ARS | Publication request: CHARACTERIZING PROTEOLYTIC INHIBITION IN RED CLOVER SILAGE

Submitted to: International Silage Conference
Publication Type: Abstract Only
Publication Acceptance Date: July 7, 1999
Publication Date: N/A

Technical Abstract: A major problem in silage production is the extensive protein degradation that occurs during the ensiling process. Native proteases degrade 44 to 87% of the plant's cytoplasmic protein into ammonia, amino acids and small peptides. Although red clover lacks many agronomic traits of alfalfa, silage produced from red clover has higher total protein available to the animal at feed out. Reduced proteolysis in red clover is not due to differences in the type or number of proteases or to unique protein composition compared to alfalfa. We have shown that red clover polyphenol oxidase (PPO) can rapidly inhibit model proteases, trypsin, chymotrypsin, and papain upon exposure to oxygen and o-diphenols. Soluble o-diphenols found in red clover are rapidly converted to quinones that react with suitable nucleophiles (proteins and other phenolics) forming cross-linked products, the typical browning response see in PPO reactions. The improved true protein content of red clover silage appears to be due to the presenc of a soluble polyphenol oxidase (PPO) and soluble polyphenols that result in the inactivation of hydrolytic enzymes upon exposure of cellular contents to oxygen.