Agriculture Reference
In-Depth Information
of the specific post-harvest handling needs of different
species, and all were treated the same after harvest
(Lopresti & Tomkins 1997). Most herbs are sold alone but
some are packaged with other herbs or leafy vegetables,
particularly
Cruciferae
. However, since herbs are
botanically diverse in origin and physiological status,
post-harvest treatments or conditions that suit one may not
suit another (Cantwell & Reid 1993). With herbs sold as
mixtures this can lead to difficulties with shelf lives in that
the different components decay at different rates. Thus the
shelf life of the whole pack is limited to the shelf life of the
most vulnerable component. Chervil, for example, is
quickly perishable but rosemary, sage and thyme are not,
and so shelf life considerations will influence the choice of
components for mixed packs.
The literature on post-harvest systems for herbs and
spices is relatively scanty, largely resulting from the limited
economic value of these commodities compared to staple
foodstuffs. However, recent increases in demand, and
improvements in processing techniques using modified
atmospheres and microprocessor control of temperature
and humidity, has drawn attention to a high value and
potentially profitable industry.
There is a wide range in the number of herbs, spices and
flavourings used around the world. Table 15.1 shows the
common leafy herbs, with their areas of origin and how
they are manipulated after harvest. Most are used fresh.
Spices, on the other hand tend to be used in the dried form.
Table 15.2 lists spices of major, world-wide economic
importance. Some spices are restricted to a limited range of
cuisines or are seldom found outside their country of
origin, and these are shown in Table 15.3.
the twentieth century, from 110 000 t, valued at US$135
million, in 1990-1991 to 235 000 t, worth US$472
million, in 1999-2000. During 2002-2003 the quantity
of spices exported from India reached an all-time high of
251 000 t, although this has since dropped to US$370
million. The decline was due to a low volume of pepper
exports coupled with a decline in unit price. Nonetheless,
India commands a formidable position in the world trade
in spices, with about 48% share in volume and 24% in
value in 2003 (SBI 2003).
Fresh herbs are seldom differentiated in production and
marketing statistics, usually being lumped together as
'miscellaneous herbs'. Thus, in the United States, domestic
shipments increased from 2800 t in 1989 to 3700 t in 1990,
an increase of 34%. Over the same period imports increased
by 280%, from 900 t to 3400 t. These trends continued into
1991, with 99% increases in domestic shipments, imports
and exports (USDA 1991).
The United States imports the largest amount of spices,
followed by Germany and Japan. The EU as a whole
imports more than the United States in terms of value at
US$2.2 billion (by 2001; see Peter 2001). Demand for
spices in the United States, particularly the 'hot' types, has
risen markedly since the beginning of the 1980s. Since
1990 over 360 000 t have been consumed every year; 40%
of these are 'hot' types such as black and chilli pepper,
mustard and ginger. Many herbs, particularly those
associated with pizza and spaghetti sauce, have also
increased in popularity and thus annual imports of basil
went from 1200 t in 1983 to 2400 t by 1993. Oregano use
nearly doubled from 3600 t to 6800 t in the same period;
use of sage also increased, though less impressively from
1500 to 1800 t (Wolf 1995). In the United Kingdom, spice
imports expanded by 27% in the five years leading to the
millennium, mainly through increases in cinnamon, cloves,
garlic and seed spices (Peter 2001).
CONSUMPTION AND MARKETING TRENDS
Approximately 85% of spices are traded internationally in
whole form. The final product has traditionally been
processed and packed by importing countries. More
recently the trade in value-added spices has increased as
exporters develop their processing technologies and quality
systems (Peter 2001). The annual global trade in spices
was about 600 000 to 700 000 t at the end of the 1990s with
a value of US$3-3.5 billion (Peter 2001), though this has
declined to approximately 520 000 t in 2002-2003, worth
about US$1.5 billion (SBI 2003). The main component of
the international spice trade is pepper, and so the value of
the trade as a whole fluctuates as the price of pepper rises
and falls (Peter 2001).
Spices can be important components of national
economic activity. For example, exports from India
registered substantial growth during the last decade of
POST-HARVEST ISSUES IN HERBS AND SPICES
Quality, authenticity and standards
The disparity between the terms 'authenticity' and 'quality'
in assessing herbs and spices has been highlighted by
Muggeridge and Clay (2001). Authenticity may be defined
as freedom from adulteration (i.e. the absence of foreign
bodies or extraneous material), but it also suggests that the
product comprises a single species. In practice, the use of
the term 'authenticity' may be misleading because some
common herbs and spices are traded as blends but are not
described as such on the label. For example, a packet
labelled as dried sage leaves may contain the 'classic' sage
