Rancidity development during the chilled storage of farmed Coho salmon (Oncorhynchus kisutch)

Coho salmon (Oncorhynchus kisutch) is a fatty fish species whose farming production has greatly increased in recent years. Lipid damage produced during Coho salmon chilled storage was studied for up to 24 d. Lipid hydrolysis (free fatty acids, FFA) and oxidation (conjugated dienes; peroxide value, PV; thiobarbituric acid index, TBA‐i; fluorescent compounds formation, FR; browning development) were determined and compared to lipid composition (polyene index, PI; astaxanthin, AX) changes and sensory assessment (rancid odour development) results. Most lipid damage indices developed slowly during storage; thus, values obtained for FFA, PV, TBA‐i and FR were in all cases under 1.5 g/100 g, 4.0 meq oxygen/kg lipid, 0.40 mg malondialdehyde/kg muscle and 0.40, respectively. Odour assessment showed a significant (p <0.05) rancidity development at day 10, when compared to starting fish material; then, non‐acceptable values were obtained at days 19 and 24. The PI analysis showed not many differences during the storage time, with the lowest mean value at day 19. AX analysis indicated a relatively high content in the white muscle, which was maintained till the end of the experiment. A low oxidation development is concluded for Coho salmon lipids when compared to other fatty fish species under the same chilling conditions. AX was found to contribute to the oxidation stability of Coho salmon lipids, due to its free radical scavenger properties.     

生物炭-臭氧技术在中水处理中的应用

采用生物炭-臭氧工艺对生活污水进行深度处理.通过实验研究分析了该工艺的原理、特点及最佳设计参数.工程实践表明,生物炭-臭氧工艺应用于中水处理中,当臭氧投加量(以污水计)为5g/m3、接触时间为10min时,系统出水水质稳定,不仅得到优质的中水,而且其出水色度、臭味等指标优于中水水质指标,且运行成本较低.     

车用聚丙烯复合材料气味分析研究

通过气相色谱-质谱对车用聚丙烯复合材料气味进行了分析研究.结果发现气味大的试样产生的挥发性有机化合物是羰基化合物与烃类化合物,而气味小的试样产生的多是烃类化合物,证明了产生气味的化合物是羰基化合物,如酮、醛与酯,这些物质是在高温加工过程中热氧降解产生的.     

The evaluation of underarm deodorants

Double-blind cross-over trials in which trained assessors evaluated axillary malodour on a 0 to 10 scale showed that ethanol at 60% and 99% w/w significantly reduced odour for up to 24 h. Reduction in odour was increased by the addition of non-volatile antimicrobial ingredients such as chlorhexidine, Irgasan DP 300 (Triclosan, Ciba Geigy) or aluminium chlorhydrate.
Volunteer panellists were able to identify statistically significant deodorant effects when they rated their own axillary odour on a 0 to 10 scale.
An odour absorber, zinc ricinoleate (Grillocin, Grillo-Werke, A. G.) was used to treat existing malodour and gave reduced perception of that malodour for up to 24 h.
A close correlation was found between panel odour scores and the bacterial status of the axilla as assessed by the replipad technique when biocidal systems were studied. Irgasan DP 300, a bacteriostat, did not perform so well in skin flora sampling procedures, but was nevertheless effective as a deodorant ingredient. Thus in vivo microbiological techniques, although often useful as predictors of deodorancy, do not replace the carefully controlled clinical trial with direct assessment of odour.
L'evaluation de l'odeur des aisselles     

Odour Control for the 1990s - Hit or Miss?

The growing importance of odour control and the failure of a high proportion of abatement schemes are discussed. A strategy for dealing with nuisance is presented, laying emphasis on a fully integrated approach, involving covering, ventilation design, and odour treatment. Some of the options for treatment are compared.     

Odour generation potential of wastewaters

The odour generation potential (OGP) of a wastewater sample is defined to be the flux of odorous substances that can be volatilized from a unit volume of wastewater. Based on a simple first order decay of the odour concentration of a wastewater sample when subjected to volatilization, a procedure is presented to determine the OGP of different wastewater streams at a municipal wastewater treatment plant. The undigested sludge samples were identified to have significantly higher OGPs than other wastewater samples and therefore have greater propensities to emit odour. The aeration of activated sludge and the anaerobic digestion processes were found to reduce the OGPs of their respective waste streams considerably, thus confirming the effective removal of odorous volatile compounds by these two treatment processes.     

Cause of catty odour formation in packaged food

In two different ‘cook-in-the-bag’ ham products packed in polyamide-ethylene ionomer laminate pouches, the same obtrusive catty off-odour was complained about. In this paper the analytical resolution of a complex off-odour problem is described. Identification of the catty odour as the mesityf oxide-hydrogen sulphide adduct 4-methyl-4-mercaptopentan-2-one is followed by investigating the formation of the off-odour with the aid of different model experiments. It is pointed out that the ethylene ionomer material that is used for the sealing layer of the multilayer packaging film has some dehydration property for diacetone alcohol, which was found as a residual solvent in the film material in question. Probably this pathway seems most likely to be responsible for the off-odour.     

Evaluation of a Pilot-Scale Bioscrubber for the Removal of Hydrogen Sulphide

This technical note describes an investigation on the feasibility of using treated wastewater to support the operation of a fixed-film bioscrubber for H₂S removal. A laboratory-scale fixed-film bioscrubber was assembled using Thiobacillus bacteria which were isolated from a sample of raw sludge, cultured in the laboratory, and immobilised onto the scrubber's plastic packing media by an immersion method.