Analysis Of Bitter Substances In Maca Extract And Quality Control

Maca is a kind of medicine and food dual-purpose plant,which is commonly used in the development of functional foods.With the enlargement of maca planting area,the market of products with maca dry powder is saturated,so the development of maca's deep processing,especially maca extract has attracted much attention.Although there have been functional foods developed with maca extract as raw materials at present,the quality of these products is uneven due to the lack of research at home and abroad of maca extract.Therefore,in order to ensure the high quality of maca functional food,this paper systematically studies the preparation process of maca extract,and focuses on the impact of the extraction process on the characteristic active ingredients of maca,and analyses the source of the bitter substance that affects the taste of the extract,and makes a preliminary analysis on its vitality.The characteristic map was used to monitor and control the quality of the extract.The main results are as follows:(1)The sources of bitter substances in maca extract were determined,and the mechanism of bitterness components was also analyzed.First,it is determined that the bitter substance that affects the taste of the extract is not from the raw material of maca,but from the drying process of the extract,and the main active ingredient of the glucosinolates and the total alkaloid is not related to the bitterness.The pretreatment of fresh maca made the glucosinolates completely hydrolyzed.The results showed that the extracts prepared in the freeze drying had serious bitterness,and there was no obvious difference from the bitterness of the extract from drying oven.(2)The optimum technological conditions for the preparation of the extract and the key factors affecting the intrinsic quality of the extract were determined.First,by comparing the total extraction of 3 main active ingredients,80% ethanol is the best extraction solvent,which not only has a higher extraction rate(32%),but also makes the content of three main active ingredients of macamides(0.62%),glucosinolates(2.70%)and total alkaloid(1.08%)in the extract.It is higher than other extraction solvents(p<0.05),and it is found that the transient high temperature(100?)in the concentration process of the extract has no obvious damage to the three components.Secondly,the effect of drying method on the content of main active components in the extract was studied.It was found that the content of macamides and glucosinolates in the extract changed significantly(p<0.01)in the drying oven(80?),and there was no obvious change in the total alkaloid content,while the 3 active components were all under vacuum drying(60?),There is no obvious change.Finally,through the detection of the content of the extracts at different time points in the drying process of the oven,it is found that the chemical reaction of the extract in the drying process of the extract in the drying process is the conversion of glucosinolates into the macamides,and the key influencing factor is the water content of the extract.With the water content no longer changing,the synthesis of macamides is terminated.And the thermal decomposition will take place.Finally,the bitter taste was derived from the hydrolysate of glucosinolates.The technology of regulation and control can reduce the glucosinolates hydrolysis and control the production of bitter substances by changing drying way or adding excipients to shorten drying time.The above research provides a theoretical basis for the preparation of high quality Maca extract.(3)Established the characteristic map of HPLC detection of key active components in the extract,and verified the reliability of the characteristic map.First,the HPLC detection method of macamides and glucosinolates in the extract was optimized.Secondly,5 common peaks in the characteristic Atlas of macamides HPLC characteristic atlas were determined by comparison of spectral similarity,and the precision,repeatability and stability of the instrument were all good by means of methodology(RSD<2%);finally,the feature map was applied to the identification of maca and other cruciferous plants.The results showed that the feature atlas was reliable and could be used for the identification and quality control of the extract.The above study lays the foundation for the subsequent development of the extract of maca as a functional food raw material.