Effects of Addition of Hydrolyzing Enzymes during Fermentation on Characteristics of Distillers’ Dried Grains with Solubles

Abstract

Various hydrolyzing enzymes are used in drygrind corn ethanol processes, mainly during liquefaction and saccharification steps, to improve yields of ethanol and/or distillers' corn oil. However, the effects of enzyme addition on characteristics of distillers' dried grains with solubles (DDGS) are not thoroughly understood. In this study, the effects of using acid-stable protease, pectinase, and cellulase enzymes during fermentation on chemical and physical characteristics of DDGS were evaluated, including in vitro digestibility using a pig digestion model. The use of a protease resulted in DDGS with a greater fiber content than the control (36% vs. 22%), as well as reduced protein digestibility (64% vs. 69%). The use of pectinase and cellulase (PC) also increased the fiber content of DDGS (29%) and significantly improved the protein content (27%) and protein digestibility (73%) compared with the other treatments. DDGS treated with hydrolyzing enzymes tended to have a darker color and lower waterholding capacity, but better amino-acid digestibility. Treatments with hydrolyzing enzymes significantly altered the composition and characteristics of DDGS, which strongly indicated that PC mix utilized is an effective combination to add during fermentation to produce high-quality DDGS without undesirable effects on ethanol production. The enzyme-treated DDGS can be an inexpensive and nutrientrich diet supply to the porcine diets; however, effects on cattle and dairy cow diets were beyond the scope of the study.

Nutrient Enhancement of Corn Distillers Dried Grains by Addition of Coproducts of the Enzyme‐Assisted Aqueous Extraction Process of Soybeans in Corn Fermentation

“…b). Addition of PCF has shown to increase free amino acid composition during fermentation and in corn DDG with solubles (Fang et al, , b; Johnston et al, ). However, in corn‐soy DDG, a decrease in amino acid concentration was observed in most of the essential amino acids (Fig.…”

Fermentation performance and nutritional assessment of physically processed lentil and green pea flour

“…29 Around 200 mg of each protein sample (control and modified) were taken, added to 100 μL of 0.2 mM norvaline internal standard, and dried in a Speed Vac concentrator (Savant SVC-100H, Farmingdale, NY, USA) overnight in pyrolyzed tubes. Acid hydrolysis was performed in the Pico-Tag workstation (Waters Corporation, Milford, MA, USA) following the protocols; 30 15 μL of EDTA (1 μL of 20% EDTA to 9 μL of water) were added to the hydrolyzed sample in the tube, and 400 μL microliters of extraction buffer (water: chloroform: methanol; 3:5:12 v/v) were added to each of the tubes and supernatant was transferred to the GC-MS vial. The extraction was done one more time with 400 μL of extraction buffer and extracts were pooled; 350 μL microliters of chloroform and 450 μL of distilled water were added; the mixture was vortexed and then allowed to settle until clear separation was seen.…”