Enzyme treatment of distillers' dried grains with solubles.

摘要

Distillers' dry grains with solubles (DDGS), a co-product of fuel and beverage ethanol manufacturing, provide substantial nutritional value as dairy cattle feed. Beyond the nutritional content of DDGS, bypass protein is a key factor in determining the marketability of distillers' grains as cattle feed. Bypass protein is that portion of protein that is not degraded in the rumen and is digested in the intestine.; In this project, enzymes were used to break down cellulose and hemicellulose present in distillers' grains to produce xylose necessary for the Maillard reaction. During the Maillard reaction, amino acids bind with sugars in the presence of heat, protecting the protein from ruminal degradation. Six enzymes from industrial suppliers were studied. A measured dose was added to 5 g of DDGS in 100 mL of water at 50°C and xylose and glucose concentrations were measured using a HPLC at every hour, Cellulase T "Amano" 4, and a combination of MultifectRTM GC and Multifect RTM Xylanase produced higher xylose concentrations in distillers' grains. In the second part of the experiment, two batches were made by adding 4 g of the enzymes to a mixture of 150 g of concentrated distillers' solubles and 150 g of centrifuge cake and heating at 150°C for 25 minutes. A control batch was made with no enzymes. Protein analysis was performed to determine the effect of enzyme utilization on bypass protein.; Heat treatment of distillers' grains with EnzecoRTM cellulase CES showed an increase in NDIP of approximately 470% and a 100% increase in ADIP over the control batch. The combination of Multifect RTM GC and MultifectRTM Xylanase showed an NDIP increase of approximately 170% while increasing the ADIP content by 60%. Thus enzyme utilization has a positive effect on bypass protein.