The Gjerstad kiln: a combined hot and cold smoking kiln

A combined hot and cold smoking kiln has been constructed for use at Lake Turkana, Kenya. Used for cold smoking, the kiln's main advantages over the traditional kilns used in this area are its greater smoking capacity and lower firewood consumption. Having the option of using the same smoke house for cold and hot smoking reduces the total construction costs for an operator producing both types of smoke cured product. The hot smoking process was found to require markedly less firewood than cold smoking, a fact of considerable importance in desert or semi-desert areas with sparse vegetation.

Effects of hot and cold smoking processes on organoleptic properties, yield and composition of matrinxa fillet

Foi avaliado o efeito do processo de defumação a quente (45-90ºC/5 horas) e a frio (27-45ºC/10 horas) nas propriedades organolépticas, no rendimento e na composição dos filés de matrinxã (Brycon cephalus). Não houve diferença significativa no rendimento de filés defumados e não-defumados. As perdas no processo de defumação foram significativamente maiores para defumação a quente (19,37%) em comparação à defumação a frio (17,08%). O processo de defumação reduziu a umidade (in natura = 72,91%; defumado a quente = 58,51%; e defumado a frio = 59,68%) e aumentou os teores de proteína bruta, lipídios e cinzas. Houve diferença significativa somente nos teores de proteína no defumado a quente (28,07%) e defumado a frio (27,14%). O processo a frio resultou em melhor aparência e cor de filé, enquanto o processo a quente melhorou o sabor, o teor de sal e a aparência geral. O aroma e a textura não diferiram significativamente entre os processos. O processo de defumação a quente melhora as propriedades organolépticas e os níveis de proteína do filé de matrinxã.

Effects of hot and cold smoking processes on organoleptic properties, yield and composition of matrinxa fillet

Foi avaliado o efeito do processo de defumação a quente (45-90ºC/5 horas) e a frio (27-45ºC/10 horas) nas propriedades organolépticas, no rendimento e na composição dos filés de matrinxã (Brycon cephalus). Não houve diferença significativa no rendimento de filés defumados e não-defumados. As perdas no processo de defumação foram significativamente maiores para defumação a quente (19,37%) em comparação à defumação a frio (17,08%). O processo de defumação reduziu a umidade (in natura = 72,91%; defumado a quente = 58,51%; e defumado a frio = 59,68%) e aumentou os teores de proteína bruta, lipídios e cinzas. Houve diferença significativa somente nos teores de proteína no defumado a quente (28,07%) e defumado a frio (27,14%). O processo a frio resultou em melhor aparência e cor de filé, enquanto o processo a quente melhorou o sabor, o teor de sal e a aparência geral. O aroma e a textura não diferiram significativamente entre os processos. O processo de defumação a quente melhora as propriedades organolépticas e os níveis de proteína do filé de matrinxã.

Veränderungen der Farbe und thermischen Stabilität der Muskelproteine von Räucherforellen während der Kühllagerung

The aim of the investigation was to prove if different farming conditions like conventional and organical farming of rainbow trout may cause differences in quality which are detectable by physical methods such as colour measurement and differential scanning calorimetry. Colour measurement revealed remarkable differences in lightness. Smoked trouts originating from conventionally farmed fish were much lighter than those of organically farmed trouts. This difference in L* could already be found when colour measurements were taken on the raw material. However, during chilled storage differences were equalized. Redness and yellowness were not significantly influenced by farming and did not change remarkably during chill storage. Based on earlier investigations on changes in thermal stability caused by heating, DSC curves of smoked trout could be used to verify that the core temperature of smoked fish had reached at least 60 °C during hot smoking process. This temperature is demanded by the guidelines of the German Food Code. In the DSC curves only the actin peak was still visible. All other proteins were obviously denatured during the hot smoking. When DSC curves were taken from smoked trout after different durations of chilled storage it could be seen that the denaturation temperature of actin decreased almost linearly with progression of storage time.

Making kippers from local herring (Sardinella spp.) smoke-cured in the Torry Kiln

(Sardinella) are available all year round in Sierra Leone. The best time to use them for baiting herrings is during the dry season when they are fattest and feeding well. The most common method of processing herring locally is hot smoking to give either soft, moist and cooked product or a dry, brittle product with very low moisture content. The author describes a curing method intended to add variety to the types of products that can be obtained from local herring. It is only mildly preservative, the product cannot be kept more than 24 hours without refrigeration. Particular attention is paid to the source and quality of the raw material used, and the processing method is detailed with attention to washing, splitting, brining, smoking, and the application of the Torry fish smoking kiln to the process.

Qualidade microbiológica e vida útil de filés defumados de tilápia-do-nilo sob refrigeração ou congelamento

The objective of this work was to evaluate the microbiological quality and shelf life of Nile tilapia fillets subjected to different smoking methods and storing conditions. Two smoking processes (cold or hot) were used in fillets with or without pigmentation. Products were stored under refrigeration or freezing, and monitored continually for 28 days for evaluation of their shelf life. Frozen fillets were monitored for 146 days for analysis of thiobarbituric acid (TBA) only. Hot- and cold-smoking reduced the coliform quantity, respectively, by 99.78% and 97.80%. Product storage under refrigeration allowed a 99.73% coliform reduction, and storage under freezing reduced them by 99.83%. Fecal coliform values were within the allowed limits. TBA values in fillets reached their maximum on the 14th storage day. TBA values were higher in treatments under refrigeration storage than in those under freezing, as well as in cold-smoked fillets in comparison to the hot-smoked ones. Hot-smoked process, followed by refrigeration storage, is the most adequate technique to ensure quality and a larger shelf life for Nile tilapia fillets, regardless of pigmentation process.

Studies on smoking of eel fillets

A procedure has been worked out to (hot) smoke eel fillets. Some of the important factors such as size of the fillets, brining, pre-drying, source of smoke, smoking period, final drying have been studied. Best quality of smoked product is obtained on smoking eel fillets with a mixture of coconut-husk and sag saw-dust in 1:1 proportion for 15 hours. Optimum moisture level of the final product was fixed in the range of 30 to 35% and it had a storage life of about 8 months at room temperature.

Preparation and keeping quality of hot smoked mackerel

A method has been standardised for the production of smoke cured mackerel by dry salting in the ratio of 1:8 salt to fish followed by smoking in a traditional smoke chamber at 70±5°C for 5h. The smoke was generated by burning moist coconut husk and saw dust. The product obtained by this method had shelf-lives of 105, 95 and 6 days in chilled storage (0 to 2°C) refrigerated storage (10±2°C) and at room temperature (29±2°C) respectively.

Air pollution levels measured at traffic hot spots : Brisbane urban corridor study

Air pollution levels were monitored continuously over a period of 4 weeks at four sampling sites along a busy urban corridor in Brisbane. The selected sites were representative of industrial and residential types of urban environment affected by vehicular traffic emissions. The concentration levels of submicrometer particle number, PM2.5, PM10, CO, and NOx were measured 5-10 meters from the road. Meteorological parameters and traffic flow rates were also monitored. The data were analysed in terms of the relationship between monitored pollutants and existing ambient air quality standards. The results indicate that the concentration levels of all pollutants exceeded the ambient air background levels, in certain cases by up to an order of magnitude. While the 24-hr average concentration levels did not exceed the standard, estimates for the annual averages were close to, or even higher than the annual standard levels.

Self-efficacy and social support as predictors of smoking after a quit attempt

Examined findings (e.g., A. J. Yates and J. Thain [see PA, Vol 73:28269]) that suggest that perceived social support for attempts to quit smoking is a determinant of self-efficacy (SE). 102 adults (aged 18–71 yrs) who participated in a trial of 4 smoking interventions were studied over a 10-mo follow-up period. The study attested to the validity of SE as a predictor of sustained success from an attempt to stop smoking. The tendency for SE theory to be more strongly supported in the longer term was highly consistent with the proposed mechanism for SE effects. The absence of a relationship with perceived social support might be an advantage for SE, since support was a poor predictor of outcomes during follow-up. Results suggest that perceived social influences had less utility than personal skills and SE in predicting sustained non-smoking outcomes.