Development Of Jackfruit Seed Protein Beverage And Flavored Fermented Milk

Jackfruit,as a typical tropical fruit,is widely planted in southern China and has a high annual yield.It is one of the main characteristic fruit tree industries in the rapidly developing tropical areas.Its peel,pulp and seeds have rich nutritional value.At present,the application of jackfruit is mainly based on pulp processing,and jackfruit seeds as a by-product are often discarded,causing a serious problem of resource wastage.Studies have shown that jackfruit seeds are rich in high dietary fiber,high starch,low fat and high quality protein.In this paper,jackfruit seeds were treated by enzymatic digestion method to determine the optimal enzymatic process parameters.On this basis,a jackfruit seed protein beverage and a jackfruit seed flavored fermented milk were developed,and the effects of different processing conditions on the stability and flavor of the beverage were investigated.The storage stability of jackfruit seed protein beverage and flavored fermented milk prepared under the optimal conditions was also studied.The purpose of this research is to provide reference for the application of jackfruit seeds in food industry.The main research results are as follows:1.The enzymatic digestion was carried out by high temperature α-amylase using fresh jackfruit seeds and water in the ratio of 1:10(w/w)as the raw material.Through single factor test and orthogonal test,with the DE value as the index,the optimal enzymolysis processes were: adding enzyme amount 50U/g raw material,temperature90℃,time 60 min,p H 5.5.Under these conditions,the DE value of enzymatic hydrolysate is 38.80%.On this basis,the stability and flavor formula of jackfruit seed protein beverage were further optimized.By measuring the centrifugal sedimentation rate,instability index,particle size and sensory evaluation,the optimal process formulation of rooibos seed protein drink was determined as follows: compound emulsifier(SE-15:GMS=4:1)addition of 0.15%(w/v),xanthan gum addition of 0.10%(w/v),CMC-Na addition of 0.12%(w/v),sodium alginate addition of 0.12%(w/v),sucrose addition of 6%(w/v),vanillin addition of 0.06%(w/v).The optimal p H range of the jackfruit seed protein drink was 6.5-7.0,and the optimal homogenization conditions were: homogenization pressure of 40 MPa,homogenization temperature of60°C,and homogenization times of 2.The jackfruit seed protein drink was prepared with the fragrance of vanillin and the unique flavor of jackfruit seeds,and the tissue state was good and stable.2.The changes of apparent stability,color,particle size,centrifugal sedimentation rate,p H value and total number of colonies of jackfruit seed protein beverage stored at4℃,28℃ and 38℃ for 90 days were investigated.The results showed that the apparent stability of jackfruit seed protein beverage was well maintained at 4℃.The jackfruit seed protein beverage stored at 38℃ for 90 days showed slight stratification and visible color change.The particle size and centrifugal sedimentation rate of jackfruit seed protein beverage increased with the extension of storage time,while the p H value decreased with the extension of storage time,and the higher the temperature,the more obvious the change.The total number of colonies in jackfruit seed protein beverage stored at 4℃ and 28℃ for 90 days conforms to the provisions of GB 7101-2022,while the total number of colonies in jackfruit seed protein beverage stored at 38℃ for 90 days has exceeded the standard,indicating that jackfruit seed protein beverage has deteriorated at this time.According to the comprehensive storage experiment,it is preliminarily estimated that the shelf life of jackfruit seed protein beverage is 3 months at room temperature(25℃)and 7 months at cold storage(4℃).3.The effects of flavor formulation and fermentation process parameters of jackfruit seed flavored fermented milk on product quality were investigated.The ratio of jackfruit seed enzymatic digest to recovered milk was determined as 1:4(v/v)and the amount of sucrose addition was 6%(w/v)by single-factor test,and the amount of compound stabilizer(sodium alginate:gelatin=7:3)in jackfruit seed flavored fermented milk was determined as 0.20%(w/v)by single-factor test with sensory score and acidity as the indexes.Through single factor and orthogonal experiments,the best fermentation processes were: inoculum amount 0.08‰,fermentation time 8h,fermentation temperature 41℃,at which the acidity was 89.3 and sensory score 87.4.The prepared jackfruit seed flavored fermented milk was sweet and sour with the unique flavor of jackfruit seeds.4.The changes of apparent stability,p H value,acidity,viable number of lactic acid bacteria,water holding capacity and texture characteristics of jackfruit seed flavor fermented milk stored at 4℃ for 28 days were investigated.The results showed that a large amount of whey was separated from jackfruit seed flavor fermented milk on the28 th day.The p H value and water holding capacity both decrease with the extension of storage time.The acidity shows a continuous upward trend during the storage period.The number of live lactic acid bacteria shows a trend of first increasing and then decreasing during the storage period.The texture characteristics of jackfruit seed flavor fermented milk changed.The hardness and consistency increased with the storage time,while the cohesiveness and viscosity index decreased with the storage time.According to the comprehensive storage experiment,the shelf life of jackfruit seed flavor fermented milk at 4℃ was preliminarily estimated to be 21 days.