Chemical composition and functional characterisation of commercial pumpkin seed oil

BACKGROUND: Pumpkin (Cucurbita pepo L.) seed oil is a common product in Slovenia, Hungary and Austria and is considered a preventive agent for various pathologies, particularly prostate diseases. These properties are related to its high content of carotenoids and liposoluble vitamins. In this study the carotenoid (lutein and zeaxanthin), vitamin E (α‐ and γ‐tocopherol) and fatty acid contents of 12 samples of commercial pumpkin seed oil were investigated together with the composition of the volatile fraction resulting from the roasting process. RESULTS: The aromatic profile obtained from the commercial samples was directly related to the intensity of the roasting process of the crushed pumpkin seeds. The roasting temperature played a crucial role in the concentrations of volatile substances originating from Strecker degradation, lipid peroxidation and Maillard reaction. CONCLUSION: The findings suggest that high‐temperature roasting leads to the production of an oil with intense aromatic characteristics, while mild conditions, generally employed to obtain an oil with professed therapeutic characteristics, lead to a product with minor characteristic pumpkin seed oil aroma. The nutraceutical properties of the product are confirmed by the high content of α‐ and γ‐tocopherol and carotenoids. © 2012 Society of Chemical Industry     

食盐浓度对虾油风味成分形成的影响研究

本文以虾头虾壳酿制虾油,研究了酿制过程中食盐浓度对风味成分形成的影响,数据显示:20%食盐浓度下酿制的虾油其游离氨基酸含量为16.8450 mg/g,挥发性成分中醛类占2.77%、吡嗪类占28.47%;而30%食盐浓度下上述各物质含量分别为14.4886mg/g、0.67%、7.33%。但TVBN值则是20%食盐浓度的虾油显著高于25%和30%食盐浓度的虾油,且前者有较明显的臭味,虾油的总体风味较差。以上结果表明;食盐浓度对虾油风味物质的形成有显著影响,虽然较低的食盐浓度有利于产生较多的游离氨基酸以及醛类、吡嗪类物质,但过低的食盐浓度不能完全抑制腐败作用。综合考虑,食盐浓度25%较为合适。     

曙光煤矿高盐度及高铁锰水处理技术

针对曙光煤矿高盐度、高铁锰地下水直接饮用不达标的问题,采用锰砂过滤 精密过滤 反渗透工艺进行深度处理.运行结果表明,该系统处理高盐度、高铁锰水,出水铁离子和锰离子质量浓度均小于0.1 mg/L、溶解性总固体小于1000 mg/L,出水水质达到了<生活饮用水卫生标准>的要求.     

名菜名点工业化生产初探

杭州楼外楼作为一个老字号的餐饮企业,成功地走出了一条名菜工业 化生产的道路,它的经验说明,中国的风味名菜应该、也可以进入工业化生产领 域;工业化生产风味名菜关键在于依托生产过程的规范化,而其规范化又要依靠 技术创新来支持。     

Optimisation and Validation of the “Strathclyde Simulated Mouth” for Beverage Flavour Research

Flavour is perceived as the result of partition and equilibrium of volatile odorants of a food during consumption. Research previously carried out with whisky has been restricted to sensory and conventional chemical analyses, which have made a contribution to understanding the process, but cannot show what happens when whisky is consumed. Dynamic headspace methods are required to take a step further into understanding the phyco‐chemical interactions that take place in the mouth of the consumer or laboratory assessor. Buccal headspace analysis has been used for whiskies, but cannot be used for model systems of non‐food materials. The “Simulated Mouth” was therefore designed and constructed to imitate the mouth. Operation of the simulated mouth was optimised using buccal headspace analysis as a reference method. Parameters that were taken into consideration were: the flow rate of hydrated air through the simulated mouth cavity, presence of artificial saliva, the size of the vessel, the amount of whisky used, the use of glass beads to simulate teeth, shaking or static condition, and the time for collection of volatiles. The simulated mouth showed systematic changes in a series of samples of different maturation times. The arrangement of the model and the methodology should also be appropriate for study of flavour release from other liquid systems.     

The Contribution of 4‐Hydroxyfuranone Derivatives to the Aroma of Commercial Beers and Malts

Analysis of hot water extracts from a range of commercial malts showed that 2,5‐dimethyl‐4‐hydroxy‐3(2H)furanone (DMHF) varied from undetectable (lager malt) to 4.2 mg/litre (crystal malt), a concentration twenty‐six times the flavour threshold in water. 5‐Methyl‐4‐hydroxy‐3 (2H)furanone (MHF) was detected in all samples except one but was always well under its flavour threshold value. 2(or 5)‐Ethyl‐5(or 2)‐methyl‐4‐hydroxy‐3(2H)furanone (EMHF) was not detected in any of the samples. Fermentation of lager, ale and crystal malt extracts with an ale strain of yeast led to the appearance of EMHF in all cases as well as additional DMHF. The greatest increases in both compounds was with the ale malt. Both increases and decreases occurred in MHF concentration as a result of fermentation but final levels were always well below the flavour threshold value. Analysis of ten commercial beers found DMHF in all the samples and in five cases levels exceeded twice the flavour threshold value in beer with flavour units from 2.4 to 9.1. A flavour panel noted that in four of these cases the beer had a distinctly sweet/caramel aroma which is typical of DMHF. EMHF was undetectable in six samples, detectable, but unquantifiable, in three cases but at about 80% of the flavour threshold value in the remaining sample. MHF was found in all samples but at insignificant levels. The results show that DMHF is an important flavour compound in British ales and EMHF may make a contribution in a limited number of situations. The contribution of malt type, brewery processing and yeast strain in determining the concentration of the two 4‐hydroxyfuranones in beer remains uncertain.     

白酒色谱骨架成分的含量及比例关系对香型和质量的影响

讨论了白洒色谱骨架成分,并例举了部分名优白酒的成分含量。指出主体香成分的含量比例构成了各种香型白酒的不同风格,酯和酸和总量构成是名酒〉优质酒〉普通白酒〉液态白酒,优质酒的总酸超过普通白酒１倍左右,超过液态白酒５￣１０倍,其总酯比普通白酒液态酒高７￣１１倍。主体香成分与助香成分的比例关系对酒质和香型的影响举足轻重。     

浅谈浓香型曲酒异味的成因及预防

介绍了浓香型曲酒的糠杂味、底锅水味、霉味、臭味、油味、黄水味、酯化液味生成的原因及预防措施.     

浓香型白酒微量成分复杂的原因

浓香型白酒微量成分复杂的原因包括不同原料带入的香气成分、大曲中不同微生物产生的芳香成分、糟醅蒸馏过程中产生的香气成分及窖泥微生物产生的香气成分等.(一平)     

扇贝香味料的研究

扇贝香味料是以新鲜扇贝汁为原料精制而成的。本文探讨了控制扇贝香味料质量的方法,确定了最佳工艺路线。