| Loach(Misrurnus anguillicaudatus) has high and comprehensive nutritional value.It is used as medicine and for health care, which possesses the effect benefiting for the spleen and vitality, clearing heat and damp, diminishing inflammation, reducing blood and press, resisting cancer and slowing the aging and so on. Loaches processing industry has a good market and development foundation, but the consumer acceptability of loach products is reduced due to its heavy specific odor substances,which has a bad influence on such industry. This study is aimed to study the ways of deodorization and the various effects on their physicochemical quality and myofibril protein function properties. Therefore a safe, economical and efficient way will be found, which has less influence on the quality of loaches, laying certain theoretical foundation for the development of loach processing industry. The main results are as follows:1. Taking the TBA values, TMA values and sensory scores and collaborating GC-MS analysis results, the discovery is that they are baker yeast cytosol, oolong,baker yeast, crtric acid-Ca Cl2, and β-cyclodextrin method ranged by the deodorization effect. The suitable conditions of yeast cytosol deodorization method is 25℃, 1.5 hour,p H 6.5, 1:2, while oolong deodorization method is 3%, 25℃, 3 hour, 1:4.2. The results of GC-MS show that the kind of volatile flavor compounds got from the loaches, β-cyclodextrin, crtric acid-Ca Cl2, oolong, baker yeast, baker yeast cytosol method is respectively 68, 51, 56, 55, 55, 51; the content of aldehydes material is respectively 73.71%, 49.82%, 45.93%, 40.17%, 42.66%, 39.76%. The fishy odour compounds of loach are possibly hexanal, nonanal, octanal, E-2-octenal, E-2-nonenal,2,4-decadienal, heptaldehyde, 2,3-octanedione and so on.3. Loaches are dealt with by crtric acid-Ca Cl2 under different circumstance, and TVBN values is smaller when the crtric acid concentration is 2%-2.5% and the time limit is 0.5-1 hour; cooking loss will be low when the crtric acid concentration is 0.5%,Ca Cl2 concentration 0.2%-0.4%, time 0.5 hour, ratio of material to liquid is 1:0.5;shear values is good when the acid concentration is 2%, Ca Cl2 concentration 0.2%,time 0.5 hour, ratio of material to liquid is 1:0.5; the color will be better when the acidconcentration is 1%, Ca Cl2 concentration 0.2%, time 0.5 hour, ratio of material to liquid is 1:0.5. Loaches are removed off-odors by baker yeast under different conditions, TVBN values is smaller when in 1%-3%, 5℃, 0.5-1 hour, p H 8.5; the cooking loss is lower when in15-25℃, 2-2.5 hour, p H 6.5-8.5; the shear values is better when in 0.5%, 15℃, 1 hour, p H 5.5; the color is better when in 0.5%-2%, 15℃,0.5-1 hour, p H 8.5. Loaches are removed off-odors by oolong under different conditions, TVBN values is smaller when in 2.5%-3%, 5-25℃, 0.5-1 hour, 1:2-1:4;cooking loss is lower when in 2.5%-3.5%, 1:2-1:6; the shear values is better when in2%, 25℃, 0.5 hour, 1:4; the color is better when in 1.5%, 5℃, 0.5 hour, 1:1. Loaches are removed off-odors by baker yeast cytosol under different conditions, TVB-N values is smaller when in 5℃, 0.5-1 hour, p H 6.0-7.0, 1:1-1:3; cooking loss is lower when in 25℃, p H 7.5; the shear values is better when in 25-35℃, 0.5 hour, p H 5.5, 1:1;the color is better when in 25℃, 2.5 hour, p H 7.5, 1:2-1:3.4. Loaches are removed off-odors by oolong under different conditions,myofibrillar protein solubility maintain a high level when oolong concentration is1.5%-3%, temperature 15-35℃, time limit 0.5-1 hour, ratio of material to liquid is1:2.5; emulsification gets a good balance when oolong concentration in 2.5%-3.5%,temperature 25-35℃, time limit 1-2 hour, ratio of material to liquid is 1:2-1:4;hydrophobic maintain a low level when concentration is 1.5%-3%, temperature 5-25℃,time limit 0.5-1 hour, ratio of material to liquid is 1:2-1:8; higher gel strength will be good when oolong concentration in 3%-3.5%, temperature 15-35℃, time limit 0.5-2hour, ratio of material to liquid is 1:4-1:8; gel water holding maintain a high level when oolong concentration in 2%-2.5%, temperature 15-35℃, time limit 0.5-2 hour,ratio of material to liquid is 1:4-1:6; myofibrillar protein gel whiteness is good when oolong concentrationin is 1.5% and 2.5%, temperature 5-15℃, time limit 0.5-2 hour,ratio of material to liquid is 1:4-1:6. G’ is firstly bigger,then smaller and again bigger when dealt in different condition. What’s more, G’ in this way is bigger than that by baker yeas cytosol. myofibrillar protein has better functional properties when the oolong concentration is 2.5%, treatment temperature 25℃, time limit 1 hour, ratio 1:4.5. Loaches are removed off-odors by baker yeast cytosol under different conditions, myofibrillar protein solubility maintain a high level when the treatmenttemperature is 5-25℃, time limit 0.5-1.5 hour, p H 6.5-7.5, ratio of material to liquid is1:0.5-1:1; emulsification get a good balance when the treatment temperature is15-25℃, time limit 0.5-2 hour, p H 6.5-7.5, ratio of material to liquid is 1:1;hydrophobic maintain a low level when treatment temperature is 5-25℃, time 0.5 hour,p H 6.5-7.5, ratio of material to liquid is 1:1-1:3; higher gel strength will be reached when the treatment temperature is 15-45℃, time limit 0.5-1 hour, p H 6.0-7.0, ratio of material to liquid is 1:3-1:4; gel water holding maintain a high level as the treatment temperature is 15-35℃, time limit 1-2 hour, p H 6.5-7.0, ratio of material to liquid is1:3-1:4; higher gel whiteness will be got when treatment temperature in 5-15℃, time limit is 1.5-2 hour, p H 6.5, ratio of material to liquid is 1:0.5-1:2. G’ is firstly bigger,then smaller and finally bigger again when dealt with different condition. Myofibrillar protein has better functional properties when the treatment temperature is between15-25℃, treatment time 2 hour, p H 6.5-7.0, ratio of material to liquid is over than 1:3by yeast cytosol deodorization.6. Loaches are removed off-odors by baker yeast cytosol, which gains a good effect of deodorizing at the same time it can maintain the loach sensory, physical and chemical processing quality. So it is a good way to remove off-odors of the loaches,and the suitable conditions of yeast cytosol deodorization method is 25℃, 1 hour, p H6.5, 1:2. |
PDF Full Text Request