Effect on <i>Arabica</i> Coffee Flavor Quality of Enhanced Fermentation With <i>Pichia membranifaciens</i> Through Change Microbial Communities and Chemical Compounds

To stabilize <i>Arabica</i> coffee quality by enhanced fermentation with <i>Pichia membranifaciens</i>, high-throughput sequencing, UPLC-MS/MS, HS-SPME-GC-MS, and SCA cupping protocol were employed for comprehensive analysis of the coffee fermentation process. Gene sequencing showed that the predominant microorganisms at the genus level were <i>Weissella</i>, <i>Lactococcus</i>, <i>Trichococcus</i>, <i>Leuconostoc</i>, and <i>Massila</i> for bacteria and <i>Pichia</i>, <i>Hanseniaspora</i>, <i>Lachancea</i>, <i>Candida</i>, and <i>Cystofilobasidium</i> for fungi. Meanwhile, 122 and 122 differentially changed nonvolatile compounds (VIP > 1, <i>p</i> < 0.05, FC > 1.5 or FC < 0.65) from 2275 nonvolatile compounds were found between PE2 versus PB2 and PE3 versus PB3, respectively. Furthermore, 26 differentially changed volatile compounds (VIP > 1, <i>p</i> < 0.05, FC > 2.0 or FC < 0.50) were found between PE and PB. Therefore, enhanced fermentation with <i>P. membranifaciens</i> inhibited the growth of other microorganisms and changed the chemical compounds during the fermentation to stabilize flavor quality.