCO from these three representative amino acids—glumatic,arginine,and proline,decrease in the order of arginine,glutamic,proline.The generation of Fe-N complexes,reduces the generation of NH_(3),HCN,CH_(3)CN,and HNCO while the catalysis effects of Fe_(2)O_(3) on the formation of H and H2 play a promoting role in the generation of NH_(3),HCN,CH_(3)CN,and HNCO.The results would provide an experimental and theoretical basis for subsequent research on the NOx precursor formation mechanisms during pyrolysis or combustion of Fe-containing sludge or sludge with additives containing Fe.

Syntheses of Coordination Compounds of 2-Amino-3-Methylbutanoic Acid Their Mixed Ligand Complexes and Antibacterial Activities

Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However, for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.

Chemiluminescence determination of 20 amino acids and the mechanism study

It was found that 20 amino acids could inhibit the intensity of the luminol-H_2O_2-CuSO_4 chemiluminescence system.Using this character,a rapid and sensitive method for the determination of 20 amino acids was developed with flow injection coupled with chemiluminescence detection.Under the optimal conditions,the detection limits of 20 amino acids were in the range of 4.5×10^（-7）- 4.3×10^（-10） mol/L,and the relative standard deviations were less than 3.2%.The proposed method was successfully applied to drug analysis.The possible mechanism was also discussed.

柱前衍生高效液相荧光检测法测定复方氨基酸注射液中甲硫氨酸亚砜的含量

目的建立测定复方氨基酸注射液中甲硫氨酸亚砜质量分数的高效液相色谱法。方法采用柱前衍生HPLCFLD法,色谱柱为Agilent Poroshell 120 EC-C18柱(3.0 mm×100 mm,2.7μm)或效能相当的色谱柱,以乙酸钠四氢呋喃溶液为流动相A,乙酸钠溶液-乙腈-甲醇(体积比20∶40∶40)为流动相B,流速为1.0 mL/min,采用荧光检测器,激发波长为233 nm,发射波长为441 nm。结果甲硫氨酸亚砜质量浓度在0.02605~2.605μg/mL范围内线性关系良好(r=0.9996),检测限为1.3×10^(-3)ng,平均回收率为100.1%,RSD为0.3%。结论建立的方法操作简单、准确、灵敏度高,适用于复方氨基酸注射液中甲硫氨酸亚砜的测定。

不同良种杜仲叶主要营养成分的动态变化与综合评价

[目的]杜仲Eucommia ulmoides叶在医疗、保健、食品及无抗养殖等领域有广泛用途。通过比较不同良种杜仲叶主要营养成分的差异及动态变化,筛选优质叶用杜仲良种资源,为杜仲叶的高效利用提供参考。[方法]分别利用HPLC法和全自动氨基酸分析仪测定13个良种不同生长期杜仲叶9种重要活性成分和15种氨基酸组分的含量,基于主成分分析和隶属函数法开展不同良种杜仲叶的营养评价。[结果]与槲皮素、桃叶珊瑚苷和京尼平苷酸相比,原儿茶酸、芦丁、绿原酸、紫云英苷、山奈酚以及松脂素二葡萄糖苷的含量在不同良种杜仲叶之间差异较大;不同良种同一活性成分含量的生长动态变化趋势基本一致。13个良种杜仲叶必需氨基酸与总氨基酸的比值(EAA/TAA)为0.40~0.45,必需氨基酸与非必需氨基酸的比值(EAA/NEAA)为0.66~0.82;天冬氨酸、苏氨酸、丝氨酸等5种氨基酸的动态变化趋势较为一致。总氨基酸、必需氨基酸、亮氨酸等9种组分的含量可作为杜仲叶营养价值的评判指标。[结论]13个良种杜仲叶的氨基酸组成和比例均达到理想蛋白质模式的标准。‘华仲10号’‘华仲24号’‘华仲13号’‘华仲30号’‘华仲12号’是优质的叶用杜仲良种资源,在规模化提取和利用杜仲叶黄酮类时应优先选用‘华仲12号’‘华仲24号’良种。

不同尺寸片烟游离氨基酸和阿马杜里化合物差异分析

【目的】明确打叶复烤后不同尺寸片烟游离氨基酸和阿马杜里(Amadori)化合物的变化规律,为稳定卷烟质量和调整配方提供理论依据。【方法】以河南中烟工业有限责任公司6个中间香型烤烟多等级配打模块打叶后的片烟为研究对象,经叶片振动分选筛筛分后得到大片、中片、小片、碎片和碎末5种不同尺寸的片烟,分别测定其游离氨基酸和阿马杜里化合物含量,并对其分别进行差异显著性分析、主成分分析和聚类分析。【结果】(1)不同尺寸片烟21种游离氨基酸总量为14 586.82~18 614.04μg/g,其中脯氨酸、天冬酰胺、丙氨酸和天冬氨酸含量较高;不同尺寸片烟17种阿马杜里化合物总量为21 674.68~29 371.17μg/g,其中果糖-脯氨酸(Fru-Pro)、果糖-丙氨酸(Fru-Ala)、果糖-氨基丁酸(Fru-Amb)和果糖-天冬酰胺(Fru-Asn)含量较高;不同尺寸片烟在多个游离氨基酸组分、阿马杜里化合物组分及阿马杜里化合物总量上存在显著差异。(2)主成分分析表明,游离氨基酸前3个主成分的累积方差贡献率为89.89%,表明这3个主成分可以反映21个变量(游离氨基酸成分)的大部分信息;阿马杜里化合物前4个主成分的累积方差贡献率为88.95%,表明这4个主成分能够反映17个变量(阿马杜里化合物)的大部分信息。(3)聚类分析结果表明,根据游离氨基酸主成分综合得分,可将不同尺寸片烟聚为3类,其中大片、中片和小片烟聚为一类;碎片烟和碎末烟各自单独聚为一类;根据阿马杜里化合物主成分综合得分,可将不同尺寸片烟聚为2类,其中大片、中片和小片烟聚为一类;碎片烟和碎末烟聚为一类。【结论】大片片烟和中片片烟具有较好的品质,工业可用性较高;碎片烟和碎末烟品质较差,在打叶复烤时应尽量减少其产出。

脂肪乳氨基酸(17)葡萄糖(11%)注射液稳定性研究

目的为临床合理使用脂肪乳氨基酸(17)葡萄糖(11%)注射液(商品名卡文)提供依据。方法将卡文3个腔室液体混匀(样品S1);再分别添加电解质(氯化钾和氯化钠,样品S2),维生素(水溶性维生素及脂溶性维生素,样品S3),多种微量元素(样品S4),以及上述所有成分(样品S5)。分别于室温下放置0,4,8,12 h时测定混合液的pH、渗透压、不溶性微粒数,并考察乳剂粒径分布情况。结果样品S1-S5室温下放置12 h内外观无明显变化,pH为5.51~5.59;渗透压,S2为934~972 mOsmol/kg,S3为816~831 mOsmol/kg,S4为810~835 mOsmol/kg,S5为934~957 mOsmol/kg;不溶性微粒变化不明显;乳剂粒径分布集中在1~10 nm。结论在卡文中添加规定限度内的电解质、维生素和多种微量元素,对其pH、不溶性微粒、乳剂粒径等影响较小,但电解质对渗透压影响较大,应予以重视。

复方氨基酸注射液中有关物质N,N′-二乙酰-L-胱氨酸测定

目的:建立测定复方氨基酸注射液中乙酰半胱氨酸有关物质N,N′-二乙酰-L-胱氨酸含量的高效液相色谱法。方法:采用Atlantis dC_(18)色谱柱(4.6 mm×150 mm,3μm),以甲酸铵溶液(取甲酸铵315 mg,加水960 mL溶解,摇匀)-乙腈-甲酸(970∶30∶1)为流动相,流速为0.7 mL·min^(-1),检测波长为210 nm。结果:N,N′-二乙酰-L-胱氨酸浓度在2.697~53.94μg·mL^(-1)范围内线性关系良好(r=0.9999),检测限和定量限分别为1.4μg·mL^(-1)和4.4μg·mL^(-1),平均回收率为100.2%,RSD为0.5%。结论:经方法学验证,证明本法适用于复方氨基酸注射液中N,N′-二乙酰-L-胱氨酸的含量测定。

瓜蒌皮注射液及其中间体中17种氨基酸含量测定及其变化规律研究

目的测定瓜蒌皮注射液及其中间体中天冬氨酸、谷氨酸、丝氨酸、甘氨酸、苏氨酸、瓜氨酸、精氨酸、丙氨酸、γ-氨基丁酸、酪氨酸、缬氨酸、苯丙氨酸、异亮氨酸、鸟氨酸、亮氨酸、赖氨酸、脯氨酸的含量,并分析其变化规律。方法OPA-FMOC在线衍生化分析采用Waters XBridge C_(18)色谱柱(4.6 mm×100 mm,3.5μm);流动相磷酸盐缓冲液-[甲醇-乙腈-水(45∶45∶10)],梯度洗脱;体积流量1 mL/min;柱温45℃;检测波长262、338 nm。主成分分析、热图分析对10道工序相应中间体的6批样品进行化学模式识别。结果17种氨基酸在各自范围内线性关系良好(R^(2)>0.9980),平均加样回收率83.4%~119.5%,RSD 0.91%~7.94%。相同工序不同批次样品较聚集,不同工序相应中间体聚为3组。醇沉和阳离子交换柱对氨基酸组成影响最大。结论本实验可为瓜蒌皮注射液质量控制的关键因素提供重要参考,以保证终产品的稳定性和均一性。

贵州苗族、水族红酸汤滋味与香气差异分析

为评价水族红酸汤的品质特征,以苗族红酸汤为参比,采用国标法、氨基酸分析法与顶空固相微萃取-气相色谱-质谱联用法(Headspace-Solid phase microextraction-gas chromatography mass spectrometry,HS-SPME-GCMS)对苗族、水族红酸汤的理化成分、游离氨基酸及香气成分进行分析。结果表明,水族红酸汤的总酸、还原糖、脂肪和蛋白质等含量均高于苗族红酸汤;两种红酸汤中共检测出19种游离氨基酸,水族红酸汤中呈味氨基酸与总氨基酸含量是苗族红酸汤的2倍,其中丙氨酸和谷氨酸的滋味活度值(taste activity value,TAV)>1,是两种红酸汤的关键呈味氨基酸;在红酸汤中共检测出101种挥发性物质。利用正交偏最小二乘法(orthogonal least partial squares,OPLS-DA)的重要性变量投影(VIP)筛选出十六酸丙酯、4-乙基-2甲氧基苯酚、5-环己基-2戊酮、山梨酸等32个关键差异物。通过相对香气活性值(Relative odor activity value,ROAV)发现苗族红酸汤中酸味较水族红酸汤明显,水族红酸汤果香味特征较苗族红酸汤明显,两种红酸汤中脂香均由水杨酸甲酯提供,但主要呈酒香的挥发性物质不同,苗族红酸汤主要由乙醇提供,而水族红酸汤主要由4-乙基苯酚提供;感官评价显示,水族红酸汤的感官评分高于苗族酸汤。综上所述,水族红酸汤作为贵州红酸汤的一种,其品质和风味较优,具有很高的市场开发价值。

凝乳酶对成熟牦牛乳硬质干酪氨基酸、脂肪酸及挥发性风味化合物的影响

为研究小牛皱胃酶、地衣芽孢杆菌D3.11凝乳酶和木瓜凝乳酶对成熟牦牛乳硬质干酪氨基酸、脂肪酸和挥发性风味化合物的影响,采用氨基酸分析仪、顶空固相微萃取和气相色谱-质谱联用等技术进行检测。结果表明,随着成熟时间的增加,3种干酪水分含量呈现下降趋势,TN,pH4.6-SN和12%TCA-SN含量呈现上升趋势,且TN与水分含量成负相关,其蛋白水解能力:BR>PR>CR;BR-YMHC中氨基酸含量显著高于其他2种干酪;3种干酪脂肪含量在成熟过程中始终呈现下降趋势,其脂肪降解能力:BR>PR>CR;与CR-YMHC相比,BR-YMHC和PR-YMHC中不饱和脂肪酸的相对含量较高,且功能脂肪酸(油酸)在BR-YMHC中相对含量最高;在3种干酪中分别鉴定出36,35和32种挥发性风味化合物,其中CR-YMHC中酮类物质相对含量最高,为26.39%;BR-YMHC中酯类物质相对含量最高,为43.02%;PR-YMHC中酸类物质相对含量最高,为31.86%。研究结果为酶凝干酪的生产加工及牦牛乳硬质干酪的风味调控提供理论依据。

干燥方式对全脂/脱脂油莎豆脆片品质的影响

该文为研究干燥方式对油莎豆脆片品质的影响,以全脂油莎豆和脱脂油莎豆为主要原料,研究焙烤干燥和真空微波干燥对全脂/脱脂油莎豆脆片微观结构、质构特性、抗氧化性、游离氨基酸含量以及挥发性风味物质含量的影响。研究结果表明,焙烤干燥-全脂油莎豆脆片(S1)、焙烤干燥-脱脂油莎豆脆片(S2)、真空微波干燥-全脂油莎豆脆片(S3)和真空微波干燥-脱脂油莎豆脆片(S4)的微观结构差异较大,其中S1和S3组织结构疏松,分布均一。S1、S2、S3和S4的硬度分别为258.90、548.40、216.33 g和473.39 g,脆度分别为2.00、1.33、2.33和1.67。S4的DPPH自由基清除能力、铁离子还原能力和游离氨基酸含量明显高于S1、S2和S3。从S1、S2、S3和S4油莎豆脆片样品中检测出9种化合物,主要包括醛类3种、醇类2种、酯类1种、烷烃类1种、烯烃类1种和杂环类1种。S1、S2、S3和S4中天冬氨酸、谷氨酸和丙氨酸这类呈味氨基酸含量相对较高,因此油莎豆适合用来生产脆片。

氨基酸复配同步抑制曲奇中多种有害物形成及其对感官品质的影响

氨基酸可有效抑制热加工食品中有害物质的形成,但食品中有多种有害物同时存在的情况,目前对于氨基酸对有害物的同步控制研究缺乏,并且氨基酸单独使用常对感官品质造成不良影响。以曲奇为研究对象,选取对活泼羰基化合物消除效果好的4种氨基酸进行复配,通过单因素和正交实验,以感官评价、色度、质构、有害物抑制效果为指标,在不影响产品感官品质的基础上,获得可同时抑制多种热加工有害物的氨基酸添加配方。最终确定曲奇中氨基酸的最佳添加配方为半胱氨酸0.15 g/kg、γ-氨基丁酸0.35 g/kg、丙氨酸0.5 g/kg、甘氨酸0.5 g/kg。采用该配方制作的曲奇与空白组相比,5-羟甲基糠醛、丙酮醛、3-脱氧奥苏糖、丙烯酰胺、羧甲基赖氨酸、羧乙基赖氨酸、荧光晚期糖基化终末产物分别降低了92%、28%、47%、38%、50%、71%、62%。同时,曲奇的酥脆性显著提高,感官品质有所改善。该研究结果为曲奇等热加工食品中有害物的控制与品质改良提供参考与指导。

云产雪茄烟叶微生物群落、游离氨基酸及挥发性风味物质特征分析

为探究云南产区(以下简称“云产”)雪茄烟叶的品质差异,采用高通量测序和代谢组学技术等对云产雪茄烟叶的微生物群落结构、游离氨基酸和挥发性风味物质进行测定,通过O2PLS分析和相关性分析系统性地揭示产地微生物与烟叶风味品质之间的关系,并确定烟叶中的功能微生物和协同作用类群。结果表明:云产雪茄烟叶微生物群落结构存在产地差异,其中优势细菌主要为Aerococcus、Staphylococcus和Corynebacterium,优势真菌主要为Aspergillus、Cladosporium和Alternaria;雪茄烟叶中共检测出17种游离氨基酸,氨基酸含量整体表现为Asp含量最高,Met含量最低,味觉活性值较高的Asp和Glu对其呈味具有较大贡献,临沧云雪2号和普洱云雪2号雪茄烟叶游离氨基酸呈味特征较为突出;雪茄烟叶中共检测出65种挥发性风味物质,主要以酮类物质为主,甲基庚烯酮、β-大马酮、β-紫罗兰酮、癸醛、二氢猕猴桃内酯等16种差异风味物质对云产雪茄烟叶的风味形成具有重要作用,普洱2号的整体风味特征更加突出;Sphingomonas、Staphylococcus、Pseudomonas和Oceanobacillus之间的协同作用对烟叶的风味形成具有重要贡献,而Penicillium相对丰度与烟叶品质呈负相关。

炸鸡翅营养组分变化及关键香气成分分析

将鸡翅裹面并采用棕榈油炸,分析炸制前后鸡翅中脂肪酸和氨基酸组成变化及炸鸡翅的关键香气成分。研究发现,油炸后鸡翅肉中脂肪酸和氨基酸总含量均升高,尤其必需氨基酸与总氨基酸的比值及必需氨基酸与非必需氨基酸的比值达到了43.23%和76.16%,营养指标提高。以二氯甲烷为溶剂,采用溶剂辅助蒸发提取炸鸡翅样品中的挥发性风味物质,结合气相色谱-质谱分析鉴定出80种挥发性化合物,频率法气相色谱-嗅闻分析鉴定出51种风味物质是油炸鸡翅的气味活性化合物,G C-O检测的强势气味化合物(NIF≥55%)为2,5-二甲基-吡嗪、己醛、3-甲硫基丙醛、3-乙基-2,5-二甲基-吡嗪、2-甲基丁醛、(E)-2-壬烯醛、γ-丁内酯等36种,对这些化合物计算OAV值,确定炸鸡翅关键香气化合物(OAV≥1)25种,分别为2-甲基-3-呋喃硫醇、双(2-甲基-3-呋喃基)二硫、(E,E)-2,4-癸二烯醛、2-乙基-3,5-二甲基-吡嗪、1-辛烯-3-酮、(E)-2-癸烯醛、(E,E)-2,4-壬二烯醛、2-甲基丁醛、(E)-2-壬烯醛、3-乙基-2,5-二甲基-吡嗪、3-甲硫基丙醛、糠醛、己醛、辛醛、二甲基二硫醚、壬醛、癸醛、苯乙醛、2-戊基呋喃、2-丁酮、2,5-二甲基-吡嗪、(E)-2-庚烯醛、2,3,5-三甲基-吡嗪、2-甲基-吡嗪、乙偶姻25种。希望研究结果可为鸡肉的烹饪加工和肉味香精的研制提供理论参考。

基于GC-IMS分析不同煸炒温度对郫县豆瓣风味影响及游离氨基酸呈味分析

为探寻不同煸炒温度对郫县豆瓣风味变化和游离氨基酸呈味的影响,使用菜籽油在60,80,100,120,140℃煸炒豆瓣,采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)技术、气味活性值(odor activity value,OAV)、正交偏最小二乘法判别分析(orthogonal partial least squares-discrimination analysis,OPLS-DA)和主成分分析(principal component analysis,PCA)确定不同煸炒温度对豆瓣风味和关键化合物的影响,结合滋味活性值(taste activity value,TAV)分析对游离氨基酸呈味的影响。结果表明,煸炒温度在60,80℃时郫县豆瓣化合物开始分解转化,煸炒温度在100,120,140℃时郫县豆瓣化合物大量聚集、浓缩为关键风味化合物。GC-IMS共鉴定出40种挥发性化合物(单体或二聚体),醇类是郫县豆瓣的主要化合物(相对浓度为12.43%~36.89%);其中,2-乙基呋喃使煸炒后的豆瓣呈现焦香风味,1-戊烯-3-醇使豆瓣呈现果香,正戊醛、(E)-2-庚烯醛使豆瓣呈现刺激气味和油脂香气。TAV分析确定120℃为煸炒最佳温度,此时郫县豆瓣的滋味最佳,谷氨酸的鲜味强度最高(TAV为44.38);当煸炒温度达到140℃时,缬氨酸的鲜味强度最高(TAV为18.21),豆瓣开始呈现苦味。Pearson相关性分析确认郫县豆瓣的TAV与OAV存在明显的相关性。