Food microscopy in food analysis

Food microscopy is one of the useful food analyses that can be used to determine food quality and safety.

1. Exercise 3
FOOD MICROSCOPY
FST 102 B-1L Group 1

2. Identification of Unknown Starch (B)
Whole mounting technique used
For powdered samples <200µm in size
Glycerol: water solution as mounting
medium
Viewed under HPO (500x)

3. Known starch samples
Maltese cross
Figure 1. The microscopic observation of sweet potato (left),
mungbean (center) and corn starch (right) under HPO
(500x).

4. Figure 2. Microscopic observation of cassava, potato and tugui
starch under high power objective (HPO).
Growth rings

5. Unknown starch sample
Corn
starch
Potato
starch
Cassava
starch

6. Effects of Processing and Added Ingredients on
Starch-Baked Products
Bread Flour
Crackers
Cake Flour
Cupcake (top and center)

7. competes with gluten-forming
proteins for water in the
batter and prevents full
hydration of the proteins
during mixing
During baking, sugar absorbs
liquid and delays
gelatinization
Adds flavour and surface
browning
produce the desirable surface
cracking

8. Counteracts the
sweetness of the baked
product
Lowers water activity by
competing with other
ingredients for water
Gives structure to
baked products
Act as emulsifying
agent

9. Effect of Heat Treatment
Heat application contributes to
water removal
Induces caramelization and
Maillard reaction
May lead to gelatinization

10. REFERENCES:
Brady, G. S.; Clauser, H. (eds). 1979. MATERIALS HANDBOOK, 11th Edition. McGraw-Hill.
D'Appolonia, B. L. 1972. "Effect of Bread Ingredients on Starch Gelatinization Properties as
Measured by the Amylograph." American Association of Cereal Chemists 532-543.
H. Cornell; A. W. Hoveling. 1998. Wheat: Chemistry and Utilization. Pennsylvania: Technomic
Publishing Company, Inc.
J. W. Lawton. 1997. "Biodegradable Coatings for Thermoplastic Starch." In Cereals: Novel
Uses and Processes, by G. M. Campbell, C. Webb and S. L. McKee, 43-45. New York:
Plenum Press.
Schlauri, M. 1999. "Altering Flow Quality by Heat Treatment." Getreide Mehl und Brot 53, 308-
309.
Tomasik, P. 2003. Chemical and Functional Properties of Food Saccharides. Florida: CRC
Press.
Twyman, R.M. 2005. "MICROSCOPY APPLICATIONS | Food." Encyclopedia of Analytical
Science (Second Edition) 50-57.
WHO. 2006. The Internationla Pharmacopoeia Fourth Edition. Switzerland: WHO Press.
Yildiz, F. 2010. Advances in Food Biochemistry. Florida: CRC Press Taylor and Francis
Group.