Study On The Storage Of Lilii Bulbus And Lonicerae Flos By Electron Beam Irradiation

Storage is an important part in circulation for Chinese herbal medicine and has a direct impact on its quality.Many Chinese herbal medicines were traditionally storaged by sulfur fumigation.However,this method can easily produces destruction of active ingredients and residue of sulfur dioxide in medicinal materials,and has been restricted for use in China.Therefore,it is very important to develop new storage techniques for Chinese herbal medicine,and is of great significance to control its quality.High energy electron beam irradiation is a new technology of food storage,but it has little application for the preservation of the Chinese herbal medicine.Lilii bulbus(Lilium brownii F.E.Brown var.viridulum Baker)and Lonicerae flos(Lonicera macranthoides Hand.-Mazz.)are two valuable kinds of medicinal materials which can be used as food and medicine.Traditionally,both the medicinal materials were processed and stored by sulfur fumigation.In this paper,Lilii bulbusand Lonicerae flos were processed by electron beam irradiation with different doses(1.5 k Gy,3.0 k Gy,4.5 k Gy,6.0 k Gy).Meanwhile,nonirradiated samples and sulfur fumigation ones were used as the control groups.The effects of irradiation treatment on storage effects were evaluated by sterilization effect,storage time,medicinal quality and sensory attributes.Moreover,the technological conditions of irradiation treatment were optimized.The main results of this paper are as follows:1 Effects of Irradiation on Lilii bulbus StorageFor the non-irradiated samples,the content of aerobes was 2.6 × 103 CFU/g,the content of mold and yeast was 1.5 × 103 CFU/g,and the survival rate of viable cells was 100% for both kinds of bacterias.After irradiation,the microbe contents of the sample decreased significantly with the increase of irradiation dose.When the irradiation dose reached 3.0 k Gy,the microbe contents dropped to a very low level(the content of aerobes: 10 CFU/g,its survival rate: 0.38%;the content of mold and yeast:<10 CFU /g,its survival rate:<0.67%).When the irradiation dose increased to 4.5 k Gy and 6.0 k Gy,the aerobes,mold and yeast in the medicinal material can not be detected.In theory,the D10 value of aerobes was 1.59 k Gy,and the D10 value of mold and yeast was 0.94 k Gy.The contents of water extract in different irradiation dose samples was between 32.28% and 35.61%,and all met the requirements of Chinese Pharmacopoeia.Furthermore,irradiation treatments had slight effects on color,smell and other sensory attributes of Lilii bulbus.During the storage period of 120 days,the microorganisms of irradiation treatment samples grew slowly.What’s more,the higher the irradiation dose,the stronger the inhibitory effect.The suitable irradiation dose is 4.5 k Gy,which can effectively extend the storage time of Lilii bulbus to 120 d.Thus,electron beam irradiation is superior to sulfur fumigation in aspect of storage for Lilii bulbus.2 Effects of Irradiation on Lonicerae flos StorageFor the non-irradiated samples,the total numbers of colony in the untreated samples was 9.2 × 102 CFU/g,the content of mold and yeast was 2.0 × 10 CFU/g,and the survival rate of viable cells was 100% for both kinds of bacterias.After irradiation,the microbe in Lonicerae flos decreased significantly with the increase of irradiation dose.When the irradiation dose reached 4.5 k Gy,the microbe contents had dropped to a very low level(the total number of colonies: 10 CFU/g,its survival rate:1.09%;the content of mold and yeast:<10 CFU/g,its survival rate:<50.00%).When the irradiation dose increased to 6.0 k Gy,the microbes in the medicinal materials were difficult to be detected.In theory,the D10 value of the total colony was 1.48 k Gy.The content of chlorogenic acid in each irradiation dose samples was between 6.43% and 6.50%,which was in accordance with the provisions of Chinese Pharmacopoeia.Irradiation treatment had little effects on sensory quality such as color,smell and so on.During the storage period of 120 days,the higher the irradiation dose,the more obvious the inhibitory effect on the microbial growth in the sample.The suitable irradiation dose is 4.5 k Gy,which can effectively extend the storage time of Lonicerae flos to 120 d.Thus,electron beam irradiation is superior to sulfur fumigation in aspect of storage for Lonicerae flos.