Miladinovic Dejan Dragan, Storebakken Trond, Lekang Odd Ivar, Salas-Bringas Carlos
Norwegian University of Life Sciences (NMBU), Faculty of Biosciences, Department of Animal and Aquacultural Sciences, Norway.
NMBU, Faculty of Science and Technology, Department of Process Engineering, Norway.
Heliyon. 2021 Dec 18;7(12):e08598. doi: 10.1016/j.heliyon.2021.e08598. eCollection 2021 Dec.
Lower energy consumption for producing feed pellets is an important part of the economy in the feed mill. The same is if physical pellet quality is degraded. The interest in using of novel ingredients is increasing due to requirements for the sustainable development goals. Defatted microalgae as by-product from biodiesel production is one of many novel ingredients. The purpose of this experiment was to understand how the addition of small amount of enzymes can reduce the flow resistance in the die during pellet discharge, without affecting the physical quality of pellets. Thus, possibly reduce the total consumption of electrical energy during compaction. Three enzymes, phytase, protease, xylanase, and combinations of those were added to defatted microalgae at 3 inclusion levels. Feed enzymes xylanase and phytase helped lowering the flow resistance of the material in the die. Reduction of flow resistance was in average 17 times lover when all three levels of enzyme phytase were used. The same was observed when 0.01% xylanase was added. All feed enzymes and their combination have evidently lowered underwater pellet swelling due to their hydrolytic activity at the surface of the microalgal particles. The hydrolytic activities of the feed enzymes did not affect hardness of the microalgal pellets. Contact angle degree between pellet surface and oil droplet was lowered when xylanase and protease was used at all three dosage levels. However, contact angle degree between pellet surface and water droplets was unaffected by the hydrolytic activity of enzymes.
降低生产饲料颗粒的能耗是饲料厂经济的重要组成部分。如果颗粒的物理质量下降，情况也是如此。由于对可持续发展目标的要求，使用新型成分的兴趣正在增加。作为生物柴油生产副产品的脱脂微藻是众多新型成分之一。本实验的目的是了解添加少量酶如何在不影响颗粒物理质量的情况下降低颗粒排出时模具中的流动阻力。从而可能降低压实过程中的总电能消耗。将三种酶（植酸酶、蛋白酶、木聚糖酶）及其组合以三种添加水平添加到脱脂微藻中。饲料酶木聚糖酶和植酸酶有助于降低物料在模具中的流动阻力。当使用所有三个水平的植酸酶时，流动阻力的降低平均低17倍。当添加0.01%的木聚糖酶时也观察到同样的情况。所有饲料酶及其组合由于其在微藻颗粒表面的水解活性，明显降低了水下颗粒的膨胀。饲料酶的水解活性不影响微藻颗粒的硬度。当在所有三个剂量水平使用木聚糖酶和蛋白酶时，颗粒表面与油滴之间的接触角度降低。然而，颗粒表面与水滴之间的接触角度不受酶水解活性的影响。
