Effect Of Additives On Histamine Content And Its Related Quality In Fast-fermented Shrimp Paste

Shrimp paste is an aquatic seasoning with a long history,which is very popular in China and Southeast Asia for its unique flavor and rich nutrition value.However,the long fermented time,unstable quality and higher salinity of traditional shrimp paste have been a bottleneck in restricting its industrialization.Besides,it's likely to produce toxic compounds such as histamine during the fermentation process.As the most toxic biogenic amines,histamine not only reduces the quality of products,but also threatens the healthy safety of consumer who excessive intake shrimp paste contained it.Therefore,using the rapid fermentation method to produce shrimp paste and to reduce the content of histamine in products,it's significant to solve the problems of traditional shrimp paste and improve the quality and safety of it.In this paper,we used the fresh shrimp head as the raw material,added external microorganisms and controlled constant temperature to ferment,in order to investigate the inhibitory effect of glycine,sucrose,glucose garlic,ginger and perilla frutescens on histamine in shrimp paste during its fermented process.Firstly,determined the primary fermented characteristices of three fermentation agents,then,studied the inhibitory effect of glycine,sucrose,glucose garlic,ginger and perilla frutescens on histamine in shrimp paste,finally,evaluated the quality of shrimp past by comparing the nutritional qualities,safety and sensory evaluation.The major results are as follows:(1)Primary fermented characteristices of three fermentation agents.We determined the growth curves of the fermentation agents in different conditions,the growth curves of single,double and triple bacteria in shrimp paste,indentified the histamine-produced bacteria and its produce ability.Results showed that the highest tolerable temperature of lactic acid bacteria,Pichia gilliermondii and Aspergillus nigerwas was 45,45 and 45-50?,respectively.The salinity tolerance of lactic acid bacteria,Pichia gilliermondii & Aspergillus niger was 10%,14-18% and 14-18%,respectively.Lactic acid bacteria,Pichia gilliermondii could growth normally whereas it could inhibit the growth of Aspergillus nigerwas when pH higher than 7.5.In theshrimp paste medium,in the case of two bacteria co-cultivated,lactic acid bacteria and Pichia gilliermondii could slightly inhibit the growth of each other,lactic acid bacteria and Aspergillus niger could normally growth in the co-cultivated model,however,Pichia gilliermondii and Aspergillus niger could significantly inhibit the growth of each other.In the co-culture of three bacteria,the most serious inhibition of growth was Aspergillus niger,followed by Pichia gilliermondii and lactic acid bacteria.In the three fermentation agents,lactic acid bacteria has the ability to produce histamine,in the MRS medium containing 500 ug / mL and 1000 ug / m L histidine,the histamine production capacity is 37.3 and 57.4 ug / m L.(2)Effects of glycine,sucrose and glucose on histamine content and the quality of shrimp paste.We determined the effects on histamine content and the quality of shrimp paste after adding glycine,sucrose and glucose during the fermentation process.Results showed that the additives could significantly reduce histamine in shrimp paste.Adding 2%,4% and 6% glycine could degraded histamine up to 35.0%,31.2% and 29.5%,respectively.The 2%,4% and 6% sucrose could degrade histamine up to 28.6%,40.0%,52.6%,respectively.The 2%,4% and 6% glucose could degrade histamine up to 43.2%,57.2%,54.6%,respectively.Meanwhile,we compared the nutritional qualities,safety and sensory evaluation of the shrimp paste and found that except for treating with glycine and glucosethe could improve production of TVB-N,the rest additives have little effect on shrimp paste quality.(3)Effects of garlic,ginger and perilla frutescens on histamine content and the quality of shrimp paste.We determined the effects on histamine content and the quality of shrimp paste after adding garlic,ginger and perilla frutescens during the fermentation process.Results showed that all the three spices had the effect of inhibiting the production of histamine under certain dosage.The optimum treatment effect is adding 6% ginger and perilla frutescens,it could reduce histamine up to20.5% and 21.8%,respectively.But,there was no significant effect on inhibiting histamine after treating with 2% garlic and ginger.Meanwhile,we compared the nutritional qualities,safety and sensory evaluation of shrimp paste and found that except for treating with 4% and 6% perilla frutescens could increase the production of TVB-N in shrimp paste,there had little effect on shrimp paste quality after adding the spices.In addition,the spices have a active effect on reducing total number of colonies and improving the color and flavor of shrimp paste.