Effect Of Oral Processing On Mouthfeel Quality Of Chinese Traditional Stewed Pork With Brown Sauce

Food oral processing is a dynamical variation in which the physicochemical properties of bolus and physiology of individuals change from first bite to swallow.During chewing,food breaks down,exposing food particles to saliva.A swallowing will be triggered when a food transforms into a cohesive bolus.Food oral processing is essential to the formation of taste.Stewed Pork with Brown Sauce is a Chinese traditional dish and is cooked with pork belly.Stewed There are rich intramuscular or subcutaneous fat in Pork with Brown Sauce and holding primitive state.This for “primitive state” fat-dependent meat food can stimulate dental nerve and affect taste.The variations of saliva secretion,texture and taste characteristics of Stewed Pork with Brown Sauce during oral processing were studied,and the main research work and conclusions were as follows:1.The sensory panel of twelve assessors was built by recruiting members for evaluation,selection and training.Twelve subjects chewed the fat layer and the lean layer of Stewed Pork with Brown Sauce.Chewing parameters and saliva added for each subject and food type during mastication were assessed,and the changes of bolus moisture content in different positions of Stewed Pork with Brown Sauce was analyzed contemporarily,which was in order to explore the possible mechanism in triggering a swallowing for “primitive state” fat-dependent meat food.Results showed that the chewing cycles for each subject and each food type increased significantly(P<0.05),whereas the chewing frequency was stabilized respectively(P>0.05);The saliva added for each subject and food style increased significant(P<0.05),while the saliva flow decreased significantly(P<0.05)tend to be stable;Moisture content of wet and dry basis in the boluses during oral processing increased significantly depending on the subject and food types studied(P < 0.05).At the same stage of mastication,the saliva added and the saliva flow for each subject chewing the fat layer of Stewed Pork with Brown Sauce were significantly lower compared to the lean layer(P<0.05).Moisture content of wet and dry basis in the fat layer boluses tended to be lower significantly compared to the lean layer(P<0.05).The differenceon bolus moisture content on the point of swallowing between food types was significant(P < 0.05),while it was similar(around 25-30% for the fat layer and60-65% for the lean layer).It was likely to be an important symbol on triggering a swallowing for the moisture content of food.2.Two subjects who produced boluses with the maximum and minimum moisture content were eliminated.Ten subjects chewed and expectorated the fat and lean layers of stewed pork with brown sauce at different stages of mastication.The potential physics differences of Chinese traditional stewed pork during mastication were investigated.The produced boluses were analyzed for their physical properties.The results suggested the subjects' saliva secretion and moisture content of the boluses during mastication increased significantly depending on subjects and food types studied(P<0.05)and led to increase of bolus apparent particle size because of saliva uptake.Bolus first peak force tended to decrease significantly,whereas bolus flowability increased significantly during mastication(P < 0.05).Further,microstructure of boluses revealed series processing was conducted by comminution,aggregation,hydration and dilution.The boluses ready-to-swallow possessed a higher flowability and a homogenetic matrix.Therefore,the changes in physics and microstructure of bolus contributed to dynamic texture perception of traditional Chinese stewed pork with brown sauce.3.Ten subjects chewed the samples of Stewed Pork with Brown Sauce;the boluses were collected at different stages of the mastication process,including the swallowing point.The moisture content,fat content,pH,sodium chloride content and nucleotide content of the food boluses were measured during mastication,as well as the taste change using electronic tongue detection technology.Results showed as follows: Moisture content of boluses during mastication increased significantly depending on the subject;Fat content of boluses during mastication continued decreasing;Both of them were achieved 55.65% and 19.40% at the swallowing point,respectively;There was no significant change within the value of pH,except 20%mastication;The sodium chloride content was showed to decrease during mastication and both of them were slightly elevated at the swallowing point with a value of 1.07g/100 g and 79.90 mg/100 g,respectively.A similar trend was observed with nucleotide content.Furthermore,the sodium chloride content of bolus was significantly negative correlated with pH,and there was a significant negative correlation between nucleotide and fat content.The electronic tongue analysis showed that a similartendency of saltiness and umami in the bolus.The two effective evaluation samples sensory score achieved the highest value during the middle-latter stages of mastication.This study showed that this new taste detection technology based on electronic tongue can be used to analyze taste variation of meat food during mastication.The release of saltiness and umami during mastication of Stewed Pork with Brown Sauce increased first and then decreased and achieved the highest value at the middle-latter chewing stage.