Packaging and storage of herbs and spices 89
so as to provide consumers with a format that is easy to use as well as protecting the
product from environmental influences.
5.3.3 Herbs and spices (dried)
Whole or ground herbs and spices
The natural whole spices are much more robust and deteriorate much slower than
spices that have been sized reduced. Ensuring the surface of the spices remains
unaltered assists in minimizing both a chemical and microbiological change in the
spice. Many spices are still packed under conventional types of packaging materials
and there is great scope for improving the type of packaging materials. Twill or
gunny bags are used depending on the value of the spices. The weave clearance of the
different types of twill and gunny bags is 1–2%, 3–5% and 4–6% respectively, which
prevents spillage but also restricts insect movement in the bags. Sometimes double
bags are used to get a better physical barrier. Polyethylene lined gunny bags and
HDPE woven sacks are used to restrict moisture ingress during storage. Besides the
conventional jute bags, multi-wall paper bags, plastic sacks and paperboard boxes
can offer better protection and appeal.
Coriander
Ground coriander can be stored for up to six months in aluminium foil bags and is the
preferable storage mechanism. Jute bags lined with polythene are ideal for storage
for large quantities of powder. Paper, polyethene and cotton bags are not suitable for
storage. It is critical that ground spices are protected adequately from oxygen as the
large surface area exposed will increase the rate that flavour deterioration occurs.
Coriander seed can be stored in polythene bags or cotton bags for six months with
minimum loss of flavour. After a period of 12 months there was a loss of 20–25%
volatile oils. Flexible plastic films and foil laminates with better physico-chemical
properties need to be used for necessary protection to the product against loss of
volatile oil, seepage of fats and ingress of moisture during storage. The seeds should
be stored under cool, dark and dry conditions so as to prevent browning, loss of
flavour and ingress of moisture. Under good storage conditions it is reported that
coriander seed will retain flavour and colour for 6–9 months.
Garlic
Among the most important garlic products are garlic flakes, dehydrated garlic powder,
garlic paste and garlic salt. Garlic harvested for dehydration is brought to a dehydration
plant in large bulk bins or open mesh bags. The bulk is broken into individual cloves
by passing between rubber-covered rollers, which exert enough pressure to crack the
bulb without crushing the cloves. The loose paper shell is removed by screening and
aspiration. The cloves are washed in a flood washer, at a time the root stabs are
floated off. Garlic is sliced and dehydrated in a manner similar to that used for
onions. Garlic is commercially dried to about 6.5% moisture. Dehydrated garlic is
sold commercially as garlic powder, granules, sliced, chopped or in a minced form.
Garlic powder is obtained by drying the garlic at temperatures of 50– 70 ∞C for five
to eight hours and results in losses of volatile flavour up to 30–35%. The non-
enzymatic browning reactions result in a yellowish brown powder which is undesirable.
Clumping is also an issue as the powder is highly hygroscopic and must be maintained
in packaging that maintains low water vapour transmission.