Optimization of solid-state fermentation parameters of citric acid residue by Aspergillus niger
ZHU Qijun
LIU Weiwei
ZHANG Haiou
LIU Baorui
DOU Zhengrong
SONG Liye
YANG Peilong
MENG Kun
Abstract：The experiment aimed to optimize the fermentation parameters(nitrogen concentration and moisture concentration)of the citric acid residue produced by Aspergillus niger in a solid-state fermentation process.The experiment involved a seven-day double-factor solid-state fermentation of the fermentation substrate(a mixture of citric acid residue and wheat bran with a mass ratio of 4:1)using Aspergillus niger.The urea addition amounts were 1％,2％,and 3％,and the moisture concentrations were 40％,50％,and 60％.The results showed that under the fermentation parameters of 50％moisture content and 3％urea content,the concentrations of crude fiber,neutral detergent fiber,and acid detergent fiber in the fermented citric acid residue were 15.36％,36.99％,and 21.53％respectively,the reduced sugar concentration was 41.56 mg/g,the crude protein concentration was 24.78％,and the total energy was 168.92 MJ/kg.The study indicates that under the optimized fermentation conditions of the experiment,the fiber content of the citric acid residue fermented by Aspergillus niger was significantly reduced,the crude protein content was significantly increased,and it had the potential to become a high-quality protein feed raw material.
Keywords：Aspergillus nigercitric acid residuesolid-state fermentationnitrogen contentmoisture content
Publication Date：2025-08-28
Online Publishing Date：2025-10-28(First online date of this platform, not the publication date of the document)
Pages：5( 99-103 )