Figures (1)  Tables (1)

    • Figure 1. 

      The challenges and future perspectives of food-grade nutraceutical delivery system[25,26].

    • Digestive organs Residence time pH Enzyme Ionic concentration Function
      Mouth cavity 5~60 s 6.2~7.6 α-amylase 0.060 M Chewing breaks down food components and saliva acts as the lubricant. Amylase can catalyze the hydrolysis of starch into maltose, glucose, dextrin and so on.
      Stomach 30 min~4 h 1.0~2.5 Pepsin, lipase 0.152 M The stomach mainly produces protein enzymatic hydrolysis, lipase hydrolysis and other reactions, and the extremely low pH can effectively kill microorganisms.
      Small intestine 1~2 h 6.0~7.4 Lipase, pancreatin 0168~0.172 M The absorption of nutrients mainly occurs in the small intestine, including the release of endogenous active ingredients and the breakdown of food by endogenous enzymes.
      Colon 12~24 h 5~7 Microbiota-secreted enzyme 0.100 M The colon provides a natural environment for the growth of microbial flora, and nutrients in the colon mainly interacts with the colonized microbial flora.

      Table 1. 

      Environmental conditions and functions of various parts of the human digestive tract[1].