Processing
Successful Sterilization:
Ensuring Safe, Microbial-Free Organic Ingredients
By Rupa Das
Over the last 25 years, the organic industry has grown tremendously and with it
so has the spectrum of organic ingredients. This includes a wonderful variety of organic herbs, which have seen double-digit
growth year after year. This strong growth
trend is expected to remain on track for the
next five years.
While this development of organic herbs
has most certainly led to improved flavor profiles for organic foods and higher functioning
supplements, ingredients such as herbs come
with a whole new set of challenges processors
must deal with in order to ensure both safety
and quality. Although organic ingredients are
far less likely to have pesticide residues or
heavy metal contamination in comparison to
their conventional counterparts— all agricultural products have microbial contamination
and organic products are no different.
What Causes Microbial Contamination?
There are many ways that ingredients such
as herbs can become contaminated; some are
more easily controlled than others. With
some plants, the inherent biological structure
predisposes it to higher levels of microbial
contamination. For example, nettle and sage
leaves have trichomes (hair-like appendages)
on their surfaces, which greatly increase the
surface area exposed for microbial contamination.
Environmental conditions where the plant
is grown and unsanitary collection and processing, drying, storage and transportation
also contribute to microbial contamination.
Both wild-crafted and cultivated sources of
herbs are subject to microbial exposure.
The amount and type of microbial load
also depends on the part of the plant used.
For example turmeric root will have a higher
and different microbial load compared to a
seed product because the root will take up
some types of bacteria from the soil. Some microbes such as E.coli and Salmonella are pathogenic and unsafe for human consumption.
Preventing and Eliminating
Contamination
Good agricultural and collection practices
(GACPs) in every phase of growing, harvesting and handling can minimize the microbial
load. The World Health Organization
(WHO) has developed guidelines on GACPs
for medicinal plants. The guidelines provide a
description of the techniques and measures
required for appropriate cultivation and collection of medicinal plants and recording and
documentation of necessary data and information during processing.
Some areas such as China, Japan and the
EU have developed regional and national
guidelines for GACPs of medicinal plants.
Despite such guidelines, there is considerable disparity between knowledge and implementation. A majority of the herbs are
grown and harvested in geographic regions
where hygiene standards and facilities are either not adequate or not as stringent as
some of the other parts of the world. Therefore, eliminating microbial issues through
GACPs is still a goal that is yet to be achieved
in most cases.
Hence, in order to reduce microbial load,
eliminate pathogens and make ingredients
safe and suitable for human consumption,
agricultural products often require some
form of sterilization.
