## 4 Conclusions and Future Studies  
Bicultured purees demonstrated significant probiotic effects, exhibiting viable counts exceeding 6-7 log CFU/mL. The free amino acid (FAA) composition of bicultured Junzao jujuube purees exhibited variability, with JLhAp displaying the highest content, followed by intermediate levels in JLpAp and the lowest in JLAp. Abundant FAs included L-aspartic acid and proline, with the noteworthy observation of methionine synthesis in JLpAp. This emphasizes dynamic enzymatic transformations facilitated by the interplay of _Lactiplantiobacillus plantarum_ Lp 28 and _Acetobacter pasteurianus_ Ap-As.1.41 HuNiang 1.01 biculture. Furthermore, a notable correlation emerged between phenolic compounds (specifically chlorogenic acid, rutin, and \(p\)-coumaric acid) and antioxidant capacities, assessed through ABTS-RSA and DPPH-RSA measurements. A significant negative correlation was also observed between overall color difference and cyanidin 3-O-rutinoside, emphasizing the influence of this compound on color variations. The analysis identified 80 volatile compounds in the lactic-actified jujuube purees, with esters emerging as the most abundant class. Ten to eleven alcohols were identified, with 2,3-butanediol prevailing as the primary alcohol in Junzao jujuube puree. Interestingly, its concentration decreased post-fermentation, potentially due to esterification with unfermented acids. SEM analysis revealed distinct structural changes, with unfermented jujuube puree (JCON) displaying a curled, sheet-like structure, possibly attributed to undigested dietary fiber and high sucrose content in dry jujuube fruit. _Lp. plantarum_ Lp 28 and _A. pasteurianus_ Ap-As.1.41, HuNiang 1.01 showcased significantly higher amounts of essential amino acids, positioning them as potentially optimal formulations. These findings highlight the impactful modifications resulting from lactic-acetic acid co-fermentation on the evaluated quality indices. The study advocates for further exploration through detailed metabolomic investigations to unveil the intricate biochemical processes within these strains. Such an approach holds promise for advancing our understanding of biological systems, health, and disease, with potential applications in scientific and practical domains.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/fermentation10010071/s1](https://www.mdpi.com/article/10.3390/fermentation10010071/s1)]([https://www.mdpi.com/article/10.3390/fermentation10010071/s1](https://www.mdpi.com/article/10.3390/fermentation10010071/s1)).  
T.A.B.: conceptualization, methodology, writing--original draft, writing--review and editing, data analysis, visualization. Y.X.: methodology, writing--review and editing. I.D.B.: review of information, data analysis, writing--review and editing. J.A.: writing--review and editing. Y.L.: writing--review and editing. Y.L.: writing--review and editing. K.C.: writing--review and editing. A.Y.A.: methodology, writing--review and editing. S.Y.: writing--review and editing. Y.M.: conceptualization, resources, supervision, project administration, funding acquisition, review of information, draft approval, and final manuscript approval. All authors have read and agreed to the published version of the manuscript.  
The authors are grateful to the management of Zhenjiang Key Research and Development Program (Modern Agriculture) for their support (grant number NY2020020).  
Not applicable.  
Data Availability Statement: Data is available upon reasonable request from the corresponding author.  
The authors declare no conflicts of interest.