Study On The Relationship Between Texture And Flavor Of Jujube Based On Oral Processing

Food texture and flavor are important indicators for consumers to choose food.As a necessary way for consumers to perceive food,changes in food texture and flavor continue to occur throughout the oral processing behavior.At present,the research on the relationship between food texture and flavor is mainly in the food itself and processed products,ignoring the changes of texture and flavor of food in the real oral processing state.The relationship between texture and flavor in oral processing is still unclear.In order to explore the relationship between food texture and flavor in oral processing,this paper takes jujube as the object,uses multiple technical means to determine the texture,odor and taste substances of jujube during oral processing,and analyzes and constructs a method to visually display the relationship between texture and flavor of jujube in oral processing in a digital way.It is expected to enrich the content of jujube fruit quality evaluation and provide reference for the study of the relationship between texture and flavor of food in oral processing.(1)In order to clarify the sensory characteristics and changing rules of taste and texture of jujube during oral processing,this paper takes jujube as the research object,through the establishment of sensory evaluation group,the taste and texture of jujube under different oral processing time were analyzed by TDS sensory method.The results showed that : 1.Jujube has six dominant tastes(sweet,sour,light,caramel,fermented and creamy)and three dominant texture sensory characteristics(hardness,chewiness,cohesiveness)in oral processing;2.Change rule : The sensory characteristics of taste showed an upward trend in 5-15 s and a downward trend in 20-30 s.In the early stage of oral processing,the main taste was sour,15-20 s was mainly sweet and fragrance,20-25 s cream flavor and caramel flavor were the most noticeable advantages,and the wine flavor was the most obvious in 30s;the sensory characteristics of texture showed a downward trend in 5-30 s,only the melting sense showed an upward trend.(2)In order to explore the change rule of jujube texture characteristics during oral processing.By selecting appropriate chewing parameters,using texture analyzer and scanning electron microscopy,the chewing ability of the evaluators,the texture properties of the bolus and the microstructure changes of the bolus during oral processing were analyzed.The results showed that during oral processing,the saliva content increased significantly,the saliva secretion was stable in 10-15 s,and the saliva flow rate showed a downward trend.The hardness,elasticity,chewiness and cohesiveness of the food balls continued to decrease from 5s to 30 s.At 5-10 s,the jujube food balls showed more gaps in the overlapping hill structure,and the gumminess and viscosity of the 15-20 s were significantly increased.(3)In order to explore the change rule of jujube odor during oral processing,establish odor fingerprint and screen characteristic odor substances.In this paper,based on GC-IMS technology,the odor substances produced by jujube in different stages of oral processing were determined,and the characteristic odor substances were analyzed by PCA and VIP value method.The results showed that : 1.During oral processing,the release of jujube odor substances was low in 5-10 s,high in 15-25 s,and less in 30 s.2.Main odor substances in oral processing stage : At 15 s,the main odor substances were : 3-hydroxy-2-butanone,acetylacetone,3-methyl-2-pentanone,diethyl ketone,2-hexanol,sec-butanol,n-propanol(monomer and dimer),2,3-pentanedione;the main odor substances of 20 s were : 2,3-butanedione,ethanol;25s main odor substances : 1-penten-3-ol,propionaldehyde(monomer and dimer),methyl hexanoate(monomer and dimer),n-butyl formate,ethyl acetate,hexanal,3-hydroxy-2-butanone,2-hexanol,dimethyl sulfide;the main odor substances at 30 s : 2-hexenal,hexanal,2-heptanone.Through VIP value analysis,it was concluded that acetic acid(monomer and dimer),3-hydroxy-2-butanone(monomer and T),n-propanol(monomer),ethanol(dimer)and acetone were important contributors to odor substances during the whole oral processing.(4)In order to explore the change rule of jujube taste during oral processing,the electronic tongue technology was used to determine the taste characteristics of food balls,and the content changes of free amino acids and total sugar in oral processing were determined.The results showed that with the prolongation of oral processing time,the taste substances increased first and then decreased,and the content of free amino acids reached the highest at 15 s.The total sugar content of jujube increased first and then decreased during oral processing except for 5s time.Proline is an amino acid that has a direct contribution to jujube in oral processing.(5)In order to clarify the relationship between texture and flavor of red jujube in oral processing,the correlation analysis method was used.The results showed that the texture of the pellets was negatively correlated with the odor substances produced by oral processing(hardness and adhesion showed a significant negative correlation),and was positively correlated with sweetness and sourness in oral processing.Bitterness and astringency were negatively correlated,and umami was significantly negatively correlated.In summary,with the extension of chewing times and time during oral processing,the texture characteristics of the bolus showed a downward trend,but the taste and odor showed a trend of first increasing and then decreasing.At 0-5s,the hardness,elasticity and gumminess of the pellets were the highest,and the overlapping hill structure began to appear with more voids.Acid flavor is the dominant flavor,and the release of odor substances is less;at 10-15 s,the sweetness and fragrance perception was obvious,and the stickiness and gumminess in the food mass had a slight upward trend.At this time,the food mass tasted soft and dense,and began to appear a homogeneous matrix.Ketone alcohols were the main contribution characteristic substances.At 15 s,the inflection point of texture and flavor change during oral processing,odor and taste reached the highest release amount at this time,and the texture characteristics appeared uniform matrix,and the taste was dense.The best flavor perception period;at 20-25 s,the structure of the food bolus was gentle,preparing for safe swallowing.Cream and caramel were the dominant flavors,and the characteristic odor substances were esters.At 30 s,the dough was sticky and the surface was smooth.The wine flavor was the dominant flavor before swallowing,and the release of odor substances was rarely similar to that at 5 s.