4238
When viscera extract from hybrid catfish was used for the production of protein hydrolysate from toothed ponyfish muscle , extract concentration , reaction time , and fish muscle / buffer ratio affected the hydrolysis and nitrogen recovery ( NR ) ( p < 0 . 05 ) .
 Chemical: nitrogen
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: nitrogen