The improved bioavailability of zein/soybean protein isolate by puerarin in vitro

As the largest emitter of greenhouse gases, the livestock and poultry industry is facing the challenge of increasing production to meet global demand while reducing environmental impacts. Improving feed digestibility by optimizing feed structure (e.g., exogenous additive) is one of the green breeding measures to alleviate carbon pressure. In this study, the interaction mechanism and in vitro digestibility properties of puerarin (PUE) with feed proteins (zein and soy protein isolate (SPI)) to form Zein-PUE and SPI-PUE complexes were investigated mainly by multispectral and molecular docking techniques. Results indicated that the addition of PUE improved the physicochemical properties of proteins (e.g., solubility and disulfide bond contents). Then, the spectral results showed that the binding processes were spontaneous, and the protein structure tended to loose and disordered after binding, and more hydrophobic residues were exposed to the hydrophilic microenvironment. Moreover, on the basis of molecular docking revealed that PUE bound to zein by hydrogen bond, electrostatic and hydrophobic interactions, while with SPI by hydrogen bond and hydrophobic interaction. Finally, in vitro digestion experiments demonstrated that the bioavailability of Zein-PUE and SPI-PUE complexes increased by 1.15 % and 2.11 %, respectively. Overall, PUE is a promising feed additive beneficial for enhancing protein digestibility and bioavailability.

Pretreatment of Luzhou distiller's grains for feed protein production using crude enzymes produced by a synthetic microbial consortium

Chinese distillers' grains (CDGs) have low fermentation efficiency due to the presence of lignocellulosic components, such as rice husk. In this study, a microbial consortium synthesized was used based on the "functional complementarity" principle to produce lignocellulolytic crude enzyme. The crude enzyme was used to hydrolyze CDGs. After enzymatic hydrolysis, lignocellulose was damaged to varying degrees and the crystallinity decreased. Subsequently, the feed protein was produced using yeast through two pathways. The results showed that the crude enzyme produced by the microbial consortium (comprising Trichoderma reesei, Aspergillus niger, and Penicillium) exhibited excellent enzymatic efficiency, yielding 27.88%, 19.64%, and 10.88% of reducing sugar, cellulose, and hemicellulose. The true protein content of CDGs increased by 53.49% and 48.35% through the first and second pathways, respectively. Notably, the second pathway demonstrated higher economic benefits to produce feed protein. This study provides a pathway for high-quality utilization of CDGs.

Using the product environmental footprint to strengthen the green market for sustainable feed ingredients; Lessons from a green biomass biorefinery in Denmark

Finding new and sustainable proteinaceous feed ingredients, especially those produced from locally available resources, is at the top of the agenda of many countries, including Denmark, to become feed protein self-sufficient. Protein concentrate (PC) production via the biorefining of green biomass has attracted considerable interest in recent years since they are more land efficient and productive than soybeans. The biorefining of clover-grass into protein concentrate (GPC) is a promising substitute for soybean and soybean meal, however, the environmental impacts of GPC have not been studied. The Product Environmental Footprint (PEF) method, developed by EU Joint Research Centre for the "Single Market for Green Products Initiative" was employed to assess the environmental footprints of organic GPC. The instructions, methodology, and guidelines detailed in Product Environmental Footprint Category Rules (PEFCR) Feed for Food-Producing Animals were followed to implement this PEF study. The results were intended for in-house management, process improvement, early guidance on the environmental footprint (EF) of compound feeds containing GPC, and the EF of livestock and animal production whose feed ration contains GPC. Our results showed that GPC would have a climate change impact of 1091.47 kg CO₂,eq/t GPC. We found that farming/cultivation, more specifically direct emissions from manure slurry, dominated most impact categories, including acidification and eutrophication. The results were found sensitive to the choice of allocation method and very case-specific. For instance, the climate change impact of GPC was higher under economic allocation than direct substation, but the acidification impact was lower in economic allocation than direct substitution. However, the direct substitution method, showed that treating the process residues in biogas plants could result in GPC with lower EFs. The sensitivity analysis confirmed that increasing the clover-grass productivity and decreasing either manure slurry application or nitrogenous emissions from its application are the keys to further decreasing the overall environmental impacts.

Black soldier fly larvae (BSFL) and their affinity for organic waste processing

There are two major problems that we are facing currently. Firstly, a growing human population continues to contribute to the increased food demand. Secondly, the volume of organic waste produced will threaten human health and the quality of the environment. Recently, there is an increasing number of efforts placed into farming insect biomass to produce alternative feed ingredients. Black soldier fly larvae (BSFL), Hermetia illucens have proven to convert organic waste into high-quality nutrients for pet foods, fish and poultry feeds, as well as residue fertilizer for soil amendment. However, better BSFL feed formulation and feeding approaches are necessary for yielding a higher nutrient content of the insect body, and if performed efficiently, whilst converting waste into higher value biomass. Lastly, this paper reveals that BSFL, in fact, thrives in various ranges of organic matter composition and with simple rearing systems.