Study On Evaluation Method Of Roast Duck Quality And The Parameters Optimization Of Infrared Steam Baking Technology

Roast duck is a traditional meat product in China.It has broad consumer market due to its excellent quality and unique flavor.However,problems,such as high energy consumption,high content of harmful substances,difficult to guarantee the quality of products,lack of advanced industrial processing technology,exist in traditional manual processing and industrial production of duck.This paper analyzed the quality characteristics of roast duck,established a method for evaluating the quality of roast duck,and optimized the processing parameters of infrared steam roast duck.In order to standardize the evaluation method and guide the industrialized manufacture of duck products,it is helpful to realize the environmental friendly roast of duck.The main results are outlined below:There were significant differences in the sensory evaluation results of different brands of roast duck products(P<0.05).It illustrated that it was feasible to classify the roast duck products.The color and tenderness of roast duck were significantly correlated with sensory quality score.Roast duck products from high to low is divided into one,two,and three level,which builds a quick evaluation method of roast duck,and provides a standard for process optimization.b*and elasticity were selected as the key indexes of duck meat,and L*and elasticity were selected as the key indexes of duck skin.For the first level of roasted duck,b*value of meat ranges from 13.24 to 18.56,elasticity value of meat is between 0.62 and 0.84,elasticity value of duck skin ranges from 0.55-0.95,and the L*value of duck skin is from 39.05 to 58.56.For the second level of roasted duck,b*value of meat ranges from 11.42 to 18.56,elasticity value of meat ranges from 0.58 to 0.84,elasticity value of duck skin ranges from 0.49-0.95,and the L*value of duck skin is from 38.45 to 58.56,.For the third level roasted duck,b*of meat ranges from 11.42 to21.51,elasticity value of meat is between 0 and 0.84,elasticity value of duck skin ranges from 0 to 0.95,and the L*value was from 26.06 to 58.56 The formula of the comprehensive quality of roasted duck score regression equation is:Y=2.65X1+0.64X2+2.22X3+9.54X4-22.94(X1:b*of duck meat,X2:L*of duck skin,X3:elasticity of duck skin,X4:elasticity of duck meat,Y:sensory score,R2=99.9%,P<0.05).It realized a quick classification of roast duck by standardizing the color of duck skin and meat.The contents of heterocyclic amines in roasted duck were significantly different in different brands of products(P<0.05),but the amine content of heterocyclic compounds and sensory quality were not significantly related,MeIQx contents and sensory evaluation score were strongly correlated(P<0.01).Apart from MeIQx,there was no correlation between the content of heterocyclic amines and sensory quality.The lower content of MeIQx,the higher scores of roasted duck comprehensive quality.The content of MelQx in roasted duck was about 0-110.64 ng·kg-1,which was in line with the requirement of national standard(MeIQx?1.0 ?g kg-1).Using standard of key parameters for the first level of roast duck,the score of roast duck comprehensive quality,standardized roast duck meat color and heterocyclic amine content as evaluation indexes,the processing parameters of steam infrared roasting have been optimized.The single factor experiment results are as follows:the optimum roasting temperature was 220?.Under this condition,b*value of duck meat was 14.98,L*value was 40.60,elasticity of duck skin was 0.69,elasticity of meat was 0.81,the comprehensive quality score was 52,the total HAAs content was 2989.75 ng·kg-1,MelQx content was 104.14 ng·kg-1.The suitable steam roasting time was determined at 40 min.Under this condition,b*value of duck was 13.59,L*value was 57.07,elasticity of duck skin was 0.69,elasticity of duck meat was 0.76,the comprehensive quality score was 58.38,the total HAAs content was 1086.63 ng·kg-1,MelQx content was 35.60 ng·kg-1.The suitable steam injection time was 4 s.Under this condition,b*value of duck meat was 18.05,L*value of duck skin was 39.85,elasticity of duck skin was 0.69,elasticity was 0.68,the comprehensive quality score was 54.58,the total HAAs content was 2214.88 ng·kg-1 MeIQx content was 109.62 ng·kg-1.Among these test groups,the key evaluating parameters,including MeIQx levels,were in line with the criterion of top level roast duck.,Orthogonal test determined the best roasting temperature(210?),the roasting time(42 min)and the steam injection time(3 s).Under this condition,b*value of duck meat was 19.06,L*value of duck skin was 34.68,elasticity of duck skin was 0.75,elasticity of duck meat was 0.71,the comprehensive quality score was 58.15,the total HAAs content was 2576.02 ng·kg-1.Temperature was in proportion with the content of heterocyclic amine.From 180?to 260?,the content of heterocyclic amine increased with raising the temperature.Moreover,roasting time and the content of heterocyclic amine were in positive correlation.When roasting time ranged from 30 to 50 min,the longer roasting time,the higher level of heterocyclic amine.However,the content of heterocyclic amine was in adverse proportion with the roasting humidity.Based on the result,when the steam injection time was 5 s,the content of heterocyclic amines was in lowest level,but the mechanism of it requires further research.