9650
The use of a hydrogen bond disruptor ( urea ) to reduce protein - tannin and protein - pigment complex formation showed that the effect of sugar concentration occurred by increasing the solubility of the tannin - protein complex , not by interfering with protein - tannin complex formation .
 Chemical: hydrogen; Chemical: urea; Chemical: tannin; Chemical: sugar; Chemical: tannin; Chemical: tannin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: hydrogen; Chemical: urea; Chemical: tannin; Chemical: sugar; Chemical: tannin; Chemical: tannin