Preparation of zinc porphyrin nanoparticles and application in monitoring the ethanol content during the solid-state fermentation of Zhenjiang Aromatic vinegar

Abstract

This work presents a real-time ethanol content measurement method during the solid-state fermentation of “Zhenjiang” Aromatic vinegar. 5, 10, 15, 20-Tetraphenyl-21H, 23H-porphine zinc (ZnTPP) which was sensitive to ethanol was employed to capture VOC from semi-solid state vinegar during fermentation. Various self-assembled nanostructures of ZnTPP based was be synthesized, while the effect of aging time and the pH on the morphology of nanoporphyrin has been studied. The result of self-assembled was characrized by change of UV spectra. After self-assembled, the colorimetric signal of ethanol VOC was, significantly enhanced. Furthermore, colorimetric sensor array made up of four colorimetric dyes with porphyrin and nanostructure porphyrin were used for VOC detection during vinegar fermentation. Meanwhile, when it is combined with back-propagation artificial neural network (BP-ANN), volatile gas messages of vinegar substrate present an high relevance with alcoholic strength measured by Gas chromatography and mass spectrometry (GC–MS). Therefore, the colorimetric sensor array based on ZnTPP nanoparticles could be well used in monitoring the ethanol content during the solid-state fermentation.