Smoke aroma

from Wikipedia, the free encyclopedia

As smoke flavoring preparations is known of condensed and purified fumes as well as in the conventional methods for, smoking of food is used. In contrast, smoke that is freshly produced and used to smoke food appears as smoke in the ingredients list . Smoke flavors come in solid and liquid form; the latter are also referred to in technical jargon as liquid smoke , liquid smoke or liquid smoke .

Tradition of smoking

Smoking combined with drying is one of the oldest methods of preserving food. Archaeological finds suggest that people knew about smoking as a preservative around 9,000 years ago. Climatic differences in the different regions were a significant factor in the development of the different conservation methods. In the traditional smoking process, a distinction is made between cold smoking at a temperature of 15–25 ° C, warm smoking at 25–50 ° C and hot smoking at 50–85 ° C. The higher the temperature, the shorter the time the food stays in the smoke.

Today smoking is used almost exclusively to impart color and flavor. Smoked is usually done with sawdust and wood chips or sawdust from various hardwoods . In addition, z. B. juniper berries, herbs, fir or pine cones and needles are added to create additional aromas. From a technological point of view, there is no difference between the individual smoking processes such as glow smoke processes , friction smoke processes ( friction smoke), steam smoke processes and smoking with smoke generated from smoke condensates .

definition

The European . Aromas Regulation (EC) No 1334/2008 divided flavors in six different categories: flavoring substances , flavoring preparations , thermal process flavorings , smoke flavorings , flavor precursors and other flavorings . Smoke aromas as defined in Article 3 (No. 1, 2 and 4) of Regulation (EC) No. 2065/2003 are produced by fractionating and cleaning smoke condensed in water . They are used to prepare foods such as B. meat, fish or snacks to give a smoky taste. In order to produce smoke aromas, manufacturers have to comply with and strictly control certain legal requirements with regard to temperature, water content of the wood and air supply.

Labelling

The addition of smoke aromas must always be labeled separately in accordance with the European Aroma Regulation if they give the food a smoky taste. The Flavor Ordinance regulates the labeling of flavors with regard to sale to the food industry and end consumers as well as for the identification of flavors in the list of ingredients of foods on the packaging. If smoke aromas are added during the production of food and they give the food product a smoke taste, then they are to be marked as "smoke aroma" in the list of ingredients.

With the Regulation (EC) no. 2065/2003 on smoke flavorings used or intended for use in or on foods , which came into force on 16 December 2003, the regulations of were Member States in the field of production, approval and use unified of smoke flavorings .

The ordinance provides for a procedure in which the Commission allows the so-called primary products - primary smoke condensate and primary tar phase - for the production of smoke flavorings. The approved substances are noted in a positive list in the annex to the ordinance. Access to the domestic market for individual smoke flavors is not regulated, but rather the control and approval of raw materials, the primary products. In the approval process, the manufacturers of primary products must provide detailed information on the starting materials and production methods. Applications for authorization must be submitted to the competent authority in the Member State. She forwards this to the European Food Safety Authority .

According to the EU regulation, the following information must be provided for smoke condensates:

  • Type of wood used
  • Precise information about the production method of the primary products and the further processing into liquid smoke derivatives
  • The qualitative and quantitative analysis of the primary products and the characterization of the portion that cannot be identified. This should be as small as possible.
  • Use of a validated method for sampling, identification and characterization of the primary products
  • Information about the intended use amount
  • Toxicological data

Production process

Smoking with smoke or liquid smoke regenerated from smoke condensates is a health and environmentally friendly alternative to classic smoking with glow smoke. In this process, the food is not directly exposed to the smoke stream containing toxic substances (ash, tar, PAH, etc.), but is treated with internal liquid smoke impregnation by atomizing or misting, dipping, sprinkling or filling into intestines. Solutions that are obtained by pyrolysis of wood are called liquid smoke . The undesirable substances such as ash and tar that arise in classic smoking, which is still predominantly used in Germany, are completely eliminated during the production of the smoke by filtering and cleaning. The smoke generated from this smoking product can be used for all common smoking processes such as cold, warm, hot and steam smoking. In addition to the desired smoke color and taste, the shelf life and texture required for the product are achieved.

In the pyrolysis process, sawdust is heated while largely excluding oxygen. The resulting smoke is condensed in water and then largely freed of undesirable substances in a multi-stage filter process. The condensate is broken down into three components by physical processes: an aqueous smoke condensate , a water-insoluble tar phase of high density and a water-insoluble oily phase . The water-insoluble oily phase is a by-product and not suitable for further processing. Some fractions of the water-insoluble tar phase and the smoke condensate are then cleaned, whereby some of the most harmful components, primarily polycyclic aromatic hydrocarbons (PAH), are removed.

This is how the so-called primary smoke condensate and the primary tar phase are obtained . These two form the primary products and are the basis for further processing into smoke aromas. This takes place physically by extraction , distillation , evaporation , absorption or membrane separation and furthermore by adding other flavors, solvents, food ingredients or food additives.

ingredients

Smoke condensate or liquid smoke consists of over 400 chemical compounds (phenols, aldehydes, carboxylic acids) and is characterized by the content of organic acids (including formic acid , acetic acid ), phenols and carbonyls . Phenols give the liquid smoke its smoky aroma, the carbonyls produce a brown color.

Health issues

The chemical composition of smoke is very complex and depends e.g. B. on the type of wood and the water content of the wood , the process used to generate smoke and the temperature and oxygen concentration during the generation of smoke. The volatile components, ash, tar and polycyclic aromatic hydrocarbons (PAH), e.g. B. Benzo [ a ] pyrene , penetrate the surface of the food. Smoked foods therefore generally give rise to health concerns, especially with regard to the possible PAHs. A study has shown that different types of wood for the smoking process result in different levels of PAH concentrations in the food being smoked, but they always contain substances that are hazardous to health.

Since smoke flavorings are made from fractionated and purified smoke, their use is generally considered to be less harmful to health than the traditional smoking process. In the safety assessments, however, the more versatile uses of smoke flavorings compared to conventional smoking must be taken into account. These include foods such as sauces (e.g. BBQ sauce), soups and snack foods that are usually not smoked, but that can be given a smoky taste through the use of smoke aromas. When using regenerated smoke from purified smoke condensate, which is used for smoking food in smoking systems, a reduced content of PAHs and 3-monochloropropanediol (3-MCPD) can be determined without changing the sensory and chemical properties.

Environmental benefits

Smoking with smoke regenerated from smoke condensate should be the preferred smoking method in view of increased environmental awareness. The smoking process with smoke condensate not only consumes less material, it is also significantly more energy-efficient. In the glow smoke process, due to the system technology, up to 500% more CO 2 is emitted compared to smoking with smoke from smoke condensate . In addition, with traditional smoking, the water consumption is greater, and the wastewater that occurs during flue gas cleaning is significantly more contaminated with chemicals ( alkaline cleaning agents such as smoke resin removers) and other contaminants (soot, tar).

In addition to the general emission levels in the vicinity of the smokehouse, there is also an increased risk of fire in the smoldering smoke process due to the risk of fire and explosion in the smoking compartments. In 2008 alone, there were at least seven fires with (in total) one fatality and total damage of 316 million euros.

Carbon dioxide

With conventional smoke generation, up to 50.8% of the material used is waste, which must be disposed of. The cleaning, waste disposal and transport of the fumigants produce around 0.5 kg of CO 2 per ton of smoked food with the conventional smoking process . In the case of liquid smoke production, on the other hand, only 0.84% ​​of the material used is waste. The substances (tar, charcoal) that are not used in liquid smoke are used to generate energy for the process heat and improve the CO 2 balance by 0.342 kg per ton of smoked food. Due to the lower amount of liquid smoke used, an emission of 0.1 kg CO 2 per tonne of smoked food for cleaning, disposal and transport can be expected.

When smoldering smoke is used, post-combustion of the flue gases is mandatory. Here, about 10 m 3 of natural gas are used per ton of food to be smoked . This corresponds to 24.85 kg of CO 2 per ton of smoked meat products (using the example of smoked ham). No afterburning is required for friction smoke generation and liquid smoke production.

Pollutants

When wood burns up, substances such as ash, tar and polycyclic aromatic hydrocarbons (PAH) are produced. The use of smoldering smoke prescribes post-combustion of the flue gases. In the exhaust gas of thermal and catalytic post-combustion systems, emissions of nitrogen monoxide and nitrogen dioxide ( NOx ), expressed as nitrogen dioxide, must not exceed a mass concentration of 0.10 g / m 3 ; At the same time, carbon monoxide (CO) emissions must not exceed a mass concentration of 0.10 g / m 3 . Investigations have shown that none of the investigated afterburners complied with these values.

By using smoke condensate, smoke emissions into the exhaust air are avoided for two reasons and the above-mentioned emission limits of the technical instructions for keeping the air clean (TA Luft) are observed. The decisive factor is that when smoking smoke is produced from liquid smoke, there is no thermal combustion, which is why CO and NO x cannot arise. And the smoking process takes place in a closed system. Due to these ecologically positive aspects, liquid smoke is assessed in the TA Luft as a primary measure to reduce emissions and is exempt from the requirements of the Federal Immission Control Act.

With the "Rauch seal of quality" for smoked meat and sausage products, the smoke flavor manufacturer Red Arrow has introduced a protected trademark for smoking products that have been freed from tar and ash.

See also

Web links

Individual evidence

  1. ↑ SEABERT, H .; WÖHRMANN, H .: On the history of food preservation ( Memento from June 23, 2015 in the Internet Archive ) (PDF; 145 kB), in: NiU Chemie 4 (1993) No. 19.
  2. ↑ a b REGULATION (EC) No. 1334/2008 on flavors and certain food ingredients with flavor properties (PDF) .
  3. ↑ a b c REGULATION (EC) No. 2065/2003 on smoke flavorings for actual or intended use in or on food .
  4. ↑ a b MEIER, D .: Liquid smoke - an analytical challenge, in: Research Report - Journal of the Senate of Federal Research Institutes, Edition 2/2004.
  5. ↑ HITZEL, A .; PÖHLMANN, M .; et al .: PAH levels in smoked meat products, in: Fleischwirtschaft 1/2013.
  6. ↑ a b c VORWOLD, G. and TÖPFL S .: Expertise on CO 2 emissions from smoking using liquid smoke in comparison to conventional smoking processes, German Institute for Food Technology eV, Quakenbrück, July 2009.
  7. ↑ BÄRWINKEL, K .: Sharpening ecological views, in: Fleischwirtschaft 4/2009.
  8. ↑ red-arrow-deutschland.de: Rauch quality seal .

literature

  • FENGEL, D. and WEGENER, G .; Wood Chemistry, Ultrastructure, Reactions Walter de Gruyter, Berlin 1984, Chapter 12 Process for the Production of Liquid Smoke Browning Agents, Patent, Hickory Specialties, Inc., Brentwood, Tennessee, US A
  • MEIER, D., Federal Research Institute Johann Heinrich von Thünen Institute, Federal Research Institute for Rural Areas, Forests and Fisheries, Hamburg
  • Guideline, communication of environmentally relevant key figures for the wood industry, German Society for Wood Research eV, Munich,