| In recent years,microbial fermented feed has gradually become a hot topic in the feed field and aquaculture industry due to its high nutritional value,green and environmental protection characteristics,and has broad market prospects.In this paper,using Bacillus Natto as the fermentation strain and Sesbania seeds as the fermentation material,the fermentation process was optimized to obtain Sesbania Natto feed,and in-depth research was conducted on it.The main research contents of this article are as follows:(1)Using Sesbania seeds as fermentation material,Sesbania Natto feed was obtained by inoculating bacillus Natto for fermentation.In order to reduce the content of phytic acid,an antinutritional factor in Sesbania,and improve the digestibility of Sesbania Natto feed,using phytic acid degradation rate as a fermentation index,first investigate the impact of factors such as inoculum amount,fermentation temperature,fermentation time,and cooking time on phytic acid degradation rate through single factor experiments.Based on the results of single factor experiments,determine four factors and three levels,and design response surface optimization experiments to obtain the optimal process conditions: inoculum amount 7% Under the conditions of fermentation time of 30 h,cooking time of 36 min,and fermentation temperature of 35 ℃,the phytic acid degradation rate of the Sesbania Natto feed obtained was 84.37%.(2)The main components of Sesbania and Sesbania Natto feed were determined and analyzed to explore the effect of Bacillus Natto on the quality of Sesbania.The results showed that after fermentation with Bacillus subtilis Natto,the nutrient content of Sesbania Natto feed increased,while the content of anti nutritional factors significantly decreased.The main components of Sesbania Natto feed were determined as follows: ash2.83 ± 0.21%,crude protein 29.95 ± 0.53%,fat 8.54 ± 0.19%,total flavonoids 83.43 ±1.21 mg/g,amino acids 22.32%,total phenols 62.55 ± 0.31 mg/g,phytic acid 4.92 ± 0.04mg/g,crude cellulose 6.04±0.30%,hydrocyanic acid 2.86 ± 0.34 mg/g,proanthocyanidins6.78 ± 0.19 mg/kg,trypsin inhibitor activity 4.18 ± 0.61 mg/g,and Natto kinase activity198.91 ± 6.39 U/g.(3)Firstly,through a single factor experiment,the effects of ethanol volume fraction,material liquid ratio,extraction temperature,and extraction time on the total flavonoids extraction amount were investigated.After that,orthogonal experiments were designed to optimize the extraction process of total flavonoids from Sesbania Natto.The optimal extraction conditions are as follows: ethanol volume fraction is 60%,material liquid ratio is 1:15(g/m L),extraction temperature is 80℃,extraction time is 80 min,and the total flavonoids extraction amount is 100.32 mg/g.Using AB-8 macroporous resin column chromatography,the extract of Sesbania Natto was isolated and purified to obtain a crude extract of total flavonoids from Sesbania Natto.Through ultraviolet spectroscopy and chemical color development methods,it was speculated that the total flavonoids in Sesbania Natto contain flavonoids such as isoflavones and flavonols.(4)The stability of the extract of total flavonoids from Sesbania Natto was measured in terms of temperature,system p H,and light,respectively.The antioxidant capacity was analyzed in terms of DPPH free radical scavenging rate,hydroxyl free radical scavenging rate,ABTS free radical scavenging rate,and reducing power.The stability results showed that the light absorption value of the total flavonoids extracted from Sesbania Natto remained basically unchanged at 4 ℃.With the increase of temperature,the decrease in light absorption value increases;It is relatively stable under neutral p H conditions,and its light absorption value significantly decreases in strong acid and alkali environments;In dark environments,the light absorption value remains basically unchanged,while in energy-saving lighting and natural daylight environments,the light absorption value is relatively stable.Under ultraviolet and other irradiation,the light absorption value decreases significantly.The results of its antioxidant capacity showed that with the increase in the concentration of total flavonoids in Sesbania Natto,its antioxidant capacity gradually increased,and its scavenging rates for DPPH,hydroxyl,and ABTS free radicals were 85.92 ± 1.86%,41.97 ± 0.28%,53.47 ± 3.19%,respectively.The maximum reducing power was 0.183 ± 0.012,indicating a good antioxidant capacity. |
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