Secondary Metabolites of Higher Plants as Green Preservatives of Herbal Raw Materials and Their Active Principles During Postharvest Processing

Abstract

Herbal raw materials get contaminated with different microbes during collection and postharvest processing, causing both quantitative and qualitative damage leading to degradation of active principles. Currently, a wide range of plant products including essential oils have been found efficacious against fungal and mycotoxin contamination of raw materials and have been recommended as green preservatives for postharvest protection of herbal raw materials. Extracts of different higher plants and bioactive constituents, viz., carvone (from Carum carvi), azadirachtin (from Azadirachta indica), and isothiocyanate (from horseradish and brassicaceous plants) have exhibited promising efficacy against microbial contamination. Currently, nanotechnological approach has enhanced the bio-efficacy of phytochemicals through controlled release, site specific delivery, and enhanced stability. The present article throws light on different plant products recommended in postharvest preservation of herbal raw materials and also explains the future technological advancements in their better utilization as preservative of herbal raw materials. Such documentation of pharmacological efficacy of traditionally used plant products would also be helpful in bioprospection of plant diversity against biopiracy.