Research Of Part Of Hongqu And Its Products In Dayaoshan Area Of Guangxi

13 Hongqu from different places of origin such as Guangxi,Fujian,Zhejiang and Guangdong were studied in this paper.Hongqu in different fermentation stages and Hongzaosuan(Hongqu products)samples in different fermentation stages were also studied.Through on-site investigation and sampling analysis,the microorganisms in the production process of Hongqu and Hongzaosuan were preliminarily studied.The research determined the dominant bacteria in each stage,the main volatile substance components in each stage,the functional component lovastatin and the harmful component citrinin.The research results provide suggestions for the optimization of the production process of Hongqu products.The results of the study are as follows:(1)The results of microbial diversity in 13 Hongqu samples showed: There were differences in the composition of microbial communities among 13 Hongqu samples in Guangxi,Fujian,Zhejiang,and Guangdong,and there were significant differences in the composition of microbial communities between Guangxi and other three regions.Among the 13 Hongqu samples,Burkholderia and Klebsiella were the dominant bacterial genera;Monascus was the dominant fungal genus.Microorganisms related to fermentation such as Lactobacillus,Acetobacter and Pediococcus were abundant in samples from Guangxi,however,in most samples outside Guangxi,the content of fermentation-related microorganisms was low.This illustrated the potential of Guangxi Hongqu as a starter.(2)Hongqu's fermentation process microbial test results show that: There are a large proportion of non-fermentative bacteria such as Burkholderia and Klebsiella in the Hongqu fermentation process.And there are a certain amount of potentially harmful bacteria such as Acinetobacter,Pseudomonas and Aeromonas.the potentially harmful microorganisms detected in Hongqu are mostly environmental microorganisms,the optimal growth temperature of which is 30?-40?,and the optimal p H is about 7.This suggests that keeping the utensils and water clean during the Hongqu production process and controlling the temperature and p H of the fermentation environment are also effective means of extremely high product safety.(3)Hongqu's fermentation process volatile substance test results show that: Hongqu's volatile substances throughout the fermentation process include esters,alcohols,aldehydes,alkanes,ketones,phenols,pyrazines,ethers,acids and some aromatic substances.The main flavor substances in rice are ethanol and 5-methylfuranal.The main volatile flavor substances in Hongqu at 24 hours of fermentation were ethanol,phenethyl alcohol and isoamyl alcohol.The main volatile substances in Hongqu during 48 h fermentation were phenylacetaldehyde,phenylethanol,ethanol and isoamyl alcohol.The most volatile substances in Hongqu washed with water after fermentation for 48 hours were phenylacetaldehyde,phenethyl alcohol,isoamyl alcohol and ethanol.The most volatile substances in Hongqu at 72 h of fermentation were phenethyl alcohol,isoamyl alcohol,ethanol,phenylacetaldehyde and phthalic ether.The most volatile substances in the washed Hongqu after 72 h of fermentation were phenethyl alcohol,isoamyl alcohol,ethanol.The most volatile substances in Hongqu at 96 h of fermentation were phenylethanol,ethanol,isoamyl alcohol,and phthalic ether.During the entire fermentation process of Hongqu,the main volatile substances were alcohol and isoamyl alcohol.(4)Hongzaosuan's fermentation process microbial test results showed that: Hongzaosuan detected a certain percentage of Escherichia / Shigella during the fermentation process,which is the main microorganism threatening the safety of Hongzaosuan products.The disinfection of related utensils in the production process of Hongzaosuan was not done well.The optimal p H of Escherichia / Shigella is 7.2~7.4 and can be killed by heating at 56?-60? for 10-15 minutes.Therefore,it is necessary to prevent Escherichia / Shigella pollution in the raw materials during the production of red glutamate.In addition,the content of Escherichia / Shigella could be reduced by lowering the p H of the product or adding bacteriostat.(5)The test results of volatile substances during the fermentation process of Hongzaosuan showed that: The volatile substances in Hongzaosuan's entire fermentation process include esters,alcohols,aldehydes,alkanes,ketones,as well as some aromatic substances and acid substances.The main volatile substances in seeds were dodecylcyclohexasiloxane,palmitic acid and ethyl hexadecanoate.The main volatile substances in Hongzaosuan on the third day of fermentation are ethanol,ethyl hexadecanoate,diallyl disulfide,(S)-1-methyl-4-(5-methyl-1-methylene-4-hexenyl)cyclohexene(S-C15H24),phenethyl alcohol,isoamyl alcohol,ethyl decanoate,and palmitic acid.The main volatile substances in the Hongzaosuan on the sixth day of fermentation are ethyl caprate,ethyl myristate,phenethyl alcohol,ethyl stearate,ethyl laurate,phenethyl acetate,and ethyl benzoate.The main volatile substances in Hongzaosuan on the ninth day of fermentation were phenylethanol,palmitic acid,ethyl myristate,ethyl stearate,and ethyl caprate.The main volatile substances in the Hongzaosuan on the twelfth day of fermentation are cyclopentadimethylsiloxane,octamethylcyclotetrasiloxane,ethylhexadecanoate,phenylethanol,and dodecylcyclomethyl Hexasiloxane and ethyl oleate.The main volatile substances in the Hongzaosuan on the fifteenth day of fermentation were phenylethanol,ethyl hexadecanoate,S-C15H24 and ethyl decanoate.The main volatile substances in the finished Hongzaosuan are phenylethanol,ethyl hexadecanoate,S-C15H24,ethyl myristate and benzaldehyde.The main volatile substances in Hongzaosuan's fermentation process were ethanol and phenylethanol.(6)The content of metabolites in the fermentation broth of Monascus was tested and the results showed that: The glucoamylase activity in strains M10,M12 and M33 was relatively good.The acid protease activity of strains M2,M13,M16,M17,M22 and M28 is relatively good.The esterase activity of strains M18,M26,M37 and M38 was relatively good.Strains M3,M13,M28,M29 and M35 produced relatively more lovastatin and did not produce citrinin under the same culture conditions.Considering the activity of various enzymes in the strain and the safety of metabolites,M10,M12,M33,M2,M13,M17,M22,M28,M18,M26 and M37 may be suitable for use in making Hongqu or other starters individually or in combination.