| In this study, raspberry was regarded as raw materials, we used ultrasonic technology, studied theinfluence of ultrasonic time, solid-liquid ratio, ethanol concentration and ultrasonic power and otherfactors on raspberry total phenolic extracts, and applied response surface methodology(RSM) tooptimize the ultrasonic-assisted extraction technology of total phenol from them. The results showedthat the optimum conditions of ultrasonic assisted extraction raspberry total phenol: ultrasonic powerwas400W,50%of the ethanol concentration, extraction time was6.54min, and total phenol extractionrate was of9.170%.Total flavonoids in raspberry water extract flavonoids content was of49.6mg/g, raspberry ethanolextract of total flavonoids content was of96mg/g, raspberry n-butanol extract flavonoids content was of207mg/g, raspberry methanol acid extract flavonoids content was of548mg/g, and total flavonoids inraspberry ethyl acetate extract was of263mg/g. Raspberry water extract total phenolic content was of72.3mg/g, raspberry ethanol extract total phenolic content was127mg/g, raspberry n-butanol extracttotal phenolic content was261.5mg/g, raspberries methanol acid extract total phenolic content was of653mg/g, and raspberry ethyl acetate extract total phenolic content was362mg/g. The results showedthat the highest raspberry extraction rate of total phenolic was methanol acid extraction, followed byethyl acetate extraction.Reducing force of different solvents at the same concentration of raspberryextract according to the IC50values was: BHT> methanol acid>ethyl acetate>n-butanol>ethanol>water.DPPH radical scavenging activity of different solvents and different concentrations of raspberry extractfrom high to low: BHT> methanol acid>ethyl acetate>n-butanol>ethanol>water. As the concentrationincreased, DPPH clearance rate increased, and when the concentration was0.4mg/mL, methanol acid,ethyl acetate extracts’ DPPH clearance rate was close to BHT, showing good reducibility. Differentsolvents and different concentrations of raspberry extractions on prevention of oxidation of oil weremeasured. The oil oxidation prevention activity was BHT> methanol acid>ethylacetate>n-butanol>ethanol>water. Raspberry solvent extract of oil oxidation rate was positivelycorrelated with the concentration of raspberry. By comparing, methanol acid has best anti-oil oxidationeffect and when the concentration reach to0.4mg/mL, methanol phase and water phase have the similaranti-oil oxidation effect, comparable with that of BHT.Antibacterial results showed that: Raspberry bacteriostatic sequence of different solvent extract ofthe test of bacteria from big to small was: Staphylococcus aureus> Bacillus subtilis> Escherichia coli>black mold. Yeast, Rhizopus, Penicillium was almost no antibacterial activity, raspberry ethanolminimum inhibitory concentrations were: E. coli0.16mg/mL, B. subtilis0.08mg/mL, StaphylococcusAureus0.04mg/mL, and Penicillium0.64mg/mL. Others were not very obvious.Raspberry water extract minimum inhibitory concentrations were as following: E. coli was of0.21mg/mL, Bacillus subtilis was of0.14mg/mL Staphylococcus aureus was of0.08mg/mL, Penicilliumwas of0.72mg/mL, and others were not very obvious. Raspberry different solvent antibacterial effect stay stable in the pH range of3to9and within the temperature of80℃, the effect on the temperatureantibacterial effect of different concentrations of raspberry extract was not very obviously, theinhibitory rate is increased with time, raspberry different solvents increased with increasingconcentration. |
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