Improving acidity and flavors of citrus juice as well as its antioxidant activity by cofermentation with deacidification bacteria combination

The high acidity and poor taste of some citrus juice (CJ) affect its application value. In this study, a Hanseniaspora pseudoguilliermondii B4 was isolated and identified from lemon which could effectively degrade organic acids in CJ. Seven lactic acid bacteria (LAB) were selected to coferment with B4 in sequential and simultaneous inoculation on CJ to improve its taste and nutritional value. The physicochemical parameters, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity were evaluated before and after mixed fermentation. The results revealed that cofermentation with B4 and Bifidobacterium lactis 20435 could not only decreased acidity by 96.05% but also increased TPC, TFC, DPPH and ABTS radical scavenging activity by 22.54%, 25.42%, 34.47% and 52.63%, respectively. In addition, 3-methyl-1-butanol, 2-methyl-1-butanol and phenylethyl alcohol were significantly (p < 0.05) increased, while terpenes were mostly decreased, compared to unfermented juice. The ester content increased and enhanced the flavor compounds of fermented CJ. This work provides a new strategy of using H. pseudoguilliermondii and LAB to adjust the acidity and taste of CJ as well as improve its bioactive substances and antioxidant activity.