Packaging and storage of herbs and spices 91
is required to prevent the round seeds running freely. The bulk mustard seed is stored
in sacks or in bulk. The mustard meal is manufactured by grinding dry, whole seeds
and should be kept fresh or sealed, using opaque containers in a cool environment.
This product is seldom used as a food-based product and is utilized more in the
medicinal industry.
Pepper
Pepper is one of the most prominent spices found in the world. There are various
forms of pepper that are manufactured. After harvesting, the pepper berries are separated
from the spike by rubbing between the palms or trampling under the feet. The green
pepper is then dipped in hot water for one minute and dried in sunlight for uniform
colour and speedy drying for 5–7 days to obtain a moisture content of 10–11%. The
dried pepper is cleaned to remove stems, husks and pinheads. The white pepper is the
product obtained from berries that are fully ripe. They are picked and piled in heaps
to ferment or are soaked in water for 5–7 days, the pulp and the outer costing of the
seed are then removed. White pepper is yellowish grey in colour and has a smooth
surface. It is also prepared from black pepper by grinding off the outer parts by
machinery.
Ginger
Ginger powder stored in glass jars at 4 ∞C showed a significant decrease in gingerol
content after eight weeks storage (23%) and after 16 weeks storage the level had
further decreased (37%). This compares to ambient storage at 23 ∞C where the
gingerol decrease was 30% after eight weeks storage and 37% after 16 weeks storage.
Heat treated herbs and spices in glass or plastic jars
There are a variety of herb pastes that incorporate the raw herb or spices with other
ingredients and the product is heat treated. This treatment will reduce the level of
quality deterioration but also reduces the level of natural essential oils that provide
the key flavour attributes of the product. These products are typically packaged in
glass or plastic jars. This type of packaging medium is quite common in the herb and
spice industry.
5.4 Essential oils...................................................................................
Essential oils are a complex mixture of volatile compounds responsible for the aromatic
characteristics of the spice. They are comprised of two basic groups which are
hydrocarbons including terpenes, sesquiterpenes and diterpenes and oxygenated
hydrocarbons such as alcohols, esters, aldehydes, ethers and ketones.
Basil
During the drying process the essential oil composition of herbs and spices changes.
The results on basil indicated a 19% overall loss of essential oil after drying and three
months of storage in aluminium polyethylene polyamide bags. After six months
storage in the bags there was a 62% loss in essential oils. During storage there was
a decrease in the total quantity of essential oils as well as volatile essential oils.
Methylchavicol and eugenol decreased linearly and some other components disappeared
altogether.