Brownsugarexporter.com - In Asia, Africa and South
America non-centrifugal sugars are made for direct consumption and are known by
a range of names: gur in India and Bangladesh, desi in Pakistan, jaggery in
Africa, and panela in South America. These sugars are a concentrated product of
the cane juice without separation of the molasses and crystals. It can vary
from golden brown to dark brown in colour and contains up to 50% sucrose, up to
20% invert sugars, moisture content of up to 20%, and the remainder made up of
other insoluble matter such as ash, proteins and bagasse fines.
In
most cases this sugar is produced using open pan boiling techniques, either in
a single open pan (see figure 1) or in a series of pans (figure 2) that are
located above a furnace.
Fig. 1: Simple juice boiling
furnace as used in Bangladesh
Note: Furnace extends about 1m
in underground. The soil dug from the hole is used to construct the walls.
The boiling pans can be round
or rectangular depending on furnace design and local tradition. In all cases,
fuel is provided by dry bagasse from the crushing operation and sometimes
additional fuel, such as wood, may be required to complete the boiling.
Before boiling the juice is
allowed to settle and some clarification is carried out by adding vegetable
matter to coagulate the particulates which come to the surface during boiling
and are skimmed off. In some of the larger factories especially in India, the
juice is often filtered and chemically clarified before boiling commences.
In Bangladesh it is common for
the product, during cooling, to be poured into clay pots which are used to
transport it to market. The pots are then broken and the product removed and
sold by weight. In India, Pakistan and African the product is usually poured
into small rectangular moulds and in South America the product is formed into
round cakes approximately 150mm in diameter.
If sodium bicarbonate, diluted
in raw juice, is added during cooling the product will become powdery and can
be packaged in small bags as a crystal sugar substitute.
Figure
1: Multi-pan shell furnace used for open pan sugar production
Khandsari
A basic raw crystalline sugar,
developed in India, that has been separated from most of the molasses.
Khandsari, varies in colour from golden yellow to brown and contains between 94
and 98% sucrose.
It is produced by the small to
medium scale sector and has a considerable market in India. At its most basic,
khandsari is manufactured using simple animal-drawn crushers, is subjected to
simple clarification, boiled to the consistency of a thick syrup, and allowed
to stand until sugar crystals are formed. The small crystals are then separated
in manually operated centrifuges and sun dried.
At the other end of the scale,
the production plant can use diesel or electrically driven crushers,
crystalliser to ensure even formation of crystals, power-driven centrifuges,
and forced-air driers to dry the product. Factories processing between one and
two hundred tonnes of cane per day are common yielding between 6.5 and 13
tonnes per day respectively.