**7. Grinding or powdering plant materials**

Lowering particle sizes increase surface contact between samples and extraction solvents and therefore, increase the yield rate and yield. Grinding resulted in coarse smaller samples, meanwhile, powdered samples gave a more homogenized and smaller particle, leading to better surface contact with solvents used for extraction. Before the extraction, pretreatments such as drying and grinding of plant materials are usually conducted to increase the extraction efficiency [48]. It is essential that the particles are of as uniform size as possible because larger particles take a longer time to complete the extraction process [49]. Usually, solvent molecules most contact the larger analytes, and particle size smaller than 05 mm is ideal for efficient extraction [8]. Conventional methods are usually used to reduce the particle size of dried plant samples viz. mortar and pestle or electric blenders and mills, etc.
