Salvia miltiorrhiza is a kind of Labiatae plant, which has the effect of removing blood stasis and relieving pain, activating blood circulation and regulating meridians, nourishing the heart and removing annoyance, and has good curative effect on coronary heart disease, chronic hepatitis, early liver cirrhosis and other diseases.Pharmaceutical microwave dryer uses material molecules to interact with high frequency microwave to heat medicinal materials by absorbing microwave. It has the characteristics of selective heating, fast heating speed, uniform heating inside and outside, low temperature sterilization and no pollution. In recent years, it has been applied to the drying of honeysuckle, ginseng, white fruit, yam and other traditional Chinese medicinal materials, and good results have been obtained.
1.Salvia miltiorrhiza pharmaceutical microwave dryer drying speed is fast. Compared with the conventional drying method, the drying speed of microwave drying machine is faster than that of conventional drying method, and the moisture content of microwave drying medicinal materials to 11%~14% does not exceed 20 minutes, while the traditional dryingmethods take more than two days, in which the moisture content of yin-dry group increases to 11% ≤ 14%, and it takes more than 500 minutes to dry by hot air dryer. Therefore, the microwave pharmaceutical dryer is used to dry, the moisture diffusion speed is fast, and the drying efficiency is high.
2.Microwave drying machine controlled temperature drying is beneficial to retain the effective components of Salvia miltiorrhiza.
Microwave drying was used to dry salvia miltiorrhiza by machine-controlled temperature, which had the characteristics of acceleration, deceleration and constant speed. Because water is a polar molecule that absorbs microwave easily when microwave irradiation is used, the interaction between microwave and water molecules leads to the increase of temperature and the decomposition of thermosensitive components. Therefore, the intermittent radiation of microwave medicinal material dryer is used to dry the medicinal materials by temperature control, which is beneficial to retain the effective components of Salvia miltiorrhiza Bunge.
The contents of tanshinone Ⅰand tanshinoneⅡA, the effective components of Salvia miltiorrhiza in traditional Yin dry and sun drying groups, were high, but the quality evaluation index of physical appearance characters was low, mainly because the medicinal materials were soft and the taste of Panax quinquefolium was not strong. It shows that this drying method is not only time-consuming, difficult to control drying conditions, but also easy to mold, turn yellow, deteriorate, suffer from all kinds of pollution, thus affecting the quality of medicinal materials. When hot air drying was used, the drying rate was greatly improved, and the physical appearance quality was also improved obviously, but the taste of ginseng was too weak, and the effective components tanshinone I and tanshinone II a were lower.
Salvia miltiorrhiza dried by microwave drying equipment not only had bright skin color, light yellow section, hard medicinal material, strong ginseng flavor, good quality evaluation index of appearance character, short drying time and high efficiency, but also the content of tanshinone I and tanshinone II a was higher than that of hot air drying group, not only the color of outer skin was bright and red, the cross section was light yellow, the taste of ginseng was strong, and the drying time was short and the efficiency was high.
For the drying of Radix Salviae Miltiorrhizae containing thermosensitive substances, in addition to obtaining good physical appearance quality, attention must also be paid to the destruction of the effective components of Radix Salviae Miltiorrhiza by drying methods in order to ensure the efficacy of Radix Salviae Miltiorrhiza. The moisture and mildew of Salvia miltiorrhiza dried by microwave drying machine were significantly better than those of conventional Yin drying, sun drying and hot air drying salvia miltiorrhiza. There was no significant change in the preservation time within 1 month. Therefore, the texture and appearance quality of Salvia miltiorrhiza can be obviously improved by using tunnel microwave drying equipment. The loss of effective components of Radix Salviae Miltiorrhiza can be reduced as much as possible and the efficacy of Radix Salviae Miltiorrhiza can be improved by proper drying of microwave dryer of Radix Salviae Miltiorrhiza.