Study On Improving Processing Technology Of Beef Bone Soup By Ultrasonic Assisted Boiling

Bone soup is popular with consumers for its unique flavor and nutrition.The pre-conditioning bags of bone soup conform to the current trend that consumers demand for convenient,healthy and delicious food,and also have broad market prospect.At present,the commercial bone soup products in China need to be developed.It is of great significance to clarify the rules of nutrition and flavor formation of bone soup for optimizing the cooking process,standardizing the processing and nutrition formula of bone soup and further realizing the commercialization of bone soup.The cooking temperature is an important factor to determine the quality of bone soup.Compared with the high pressure cooking,the bone soup cooked under atmospheric pressure has better flavor and color.In this paper,the changing of nutrition,flavor and sensory of bone soup with cooking time was studied in this paper.The changing trends of crude protein,minerals,free amino acids,5'-nucleotides and volatile compounds in bone soup were analyzed,The sensory evaluation of bone soup of different cooking time was carried out by scoring test.Then ultrasonic technology was used to improve the processing technology of bone soup.The effects of ultrasonic pretreatment,ultrasonic assisted enzymatic pretreatment and ultrasonic assisted cooking on the quality of bone soup were studied.It was confirmed that ultrasonic assisted cooking could be used to improve the quality of bone soup.Finally,the effects of different ultrasonic assisted cooking temperatures(80,90 and 95?)on the nutrient and flavor dissolution,volatile flavor substances,color,micro distribution and sensory of bone soup were studied under the condition of ultrasonic frequency of 40 KHz and ultrasonic power of 480 W.The optimum ultrasonic assisted cooking temperature was defined.The main results are as follows(1)The changing trends of nutrients,flavor components and sensory score of pure beef bone soup during the process of atmospheric cooking were revealed.The crude protein and free amino acids reached the dissolution balance during the process of atmospheric cooking,and the minerals(K,Ca,Na,Mg)content increased with the prolongation of cooking time.The changes of the compounds related to the flavor of bone soup,such as 5'-nucleotides and volatile compounds,were similar to the trend of protein and free amino acids.The samples of bone soup at the 7^thhour contained the highest content of IMP+GMP.The volatile flavor compounds in bone soup were mainly aldehydes(hexanal,heptyl,octanal,nonaldehyde,etc.),and the types and relative content of aldehydes changed during cooking.The samples in the 4^thand 5^thhours have the best richness,containing 24 kinds of volatile flavor compounds except alkanes.The sensory score of bone soup first increased and then decreased,and the sensory score of bone soup samples was the highest at the 6^thhour.In conclusion,long-term cooking was beneficial to the dissolution of nutrients,but excessive heat reaction destroyed the diversity of flavor and flavor substances of bone soup,resulting in loss of volatile flavor compounds and bad for the overall palatability of bone soup.Therefore,long-time heating should be avoided to keep good flavor characteristics of bone soup.(2)It is confirmed that ultrasonic assisted cooking can be used to improve the flavor and sensory characteristics of bone soup.The temperature of ultrasonic pretreatment was low and the treatment time was short,which can not significantly improve the dissolution of crude protein in the cooking process of bone soup.The tight structure of bovine bone limited the contact between enzyme and protein substrate,so ultrasonic assisted enzymatic pretreatment was not suitable for improving nutrition and sensory quality of bone soup.When the temperature of the ultrasonic assisted cooking was 80?,the content of crude protein and soluble solid in bone soup was significantly lower than that of the control group(P<0.05),but the rapid dissolution of fat was promoted by ultrasonic assisted cooking.The ultrasonic assisted cooking was helpful to improve the volatile flavor characteristics of bone soup,and the brightness of bone soup was significantly improved by ultrasonic assisted cooking(P<0.05).(3)The optimum temperature of ultrasonic assisted cooking was determined to be 90?.The effects of ultrasonic assisted cooking temperature at 80?,90?and 95?on protein dissolution,soluble flavor substances,volatile flavor compounds and relative content,color,micro distribution and sensory score of bone soup were studied under the condition of ultrasonic frequency of 40 KHz and power of 480 W,the results showed that the comprehensive quality of bone soup was the best when ultrasonic assisted cooking at 90?.There was no significant difference between the crude protein content of 90?and the control group(P<0.05),and the content of K,Ca,Na and Mg in bone soup increased significantly by ultrasonic assisted cooking(P<0.05).Ultrasound promoted the dissolution of 5'-nucleotides,and was beneficial to the retention of free amino acids and tasted 5'-nucleotides.Ultrasonic assisted cooking accelerated the dissolution of fat.Most of the volatile flavor substances in bone soup were derived from the oxidation,degradation or hydrolysis of fat.So ultrasonic assisted cooking affected the types and contents of volatile compounds in bone soup.The content of nonaldehyde,D-limonene and ester directly related to flavor was significantly higher than that of the control group(P<0.05).The brightness of the bone soup of 90?was the best(P<0.05).The effect of ultrasonic emulsification changed the micro distribution of the emulsion of bone soup.The system of bone soup was more uniform by ultrasonic emulsification,the number of oil-containing particles increased and the particle size decreased.The sensory evaluation results showed that the samples cooked by ultrasonic cooking at 90?had the highest score,and had the best color,flavor and taste.In conclusion,the flavor and sensory characteristics of bone soup can be improved by ultrasonic assisted cooking at 90?.