Optimization of biological deodorization process and analysis of volatile flavor in Gracilaria lemaneiformis

  Objective  Optimize the microbial fermentation and deodorization process of Gracilaria lemaneiformis (GL), and provide certain technical support for the deep processing and utilization of GL.

  Method  Through the fuzzy comprehensive evaluation of sensory, on the basis of screening out the combination of biological deodorizing microorganisms, using the Box-Behnken response surface method o logy to optimize the added amount of malic acidandsugar, inoculation amount, time of fermentation, fermentation temperature factor parameters. Analyze the changes of volatile flavor compounds in GL before and after fermentation by HS-SPME-GC/MS and other techniques.

  Results  The optimal deodorization process is: the combination of deodorizing microbial strains is 1∶1 Saccharomyces cerevisia JJ4 and Lactobacillus paracasei subsp. Paracasei RP38;sugar added 2.0%, malic acid added 0.2%, inoculation amount 5% each, fermentation time 68 h, fermentation temperature 29℃.After fermentation and deodorization, cyclooctanol, 1-methylcycloheptanol, octanal, nonanal, 2-nonenal, (E)-which have fatty, fishy and fishy odors disappear, the content of 3-octanoneis significantly reduced, added aromatic phenylethyl Alcohol, fruity hexanoic acid, ethyl ester, wine scented octanoic acid, ethyl ester, sweet scented hexanoic acid, 2-phenylethyl ester, coconut scented nonanoic acid, ethyl ester.

  Conclusion  The combination of JJ4 and RP38 is used to ferment GL to remove the smelly substances such as alcohol and aldehydes, and increase the flavor substances such asphenylethylalcohol and esters.Andit has obvious deodorant and fragrance effect on GL.