Research On Preservation And Freshness Of Loach (Misgurnus Anguillicaudatus) And Its Surimi Gel Preparation Technology

Loach (Misgurnus anguillicaudatus) is widely distributed all over our country in natural fresh waters, and its protein content in edible parts of more than 17%, fat content is about 2%, which is a typical high protein low fat fish.Because of its high nutritional value, delicious, market demand is increasing in recent years, live loach has not been slaughtered package dealing with direct access to the markets of such consumption will gradually be eliminated,fresh research on preservation and freshness of loach and its deep processing products is particularly important. Preservation process includes transportation, processing, marketing and many other aspects, all aspects of the environmental conditions are different, therefore aiming at storage temperature and packagin-g on its physical and chemical properties, myofibrillar protein functional properties of loach meat during storage as well as fresh loach fish surimi gel pre-paration technique is studied, the main conclusions are as follows:(1)Storage temperature have a significant influence on physical and chemical properties of air-packaged loach meat during storage. With the extension of storage time, total bacterial count, total volatile basic nitrogen, thiobarbituric acid value, wastage rate value of juice, b* values in color of loach meat sample showed a gradual upward trend; Sensory score and L* value and the a*value of the fish showed a gradual downward trend; Its pH value showed anupward trend after the first downward trend; Its shear values showed an downward trend after the first upward trend. The special case, Its pH value continues to rise and thiobarbituric acid value showed an downward trend after the first upward trend at 25℃ during storage; Determination of histamine under various storage temperatures condition during storage, may not be a valid content. Sensory evaluation, total bacterial count, total volatile basic nitrogen could be used as air package under different storage temperature meat freshness evaluation indexes of misgurnus anguillicaudatus, loach air packaging meat at 4℃, respectively,12 and 25℃ storage 6d,3 d and 12h for shelf end, colony and TVB-N values, respectively:5.92 lgcfu/g,12.9mg/100g; 6.04 lgcfu/g,13mg/100g;5.8 lgcfu/g,12.48 mg/100g; pH value, thiobarbituric acid value loss of colour and juice, fish, cut value can be used as a reference index;Histamine can be ignored.(2)Modified atmosphere packaging to meat loach qualities have a significant protective effect in the refrigeration process, higher CO2 concentration catfish meat more backwards to extend the storage and shelf life of end, when CO2 concentrations in excess of 50%, no significant differences in efficacy (P>0.05).75%CO2+25%N2 and 50%CO2+50%N2 under modified atmosphere packing group 4℃refrigerated shelf life of at least 10d,25% CO2+75%N2 modified atmosphere packing group 4℃ refrigerator shelf for 8d.Refrigerated meat loach under modified atmosphere packaging advantages of inhibition of total bacterialcount, total volatile basic nitrogen value, thiobarbituric acid value increase of pH recovery, fish after fish and stiff color changes and changes in shear values have a delaying effect;The drawback is the high concentration of CO2 wil increase the Loach meat juices drain, CO2 leads to bags a serious collapse ofthe 75%.Should select the appropriate CO2 concentrations for modifyed atmosphere packaging of fresh meat storage and fresh-keeping of loach,50% of CO2 is more appropriate.(3)During the process of refrigeration, modified atmospheric packaging group and the packaging group of myofibrillar protein functional properties of misgurnus anguillicaudatus trend is basically the same, two sets of specimen catfish meat packaging myofibrillar protein of emulsifying activity index, solubility, stability, gel and gel strength is first increased and then decreased waterretention trends;Hydrophobic showed upward trend after the fall;Gel whiteness,shows a decreasing trend; myofibrillar protein rheological properties of G ’in the heat during showed an up-down-upward trend, during storage G’ of the first peak showed a downward trend after the first rise, when at 85℃, modifyed atmosphere packaging group and the group of air samples loach myofibrillar protein G’ respectively in the 3d and 4d maximum, which is consistent withthe gel strength measurement results. And modified atmosphere packaging group on loach myofibrillar proteins have significant protective effects.(4)When loach fish surimi gel preparation, with insulation insulation 40℃ 30min-90℃20min segment formed by the heating of gelatin is best;Using different kinds of compound food gum alone, add xanthan-konjac glucomannan-carrageenan (3:1:3) of gel properties formed by the best; TG optimal enzyme dosage 0.3%; SPI optimal concentration of 3%; mixed gum (xanthan gu-m:konjac gum:Carrageenan= 3:1:3) optimal concentration of 0.6%.