| The amino acids,dietary fiber and phenolic substances in the grains are abundant.However,the proportion of amino acids in most miscellaneous grains is not balanced.There are few miscellaneous grains in the market,and there are disadvantages such as rough taste,low content of miscellaneous grains and unsightly appearance.It is significative for human health to conduct in-depth research on miscellaneous grains and develop miscellaneous grains.In this paper,the composite grains were treated by fermentation and enzymatic hydrolysis,and their nutritional value and antioxidant activity were studied.The nutritional value,antioxidant activity and sensory score were considered to make the multigrain biscuits,which laid a foundation for the development of miscellaneous food products.The experimental results are as follows:(1)The proportional screening of oat,buckwheat and millet: The first limiting amino acid was calculated according to the AAS and CS,and the optimal compounding proportion of each grain was screened by SRCAA.The best compounding ratio is: oatmeal: buckwheat: millet is 6:30:7(mass ratio).(2)The optimization of fermentation process and the comparison of nutritional value: Firstly,the parameters of liquefaction process were optimized,the enzyme concentration was 7 U/g,the time was 50 min,the temperature was 60°C,and the content of reducing sugar was 31.08%.Next,the parameters of fermentation process were optimized.The ratio of inoculation was 2.15:1,volume of inoculum was 5.79%,fermentation time was 12.52 h,and the theoretical prediction of sugar to acid ratio was 1.59.It was verified that the ratio of sugar to acid was 1.60,the relative error with the theoretical prediction was 0.63%,and the sensory score was 93.3.Compared with the raw material composite powder,the content of protein,essential amino acids,dietary fiber,flavonoids and other substances increased after fe-rmentation,and the SRCAA decreased.(3)The optimization of enzymolysis process and the comparison of nutritional value: the optimal conditions of enzymolysis were optimized: concentration of enzyme was 4.06%,ratio of solid-liquid was 1:17.61,the time was 4 h.At this time,the theoretical prediction value of hydrolysis degree was 10.26%.After verification,the measured degree of hydrolysis was 10.32%,the relative error with the theoretical prediction value was 0.58%,and the sensory score was 63.2.Compared with the raw material composite powder,the content of protein,essential amino acids,dietary fiber,flavonoids and other substances increased after enzymolysis,and the SRCAA decreased.(4)The comparison of antioxidant activities of fermentation broth and enzymatic hydrolysate: comparison of antioxidant activity from total antioxidant capacity,the scavenging ability of DPPH free radical,the scavenging ability of hydroxyl radical,reducing power and the scavenging ability of superoxide anion.The results showed that all the indexes of the fermentation broth were higher than the enzymatic hydrolysate.(5)The process optimization of biscuit preparation: take flavor,nutritional value,antioxidant activity,etc into consider.The composite multigrain powder obtained by fermentation was selected as the main raw material for the preparation of multigrain biscuits.An orthogonal test was designed based on single factor test.The results showed that the best process for preparing multi-grain biscuits was as follows: the ratio of composite powder to wheat flour was 1:1,the amount of baking soda was 0.6%,the baking temperature was 180°C,and the baking time was 20 min.It was verified that the score of multi-grain biscuits was 94.2 in ths condition. |
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