Plant extracts will improve the stability of livestock and poultry products

In the process of food processing and storage, hydrogen peroxide will be produced due to the oxidation of polyunsaturated oil, which will further oxidize and decompose into secondary reaction products, such as short chain acetaldehyde, ketone and other oxidation compounds, affecting the overall quality of food, including the production of fragrance, taste, nutritional value and toxic compounds In the food industry, synthetic antioxidants are commonly used to inhibit the oxidation of oil Two kinds of synthetic antioxidants, dibutyl hydroxytoluene (BHT) and butyl hydroxyanisole (BHA), are widely used However, their use in the food industry is limited due to their instability and carcinogenicity Many medicinal plants or spices have been proved to have an effective anti lipid peroxidation effect on oil and fat food Therefore, natural antioxidants have attracted the attention of many research institutions A large number of experimental studies have proved that plant extract additive is a "safe, efficient, stable and controllable" feed additive, which has been marketed and used in feed and animal production The results showed that the plant extracts of Labiatae had strong antioxidant activities, such as dysentery, oregano, thyme, rosemary, clove and cinnamon Further study on the antioxidative effect of the extract of zhishicao in vitro showed that thymol and carvol, the main components of zhishicao, had strong antioxidative properties, while other minor components played an important synergistic role in antioxidation Oxidation is one of the reasons for the decline of meat quality during storage This process is accompanied by the emergence of free radicals to produce aldehydes, resulting in changes in the taste and color of meat The advantage of poultry meat in nutrition is high protein content, which contains essential polyunsaturated fatty acids Broilers have an average of 3.5% - 5.0% fat Polyunsaturated fatty acids are the most sensitive part in the oxidation process In recent years, studies have shown that the addition of dysentery essential oil products to Turkey diet can delay lipid oxidation of breast and leg meat during cold storage Some scholars pointed out that adding 200 mg / kg essential oil of dysentery, cinnamon and pepper, or 5000 mg / kg essential oil of sage, thyme and rosemary can improve the feed digestibility of broilers Plant extracts containing different molecules have inherent biological activities on animal physiology and metabolism Thymol and carvol can destroy the integrity of cell membrane, change the balance of pH and make inorganic iron unbalanced Therefore, plant extracts can inhibit the growth and reproduction of pathogenic bacteria and non pathogenic bacteria in the intestine The effect of plant extracts on hatchability egg seems to be born with antioxidant properties, which can maintain flavor during long-term storage However, eggs with high unsaturated fat are easy to oxidize during storage, especially at low pH It is important that, in the later period of egg hatching, excessive heat causes stress to chicken embryo With regard to the effect of plant extracts on the performance of laying hens, the researchers studied the effect of edible natural antioxidants including dysentery herb, thyme, rosemary and turmeric on the performance of laying hens, and compared them with vitamin E (100 mg / kg and 200 mg / kg) in different doses The results showed that the performance of laying hens could be improved by adding plant extracts during laying period, and the egg production, egg weight and feed conversion rate could be increased by adding dysentery herb, thyme, rosemary or turmeric The mechanism of action may be that the plants of Labiatae (dysentery herb, thyme, rosemary) contain phenolic compounds (thymol and carvol), which effectively inhibit the activity of bacteria and fungi and improve the production performance A large number of studies have shown that the extracts of Labiatae (dysentery herb, thyme and rosemary) can improve the oxidative stability of chicken and eggs In addition to carvol and thymol, other phenolic compounds (caffeic acid, paracymosin-2, 3-diol and some bisphenol and flavonoids) also have antioxidant activities, some of which are higher than α - tocopherol The high antioxidant activity of thymol is due to the fact that the hydroxyl group of thymol acts as hydrogen donor in the first stage of oil oxidation, which hinders the formation of hydroxyl peroxide Therefore, MDA is not produced during the storage period of eggs, and the addition of plant extracts can reduce the oxide in yolk more than the addition of vitamin E Plant extracts can also reduce the total amount of oil in plasma and yolk, which may be due to the reduction of the production of oxides into the yolk, the reduction of free radical generation, thus reducing the MDA content in the egg At present, many scholars are using modern research methods such as modern nutrition, immunology and molecular biology to further strengthen the research on the action mechanism of plant extracts from the aspects of metabolic utilization of nutrients in vivo, immune regulation mechanism, antioxidant mechanism and hormone secretion regulation, so as to ensure the safety and wide application of plant extracts in feed industry And efficient use.