Production of 1,3-propanediol using enzymatic hydrolysate derived from pretreated distillers' grains

Bioactive composite films with improved antioxidant and barrier properties prepared from sodium alginate and deep eutectic solvent treated distillers' grains

In this work, a straightforward approach utilizing distillers' grains (DG) waste and sodium alginate (SA) was developed to prepare functional and bioactive packaging films. Deep eutectic solvents (DESs) were initially synthesized from choline chloride (CO), betaine (BO), glycerol (GO), and oxalic acid. Composite films were then prepared from DES-treated DG slurry and SA at different ratios. Characterization and analysis revealed that adding 75 % CO-treated DG slurry reduced the water vapor permeability (WVP) by over 66 % compared to that of the SA film. Composite films containing CO/BO-treated DG slurry had an ultraviolet light barrier rate exceeding 99 %, while those with 75 % DES-treated DG slurry demonstrated excellent antioxidant activity, with a 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging rate of 80.14 %-88.35 %, representing a 322.45 %-365.73 % increase compared to that of the pure SA film. These composite films also exhibited favorable mechanical properties (31.58 MPa, 5.53 % EB), thermal stability, and biodegradability, extending the shelf life of grapes by 1.8 times. In conclusion, bioactive composite films derived from DES-treated DG are expected to replace petroleum-based plastics, enhancing sustainable biomass use and environmental responsibility.

Production of cost-competitive bioethanol and value-added co-products from distillers' grains: Techno-economic evaluation and environmental impact analysis

Here, Baijiu distillers' grains (BDGs) were employed in biorefinery development to generate value-added co-products and bioethanol. Through ethyl acetate extraction at a 1:6 solid-liquid ratio for 10 h, significant results were achieved, including 100 % lactic acid and 92 % phenolics recovery. The remaining BDGs also achieved 99 % glucan recovery and 81 % glucan-to-glucose conversion. Simultaneous saccharification and fermentation of remaining BDGs at 30 % loading resulted in 78.5 g bioethanol/L with a yield of 94 %. The minimum selling price of bioethanol varies from $0.149-$0.836/kg, contingent on the co-product market prices. The biorefinery processing of one ton of BDGs caused a 60 % reduction in greenhouse gas emissions compared to that of the traditional production of 88 kg corn-lactic acid, 70 kg antioxidant phenolics, 234 kg soybean protein, and 225 kg corn-bioethanol, along with emissions from BDG landfilling. The biorefinery demonstrated a synergistic model of cost-effective bioethanol production and low-carbon emission BDGs treatment.