From a chemical point of view, the number of odorous nucleotides increases with the growth cycle. Its ingredients are the same as food flavoring agents, such as chicken essence, chicken powder, seasoning monosodium glutamate, soy sauce, instant noodle seasoning package and so on. All kinds of meat and mushrooms have flavor nucleotides. This will make them "smell like chickens" and "smell like ducks".
However, the old pig and cow are not so lucky. Because if their growth cycle is long, it will lead to rough muscle fibers and increased connective tissue, which is called "poor meat quality".
From the perspective of Chinese medicine, "medication is not as good as diet therapy".
Let's talk about ducks first. Li Shizhen's Compendium of Materia Medica in the Ming Dynasty records: "Duck waterfowl is also used to treat water conservancy and urination, and it is appropriate to use mallard; It is easy to use black bone and white duck to treat body deficiency and heat toxicity "; In the Qing Dynasty, Wang Shixiong's famous Chinese medicine dietotherapy book "Living Interest" contains: "Duck meat can nourish the yin of the five internal organs, clear the heat of fatigue, replenish blood and promote water, nourish the stomach and promote fluid production, and relieve cough and promote fluid production. Male fat, very old and very good. " There is also a folk saying that "old ducks save food in summer".
The protein content of ducks is much higher than that of other birds, the iron content is four times that of other meats, the fat content is moderate and evenly distributed, and most of them are unsaturated fatty acids. They are aquatic creatures, so their meat is sweet and cold. People with weak constitution, fever, excessive internal heat, dry stool and edema should eat more. Deficiency cold, stomach cold, obesity and arteriosclerosis are not suitable for eating.
The cost of raising old-age ducks is too high (you can't lay eggs or crow), so it is rare. Therefore, an old duck generally refers to a female duck over three years old.
Let's talk about chickens. "Life Taste Diet Spectrum" says: "Eat more to generate heat and move the wind"; Bielu, a pharmaceutical work in the Han Dynasty, once wrote: "Dan rooster: the main cause of long-term injury and less sores." White rooster: Treat lower qi, treat madness, level the five internal organs, and quench thirst when injured. Yellow hen: main injury, thirst quenching, urinary incontinence, intestine? Drainage, nourishing five internal organs, continuing traumatology, treating fatigue and benefiting qi. Black cock: mainly tonic and analgesic. "
There are many kinds of chickens with different functions. Black-bone chicken is often used as medicine. Black-bone chicken can cure all kinds of deficiency diseases and is known as "the holy medicine of gynecology". The rooster belongs to Yang, and its sex is not as good as that of hen. Hens are easier for the elderly, women, pregnant women and the infirm. Among them, the little hen is tender and tender, which is mostly used for nourishing the young and the old, while the old hen is mostly used for lying-in. Compared with ducks, chickens are gentle.