Page 282 - Analytical method for food addtives

16

E416: Karaya gum

16.1 Introduction

The major food groups contributing to dietary intake of karaya gum are desserts,
emulsified sauces and snacks with the maximum permitted level of 10 000 mg/kg
being allowed in emulsified sauces, egg-based liqueurs and nut coatings. The ADI
for karaya gum is 12.5 mg/kg body weight/day.
Gum karaya is a dried exudate from deep incisions in the heartwood of large
foliate trees of the Sterculia family, native to India and Pakistan. Harvesting of the
gum is undertaken quickly after the incisions have been made. The colour is very
variable, ranging from colourless to a deep pink-brown and the paler the gum, the
better the quality. Chemically, it is a glycanorhamnogalactouran, with alternating
backbone units of α-D-galactouronic acid linked at C to α-L-rhamnose at
4
the C position. Substitution occurs on the hydroxyl groups by D-galactose and D-
2
glucuronic acid. The gum is employed in the food and textile industries as a
1
stabiliser and adhesive. Among the naturally occurring gums, gum karaya (Sterculia
spp.) is one of the most profusely used gums at present and ranks only second to
gum arabic (Acacia spp.) in commercial importance as a food additive. 2

16.2 Methods of analysis
The only references that could be found for karaya gum were for the analysis of the
1–3
gum, and as in general tabulated in Table 16.1, not for the analysis of karaya gum
in foodstuffs.