Smoked flavor production

Tobacco, unlike most other commodities, is not produced as a food crop, but it is used for manufacture of smoking materials and other products. The essential oils in tobacco are important for impact and balance in smoking (11). Smoking pleasure is derived from a balance of nicotine and volatile components. Tobacco chemists and flavorists are certain that carotenoid derivatives contribute to smoke flavor and aroma (5) Over a hundred compounds related to carotenoids have been isolated from tobacco and tobacco smoke. 

Because of the complexity of the chemical interactions and transformations involved, the types and ratios of active flavor products formed by nonenzymatic browning are dependent on the reaction conditions that may occur during aging or during the smoking process itself. 

The development of the low-tar cigarette required enrichment of smoke flavors in order to make the product acceptable to the consumer. The flavor is enhanced by addition of undescribed materials that may include concentrates of flavor precursors obtained from tobacco, licorice, extracts from other plants, or semisynthetic or fully synthetic flavor components. Because these additives have not been identified, no... 

Processing of meat and fish, such as curing and/or smoking, creates a characteristic flavor in the products especially in sausages or bacon [106], Commercial smoke flavorings used in the food industry have different organoleptic features, due to their different compositions. Many factors have an important influence in the composition of these mixtures such as the processes followed in their manufacture [107]. 

There are several studies investigating the flavor composition of smoked products that gives the products their characteristic flavors. The main components responsible for the smoke flavor are phenol derivatives. In addition to the flavoring compounds arising from wood pyrolysis, flavoring compounds derived from plants are also present. The soluble fraction mostly contains fatty adds and fatty esters, in addition to acids, alcohols, carbonyls, esters, furans, lactones, furans, and many miscellaneous compounds [108]. The phenolic fraction of traditional kiln-smoked Bacon contains phenols, furfuryl alcohol, and cyclotene while different compounds, such as 2,4,5-trimethyl-3(2//)-furanone, have been isolated from cooked Oscar Mayer bacon [109],... 

Formation, factors affecting concentrations, legal limits and occurrence of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavor additives are briefly reviewed by Simko. The most widely employed techniques such as thin-layer chromatography (TLC), gas chromatography (GC), and high-performance liquid chromatography (HPLC) are evaluated. Moreover, sample preparation, pre-separation procedures, separation and detection systems being used for the determination have been evaluated with emphasis on the latest developments in applied food analysis and... 

Simko, R, Determination of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavoring food additives, J. Chromatogr. B, 770, 3, 2002. 

Smoking is a slow process and it is not easy to control the process. Smoke contains phenolic compounds, adds, and carbonyls and smoke flavor is primarily due to the volatile phenolic compound [10,20,34]. Wood smoke is extranely complex and more than 400 volatiles have been identified [43]. Guillen and Manzanos [26] identified around 140 compounds in liquid smoke prepared from Thymus vulgaris wood. Polycyclic aromatic hydrocarbons are ubiquitous in the environment as pyrolysis products of organic matter. Their concentrations in smoked food can reach levels hazardous for human health, especially when the smoking procedure is carried out under uncontrolled conditions [46]. Wood smoke contains nitrogen oxides, polycyclic aromatic hydrocarbons, phenolic compounds, furans, carbonylic compounds, aliphatic carboxylic acids, tar compounds, carbohydrates. 

Charcoal briquettes are made of two primary ingredients (comprising about 90% of the final product) and several minor ones. One of the primary ingredients, known as char, is basically the traditional charcoal, as described earlier. It is responsible for the briquette s ability to light easily and to produce the desired wood-smoke flavor. The most desirable raw material for this component is hardwood such as beech, birch, hard maple, hickory, and oak. Some manufacturers also use softwoods like pine, or other organic materials like fruit pits and nut shells. 

By compounding chemically defined flavoring substances. Smoke flavors should contribute no more than 0.03 ppb 3,4-benzopyrene to the final food product. ... 

More recent manufacturing processes consist of inclined rotary calciners. Sawdust is fed continuously into one end of the inclined tube and discharged at the other end as charcoal. The vapors are handled as already described. The rate of feed, inclination of the tube, and rate of air flow are optimized to give a product with the best smoke flavor and the lowest content of polycyclic aromatics. 

In meat curing, nitrite is traditionally used for developing the pink, heat-stable pigment. Its other important role is the inhibition of the outgrowth of Clostridium botulinum spores in pasteurized products and, in some countries, in several types of smoked fish. Nitrite also serves as an antioxidant and contributes positively to the development of the flavor of cured-meat. The undesirable side-effect, however, is the reaction of nitrite with amino groups of food constituents, leading to the formation of NNCs. 

---