| With the improvement of people’s living standard,more and more refined food and unreasonable lifestyle lead to the increase of hyperglycemia,hyperlipidemia and obesity patients in China year by year,and the trend is younger.Research shows that dietary fiber plays a physiological role in improving intestinal health,controlling blood sugar,lowering cholesterol levels,controlling body weight and increasing mineral absorption.Sporisorium reilianum is a kind of edible fungi parasitic on sorghum ears.It is rich in various nutrients including protein,polysaccharides and fiber,which makes it a potential source of natural dietary fiber.Current research on the active components of Sporisorium reilianum focuses on polysaccharides and melanin,while other active components are less studied such as dietary fiber.Therefore,in this study,soluble dietary fiber(SDF)and insoluble dietary fiber(IDF)were extracted from Sporisorium reilianum using alkaline,enzymatic,acid and water extraction methods,respectively.The best extraction method was selected by yield.The conditions of the extraction process were optimized on the basis of the best extraction method.Then SDF and IDF from Sporisorium reilianum were characterized their structure,physicochemical properties and functional characteristics.Finally,the functional product(meal replacement powder)was developed with better physiological activity of dietary fiber and certain excipients,and the formulation and quality were analyzed.The main results of this research are as follows:(1)Four methods were used to extract SDF and IDF from Sporisorium reilianum,and the best extraction method was selected by yield.The conditions of the extraction process were optimized by the best extraction method.The results indicated that the SDF yield of Sporisorium reilianum extracted by alkali method was significantly higher than the other three methods.The optimal extraction process conditions of SDF were obtained by single-factor experiment and response surface optimization.The SDF yield was20.21±0.08% at 1:21 g/m L,2% alkali concentration,91 min alkaline digestion time and59℃ extraction temperature.Meanwhile,the highest yield of IDF was obtained by enzymatic extraction,which was 64.78±0.05% at the optimal process conditions of enzymatic digestion temperature of 42℃,enzymatic digestion time of 116 min and p H 6.7.(2)The structural analysis of SDF and IDF of Sporisorium reilianum was carried out,and it was found that SDF showed more loose structural features compared to IDF.Fourier infrared spectroscopy(FT-IR)analysis also indicated that the SDF presented more significant absorption peaks of functional groups.Meanwhile,the physicochemical analysis of dietary fiber revealed that SDF had higher water holding capacity and swelling capacity compared to IDF,which were 3.48 ± 0.05 g/g and 13.22 ± 0.03 m L/g,respectively.In addition,SDF also exhibited a high cation exchange capacity and nitrite adsorption capacity.(3)The physiological functions of SDF and IDF of Sporisorium reilianum were studied.Compared with IDF,SDF showed stronger antioxidant,hypoglycemic and hypolipidemic abilities in vitro,which laid a foundation for the development of functional food.(4)The optimal formulation of Sporisorium reilianum dietary fiber meal replacement powder was optimized by single-factor and orthogonal experiments.The maximum sensory score of the meal replacement powder was 92.13 at the addition of 23.08% of xylitol,7.69% of konjac flour,30.77% of Sporisorium reilianum SDF and 38.46% of skim milk powder.Meanwhile,the meal replacement powder was further analyzed for nutrient composition,instant solubility and microbiological indexes under the optimal formulation.The results showed that the protein,fat,carbohydrate and dietary fiber contents were12.5%,2.2%,57.1% and 20.6% in the meal replacement powder.In addition,the solubility was 70.20% for this meal replacement powder,and the time was 25±0.07 s and 9.58±0.04 s for all wetting and sinking under two conditions of static and magnetic stirring,respectively.Finally,the results of microbiological testing indexes for meal replacement powder were in accordance with national standards.In conclusion,the meal replacement powder of Sporisorium reilianum dietary fiber has the advantages of rich nutrition,good instant solubility,high dispersibility,making it promising for application. |
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