88 Handbook of herbs and spices
∑ Moisture and oxidation sensitivity. The smaller the particle size in ground spices,
the larger the surface area exposed to atmospheric conditions and the more
susceptible the product is to moisture penetration and oxidation. Increasing the
moisture content of the spices can also lead to problems with insect damage and
possibly potential microbial risk factors if the water activity of the product
medium reaches high levels. In order to reduce the oxidation reactions it is
important to avoid high-temperature storage, utilize packaging with low oxygen
permeability and gas flush with controlled atmosphere or modified atmosphere
conditions.∑ Grinding. As soon as dried or fresh spices are size reduced this increases the
surface area exposed to atmospheric conditions. In doing this it can cause increased
susceptibility to oxidation reactions, moisture increases and flavour loss. To
limit these reactions it is important to control the temperature, contact with
oxygen, the humidity surrounding the product and reduce the contact with light.Grinding of spices is an important processing step during which loss of volatile
aromatics occurs. The technology used at present for grinding spices has inherent
disadvantages of high heat generation, loss of volatile oil and low efficiency. This
method of grinding is not desirable for materials of plant origin including spices with
high heat sensitivity, high fat and fibre contents. Loss of volatile oil could be overcome
partly by lowering or maintaining the mill temperature as low as possible (less than
the boiling temperature of the volatile constituents of the spices volatile oil). The
shelf life of ground spices is about three to four months at refrigeration temperature
and whole spices will have about one and a half years of shelf life.
5.3.2 Herbs and spices (refrigerated formats)
Herbs are found in a variety of forms including fresh herbs, fresh herbs and other
ingredients packaged in a tube format, herbs in a paste format that have been heat
treated and dried herbs.
Fresh herbs
Fresh herbs are mainly sold in bunches with an elastic band holding the product
together. In this format the level of deterioration that occurs during storage will vary
depending on the type of herb being analysed and the environmental conditions.
Most herbs are unlikely to be satisfactory after one week of storage in refrigerated
conditions, some will last up to two weeks providing the environmental conditions
are acceptable. Fresh herbs can also be stored in plastic bags but this procedure
requires more attention to the type of plastic used and the atmosphere present within
the bag in order to ensure product quality and safety is maintained.
Fresh herbs and spices in a tube packaging format
Herbs are also sold in a patented formulation that uses fresh herbs in combination
with other ingredients to maintain a high-quality product that ensures the essential
oils and the microbial safety remain acceptable during storage. This unique product
format is now located world-wide in Australia, New Zealand, USA, Canada, Europe
and Asia. This product format uses innovation in the packaging to provide consumers
with a tube format that allows individual choice as to the amount of herb or spice
added to a food as well as a single-serve packaging format to provide consumers with
convenience. The tube format incorporates a higher level of technology in the packaging