SMOKE FLAVOURS

Smoking of food products has been used for centuries in many countries. Originally the purpose was to preserve the food, partly by drying and partly by adding antimicrobial constituents like phenols from the smoke to food. 

Besides the traditional smoking process, the use of smoke flavouring preparations based on the smoke condensates and to some extent on artificial smoke flavouring substance has been introduced in many countries. 

As some of the constituents in smoke and in the smoke condensates may give rise to the health problems, limits should be set for the quantities of these components in the flavouring or in the final food.

INTRODUCTION

Smoked food is the food produced either by the use of traditional smoking process or by the use of smoke flavoring's or by the combination of both methods.

In principle four different ways can be used to produce smoke food under two methods.

I) TRADITIONAL METHOD

1)      Smoking with freshly generated smoke from wood.

II) NEWLY EMERGED METHOD

            1) Smoking with smoke regenerated from smoke condensates.

            2) Flavouring with smoke flavor preparations derived from smoke condensates.

            3) Flavouring with smoke flavor prepared by mixing chemically defined substances.

   

SMOKING TECHNOLOGY

In smoking process, the first step is to make a fire using dried wood. The kind of wood may depends on tradition and normally it will differ from country to country. For instance in the United Kingdom the use of oak is common, whereas in Denmark beech is normally used, Besides the use of wood, some lands of aromatic herbs and spices and twigs of juniper can be used in order to give a special taste to the smoked products.

After having made the fire, the flames are reduced to a glow. The wood is then decomposed by the high temperature in the ignition zone. The composition of the smoke depends very much on the temperature in this area.

The period of time during which the food products are exposed to the smoke is highly important for flavor of food. This process can be regulated by several means including cooling of the smoke and addition of water and or air. 

By this regulation the flavor of the products can be changed but in some degree this regulation might also influence the formation of unwanted impurities which are transported from the smoke to food. As changes in the composition of smoke might also influence the taste of the food product, changes like this would often have to be the result of compromise.

The use of smoke flavorings often comprises atomizing of smoke flavouring and then spraying it on the surface of the food. The result in taste, appearance and preservation is more or less the same as that obtained by using the traditional smoking process.

IMPORTANCE OF SMOKE

Smoke from wood consists of several components such as gas, liquid and solid particles. Most of the smoke is air with mixture of small particles of different size. These particles spread the light and give appearance to the smoke.

The particles in the smoke are to some degree left on the food, but this is only of minor importance of smoke process and major importance is the absorption of gases by the food products. This is the part of the smoke which gives the characteristics color and the flavor, which the particles are responsible for anti-oxidizing effect.

METHODS IN SMOKING

Traditionally, smoking only allows limited possibilities for control of temperature, humidity, content of smoke, circulation and so on. The development of equipment for smoking of food has concentrated on the possibility of possibility of all these factors.

The methods are actually categorized by temperature used :

COLD SMOKING: Where the temperature is normally 18-50 degree Celsius. The process is typically used for salmon, salamis, kippers, ham and special cheese. A cold smoking may last several weeks. Normally the smoking process lasts for 6-24 hrs.

WARM SMOKING: The temperature used here is about 40 degree Celsius used for baron and some types of sausages. Warm smoking is a combination of drying, coking and smoking process.

HOT SMOKING: It is a combination of strong heating and smoke, which gives a temperature in the products of 70-90 degree Celsius.

FACTORS INVOLVED

During smoking process many different factors are of importance, and some of them also influence the absorption of smoke by food.

Some important factors are

· Density of smoke

· Humidity

· Temperature

DENSITY OF SMOKE: As far as the density of smoke is concerned, the result of high smoking density more smoke particles gets condensed on to the surface of food. Absorption of smoke components during the process is also affected by humidity.

HUMIDITY: If the relative humidity is high, steam will condensate of the surface of the product and the absorption of water soluble parts of the smoke will increase. If the surface remains moist the formation of color will be inhibited as the color formation is increased by lower the water content. However, if the surface is too dry, penetration of the smoke into the food will be decreased with loss of flavor and preservative effect.

TEMPERATURE: Heating of smoke can be done by using steam, gas or electricity has a minor influence of the composition of smoke but heating by direct burning of gas in the smoke chamber can initiate some secondary reaction because of high temperature of flame and give rise to formation of nitrogen oxide in smoke.

In a modern, industrial smoking process whereas the smoke generator and the smoke chamber are separated, the ability to control density of smoke, humidity and temperature is quite good .

APPLICATION

1) Can blended directly into the food.

2) Can prevent drying loss which normally takes place during smoking process .

3) Food products does not loss weight.

4) Processing time gets reduced.

5) Price of the products gets reduced because of less processing steps.

6) Color of the products does not affect

7) By the same time preservation process also occurs.

HEALTH ASPECTS

1) First observation on cancer from smoke or condensed smoke were made in 1775 by an English scientists Dr. Pott , who describes the appearance of skin cancer due the presence of polycyclic aromatic hydrocarbon (PAH) and nitroso components.

2) Many of the others components in smoked food are known to be toxic. This is the case for some of carboxylic components, for instance formaldehyde, which is carcinogenic in testing animals.

TECHNOLOGY DEVELOPMENT

1) To get a better controlled process thereby a better controlled development of flavor and appearance.

2) To reduce the amount of possible carcinogen or other toxic components in the smoke.

3) To reduce the contamination of the environment by smoking process.

4) To increase turnover in production.

5) To develop electrostatic filters in order to remove unwanted impurities.

6) To develop water filters for washing of smoke.


CONCLUSION

It must be concluded that smoked foods do give rise to some health concern, especially with respect to possible content of nitroso components and PAH. Fortunately, however there are several means available to minimize some of health concern by removing or reducing the amount of relevant components , by using smoke flavouring with well known and safe composition or by modifying smoking process.