杨梅浸膏挥发性成分分析

为开发新型烟用天然香原料,使用涡旋振荡萃取的前处理方法提取杨梅浸膏挥发性成分,采用GC-MS法分离鉴定出25种挥发性成分,主要有丙二醇酯、5-(1,1-二乙烷基)-1,3-苯二甲酸、2-乙酸-1,2-丙二醇、乙基麦芽酚、5-羟甲基糠醛、肉桂酸乙酯、1,2-丙二醇二乙酸酯、油酸乙酯、3-己烯-1-醇、糠醛等。     

5种市售枫槭浸膏挥发性成分的HS-SPME-GC/MS分析

为了分析市售枫槭浸膏挥发性成分,建立了枫槭浸膏挥发性成分的顶空-固相微萃取-气相色谱质谱联用(HS-SPME-GC/MS)方法,分析了5种市售枫槭浸膏的挥发性成分,并采用单因素方差分析和主成分分析比较了其挥发性成分差异。结果表明:(1)该方法采用双保留指数对挥发性成分进行定性,提高了定性结果的准确性;(2)5种枫槭浸膏中共鉴定出104种挥发性成分,其中95种成分具有香气特征,但仅有11种香气成分为5种枫槭浸膏共有成分,这些成分多表现出焦香和甜香特征,是构成枫槭浸膏香气特征的重要物质基础;(3)5种市售枫槭浸膏挥发性成分存在显著差异,而枫槭浸膏W、XH分别与DP具有一定相似性,枫槭浸膏GZ中的柠檬烯、茴香醛、肉桂酸乙酯等香气成分使其呈现果香和辛香香韵,从而有别于其他枫槭浸膏。     

3种桂花浸膏的挥发性物质分析

目的量化分析桂花浸膏的主要挥发性成分,为规范桂花浸膏的质量标准提供基础数据。方法利用固相微萃取(SPME)结合气相色谱-质谱(GC-MS)分析3种浸膏中的挥发性成分,利用谱库、标准品及保留指数对挥发性物质进行定性,并用2-辛醇做内标物,对挥发性物质进行半定量分析。结果共检出51种挥发性物质,主要的挥发性风味物质为酯类、醇类、酮类,其中桂花浸膏1中共检出27种,桂花浸膏2中共检出31种,桂花浸膏3中共检出20种。半定量结果表明桂花浸膏2中挥发性成分含量最高,为959.50 mg/g,桂花浸膏1中挥发性成分含量最低,为89.37 mg/g。结论 3种浸膏中共有的挥发性风味物质分别为反式芳樟醇氧化物、芳樟醇、2-乙基苯酚、二氢-β-紫罗兰酮、二氢-β-紫罗兰醇、γ-癸内酯、α-紫罗兰酮和β-紫罗兰酮。     

菊苣主要挥发性香气成分分析

目的:开发利用菊苣提取物。方法:采用顶空—固相微萃取—气相色谱质谱联用(HS-SPME-GC/MS)分析菊苣提取物中的挥发性化学成分,通过挥发性成分含量/感官阈值即香气活力值分析其中的主要挥发性香气成分。结果:样品中共检测到78个挥发性成分,相对含量>1%的挥发性成分顺序为丙二醇>5-羟甲基糠醛>乙酸>1,2-丙二醇-二甲酸酯>甲酸>1,2-丙烷二醇-2-乙酸酯;分析了24种香气成分的香气活力值,香气活力值>1的主要挥发性香气成分顺序为乙酸>异丁酸甲酯>肉桂酸乙酯>甲酸>甲基环戊烯醇酮>2,4-二叔丁基苯酚>5-甲基糠醛>丙二醇。结论:菊苣提取物中主要的挥发性成分为丙二醇、5-羟甲基糠醛、乙酸、1,2-丙二醇-二甲酸酯、甲酸、1,2-丙烷二醇-2-乙酸酯,主要的挥发性香气成分为乙酸、异丁酸甲酯、肉桂酸乙酯、甲酸、甲基环戊烯醇酮、2,4-二叔丁基苯酚、5-甲基糠醛、丙二醇。     

模拟卷烟燃吸条件下款冬花浸膏的热裂解

在模拟卷烟燃吸状态下采用在线热裂解-气相色谱/质谱联用(Py-GC/MS)技术对款冬花浸膏进行了热裂解和裂解产物分析。结果表明:款冬花浸膏的热裂解产物中共鉴定出45种挥发性成分,主要包括5-羟甲基-2-呋喃甲醛(21.19%)、糠醛(5.34%)、亚油酸乙酯(3.96%)、棕榈酸乙酯(3.89%)、2,5-二甲酰基呋喃(3.75%)、5-甲基-2-呋喃甲醛(2.68%)和2-甲基丁酸(2.32%)等致香物质。该结果为款冬花浸膏在卷烟中的应用提供了参考。     

循环超声提取制备含羞草浸膏及其在卷烟中的应用

为开发新的天然烟用香料,利用循环超声方法制备了含羞草浸膏,研究了提取时间、超声功率及提取温度对含羞草浸膏得率的影响,并采用正交试验方法优化了提取条件。采用固相微萃取-气相色谱-质谱(SPME-GC/MS)技术分析了浸膏的挥发性成分,并进行了卷烟加香试验。结果表明:①最佳提取工艺条件为提取时间30 min,超声功率550 W,提取温度55℃。此条件下的浸膏得率为9.83%。②共鉴定出66种挥发性成分,其中十六酸(8.032%)、十六酸乙酯(6.807%)、六氢金合欢基丙酮(6.032%)等含量相对较高。③含羞草浸膏能改善和修饰卷烟烟气,提升香气质,掩盖杂气,降低刺激性,改善余味。     

菠萝蜜芳香浸膏提取工艺及挥发性成分分析

以干苞菠萝蜜干果粉为原料,无水乙醇为浸提剂,提取菠萝蜜芳香浸膏并进行风味分析。采用Box-Behnken响应面优化浸提工艺,采用气质联用(Gas chromatography-mass spectrometry,GC-MS)鉴定挥发性成分。菠萝蜜芳香浸膏最佳提取条件为:菠萝蜜果粉与无水乙醇料液比为1∶42(g/mL),于70℃下浸提2 h,此条件下浸膏最大得率为42.81%,与预测值43.00%较为接近;芳香浸膏经GC-MS检测出36种风味物质,其主要芳香成分有4-(1-甲基乙基)苯甲醇(6.22%)、1,6-二甲基十氢化萘(15.06%)和5-[N(2)-(异亚丙基丙酮)]咪唑(14.58%)。本工艺制得的浸膏风味良好,在食品香精及烟用香精行业具有广阔的市场前景。     

顶空固相微萃取-气相色谱-质谱法测定乌骨藤中的挥发性成分

目的:顶空固相微萃取-气相色谱-质谱法(HS-SPME-GC-MS)分析乌骨藤挥发性成分。方法:前处理采用干法和湿法2种不同方法,顶空固相微萃取提取后,用气相色谱-质谱联用技术检测乌骨藤挥发性化学成分。结果:采用干法前处理共鉴定了71种成分,占总成分含量的93.5%;湿法前处理共鉴定了53种成分,占总成分含量的99.55%。干法处理后所提取的挥发性成分主要为萜烯类(20.01%)、醇类(17.86%)和脂类(11.92%),湿法处理后所提取的挥发性成分主要为醇类(60.31%)、醛类(12.80%)。结论:干法和湿法前处理测得的挥发性成分差异较大,各成分含量差异也较大。同时用干法和湿法前处理后,再用HS-SPME-GC-MS方法提取和分析乌骨藤中挥发性成分,既简单快速又能全面科学的分析出各挥发性组分。     

发酵对葫芦巴挥发性化学成分的影响

采用水蒸气蒸馏与溶剂萃取相结合的方法对未发酵和发酵后的葫芦巴茎叶挥发性成分进行提取,运用毛细管气相色谱-质谱联用法分析测定,用计算机检索NIST02质谱数据库确定其挥发性化学成分,用面积归一化法进行定量分析。结果表明,两种方法提取的挥发性化学成分及含量皆有很大差异,发酵的葫芦巴挥发油产率明显提高。经毛细管色谱从未发酵的葫芦巴茎叶挥发油中分离出93个峰,鉴定出65种成分,占挥发油总相对含量的69.89%,从发酵后的葫芦巴茎叶挥发油中分离出134个峰,鉴定出49种成分,占挥发油总相对含量的36.57%,二者共有成分32种,这与已有文献结果存在明显的区别。     

基于GC-MS与电子鼻技术结合化学计量学方法分析不同品种桂花浸膏的挥发性成分

采用气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）和电子鼻技术结合化学计量学方法对不同品种桂花浸膏挥发性成分和整体气味进行分析。结果表明：GC-MS检测到4种桂花浸膏中共65种,8大类挥发性成分,包括醇类28种、酮类6种、醛类4种、酚类4种、酸类4种、烷烃类5种、酯类8种、其他类物质6种,其中醇类、酮类和酯类是桂花浸膏挥发性成分的主要贡献物质。GC-MS Venn图和聚类热图表明,4种桂花浸膏中各挥发性成分的种类和含量有显著差异。采用偏最小二乘判别分析确定了4种桂花浸膏的9种差异性特征挥发成分,分别为正四十烷、氟丙酸、二氢-β-紫罗兰醇、二十八烷醇、棕榈酸、醋酸(9Z,12E)-9,12-四环戊二烯、2,3-二甲基环己醇、二氢-β-紫罗兰酮和豆甾醇。电子鼻结果显示,W2W、W2S、W1W、W1S、W5S是区分不同桂花浸膏气味的主要传感器。4种桂花浸膏的整体气味区分度较好,浏阳金桂和浏阳银桂浸膏挥发性成分更为接近,咸宁金桂和浏阳丹桂浸膏有较为明显的区别,这与GC-MS聚类分析结果一致。本研究结果表明基于挥发性成分对不同品种的桂花浸膏...     

Indian culinary plants enhance glucose-induced insulin secretion and glucose consumption in INS-1 β-cells and 3T3-L1 adipocytes

Six Indian plants, commonly used as culinary plants, herbs or spices (kikar; jamun; neem; harad; fenugreek; bitter gourd), were screened and compared for their antidiabetic potential in vitro. Aqueous plant extracts were prepared and assessed for their effect on the insulin secretion activity of rat pancreatic INS-1 β-cells and glucose consumption in mouse 3T3-L1 adipocytes in order to study their specific mechanisms of action. The effect of the plant extract concentration (25–1000 μg/ml) on insulin release and glucose consumption was also studied. All the extracts had a significant stimulatory effect on the insulin secretion of INS-1 cells. In the presence of kikar extract (100 μg/ml), an increase of 228% in insulin release was recorded compared to the control (5.6 mM glucose) whereas that was 270% and 367% in the presence of kikar and jamun extracts (500 μg/ml), respectively. 3T3-L1 cells treated with jamun extract (100 μg/ml) exhibited the highest increase in glucose consumption by the cells (94%, compared with the control) followed by harad (53%) and fenugreek (50%) extracts. A significant inhibitory effect of the fenugreek, kikar and jamun extracts on glucose diffusion across a dialysis membrane suggested that these extracts could partly act by decreasing glucose absorption in the small intestine. The results showed that a combination of these plants in diet could help in the management of both type 1 and type 2 diabetes.     

Analysis of human male armpit sweat after fenugreek ingestion: Instrumental and sensory optimisation of the extraction method

In this study, we intend to develop a simple and selective procedure to extract compounds involved in the strong odour which appears after fenugreek ingestion (this odour is responsible of the so-called pseudo-maple syrup urine disease). Two procedures, solvent extraction and headspace solid-phase microextraction (HS-SPME), were employed to extract compounds from armpits sweat samples collected from two volunteer subjects. The HS-SPME extraction parameters were first optimised and then applied to extracts of armpit sweat collected from subjects after fenugreek ingestion. The sensory evaluation of the different extracts was carried by eight trained assessors; the HS-SPME and solvent extracts were, respectively, smelled by direct gas chromatography–olfactometry and direct olfaction. The results of sensory evaluation indicate that HS-SPME with a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre, of 50/30 μm film thickness and 2 cm length, gives a global odour close to that of sweat after ingestion of fenugreek infusion.     

Gel and Pasting Behaviour of Fenugreek‐Wheat Starch and Fenugreek – Wheat Flour Combinations

The influence of fenugreek material on starch and flour rheological characteristics was determined. Ground fenugreek grain material, and a purified fenugreek extract (Fenulife®) were used as replacement or as addition to flour or starch. Evaluation of the pasting properties of starch and flour fenugreek mixtures illustrated that fenugreek addition increased the peak and final viscosity of the mixtures in relation to the level of fenugreek addition used. The ground fenugreek seeds yielded a lower response than the purified Fenulife® sample, due to the presence of protein, starch and other polysaccharide material in the ground flour. Rheology of the pastes showed that the addition of fenugreek material (especially Fenulife®) increased the viscoelastic nature of the material. Textural analysis of the cooled gels illustrated that the inclusion of fenugreek into flour mixes generally raised the hardness of the gels, although the gels became softer with higher levels of fenugreek material used. The inclusion of fenugreek into starch gels showed similar patterns of pasting and textural properties, with a general decrease in texture related to the level of fenugreek included.     

Chemical composition and antioxidant activity of the husk and endosperm of fenugreek seeds

Fenugreek (Trigonella foenum-graecum) is used as a spice, vegetable and a medicinal plant. In the present study, fenugreek seeds were separated into husk and endosperm. The proximate composition of fenugreek seeds, husk and cotyledons showed that endosperm had the highest saponin (4.63 g/100 g) and protein (43.8 g/100 g) content. In contrast, husk had higher total polyphenols (103.8 mg of gallic acid equivalent/g, and TDF (77.1 g/100 g), comprising IDF (31.9 g/100 g) and SDF (45.2 g/100 g). At 200 μg concentration, extracts of husk, fenugreek seed, and endosperm exhibited 72%, 64%, and 56% antioxidant activity respectively by free-radical scavenging method. The study indicated that separation of fenugreek seeds into husk and endosperm could have advantage of process viability with respect to prior selective fractionation of bioactive components for their effective isolation.     

Sensory,functional characteristics and in vitro digestibility of snacks supplemented with non-traditional ingredient raw and processed fenugreek

Fenugreek seeds were germinated, soaked and roasted and were evaluated for nutritional properties. Raw and processed fenugreek seeds were used to develop snack product. Snacks were examined for the sensorial, functional, antinutritional properties and in vitro digestibility. Using sensory analysis, 5% level of substitution of raw and processed fenugreek was accepted for the development of extruded snacks. Lateral expansion was highest for snacks prepared from processed fenugreek (163.0% to 206.1%) than raw fenugreek (162.5 to 168.7%), and vice versa for bulk density. The antioxidant activity and total phenolic content were highest for snacks prepared from germinated fenugreek (7.30% to 9.87% and 1.352 to 3.561 mg GAE g⁻¹ of sample) and lowest for snacks prepared from raw fenugreek (6.68% to 7.03% and 1.29 to 2.76 mg GAE g⁻¹ of sample). Not only extrusion but also processing such as soaking, roasting and germination reduced the antinutritional content of the snack product. Both in vitro digestibilities increased with extrusion cooking. In vitro digestibility was also found to be higher in snacks prepared from processed fenugreek than raw fenugreek. Therefore, development of such functional foods using processed fenugreek would raise the consumer demand and benefit the population by increasing the health status.     

Ultrasound and microwave assisted extraction of diosgenin from fenugreek seed and fenugreek-supplemented cookies

Fenugreek has been recognized as the most important medicinal plant. The presence of diosgenin in fenugreek seed is known to have promising health benefits. In the present work the extraction of diosgenin from the fenugreek seed was performed and its supplementation in cookies was done. The ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) methods have been applied for extraction of diosgenin. In case of UAE, the maximum diosgenin was obtained from fenugreek seed powder with 80 % ethanol solution for 50 min, whereas the maximum diosgenin in MAE was obtained at 80 % ethanol solution for 4 min. Overall, the extract yield of UAE was higher than MAE. The UAE method with an ethanolic concentration of 80 % was considered as optimum for the determination of diosgenin in cookies. The diosgenin content of the cookies supplemented with fenugreek seed powder increased with its increase and the diosgenin content ranged from 0.099 to 0.191 g diosgenin equivalent/100 g of cookies. Further research on the incorporation of fenugreek seed powder and diosgenin in ready-to-eat foods are of great value because of health benefits of diosgenin and market demand of ready-to-eat foods.     

Antioxidant properties and quantitative UPLC-MS analysis of phenolic compounds from extracts of fenugreek (Trigonella foenum-graecum) seeds and bitter melon (Momordica charantia) fruit

Freeze-dried fenugreek (Trigonella foenum-graecum) seeds and bitter melon (Momordica charantia) fruit were extracted sequentially using non-polar to polar solvents, with further separation carried out on polar extracts by molecular weight cut off dialysis. The fenugreek ethyl acetate crude extract (FGE3) demonstrated the highest antioxidant activity, in terms of Trolox Equivalents (TE), for both the DPPH (35.338 ± 0.908 mg TE/g) and FRAP (77.352 ± 0.627 mg TE/g) assays. This extract also contained the highest phenolic content, in terms of Gallic Acid Equivalents (GAE) (106.316 ± 0.377 mg GAE/g). Despite having considerably lower antioxidant activity than fenugreek, the highest antioxidant activities for bitter fruit were observed in the hexane (BME1) and methanol hydrophilic < 3.5 kDa dialysed (BME4 < 3.5 kDa) extracts, while the highest phenolic content was found in the methanol hydrophilic > 3.5 kDa (BME4 > 3.5 kDa) dialysed extract. UPLC-MS was used to quantify 18 phenolic compounds from fenugreek and 13 from bitter melon in active crude extracts. The flavonoids apigenin-7-O-glycoside (1955.55 ng/mg) and luteolin-7-O-glycoside (725.50 ng/mg) were the most abundant compounds in FGE3, while bitter melon extracts contained only small amounts of mainly phenolic acids. A further 5 fenugreek and 1 bitter melon compounds were identified in trace amounts from the same extracts, respectively.     

Analysis of human male armpit sweat after fenugreek ingestion: Characterisation of odour active compounds by gas chromatography coupled to mass spectrometry and olfactometry

In this study, the strong “maple-syrup” odour which appears after fenugreek ingestion was investigated. Headspace solid-phase microextraction (HS-SPME) was applied to extract volatile odourant compounds from human male armpit sweat samples. Two male volunteers were considered who have similar diet; they had to ingest fenugreek infusion over the same period of time. The HS-SPME extracts obtained were then analysed by gas chromatography coupled either to mass spectrometry (GC–MS) or flame ionisation detection and olfactometry (GC–O). In that latter case, a panel of eight assessors was used, and the detection frequency methodology was applied. A total of 44 compounds could be identified in sweat samples, with a wide range of chemical structures, some of them being reported for the first time in human armpit sweat. Eight compounds appearing only after fenugreek ingestion could be identified: 2,5-dimethylpyrazine, β-pinene, 3-octen-2-one, camphor, terpinen-4-ol, 4-isopropyl-benzaldehyde, neryl acetate and β-caryophyllene. Due to their odourant notes, such compounds should be responsible for the strong “maple-syrup” odour present in sweat after fenugreek ingestion. GC–O confirmed the role of some odourant compounds in the “maple-syrup” odour of sweat, especially 2,5-dimethylpyrazine which was the best perceived odour. Among these eight compounds, some of them were previously reported in the fenugreek seeds, namely β-pinene, 3-octen-2-one and camphor.     

Effect of germination on the nitrogenous constituents,protein fractions, in vitro digestibility and antinutritional factors of fenugreek seeds (trigonella foenum graecum L.)

This study was designed to determine the effect of germination on nitrogenous constituents, protein fractions, in vitro digestibility and antinutritional factors (namely trypsin inhibitor and haemagglutinin) of the Egyptian fenugreek seeds Geiza 2 variety. After 96 h of germination, there was 18% decrease in the dry weight of seeds, a slight increase of total nitrogen (TN), a decrease of protein nitrogen (PN) and a marked increase of both non-protein nitrogen (NPN) and free amino acid nitrogen (FAAN). Non-protein nitrogen other than FAAN, amido nitrogen and ammonia nitrogen also increased. The protein fractions (namely albumin, globulin, prolamin and glutelin) were separated according to their solubilities in different solvents. The ratio between the four protein fractions in ungerminated seeds was 4:3.5:2.8:1 and became 2:6.5:7.7:1 after germination as calculated on the basis of their PN.Trypsin inhibitor activity per gramme of fenugreek was found to be higher by 66% in germinated fenugreek than ungerminated seeds. Both ungerminated and germinated fenugreek was found devoid of the haemagglutinin activity.Germination resulted in a slight increase in pancreatic digestibility, 33.7% decrease in digestibility by pepsin followed by pancreatin, while a small decrease was found in peptic digestibility.     

Determination of bioaccessibility of beta-carotene in vegetables by in vitro methods

The in vitro method in use for the determination of beta-carotene bioaccessibility involves simulated gastrointestinal digestion followed by ultracentrifugation to separate the micellar fraction containing bioaccessible beta-carotene and its quantitation. In this study, the suitability of two alternatives viz., membrane filtration and equilibrium dialysis were examined to separate the micellar fraction. Values of beta-carotene bioaccessibility obtained with the membrane filtration method were similar to those obtained by the ultracentrifugation method. Equilibrium dialysis was found not suitable for this purpose. Among the vegetables analyzed, fenugreek leaves had the highest content of beta-carotene (9.15 mg/100 g), followed by amaranth (8.17 mg/100 g), carrot (8.14 mg/100 g) and pumpkin (1.90 mg/100 g). Percent bioaccessibility of beta-carotene ranged from 6.7 in fenugreek leaves to 20.3 in carrot. Heat treatment of these vegetables by pressure cooking and stir-frying had a beneficial influence on the bioaccessibility of beta-carotene from these vegetables. The increase in the percent bioaccessibility of beta-carotene as a result of pressure-cooking was 100, 48 and 19% for fenugreek leaves, amaranth and carrot, respectively. Stir-frying in presence of a small quantity of oil led to an enormous increase in the bioaccessibility of beta-carotene from these vegetables, the increase being 263% (fenugreek leaves), 192% (amaranth leaves), 63% (carrot) and 53% (pumpkin).