This document discusses contamination, spoilage, and preservation of sugar and sugar products. Contamination can occur at various stages of production from sugarcane to refining and packaging. Microorganisms like bacteria, yeasts and molds are common contaminants. Spoilage is caused by the microbial growth and activity of osmophilic and psychrotrophic microbes. Preservation methods include maintaining low moisture levels, high sugar concentrations, and use of preservatives, heat treatments and controlled storage conditions to inhibit microbial growth and extend shelf life.

1. CONTAMINATION, SPOILAGE &
PRESERVATION
SUGAR & SUGAR PRODUCTS

2. CONTAMINATION
• Latin word contaminat = “made impure.”
• Contaminate = pollute
• Contaminate something = impure or
hazardous.

3. SPOILAGE
• The action or process of spoiling of perishable
goods.
• Spoiled food = damaged/ injured food
undesirable for human consumption
• Food spoilage causes:-
Physical injury
Enzyme activity
Microbes

4. PRESERVATION
• The action of preserving something.
• Food preservation – action of preserving food
in order to maintain it as desirable for human
consumption.

5. CONTAMINATION
Sucrose Maple sugar
• Honey
Candy Honey

6. SUCROSE

7. Contaminating sources
• Sugarcane
• Soil
• Handlers
• Transportation
• Air
• Debris/ fine particles on the sides/ joints of
troughs at the plant
• Industrial equipments & machines

9. Contaminants
• Slime producers, like species of Leuconostoc
and Bacillus; representatives of the genera
Micrococcus, Flavobacterium, Alcaligenes,
Xanthomonas, Pseudomonas, Erwinia, &
Enterobacter.
• A variety of yeast, chiefly in the genera
Saccharomyces, Candida, & Pichia.
• A few moulds.

10. Stages when organism gets added
• Bagging of raw sugar
• Sugar refining
• From equipment
• From flume & diffusion battery waste

11. Microbial action
Cutting of cane
Extraction
Clarification
Result
• Sucrose inversion
• Sugar destruction

12. MAPLE SUGAR

13. Contaminating sources
Tree
Collection
bucket
Handlers
Instruments
Air
Plastic
tubings
spouts

14. Contaminants
• Enter between its flow & being boiled &
concentrated
• A moderate amount of growth - improve flavor
and color
• The sap often stands under conditions that favor
excessive growth of micro organisms and hence
spoilage.
• Mostly psychrotrophic, G - rods + yeasts + molds
• Bacterial count - <10,000/ml

15. Prevention of contamination
• Paraformaldehyde taphole pellet
• Plastic tubing

16. HONEY

18. Contaminats
Yeast Bacteria
Bee
(intestine)Nectar

19. Contaminats
• Streptococci/ enteric bacteria – rare
• Common isolates – lysosome +
• Antibiotics- streptomycin, neomycin
• C. botulinum – infant botulism
• Gluconobacter & Lactobacillus – present
during maturation of nectar to honey

20. CANDY

21. Contaminating sources
MICROBIAL LOAD – 0-2 MILLION BACTERIA/ PIECE

22. Classification of candies &
confectionaries
• Cold processed • Hot processed

23. Result of contamination
• Food poisoning outbreaks
• Salmonellosis

24. SPOILAGE
• Osmophilic/ xerotolerant microbes
• Principle spoilage flora : Saccharomyces spp. &
certain moulds.
• Bacterial spoilers – Bacillus spp. & Leuconostoc
spp.
• Sugar concentration ∞ 1/micrbial load

25. SUCROSE
• At each processing stage it get more n more
purified
• Sugar concentration increases – crystallization
– sugar crystals + molasses
• Purity ∞ 1/micrbial load

26. Raw sugar cane juice
• Low sugar content
• Good source of accessory foods for microbes
• Readily deteriorates
• Spoilages until clarification
Gum/ slime : L. mesenteroids/ L.dextranicum
Levan : Bacillus spp. (mostly); yeasts/ molds(rarely)

27. Sugar in storage
• Liquid sugar :-
i. 67 – 72 brix sugar
ii. support yeast’s growth (Saccharomyces,
Candida & Rhodotorula) & molds from air.
• Absorption of atmospheric moisture at
surface – microbial growth – product
deterioration.
Preservation : circulation of filtered sterile air

28. Molasses & syrups
• Microbial spoilage – not common
• Tough to heat sterilize
• Canned one’s : spoiler’s osmophilic yeasts
• Exposure to air – air left in containers –
spoilage before sealing
• Acidic one’s – hydrogen swells on storage

29. SL.
NO.
SPOILAGE TYPE CAUSATIVE AGENT
1 Ropy or stingy sap Enterobacter aerogenes (mostly), Leuconostoc
(responsible)
2 Cloudy, sometimes greenish sap P. fluorescens + Alcaligenes spp. + Flavobacterium
spp.
3 Red sap Colored by pigments of red bacteria, e.g.
Micrococcus roseus, /of yeasts / yeast like fungi,
4 Sour sap (a group o spoilages
without marked color change
but have a sour odor)
Variety kinds of bacteria or yeasts
5 Moldy sap Molds

30. Honey
• ≤ 25% moisture
• 70 – 80 % sugar
• Sugars : glucose(mostly) & levulose
• Ph : 3.2 – 4.2
• Chief spoilers : Zygosaccharomyces, such as
Z. mellis, richteri, or nussbaumeri, or Torula
(Cryptococcus) mellis.
• Penicillium spp. and Mucor spp. have develop
slowly.

31. Special theories for initiation of growth of yeast/
causes of spoilage of honey
• Honey- hygroscopic- surface dilution- yeasts
multiplication & adaptation to high sugar
concentrations.
• Crystallization of glucose hydrate from honey-
lowers sugar concentration in solution
• Long standing- yeast’s gradual adaption to
high sugar concentrations.

32. Factors effecting microbial growth in honey
• Critical moisture content of yeast – 21%
• Degree of sucrose inversion to by bees
• Available N content

33. Honey fermentaion
• Slow, lasts for months
• Chief products : CO2, alcohol, & non-volatile
acids (give off-flavor)
• Usually accompanied by darkening &
crystallization

37. Candy
• Not subject to microbial spoilage - high sugar
& low moisture content.
• Exceptions - soft fondant/ inverted sugar
centered chocolate- burst or explode.
• Yeast growth develops a gas pressure - disrupt
the entire candy/ push out some of sirup or
fondant through a weak spot in chocolate
coating.
• Often this weak spot is on the poorly covered
bottom of the chocolate coating.

38. PRESERVATION
• Storage conditions: keep out vermin -the sugar
remains dry.
• Can or sugar beet - stored in a controlled
atmosphere.
• Fungal growth inhibition by 6% CO2 & 5% O2.
• During sugar manufacturing the refining processes
reduce microbial load present

39. • Chemical preservatives used in sugar refining.
• Care to avoid buildup of organisms and their
spores during processing.
• Numbers may be reduced by irradiation with
UV/ heat + H2O2
• Chocolate bursting - prevented by a uniform,
thick chocolate coating & use of fondant/ other
filling.

40. • Sirups and molasses - stored at cool T.
• The boiling process (evaporation of maple sap
to maple sirup) kills the important spoilage
organisms.
• Honey crystallization: heat to at least 71 C,
hold there for 5 minutes, and cool promptly to
32.2 to 38 C.
• Molasses & sirups : high osmotic P (∞ degree
of sucrose inversion). Mold growth prevented
by complete filling of container & reduced by
their periodic mixing.

41. REFERENCES
• Dennis C. Westhoff, William C. Frazier –
Food Microbiology – fourth edition - The
McGraw Hill companies – NewDelhi- pg.no. :
187 – 195.
• James M. Jay– Modern Food Microbiology –
third edition – AVI book publications– usa-
pg.no. : 193, 244-245

42. HIMA HARIDASAN