Solid state fermentation of Moringa oleifera leaf meal by mixed strains for the protein enrichment and the improvement of nutritional value

PeerJ

article

Honghui Shi¹  Bin Su¹  Xiaoyang Chen¹  Ruiqi Pian¹ 

[1] College of Forestry and Landscape Architecture, South China Agricultural University;Guangdong Province Research Center of Woody Forage Engineering Technology;Guangdong Research and Development Centre of Modern Agriculture;Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm;State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources

关键词: Solid-state fermentation;    Moringa oleifera leaf meal;    True protein;    Response surface methodology;    Nutritional value;   

DOI  :  10.7717/peerj.10358

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Moringa oleifera Lam. (MO) is a fast-growing multi-purpose deciduous tree with high biomass and nutritional value. However, the presence of antinutritional factors, poor palatability, and indigestibility of Moringa oleifera leaf meal (MOLM) restrict its application to animal feed. This study aimed to obtain high-quality protein feeds via solid-state fermentation (SSF) of MOLM. The process conditions for increasing the true protein (TP) content using Aspergillus niger, Candida utilis and Bacillus subtilis co-cultures were optimized, and the chemical composition of MOLM was compared before and after fermentation. The results of this study showed that the highest TP content could be obtained through mixed-strain culture of A. niger, C. utilis and B. subtilis at a ratio of 1:1:2. The MOLM was inoculated with A. niger, followed by C. utilis and B. subtilis 24 h later. The optimized co-culture parameters were as follows: total inoculation size, 24%; temperature, 32 °C; fermentation time, 6.5 days; and initial water content, 60%. The maximum TP yield was 28.37%. Notably, in the fermented MOLM (FMOLM), the content of nutrients such as crude protein (CP), small peptides, and total amino acids (AAs) were significantly increased relative to unfermented MOLM, whereas the contents of crude fiber (CF), tannin, and phytic acid were significantly decreased. MOLM analysis using scanning electron microscopy (SEM) revealed that SSF disrupted the surface structure of MOLM, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) indicated that macromolecular proteins were degraded. The in vitro protein digestibility (IVPD) of FMOLM was also improved significantly. Our findings suggest that multi-strain fermentation with A. niger, C. utilis and B. subtilis improves the nutritional quality of MOLM, rendering it a viable functional feedstuff for use in livestock industries in the future.

【 授权许可】

CC BY