Effects Of Different Processing And Storage Technologies On The Active Ingredient Of Purple Perilla Frutescens Leaves

Perilla frutescens with high medicinal values is an annual herbaceous plant,which belongs to the Labiatae family.In this study,the changes of flavonoid,phenolic,rosmarinic acid and essential oil of purple perilla frutescens leaves during processing and storage were investigated.The new findings of this study would provide theoretical basis for the development and utilization of perilla frutescens.The main research contents and results are as follows:(1)The effects of different drying methods(shade,sun,oven,mid-infrared drying and freeze drying)on the content of total flavonoids,phenolic,rosmarinic acid and the chemical composition of essential oils of purple perilla leaves were studied.Results showed that a*/b*value of oven was the lowest,with values of-0.42.Freeze drying treatment could obtain the highest flavonoid,PHENOLIC and rosmarinic acid contents,with values of 63.20,29.72 and5.73 mg/g,respectively.However,the highest essential oil yields(w/w)were obtained by oven drying and shade drying treatments(ca.0.45%).Furthermore,35 components were detected in the essential oil and the main components included 2-hexanoylfuran(398.35 mg/L,83.17% of the total components),caryophyllene(30.85 mg/L and 6.44%),trans-?-bergamotene(23.87 mg/L and 4.98%),linalool(5.11 mg/L and 1.07%).In addition,the composition of essential oil changed significantly with the different drying methods.It was demonstrated that freeze drying was suitable for the collection of high flavonoid,PHENOLIC and RA,while oven drying was better for high essential oil yield.(2)The effects of ultrasonic-assisted,cellulase-assisted,ultrasonic-cellulase-assisted,cellulase-ultrasonic-assisted and simultaneous processing on the content of flavonoid,PHENOLIC and rosmarinic acid were compared,and the antioxidant activities of extracts were evaluated.Results showed that simultaneous ultrasound and cellulose treatment could obtain the highest contents of flavonoid,PHENOLIC and RA,with values of 28.1,17.46,1.94 mg/g,respectively.Furthermore,the free-radical scavenging ability of DPPH and reducing power of the related extracts were also the highest,with values of 614.24,3277.72?mol/L Trolox equivalents.In addition,there were significantly positive correlations between the antioxidant capacity and PHENOLIC content(P <0.01).The correlation coefficient of PHENOLIC content and the free-radical scavenging ability of DPPH and reducing power were 0.878 and 0.804,respectively.(3)Effect of different storage conditions on the composition of essential oil of purple perilla leaves and the antimicrobial activity of essential oil were stuided.The main composition of essential oil were perilla aldehyde(1078.49 mg/L,37.92%),limonene(332.68mg/L,11.70%),trans-?-bergamotene(185.61 mg/L,6.53%),caryophyllene(176.15 mg/L,6.19%),linalool(34.26 mg/L,1.2%),germacrene B(30.97 mg/L,1.09%).The total content of the composition of essential oil was decreased with the extension of storage time,and the loss of essential oil under 25°C and 4°C was greater than-20°C.The essential oil showed strong inhibiting activity against Staphylococcus aureus,Bacillus subtilis,Escherichia coli and Salmonella.Its inhibiting activity was decreased with the reduction of essential oil concentration.The minimum inhibitory concentration(MIC)of essential oil against Staphylococcus aureus,Escherichia coli,Salmonella,Bacillus subtilis were 4%,1%,2%,4%,respectively.(4)Different extraction methods,processes and storage conditions on active ingredient of purple perilla beverage were studied.The optimum conditions of hot water were as follows:solid-liquid ratio of 1:30,extraction temperature of 90°C,extraction time of 1h.Under these conditions,the content of flavonoid and phenolic were 95.74,49.48 mg/g,respectively.The physicochemical quality of the beverage were improved by sterilization.Purple perilla beverage showed good storage stability when stored at 37°C for 21 d.Most of indicators of beverage in the dark and light conditions showed the same trend,except color value.Dark condition was sutiable for the storage of purple perilla beverage.