Safety Evaluation and Whole Genome Sequencing of Aspergillus japonicas PJ01 Reveal Its Potential to Degrade Citrus Segments in Juice Processing.

Yujiao Qian,Yang Shan,Gaoyang Li,Chen Wang,Zhipeng Gao,Fuhua Fu,Jieyi Wang,Jiajing Guo

doi:10.3390/foods10081736

Abstract

Aspergillus japonicas PJ01 (A. japonicas PJ01) is a strain isolated from the rotten branches. In previ-ous studies, it was shown that it can produce complex enzymes to degrade polysaccharide com-ponents. In this study, we evaluated the safety of its crude enzyme solution. Acute oral toxicity, subchronic toxicity, micronucleus and sperm malformation tests all validated the high biologi-cal safety for the crude enzymes. Secondly, we carried out the citrus segment degradation ex-periment of crude enzyme solution. Compared with the control group, the crude enzyme solu-tion of A. japonicas PJ01 can completely degrade the segments in 50 min, which provides the basis for enzymatic peeling during juice processing. The whole genome sequencing showed that the genome of A. japonicus PJ01 has a GC content of 51.37% with a size of 36204647 bp, and encoded 10070 genes. GO, COG, KEGG and CAZy databases were used in gene annotation analyses. Pathway enrichment showed many genes related to carbohydrate metabolism, rich in genes re-lated to pectinase, xylanase and carboxylcellulase. Therefore, the complex enzyme produced by A. japonicus PJ01 can be used in gizzard juice processing to achieve efficient enzymatic decapsu-lation.

Highlights

China is a main producing area of citrus, and the fruit juice processing industry is huge
The results showed that the crude enzyme produced by A. japonicus PJ01 contained xylanase, pectinase and carboxyl cellulase, which could effectively degrade citrus segments
It is expected to be applied in the production of sachet juice or clarification of fruit juice

Summary

Introduction

China is a main producing area of citrus, and the fruit juice processing industry is huge. With the change of public health awareness, fruit juice has changed from traditional juice drinks to gizzard juice with fruit grains, the most famous of which is “Minute Maid”, which has complete citrus cysts. The cysts used in the production of Minute Maid orange beverage are mainly produced by the acid–base method. It will produce a large number of broken fragments, which will have adverse effects on the senses [1]. The application of enzymatic decapsulation has attracted great attention and has achieved good results in the production of citrus cans. The key problem in citrus juice production is how to remove the segments with high quality and low cost

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Methods

Discussion

Conclusion