Optimization Research On High-temperature Drying Proess Of Chinese Dry-cured Chicken

Dry-cured chicken is one of the typical Chinese traditional meat products,famous for its unique flavor and taste.Traditional dry-cured chicken production is mainly based on naturalmaturationin winter at low temperature with a long process,which is climate limited and time consuming.This brings about the limits of production and marketing.With the renovation of food science and technology,the natural drying processof most of the dry-cured meat product Increasing drying-temperature is a potential way to shorten the process of dry-cured meat producthas gradually been replaced by the commercial production.However,not many studies have concerned the use of high-temperature drying-process on dry-cured chicken or those important effects on the proteolysis and sensory quality of the product.In this study,the high temperature drying process was studied as an alternative method to accelerate the drying-process of Chinese dry-cured chicken.The effects of salt content,drying temperature and drying time on the physicochemical properties,lipid oxidation,protein degradation,flavor and sensory quality of dry-cured chicken were analyzed,in order to determine the feasibility of using high temperature to reduce the production time of Chinese dry-cured chicken,and to find out the optimum process parameters.Details are as follows:1.Effect of high temperature drying-process on the physicochemical properties,lipid oxidation,protein degradation and sensory attributes of Chinese dry-cured chickenApproriate high temperature can effectively shorten the drying time of dry cured chicken,without bringing bad influence on the physical and chemical properties or sensory quality.Based on the same level of moisture content,tenderness was significantly(P<0.05)affected by the temperature,indicated by the increasing WBSF.The oxidation of both protein and lipid were both accelerated by the high temperature-treatment while no undesirable flavors or tastes were observed in the sensory evaluation.Samples treated by 55HT brought about the highest content of total FAA and most of the individual FAA.The scores of color,aroma and taste in high temperature groups weresignificantly(P<0.05)higher than the control.The best sensory attributes were observed in 55?-25h-treated samples.According to the results of the physical and chemical properties and sensory evaluation,55?-25 h was the optimal temperature-time to accelerate the manufacture and to improve the sensory propertiesof Chinese dry-cured chicken.2.Optimization of high-temperature drying-process of dry-cured chicken using response surface methodologyUnder the condition of high temperature-drying process,with the increase of salt content,there were no significant difference found between the moisture contents,while the value of L*increased significantly as the value of a*decreased.Comprehensive view of the texture and the sensory quality,the best salt content of curing water would be 10%(m/v),and the best drying-time would be 28 h.Appropriate salt content and drying-time could significantly improve the texture index and the sensory quality of dry-cured chicken under the condition of high temperature-drying process.The Box-Behnken response surface methodology was applied to optimize the processing parameters for the high-temperature drying process.Two quadratic polynomial regression modelabout WBSF and sensory quality were built.The results showed that the responses surface model with saltcontent,drying-temperature and drying-time as independent variables,were fitted.According to the model,the optimumquality of Chinese dry-cured chicken was obtained when salt content was 9.5%,drying-temperature was 54 ? and drying-time was 27 h.The optimum process significantly improved the texture and sensory quality of Chinese dry-cured chicken,and greatly shortened the process time.3.Effects of high-temperature drying process on volatile flavor compounds of dry-cured chickenA total of 77 volatile flavor compounds were identified from dry-cured chicken in both control group and high-temperature-treated group,among which there are 36 species in the final product of the control,and 34 in high-temperature-treated group.The main ingredients of the volatile flavor compounds were alcohols,acids,aldehydes,ketones and hydro-carbons.During the drying process,the relative content of alcohol,aldehyde and ketone increased significantly,while those of acids,esters,hydrocarbons decreased.It was found that aldehydes in high-temperature-treated groupwere significantly higher than the control,and the main flavor compound was hexanal.The contents of acids,esters and hydrocarbons in high-temperature-treated group were significantly lower than the control.There was no significant difference of the total peak area of volatile flavour compounds found between the high-temperature-treated groupand the control in the late drying process.The results showed that high-temperature drying processcan stimulate the formation of flavor substances in dry-cured chicken and would be able toreach the same level of total peak area as the control,with an effective reduction of drying-time.