Mango juice (MJ) has high nutritional value and decent flavor. However, its aroma could be easily changed by heat treatment during processing, which affects its acceptability and quality. In this study, Bacillus subtilis -HNU-B3 that could transfer carotenoid, was obtained from orchard soil to improve the aroma of fermented mango juice (FMJ). Compared with MJ, the organic acid content of FMJ by B. subtilis -HNU-B3 was significantly changed, and the contents of succinic acid and malic acid were increased to 3.68 mg/mL and 2.04 mg/mL, respectively. Moreover, volatile compounds identified by headspace solid-phase micro-extraction gas-phase mass spectrometry in FMJ were norisoprenoid and acetoin, accounting for 51.52 % of the total volatile substances. In addition, B. subtilis -HNU-B3 fermentation significantly increased the antioxidant capacity and total phenol contents of MJ, and the activity of carotenoid cleavage dioxygenase was 188 U/L. In conclusion, the aroma of FMJ could be improved by B. subtilis -HNU-B3 through increasing the content of norisoprenoid and acetoin. Our results provide theatrical support for Bacillus subtilis to improve the aroma quality of FMJ.
Reactions of a crude enzyme extracted from S. pasteuri TS-82 to cleave carbon-carbon bonds in bicyclic and monocyclic carotenoid substrates were investigated. Dependencies of enzyme activities on processing temperature and pH were investigated and non-volatile and volatile breakdown products were characterized. The crude enzyme showed a maximum activity with zeaxanthin, followed in decreasing order by β-carotene, canthaxanthin, astaxanthin, and β-apo-8'-carotenal. The optimum pH value of the enzyme was 3.0 for both bicyclic and monocyclic substrates, whereas the optimum temperature of the enzyme was substrate specific at 60°C for C 40 carotenoids and 50°C for β-apo-8'-carotenal. Liquid Chromatography-Mass Spectra (LC-MS) and Gas Chromatography- Mass Spectra (GC-MS) indicated that the crude enzyme was able to catalyze substrates with cleavage at 9-10 and 9'-10' double bonds with C 13 norisoprenoids being the main volatile reaction products in each case. Astaxanthin is a major source for α,β-dihydro-β-ionone.
危险品化学品经营许可证（带存储）