Development Of Pollen Honey Fermented Milk

In this study,a new type of nutritive and health fermented milk was developed based on the nutritional and health functions of lotus bee pollen,honey and yogurt.The main raw materials contain bee pollen solution and whole milk powder,and replace part of the sugar with honey,adding lactic acid bacteria to ferment.Firstly,this experiment uses the enzyme hydrolysis method to break the wall of the lotus pollen,and optimize the technique of breaking cell wall of bee pollen.then the single factor and orthogonal experiments were adopted to determine the optimum production process of pollen and honey fermented milk,and the quality and volatile flavor compounds were analyzed.Finally the optimum compound stabilizer was screened,and the storage stability of pollen and honey fermented milk was studied.The results are as follows:(1)The rate of wall-breaking of pollen and the flavonoid content were used as evaluation indexes to optimize the process of pollen enzyme hydrolysis.The results showed that the optimum conditions were as follows:amounts of 200 U/g cellulase,amounts of 100 U/g pectinase,solid-liquid ratio 1:30(g:mL),temperature 50? and time 6 h.The rate of wall-breaking of pollen reached 95.88%,the content of flavonoids was 0.98 mg/g.After pollen enzyme hydrolysis,the contents of soluble protein,reducing sugar,flavonid and soluble polysaccharide in the solution were significantly increased(P<0.05),and the content of vitamin C was decreased,but the difference was not significant.Therefore,as a whole,the dissolution of the nutrient components of pollen broken walls is beneficial.(2)The lotus bee pollen enzyme hydrolysis solution contains substances that promote the growth of lactic acid bacteria(Lactobacillus bulgaricus and Streptococcus thermophilus),but when the substance reaches a certain amount,it will weaken its growth promoting effect.The addition of honey in the range of 0.5%to 7%,with the increase of honey content,the inhibitory ability of lactic acid bacteria growth and proliferation was stronger.According to the results of single factor and orthogonal experiments,the best fermentation conditions were:4%sugar,2%honey,30%pollen enzyme hydrolysis solution,inoculating 5%,fermentation temperature 42 ?,fermentation time 5 h.In order to verify the reliability of the combination conditions,three parallel experiments were conducted under the optimum conditions.The average sensory score of the fermented milk was 92.2.Compared with common fermented milk,the volatile compounds of alcohols,aldehydes,acids,ketones,olefins and others(ether,aromatic heterocyclics,furan,etc)in the lotus pollen and honey fermented milk were increased by solid phase micro-extraction combined with GC-MS,and these substances were more or less in the honey or pollen hydrolysis solution.(3)Compared with the common fermented milk,the addition of pollen hydrolysis solution reduced the water-holding capacity of fermented milk,which is not conducive to storage and transportation.Therefore,it needs to add stabilizer to improve its texture and taste.The results showed that the addition of flaxseed gum and guar gum not only failed to increase the stability of fermented milk,but also reduced the product's flavor and texture stability to a certain extent.The proper amount of xanthan gum,modified starch and CMC-Na can increase the water-holding capacity and hardness of fermented milk,make the product soft and elastic,and can increase the stability and flavor of the product.When the adding amount was 0.20%,the sensory score reaches the maximum.When the ratio of modified starch and CMC-Na was 0.15%:0.05%,the water-holding capacity was best,and reached to 78.72%.The pollen and honey fermented milk products,curd was uniform,tasted delicious,sensory score reached the highest.After 15 days of storage,the pollen and honey fermented milk added with compound stabilizer could increase the water holding capacity of fermented milk and retard the post-acidification.The content of lactic acid bacteria and diacetyl decreased slowly,which had a certain effect on extending the shelf life of fermented milk.The content of flavonoids in the fermented milk was still 0.134 mg/g after 15 days.This is beneficial to give full play to the health benefits of pollen honey fermented milk.