Betaine, also known as glycine trimethyl inner salt, is a non-toxic and harmless compound. The appearance is white crystalline powder or granule, molecular formula is C5H12NO2 and molecular weight is 118, and melting point is 293°C. It has light sweet taste and is a substance similar to vitamins. Currently widely used in feed breeding industry, betaine is used as a feed additive to increase pig body weight and improve feed conversion efficiency.

The color of pork mainly depends on the content of myoglobin in the muscle. Pork with a high content of myoglobin in the muscle has a bright and ruddy color. Increasing the content of crude fat or intramuscular fat in the muscle can improve the tenderness, juiciness and flavor of the meat. The umami taste in muscles mainly comes from inosinic acid and umami amino acids, especially the intermuscular fat,its umami taste is more than 50 times that of MSG.

The study showed that the carcass fat rate of the pigs in the diet with 1 000 mg/kg betaine was reduced by 18.27%, and the carcass lean rate increased by 5.71%. The longissimus dorsi of the test group The content of myoglobin, intramuscular fat and intermuscular fat increased by 14.88%, 17.66% and 21.79%, respectively. It shows that betaine improves the lean meat rate of pig carcass and at the same time improves the color, aroma and taste of pork, and effectively improves the quality of pork.