The Effect Of Storage Temperature And Microporous Membrane Filter Sterilization On The Quality Of Rose Water

Rose water,as the main by-product in the processing of extraction of rose essential oil,has been widely used as material in food,cosmetics and skin care products according to its natural aroma compounds and functions in maintaining beautiful and young skin.In China,the late and limited studies on rose water,combined with the lack of standard in production,circulation and marketing,even non-normalization in production,have caused lots of serious problems,especially about microbiological contamination and changed aroma in the process of storage and marketing.In this study,the comparative analysis of aroma compounds in rose water based on different methods of extraction(organic solvent extraction,OSE and solid phrase microextraction,SPME)had been demonstrated,additionally discussing the advantage and disadvantage between two analytical methods.The microorganism isolated and identified from rose water,combined with the effects of storage temperature and microporous membrane filtration on rose water quality have been investigated,aiming to provide a theoretical basis and a pratical reference for the storage and sterilization of rose water.The results concerned are as follows:1.In two different rose water,the number of aroma compounds extracted by SPME(31 and 28,respectively)were more than that by OSE(23 and 21,respectively).By SPME,the well-rounded composition of aroma compounds in rose water has been shown as a result of extracting terpenes,ethers and thioethers with low-boiling point,volatile and active chemical character from rose water.Compared with OSE,the technique of SPME seem to simple and time-saving in extraction.2.My studies found that the contents of terpenes and citral in rose water decline significantly with the increasing time of storage,accordingly leading to poor top note and fruit aroma.In terms of storage temperature grandients(5 ?,25 ?,40 ? and room temperature),the optimal temperature 5 ? has been reported for storage of rose water due to slow growth of microorganism and minimum change of aroma.3.In order to figure out microorganism that probably cause the contamination of rose water,the main species has been isolated and identificated from rose water,involving in bacteria(Bacillus,Staphylococcus and Burkholderia)and fungi(Pichia,Talaromyces and Cladosporium).4.In my findings,by employing microfiltration membranes(aperture? 100 nm),the microbes have been effectively removed,meanwhile,the lesser impact on aroma compounds has been shown in rose water.Compared to those without filtration,the contents of microbes in filtered rose water maintained a lower level with the increasing time of storage,while the extent of aroma compounds change was larger than the former.