EFFECT OF PARTICLE SIZE ON YIELD OF PLANT EXTRACT

Plant extracts are in use in the form of decoctions and water infusions in Ayurvedic systems of medicine since ancient times.  It is generally believed that particles finer in size, produce more amount of extract yield. However, there appears to be no uniformity in using powders of any particular particle size for extraction. Coarse and fine powders of different particle sizes have been observed used, by researchers and manufacturers for extraction. The object of the present study is to study the effect of the coarse and fine particles on percentage of extract yield in plants. The study is conducted on 27 medicinal plants frequently used in Ayurvedic medicine. Soxhlet extraction method using water as solvent is followed in this study. The study concludes that certain group of plants yield higher extract from coarse powders while some produce higher extract yield from fine powders.  Whereas, no difference in yield of the coarse and fine powders is observed in some plants. Ayurvedic texts classify the plant material in accordance with material consistency such as very hard, moderately hard and soft, for preparation of decoctions. The present study indicates that such classification may be helpful in determining the requirement of appropriate particle size for obtaining higher extract yield.