Low-polygalactose (Galactooligosaccharides, GOS) is a naturally functional oligosaccharide with a molecular structure that typically consists of 1-7 galactose units attached to a galactose or glucose molecule, represented as Gal-(Gal)n-Glc/Gal (where n is 0-6). In nature, trace amounts of GOS exist in animal milk, with higher concentrations found in human breast milk. The establishment of bifidobacteria flora in infants largely depends on the GOS components in breast milk.

In nature, trace amounts of low-polygalactose exist in animal milk, with slightly higher concentrations in breast milk. Low-polygalactose has a pure sweet taste, low caloric value (7.1J/g), and a sweetness level of 20%-40% of sucrose. It also exhibits strong moisture retention properties. Under neutral pH conditions, it exhibits high thermal stability, with no decomposition observed after heating at 100°C for 1 hour or at 120°C for 30 minutes. When heated with protein, low-polygalactose can undergo the Maillard reaction, making it suitable for the processing of special foods such as bread, pastries, dairy products, and more.