Preparation And Properties Of Fried Battered And Breaded Fish Nuggets With Low Fat

Fried battered and breaded fish products with tender texture, crisp outside, golden color and unique flavor, are one of the popular series flavor food. However, there is high oil content(30%), excessive oil intake can lead to obesity and cause various cardiovascular problems, to some extent, limits the development of fried battered and breaded fish products. The effects of different kinds of starch and protein, the ra tio of starch or protein to flour, and process(ratio of flour to water, mixing time, fried conditions, and cooling conditions) on the oils and water content, sensory properties, and microscopic structure of fried battered and breaded fish nuggets were inv estigated, and also the oil absorption and distribution in the process of frying. Moreover, the process for reducing oil content in the fried battered and breaded fish nuggets was optimized in this paper. The main experiments and conclusions are as follows :1. The batters added with corn starch, hydroxypropyl corn starch, rice starch and glutinous rice starch at different proportion of flour and starch(ratio of flour to starch) were deep-fried. The results showed the oil content of group with 3:2(ratio of flour to starch) was relatively low and water content was relatively high, and oil and water content were 17.67% and 15.81%, respectively. Fried battered and breaded fish nuggets added with corn starch in the batters were deep-fried. The results showed that the ratio of flour to starch obvious influenced the quality of fried battered and breaded fish nuggets. The oil contents of shell and internal fish nugget with 3:2 of ratio(flour to corn starch) were 22.36% and 2.23%, respectively, and water content we re 38.89% and 70.19%, respectively, and also shell chewiness of 2.64 kg and internal fish springiness of 0.92. Moreover, L, a, and b of fried battered and breaded fish nuggets were 62.18, 3.15 and 24.32, respectively, and also high sensory score. Scanning electron microscope(SEM) analysis showed that the porosity structure of fried battered and breaded fish nuggets was different from ratio of flour to starch. When the ratio of flour to starch was 3:2, shell had close structure and a small amount of porosit y. Moreover, porosity distribution of internal fish nuggets was relatively uniform.Sudan red-dyed dyeing experiments showed that surface sediment firstly decreased and then increased with the increase of the ratio of starch to flour, and the dyeing oil ent ered the internal fish nuggets through the pores forming by water evaporation. When the ratio of flour to starch was 3:2, the lighter Sudan red-dyed level, the less amount of internal pore were gained.2. The batters added with rice protein, soy protein isolate, whey protein, egg white protein at different amounts were deep-fried. The results showed that the oil content adding 4% whey protein group was relatively low and water content was relatively high, and oil and water content were12.29% and 20.93%, respectively. Fried battered and breaded fish nuggets added with whey protein powder in the batters were deep-fried. The results showed that the oil contents of shell and internal fish nugget with 4% of whey protein reduced to 21.55% and 2.01%, respectively, and water content increased to 39.89% and 70.81%, respectively, and also shell chewiness of 2.85 kg and internal fish springiness of 0.99. Moreover, L, a, and b of fried battered and breaded fish nuggets were 68.22, 5.65 and 28.91, respectively, and also bri ghtness white and gold color. SEM analysis showed that a small amount of large pores were presented in shell of fried battered and breaded fish nuggets without adding whey protein, and also more porosity with nonuniform and irregular distribution in intern al fish nuggets. When the amount of whey protein increased from 2% to 4%, the pores in fried battered and breaded fish nuggets was significantly less, smaller and equally distribution. When the amount was among 6-10%, more large pores were presented in the shell, and also the porosity structure became roughand appeared. Moreover, more porosity was presented in internal fish nuggets, and also the distribution was more nonuniform and irregular. Sudan red-dyed dyeing experiments showed that fried battered and breaded fish nuggets without adding whey protein had deeper and wider dying level. Moreover, The dying level in fried battered and breaded fish nuggets firstly decreased and then increased with the increase of whey protein. When the amount of whey protein was 4%, the dying level was the lightest.3. Battered and breaded fish nuggets were used to investigate the effect of coated powder and water ratio(powder water ratio), mixing time on content of oil and moisture, pick-up value of fried battered and breaded silver carp nuggets, and also investigate fried and cooling conditions on the effect of content of oil and moisture, color, microstructure of the nuggets and the oil transfer in the nuggets to reduce oil content in this study. The results showed that the powder water ratio of 12:11, mixing time of 10 min, fried temperature of 170℃for 40 s(first) and 190℃ for 30 s(second), cooling temperature of 30℃ for 60 min, oil and water content of the coated layer and internal fish nuggets of fried battered and breaded fish nuggets were 19.83%, 1.85% and 36.02%, 65.18%,respectively.The preparation process significantly reduced the oil content of fried battered and breaded fish nuggets and can be used to guide the scale production.