Smoke and liquid smoke. Study of an aqueous smoke flavouring from the aromatic plant Thymus vulgaris L

An aqueous smoke flavouring from Thymus vulgaris L was obtained. The qualitative and quantitative composition of its dichloromethane extract was studied by gas chromatography and gas chromatography/mass spectrometry. In addition to the common smoke components such as aldehydes, ketones, diketones, esters, acids, furan and pyran derivatives, alkyl aryl ethers, phenol, guaiacol and syringol derivatives, some terpenic compounds were detected. Differences between this aqueous liquid smoke and others from various kinds of wood are due not only to the absence or presence of some compounds but also to the proportions of the different groups of components present in the mixture. Some aldehydes, esters, guaiacol and its derivatives and terpenic compounds contribute to the overall odour of this liquid smoke more significantly than the ketones, furan and pyran derivatives, acids, phenol and its derivatives and syringol. The yield in smoke components obtained from the pyrolysis of Thymus vulgaris L at 488 °C is of a similar order to that obtained from other woods. © 1999 Society of Chemical Industry     

西洋参须固体饮料酶解法制备过程中挥发性成分的变化研究

目的 研究西洋参须固体饮料在制备过程中挥发性成分的变化,解析西洋参须固体饮料的风味品质。方法 采用顶空固相微萃取-气相色谱-质谱法对西洋参须不同酶解加工阶段的挥发性成分进行检测,利用主成分分析法分析不同加工阶段的挥发性成分特征差异。结果 从西洋参须不同酶解产物中共检测出97种挥发性物质,主要是萜烯类、醇类、醛酮类、烷烃类、酯类、酚酸类、芳香族及杂环类化合物,酶解处理降低了大部分挥发性物质的含量,相对含量较大的挥发性成分是芳樟醇、柠檬烯、己酸、桧烯、(IS, 8a?)-十氢-1, 4aβ-二甲基-7β-异丙烯基-1-萘酚、β-石竹烯、β-红没药烯、十四烷、庚酸、橙花叔醇,通过主成分分析可以显著区分不同酶解样品。结论 酶解处理影响了西洋参须固体饮料中挥发性成分的变化,为西洋参须固体饮料的风味品质调控提供支撑。     

回流脱水体系中固体酸催化合成调香剂乳酸乙酯的研究

以NH4Fe(SO4)2·12H2O、Na2SiO3、NH4NO3和Ce(SO4)2·5H2O为原料,采用共沉淀法制备了固体酸SO2-4/CeO2-Fe2O3-SiO2催化剂,并对催化剂进行了FTIR和TG-DTA表征,以回流脱水合成乳酸乙酯反应为探针反应,得酯化反应的最佳反应条件:催化剂用量为乳酸质量的3.4%(0.25 g),醇酸物质的量的比为2.5∶1.0(乳酸6 mL),反应时间3 h,带水剂环己烷用量为乙醇体积的62.5%(7.5 mL),脱水剂无水硫酸镁用量为2.9 g,该反应条件下酯化率平均达96.0%,催化剂重复使用五次后,反应酯化率依然可达91.6%。产品经FTIR、GC-MS分析确认,并由GC-MS分析知其纯度为94.59%。     

香料乳状液的稳定性研究

香料在乳状液中因明胶(成膜材料)所形成的保护性包膜而增强稳定性.影响乳状液稳定的因素有乳化剂浓度、乳化温度以及明胶浓度等.正交试验结果表明,香料乳状液稳定的优化条件是乳化剂浓度0.3%～0.4%、乳化温度60℃、明胶(成膜材料)浓度4.0%～5.0%.     

Experimental design-based isotope-dilution SPME-GC/MS method development for the analysis of smoke flavouring products

ABSTRACT

For the implementation of Regulation (EC) No 2065/2003 related to smoke flavourings used or intended for use in or on foods a method based on solid-phase micro extraction (SPME) GC/MS was developed for the characterisation of liquid smoke products. A statistically based experimental design (DoE) was used for method optimisation. The best general conditions to quantitatively analyse the liquid smoke compounds were obtained with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre, 60°C extraction temperature, 30 min extraction time, 250°C desorption temperature, 180 s desorption time, 15 s agitation time, and 250 rpm agitation speed. Under the optimised conditions, 119 wood pyrolysis products including furan/pyran derivatives, phenols, guaiacol, syringol, benzenediol, and their derivatives, cyclic ketones, and several other heterocyclic compounds were identified. The proposed method was repeatable (RSD% <5) and the calibration functions were linear for all compounds under study. Nine isotopically labelled internal standards were used for improving quantification of analytes by compensating matrix effects that might affect headspace equilibrium and extractability of compounds. The optimised isotope dilution SPME-GC/MS based analytical method proved to be fit for purpose, allowing the rapid identification and quantification of volatile compounds in liquid smoke flavourings.     

Study of the volatile composition of an aqueous oak smoke preparation

An aqueous smoke flavouring from oak (Quercus sp.) sawdust was obtained on the laboratory scale. Its qualitative and quantitative composition was studied by gas chromatography after previous extraction. A high number of compounds (215) was detected. In addition to the well-known smoke components, others, only recently described as smoke components, were also detected. In the first group there are aldehydes, ketones, diketones, esters, alcohols, acids, furan and pyran derivatives, syringol, guaiacol, phenol and pyrocatechol derivatives, alkyl and aryl ethers; in the second group the presence of some furan and pyran derivatives is noteworthy, as well as a significant number of lignin dimers in low proportion, a considerable number of anhydrosugars in very high proportion and some nitrogenated derivatives in low proportions. Differences between this oak aqueous liquid smoke and others previously obtained from several woods, under similar operative conditions, are due, not only to the absence or presence of some compounds, but also to the proportions of the different groups of components present in the preparation.     

Some changes in an aqueous liquid smoke flavouring during storage in polythene receptacles

Aqueous liquid smoke produces a brown layer on the wall of the polythene receptacle in which it has been contained. The constituents of this brown layer have been extracted using dichloromethane and were studied by means of gas chromatography/mass spectrometry (GC/MS) and Fourier transform infrared spectroscopy (FTIR). Some changes in the liquid smoke were deduced through comparisons of data from the brown layer with the previously obtained liquid smoke data. Due to interactions between polythene molecules and compounds of the liquid smoke, some of these latter compounds migrate into the wall of the receptacle and are retained there. The extent of these migrations depends on the size of the hydrocarbon part of each compound. However, far from being harmful, this migration is useful, since compounds irrelevant from the point of view of flavour, and harmful to health are the main compounds affected by the retention on the polythene wall. Some of the adsorbed compounds have not previously been reported to be present in liquid smoke.     

Protective effects of three smoke flavouring phenols on oxidative damage and nitric oxide production

In this study, the effects of three smoke flavouring phenols, including 4-methoxyphenol (4-MP), 4-ethyl-2-methoxyphenol (EMP), and 4-propenyl-2-methoxyphenol (isoeugenol), on oxidative damage and nitric oxide production, were examined. In the range 5–20 μM, EMP displayed the highest inhibitory effects on radical production and biomolecule oxidation in the acellular systems of the three smoke flavouring phenols. In addition, 4-MP, EMP and isoeugenol, in the range 5–20 μM, protected liver cells against tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity, correlating with protection against intracellular glutathione depletion. Meanwhile, the inhibitory effects of the three smoke flavouring phenols on nitric oxide (NO) generation, in lipopolysaccharide (LPS)-stimulated macrophages, increased with increasing concentrations. The decrease in NO production was attributed to the reduced inducible nitric oxide synthase (iNOS) expression in macrophages. These data suggested that the three smoke flavouring phenols, particularly EMP, show biological activities that contribute to antioxidation as well as anti-inflammation.     

酶法制备干酪风味剂的研究

研究了利用商业酶制剂酶解新鲜凝块制备干酪风味剂的工艺。通过单因素实验和正交实验,确定了最佳酶解条件:蛋白酶添加量0.4%,调整初始pH值6.5,45℃下酶解4 h;脂肪酶添加量1.5%,35℃下搅拌酶解8 h,搅拌转速为200 r/min。由此工艺制备的干酪风味剂口感较好,但香气强度稍差。利用GC-MS法对干酪风味剂中主要挥发性风味化合物进行分析,共鉴定出26种风味物质,其中酸类物质的总含量为35.07%;醛类、酮类和酯类物质的总质量分数为15.47%。     

固体发酵制备毛霉蛋白酶的研究

该文研究了毛霉M2产蛋白酶的若干影响因素，包括培养基的成分以及发酵条件等。结果表明：在麸皮与水的合适比例为1：0.8；在基本培养基上添加一定浓度的碳源、氮源及无机盐有利于蛋白酶的合成；菌体较为合适的产酶条件为温度28℃，pH6．0，发酵时间36h。     

袋装调味裙带菜的研制

以盐渍裙带菜为原料,研制出袋装调味裙带菜。该产品新鲜、味美、食用方便、盐度<5%、色泽真实。其生产工艺简单,原料来源可靠,适合于沿海或内陆地区小型企业生产。     

卷烟燃烧参数、灰分外观和烟气成分相互关系研究

【目的】揭示卷烟燃烧三个维度之间相互关系。【方法】利用统计分析方法研究了卷烟燃烧参数（燃烧温度、耗氧量和燃烧速率）、灰分外观指标（灰色值、裂口率、缩灰率、炭线宽度、炭线整齐度和持灰力）和烟气成分（烟气常规成分和七种有害成分）之间的相关性。【结果】(1)烟丝静燃速率、卷烟吸燃速率和耗氧量之间呈极显著正相关,但均与燃烧温度和卷烟纸阴燃速率无显著相关性;卷烟静燃速率仅与耗氧量显著正相关,燃烧温度仅与卷烟纸阴燃速率呈极显著负相关。(2)燃烧速率参数不仅与多种烟气成分显著负相关,亦与灰分外观质量显著正相关,与燃烧温度和耗氧量相比,是调节卷烟烟气和灰分外观质量更为有效的燃烧参数。     

即食调味海带结生产工艺研究

探讨了以干海带为原料,通过打结、脆化、护绿、脱腥、调味、杀菌等加工工序,生产即食调味海带结的方法,并对其生产过程中关键工艺技术进行研究,得出即食调味海带结生产的最佳工艺条件。护绿最佳条件:乙酸铜溶液浓度为15mg/kg、pH4.5、温度为100℃、时间为10min;在60℃下,海带结泡于0.2%醋酸与0.6%柠檬酸混合液中15min,脱腥效果好;以0.08?Cl2溶液脆化处理15min 口感脆嫩。     

高纯度低聚半乳糖单一组分的制备研究

采用聚丙烯酰胺凝胶Bio-Gel P-2柱对低聚半乳糖混合物进行分离纯化,考察了柱温、洗脱流速和进料量对分离的影响。结果表明,采用1.6cm×120cm凝胶柱,脱气蒸馏水为洗脱剂,最佳操作条件为:柱温度50℃,洗脱流速15～20mL/h,进料量3mL。此条件下,可以制备纯度85%左右的三糖、四糖和五糖粗品,将一次分离产品浓缩后二次分离,得到纯度98%以上的三糖、四糖和五糖单一组分,收率分别为95.5%、74.4%和96.7%,达到了标准品的纯度要求。     

麻竹笋营养成分、风味物质和功能组分的研究进展

麻竹笋是我国常见竹笋中品质优良的一种禾本科植物, 常出现于南方地区, 其含糖率高, 富含氨基酸、膳食纤维等, 是一种营养丰富的天然优质食材, 深受人们的喜爱。本文首先系统综述了麻竹笋中的主要营养成分, 包括多糖、蛋白质、氨基酸、矿物质元素等物质; 总结了麻竹笋中的主要风味物质并明确了其关键醛类风味化合物, 对麻竹笋中苦涩风味的来源进行讨论, 发现单宁是引起麻竹笋苦味的主要原因, 简要总结了降低麻竹笋苦味的措施; 重点探讨了麻竹笋中的黄酮、多酚、甾醇等生物活性物质及其功能, 同时对膳食纤维在麻竹笋中发挥的功能性进行了简要的叙述。本综述可为麻竹笋的进一步应用推广, 尤其是功能产品的开发提供理论依据, 并为提高麻竹笋的利用率提供参考意义, 进而拉动产区的经济效益。     

Comparative evaluation of the antioxidant capacity of smoke flavouring phenols by crocin bleaching inhibition, DPPH radical scavenging and oxidation potential

The antioxidant capacity of the main phenolic compounds present in wood smoke and smoke flavourings used in the food industry was investigated by three methods, based on a kinetic and thermodynamic approach: the bleaching of the carotenoid crocin, the scavenging of the DPPH radical, and the determination of the oxidation potential. The reaction with the DPPH radical was evaluated calculating the effective concentration (EC₅₀) and the antiradical efficiency (AE). The compounds tested were 2-methoxyphenols (guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-vinylguaiacol, 4-propylguaiacol, eugenol, isoeugenol, vanillin, acetovanillone, 2-propiovanillone), 2,6-dimethoxyphenols (syringol, 4-methylsyringol, 4-allylsyringol, syringaldehyde, acetosyringone) and dihydroxybenzenes (catechol, 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol and hydroquinone). The trend in antioxidant capacity was similar in all the three methods, with dihydroxybenzenes > 2,6-dimethoxyphenols > 2-methoxyphenols, although some discrepancies in the ranking within the groups were present. Considering the overall ranking, isoeugenol was amongst the most active compound, like dihydroxybenzenes, evidencing the role of a conjugated double bond at para position for the stabilization of the phenoxyl radical in the radical scavenging process.     

厨房常用味汁配方(二)

8　常用家常味汁的调制8 1　郫县豆瓣 2 0ｇ、盐 3ｇ、酱油 7ｇ、味精 2ｇ、胡椒粉 1ｇ、糖 4ｇ、料酒 8ｇ、葱花 1 0ｇ、姜末 5ｇ、青蒜 5ｇ8 2　郫县豆瓣 5ｇ、盐 5ｇ、味精 1ｇ、花椒粒 1ｇ、糖 3ｇ、生粉 2ｇ、蒜茸 4ｇ、料酒 5ｇ、鸡粉 2ｇ8 3　泡辣椒 6ｇ、盐 3ｇ、味精 2ｇ、糖 2ｇ、料酒5ｇ、鸡油 5ｇ、葱片 8ｇ、姜片 2 3ｇ、蒜片 4ｇ8 4　酱油 1 5ｇ、盐 2ｇ、味精 2ｇ、泡椒 4ｇ、姜 2ｇ、料酒 1 5ｇ8 5　梅林 1 5ｇ、酱油 1 6ｇ、盐 2ｇ、胡椒粉 3ｇ、番茄汁 5ｇ、白糖 8ｇ、姜 3ｇ、鸡粉 2ｇ、味精 2ｇ8 6　红油 50ｇ、椒盐 5…     

Effect of freezing on the physicochemical, textural and sensorial characteristics of salmon (Salmo salar) smoked with a liquid smoke flavouring

This study reports the effect of different refrigeration/freezing treatments on the physicochemical, textural and sensorial properties of farmed Atlantic salmon (Salmo salar) treated with a commercial liquid smoke flavouring. Observations were made on three groups of fillets - group RFS: salted, smoked and stored at 4 °C; group BFS: frozen at −25 °C for 24 h, thawed, salted, smoked and stored at 4 °C; and group AFS: salted, smoked and frozen at −25 °C for 24 h and stored at −18 °C - over a period of 45 days. Scores (on a scale of 1-9) were provided for different sensorial attributes by a panel of 10 trained tasters. Sixty percent of the panellists consistently preferred the AFS fillets. The maximum shelf life associated with each treatment was defined as the last sampling day on which a mean score of ≤5 was awarded for the fillet sensorial attributes by ≥50% of the panellists. Freezing the salmon for 24 h before smoking (BFS) did not increase its shelf life (30 days) over that of refrigerated smoked salmon (RFS). In addition, the former treatment had a negative effect on the adhesiveness, cohesiveness, smoke odour intensity and colour intensity of the flesh. However, maintaining the fish frozen at −18 °C (AFS) increased its shelf life (>45 days) and invested the flesh with greater firmness, cohesiveness and colour intensity.     

钙基固体碱法制备生物柴油工艺的研究

研究了钙基负载型固体碱制备生物柴油的酯交换反应,通过正交试验得出菜籽油制备生物柴油的最佳工艺条件为:反应温度70 ℃、反应时间6 h、催化剂用量4%,醇油摩尔比8∶1,在最优条件下,生物柴油转化率97.62%.     

固体聚合物电解质大豆油氢化反应器中膜电极制备条件的研究

利用固体聚合物电解质氢化反应器,在60℃和常压条件下氢化大豆油。对固体聚合物电解质氢化反应器的核心关键部件膜电极的制备条件进行了优化研究。膜电极最佳制备条件为使用RuO_2为阳极催化剂,40%Pt/C为阴极催化剂,催化剂的载量均为0.6 mg/cm~2,其中阳极和阴极黏合剂占催化层总质量的30%,膜电极最佳热压压力为2 MPa。利用优化条件下制备的膜电极获得了碘值为110 g I/100 g油、反式脂肪酸仅为1.55%的氢化大豆油。