Non-Isothermal Drying of Medicinal Plants

Abstract

An intelligent system for non-isothermal drying of medicinal plants, based on machine vision, sensor fusion and neural network was developed. Air temperature, velocity and humidity, along with material size and moisture content were inputs to the neural model for diffusivity. Temperature, time, mass, volume and colour were inputs to the neural model for quality. Isothermal low-temperature drying of ginseng root and blueberry showed extremely low effective diffusivity (0.2 -0.75)*10 -10 m 2 /s. In contrast, nonisothermal drying demonstrated a potential to increase diffusivity and prevent quality losses. Testing of the intelligent drying system showed reduced drying time from 240 to 60 hours for ginseng, and from 110 to 30 hours for blueberry with desired product quality.

The impact of ultrasound and steam blanching pre-treatments on the drying kinetics, energy consumption and selected properties of parsley leaves

“…However, it is well known that vitamins, colourants and antioxidants are sensitive to high air temperature values, which imposes use of lower dehydration temperature and considerably decrease drying intensity [18]. On the other hand, even when drying is carried out at low temperature, a prolonged exposition to the oxygen could decrease nutrient content significantly [17,31].…”

Investigating the Effect of Different Drying Strategies on the Quality Parameters of Daucus carota L. Using Dynamic Process Control and Measurement Techniques

“…In most cases, isothermal air conditions are assumed and factors such as product temperature are not measured. While the assumption of isothermal air conditions might potentially work for fruits and vegetables, several medicinal plants such as ginseng roots with high initial water content undergo overheating or overdrying (Martynenko & Kudra, 2015) due to the lack of consideration of non-isothermal behaviour of the product, which in turn reduces the quality of the product. This behaviour could easily be measured through consideration of product temperature.…”

AVALIAÇÃO ANTIOXIDANTE E TOXICOLÓGICA DO EXTRATO AQUOSO DO CAULE DE Mesosphaerum suaveolens (L.) KUNTZE

“…Além disso, a qualidade das plantas medicinais depende de outros fatores, como o método de secagem e as características da planta que está sendo seca (Rocha et al, 2011;Rahimmalek & Goli, 2013). Portanto, há a necessidade do emprego ou desenvolvimento de novas técnicas de secagem que sejam mais adequadas às plantas medicinais Martynenko & Kudra, 2015).…”