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Ch. 6— The Food Processing Industry • 111 
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Microbial polysaccharides 
rhe food [)i’ot’essin^ industry uses [jolysac- 
eharides (poK iiierie sugars) to alter or contiol 
the physical pi'operties of foods. Many ai'e in- 
corporated into foods as tliickeners, gelling 
; agents, and agents to control ice crystal foi ina- 
' tion in frozen foods. They are used in instant 
foods, salad dressings, sauces, whips, to[)pings, 
processed cheeses, and tlair\' products. New 
uses are constantly appearing. The annual mai'- 
ket in the I'nited States is leported to he o\er 
36,000 tons, not including starches atid deri\ a- 
ti\ es of cellulose. 
Since many of the pol\ meric sugars now used 
in food processing are derixed from plant 
sources, microbial polysaccharides ha\e had 
limited use. To compete economically, a micro- 
bial pohsaccharide must offer new properties, 
meet all safety requirements, and he readily 
av ailable. \ ery few have reached the level of 
commercial applications: the onlv one in large- 
scale commercial production is .xanthan gum.* 
'The history of the development of .xanthan gum indicates that 
the commercially significant organisms resulted from an extensive 
screening program for gum producers stored in the .Northern Uti- 
,\ wide variety of polysaccharides could theo- 
retically he produced foi’ use in food processing. 
.Applied genetics may increase their production, 
modify those that are produced, eliminate the 
degi'adative enzymes that break them down, or 
change the microbes that produce them. How- 
ever, as with other microbial processes, the ap- 
plication of genetics depends on an understand- 
ing of both the biochemical pathway for synthe- 
sis of a given polysacchai'ide and the systems 
that control microbial production. For many mi- 
crobial polysaccharides, this information does 
not vet exist: furthermore, little is known about 
the enzymes that may he used to modify poly- 
saccharides to more useful forms. Progress will 
only he able to occur when these information 
gaps are filled. 
lii'alion Kcscai'i'h and Ocvclopmcnl Division of llSO.V's largo mi- 
(■|■ol)ial fullurc colleclion. Xanllian gum produced hv Xanlhomo- 
nas camppstris \RRI. R- 14.)9 was found lo ha\ e characlerislics that 
rendei ed it \ei'v promising as a commercial product. In 19G0, the 
Kelco ilivisioti of VIerck <4 Co.. Inc., cai ried out pilot plant feasihili- 
ty stiulies. and suhstantial commercial pi'oduction began in 19(i4. 
Vllhough much of the work to date has hee?i (uirried out with 
polysaccharides from one particular strain, there is increasing e\ i- 
dence to suggest that they could also he produced fj'om other 
strains. 
Enzymes 
Enzymes are produced for industrial, med- 
ical, and laboratory use both by fermentation 
processes that employ bacteria, molds, and 
yeasts and by extraction from natural tissues. 
The present world market for industrial en- 
zymes is estimated to be S150 million to SI 74 
million: the technical (laboratory) market adds 
another S20 million to S40 million. Fewer than 
50 microbial enzymes are of industrial impor- 
tance today, but patents have been granted for 
more than a thousand. This reflects the increas- 
ing interest in developing new enzyme prod- 
ucts; it also show's that it is easier to discover a 
new enzyme than to create a profitable applica- 
tion for it.* 
Most industrial enzymes are used in the de- 
tergent industry and the food processing in- 
*The enzvme literature is exlensiv'e aiid comprises well over 
10,000 papers per year. .Although less than SO percent of these 
publications are concerned with microbial enzymes and most are 
found to have no industrial interest, a few thousand papers per 
year are of potential interest for the industrial development of en- 
zymes. Less than 100 papers dealing with industrial processes ap- 
pear e\ erv year, and few descrjbe processes of great economic sig- 
nificance. 
