Smoked products mainly include smoked bacon, fish, and soy products. Because of their unique flavor and long shelf life, they have been loved by consumers. Traditional smoked food mainly uses direct oxidation smoked materials to increase food flavor, improve color and make it have a longer shelf life. At present, a considerable part of the products on the market still use traditional smoking methods, but this method not only has high investment cost and long processing time, but also easily causes smoked foods to form toxic and harmful carcinogens such as polycyclic aromatic hydrocarbons. The advocated concept of a healthy environment does not match.
The smoke liquid is produced by condensing wood smoke (produced by the pyrolysis of wood chips or wood chips) and then removing carcinogenic polycyclic aromatic hydrocarbons. Compared with traditional smoking methods, the food has almost the same smoky flavor. The advantage is that it can not only use the leftover material of trees to achieve the purpose of waste utilization, but also reduce the smoke generated during incineration, protect the environment, and does not contain harmful substances such as polycyclic aromatic hydrocarbons, which meets people’s requirements for green food.
1. Composition of Smoking Liquid
The main components are phenols, carbonyls, organic acids, alcohols, and esters. The existence of phenolic compounds is the main reason for the bactericidal effect of fumigation liquid; In addition, it also has a synergistic bactericidal effect with organic acids, carbonyl compounds, and alcohols. The type and content of phenolic compounds directly determine the aroma and color of the smoking liquid, and the existence of carbonyl compounds can affect the formation of smoking color. Furfural, 5-methylfurfural, and acetylfuran are related to the formation of sweet flavor in fumigation liquid.
2. Function of Smoking Liquid
The smoke liquid is generally used to smoke food, can improve the flavor, promote the color of smoked products, so as to give the food its due smoke color and smoky flavor。 And it can also form a protective film on the surface of the food to improve the texture. It also has anti-oxidation and antibacterial functions. Within a certain concentration range, it can completely inhibit the growth of common flora, which is beneficial to extend the shelf life of food and can be used for food preservation.
2.1. ImpartingFlavor
The smoke liquid contains a large amount of phenolic compounds, which gives the product a special smoke smell. The GC-MS method was used to analyze the flavor components of the squid before and after smoking. The results showed that the flavor components of the squid increased after smoking, and the flavor components increased significantly, and the main components identified were phenols. Only the smoky taste of phenolic substances is relatively monotonous, while furfural, acetylfuran, and other substances are vital to the formation of sweetness in smoked products, making the strong smoky smell softer, pleasant and acceptable. In addition, carbonyl compounds and organic acid compounds also play an important role in the formation of smoky flavor.
2.2. Color Enhancement
The change in the color of the product during the smoking process is due to the absorption of carbonyl compounds. It is the root cause of the golden yellow or tan on the outside of the food. The browning reaction of it with amino groups, the oxidative polymerization reaction of phenols and aldehydes, and the browning reaction of meat protein itself during processing will all form a smoky color. The role of organic acid is to combine with carboxylic acid to form a protective color film on the surface of the meat. Studies have shown that the content of carbonyl compounds is positively correlated with the color of applewood smoking liquid. By immersing fresh pigs with different concentrations of ks2 smoke liquid (salted in advance), the formation of smoke color is studied. The main ways to form smoke color include the self-polymerization of phenol and the phenolic condensation and oxidation of certain components. At the same time, the smoke color is closely related to the amount of smoke liquid added, the time of soaking pigskin, the temperature and humidity of pickling and baking.
2.3. Antioxidant Function
Phenolic substances have anti-oxidation properties, and its content in smoked liquid plays an important role in smoked products. Analyzing the smoking liquid by GC-MS technology, it was found that lignin dimers existed; in addition, lignin trimers and new lignin were detected in the brown layer left on the wall of the container containing the smoking liquid Dimers, these compounds tend to move towards the container wall and have not previously been described as smoke or smoke flavoring components. Because lignin trimer and lignin dimer have high antioxidant activity, they are very important in the preservation of smoked food, and the effect is even better than that of lignin monomer. Studies have shown that the antioxidant capacity of smoked products is related to the phenolic substances in the smoke, and the antioxidant capacity of dimethoxyphenol compounds is better than that of methoxyphenol compounds. When studying the effects of 4-methoxyphenol, 4-ethylguaiacol and isoeugenol on oxidative damage, the results show that these phenolic compounds have very strong antioxidant effects, especially 4-ethyl guaiacol and isoeugenol. Guaiacol. And they have inhibitory effects on the generation of free radicals and the oxidation of biomolecules in non-cellular systems.
2.4. Antibacterial Function
Smoke liquid has an antibacterial effect to extend the storage time of smoked products. The phenolic compounds in the smoking liquid have an antioxidant effect because they can destroy the cell membrane of the bacteria to a certain extent, solidify the protein in the bacteria, and inhibit the growth of the bacteria. The smoke liquid is used as a substitute for smoked traditional meat products. By combining it with bacon, the evaluation of its potential as an antioxidant and bacteriostatic agent in the product has shown that due to its oxidative stability, it has Staphylococcus, Escherichia coli, Listeria monocytogenes, and Salmonella cholerae have inhibitory effects, and the minimum sterilization dosage is 7.5%-15.0%.
Therefore, applying it to the food industry can not only obtain the color and flavor similar to traditionally smoked products, but also does not contain 3,4-benzopyrene and other polycyclic aromatic hydrocarbons, making it easier and more convenient to use, and has no pollution to the environment. In addition, it also contains phenols and organic acids, which have certain antioxidant and antibacterial effects, and can prevent smoked products from being infected by harmful microorganisms.
3. The application of Smoking Liquid in Meat Products Processing
Japan and European and American countries have already used liquid smoked flavors to make smoked-flavored meat products before and in the middle of the 19th century. Although China’s research on smoke liquids is relatively late, its applications are relatively wide. Compared with traditional wood smoking, it is considered to be a safer and healthier method. Therefore, many researchers have devoted themselves to researching smoked products with smoked flavors, diverse varieties, and conforming to modern people’s green concepts.
In China, the liquid smoke is mainly used in smoked enemas, bacon, and ham. For example, using bagasse smoked liquid, pecan shell smoked liquid, and hawthorn core smoked liquid to smoke enema, the results show that the smoked liquid can significantly inhibit fat oxidation and the growth of microorganisms, and the antioxidant capacity is proportional to the concentration. It can improve the texture properties, water holding capacity, and sensory quality of enema to a certain extent.
The effects of the components of applewood smoke liquid, walnut smoke liquid, and hawthorn core smoke liquid on the mechanical properties and color of natural casings and collagen casings were explored. The results showed that the color of casings treated with 3 kinds of smoked liquids Both are significantly deepened, and the mechanical properties are significantly improved, and the hawthorn core smoked liquid has the most obvious effect on the improvement of the mechanical properties of the casing.
By applying applewood smoke liquid to Chinese bacon, it gave the bacon a good quality. The product has a fresh smoky flavor and no 3,4-benzopyrene was detected. The refined wood pineapple smoke liquid and eucalyptus smoke liquid are used to smoke ham and enema, and the sensory score and texture, and other comprehensive scores are used as indicators. The results showed that the effect of wood pineapple smoke liquid was better than eucalyptus smoke liquid, and the detection amount of 3,4-benzopyrene in meat products was far below the national standard limit.
Compare the effects of liquid smoked, paper smoked, and wood-smoked techniques on the quality of Western-style bacon. The results show that liquid smoked products can achieve the same flavor as wood smoked products. And the detected amount of benzopyrene in paper smoked and liquid smoked products is lower than that of wood-smoked products, and is greener and safer. It can be seen that the use of smoking liquid as a substitute for traditional foreign smoked products also has advantages.
In summary, because the smoked liquid can effectively inhibit the growth of bacteria, the content of 3,4-benzopyrene in the refined smoked liquid is very small. Therefore, the smoked liquid is used in the processing of modern smoked meat products. It can ensure that the product has almost the same flavor as traditionally smoked meat products, and can obtain healthier and safer products.
