Boilable Healthy Foods By Fermented Coarse Grains With Probiotics For The Aged

The coarse grains are rich in nutrients,among which the protein,vitamins,minerals,minerals,cellulose and other nutrients are high in content and reasonable in proportion.They have strong health care functions and are important nutritional and health food resources.However,due to coarse coarse grains,and the presence of phytic acid and other anti-nutritional factors,it is not conducive to digestion and absorption of nutrients,limiting the development of coarse food products market.The use of microorganisms to ferment coarse grains can effectively change the chemical structure of the nutrients,improve the cooking quality,increase the taste of grains,reduce the phytic acid content,and make the degradation of macromolecular proteins easier for the elderly to absorb.In this study,seven kinds of coarse grains such as corn,millet,black rice,oats,sorghum,red beans and mung beans were fermented using the mixed strains of Lactobacillus bulgaricus and Bifidobacterium,and the fermentation process was optimized according to the physiological characteristics of the elderly,and suitable foods for the elderly were developed.Crude cereal healthy food that can were cooked directly,the changes of nutrient composition,phytic acid content,in vitro protein digestibility,and polyphenols antioxidant properties of pre-and post-fermented coarse grains before and after fermentation,as well as cooking quality evaluation and sensory evaluation before and after fermentation were determined,which provides a full theoretical basis for the development of coarse grains applications.The specific experimental results are as follows:(1)Response surface methodology was used to optimize the process of fermenting coarse grains with mixed strains of Lactobacillus bulgaricus and Bifidobacterium in response to the content of soluble dietary fiber(SDF)in coarse grains,and the mixed strains of Bifidobacterium and Lactobacillus bulgaricus were determined.The optimum process parameters of fermented coarse grains were as follows:strain ratio 0.9,inoculation amount 8.4%,fermentation time 64 h,fermentation temperature 37°C.Under this fermentation condition,the content of soluble dietary fiber in coarse grains was 7.23%.(2)Under the optimal fermentation conditions,the conventional nutrients in coarse grains varied to varying degrees,and the contents of soluble dietary fiber,reducing sugar,vitamin B1,vitamin B2,and vitamin B6 increased by 2.46 times,0.56 times,0.85 times,0.6 times,and 1.38 times respectively.After boiling,there is less loss of nutrients and it is suitable for elderly people to directly boil and eat.(3)The content of phytic acid in coarse grains before and after fermentation was determined.The results showed that the content of phytic acid in coarse grains after fermentation was reduced to 3.06 mg/g,which was only 20% of the phytic acid content of unfermented coarse grains.The digestibility was measured and the in vitro protein digestibility of crude coarse grains compared with unfermented coarse grains was increased by 15%.After fermentation,coarse grains were cooked and the phytic acid content continued to decrease by 11%.(4)Analysis of polyphenol contents and antioxidant capacity of coarse and coarse grains before and after fermentation showed that the content of polyphenols in the coarse grains after fermentation was increased by nearly 1 time compared with unprocessed coarse grains;at the same time,the crude polyphenols extracts after fermentation were compared.The DPPH radical scavenging rate is higher than that before fermentation.When the concentration reaches 30 mg/ml,the radical scavenging rate reaches 55.53%;when the polyphenol extract concentration is the same,the coarser grains of fermented coarse grains have greater reducing power to trivalent iron ions.Unfermented coarse grains,and their reducing power increases with the increase of concentration,the absorbance level is used as a measure of the reduction ability of the sample.When the concentration of crude polyphenol extract increases to 30mg/mL,fermentation and unfermented crude Absorbance values of coarse grains were 0.39 and 0.32,respectively.(5)The coarse grains samples are cooked,and the cooking quality changes before and after fermentation are analyzed.The fermentation significantly shortens the cooking time of coarse grains and improves the eating quality of coarse grains such as chewiness and stickiness.The coarse grains have improved solubility,swelling,rice soup solids content,and alkali depletion.The solubility of fermented coarse grains increased from 3.26% to 5.69%,an increase of 75%;the degree of swelling increased from 9.71 g/g to 12.41 g/g,an increase of 28%;the water retention of crude coarse grains before and after fermentation was significantly increased,and unfermented coarse grains were obtained.The water retention capacity was 1.58g/g,increased to 2.19g/g after fermentation,increased by 39%;the pH value of crude miscellaneous rice soup decreased after fermentation,there was more dissolved solids in rice soup,and the response to lye soaking test was stronger.Starch gelatinization temperature decreases,the hardness is lower and the viscosity is higher after cooking,the hardness after cooking is lower,and the viscosity is greater.(6)The coarse and coarse grains are boiled before and after fermentation,and 10 elderly people are asked to perform sensory evaluation on cooked samples.The test results showed that the coarse grains after fermentation were higher than unfermented coarse grains in terms of flavor,taste color,appearance structure,and total score.After cooking,coarse grains are boiled and the grains are soft,delicate and easy to chew.It has both the unique flavor of fermentation and the natural aroma of grains,suitable for the aged.