Response Surface Optimization Of Formula And Shelf Life Prediction Of Semi-dry Roasted Spanish Mackerel

Scomberomorus commersoni is a warm pelagic fish with delicate meat,excellent taste and rich nutrition.The fat content per 100 g of fish is 2.5 g,and the protein content is more than 19 g.Most of them are high-quality proteins with a high absorption rate of about 87-98%.At present,the processing of aquatic products has always been a weak link in China's fishery development.As one of the economic fish in the north,Spanish mackerel has some problems,such as narrow market,high transportation cost,single product and so on,due to its heavy fishy smell and poor freshness.In this paper,the economic fish mackerel in Bohai Sea and Yellow Sea around Liaoning Province was used as experimental materials,sensory index,texture index and water activity were used as orthogonal evaluation indexes,and the best curing formula was obtained by comprehensive balance method in order to remove its fishy smell.Then,parameters such as semi-dry and baking were optimized by response surface software in order to prolong the shelf life of semi-dry baked mackerel products.Finally,by Pearson correlation coefficient,The quality change(microorganism,physics and chemistry,sense)of semi-dry baked Spanish mackerel products at different temperatures was studied.Based on the idea of dynamic modeling,two optimal indexes of quality change(microorganism,physics and chemistry,sense)of semi-dry baked Spanish mackerel products at different temperatures were selected,and the shelf life dynamic model was established.The conclusions are as follows:Compound marinade juice was prepared with pepper powder,cooking wine,salt and lemon juice.Through single factor and orthogonal experiment optimization,sensory score,texture score and water activity results were comprehensively balanced,and the final optimal compound marinade juice was determined:pepper powder 1.2%,cooking wine 3%,salt 6%and lemon juice 1%.Under these conditions,the highest sensory score is 4.82±0.23,texture score is 2.89,and water activity is 0.8343.Picked Spanish mackerel was baked at different temperatures and different times,and the best water activity was obtained by texture:elasticity,hardness,chewiness,cohesion,shear force and sensory evaluation.The sensory score and texture evaluation of the best water activity at different temperatures were compared,so that the best baking conditions were 80?,6 h and the water activity was 0.82.Taking the semi-dry Spanish mackerel obtained as raw material,taking temperature,time,the material-liquid ratio of smeared honey to white vinegar as three factors,taking color difference and sensory score as response values,the best baking formula of semi-dry grilled Spanish mackerel was obtained by Box-Behnken experiment:baking temperature 173.99?,baking time 12.81,material-liquid ratio 2.69(honey:white vinegar Considering the economy and realizability,the best baking parameters were determined as follows:baking temperature 175?,baking time 13 min,and solid-liquid ratio 3(honey:white vinegar)respectively.Under this extraction condition,the verification experiment was carried out,and the color difference of semi-dry baked Spanish mackerel was1.38(P<0.05),and the sensory evaluation was 4.3(P<0.05),which passed the model.The quality of the finished product was analyzed:volatile basic nitrogen,determination of basic components,determination of texture index,determination of microbial index,determination of nitrite and salt content,etc.Among them,the content of volatile basic nitrogen was 7.74 mg/hg,nitrite content was less than 0.2mg/kg and salt content was less than 6%.The low salt state indicated that the product was lightly pickled and had the characteristics of green health.The quality indexes of semi-dry baked Spanish mackerel at different temperatures(4,25,37,60?)and different storage times:sensory indexes(chroma value),microbial indexes,physical and chemical indexes(volatile basic nitrogen,TBA,PH).Through Pearson correlation coefficient verification,the volatile basic nitrogen and the total number of colonies were significant except PH and TBA,and(4 Combined with the Arrhenius equation,the activation energy Ea of the change of the total number of colonies is 5.6×10~4J/mol,and the pre-factor k₀is 3.93×10~9.According to this model,the theoretical shelf life of semi-dry baked Spanish mackerel at 15?,20?and 30?is18 days,12 days and 5.6 days respectively,which is in good agreement with the measured shelf value,and the relative error is less than 20%,indicating that Arrhenius equation has a high fitting degree,the activation energy Ea of TVB-N change is 4.93×10~4J/mol,and the pre-factor k₀is 5.26.The relative error is about 15%.The two models can be used to predict the theoretical shelf life of semi-dry baked Spanish mackerel at different storage temperatures,and at the same time,they can provide some reference for the shelf life model prediction of pre-cooked aquatic products.