This document discusses food quality parameters and methods for analyzing food products. It outlines factors that contribute to food quality like appearance, taste, and nutritional value. Physical, chemical, and microbiological tests are used to analyze raw materials and finished products to ensure safety and purity. Parameters like moisture, fat, protein, and packaging materials are evaluated using methods like the hot air oven test and chemical analysis. Instrumental techniques like gas chromatography-olfactometry and electronic nose are also used to objectively measure organoleptic properties and identify volatile compounds that influence flavor.

1. TOPIC:
FOOD QUALITY PARAMETERS
By:
Maryum Atique
M. Phill chemistry
University of Agriculture
FSD.

2. FOOD QUALITY
 Food
quality is the quality characteristics
of food that is acceptable to consumers.
 Food
quality is an important food
manufacturing requirement, because food
consumers are susceptible to any form of
contamination that may occur during
the manufacturing process.

3. FACTORS CONTRIBUTING TOWARDS QUALITY OF
FOOD
 The
various factors contributing towards quality of
food are :
 Appearance
 Color
 Taste
 Odor
 Nutritional value
 Adulterants
 Contaminants
(Physical,
Chemical
&
Microbiological

4. WHY IS IT NECESSARY TO ANALYZE
FOOD PRODUCTS BEFORE OR AFTER
PROCESSING?
 To
know the quality of raw materials and final
products.
 To
understand
occurrence
of
any
physicochemical changes during processing or
storage.
 To ensure purity, freshness and safety of the food
products at the time of consumption.

5. VARIOUS PARAMETERS EVALUATED FOR
CERTIFYING QUALITY OF FOOD
 In
order to ensure the right quality of various
food products, several parameters are
evaluated as by different methods:
 Physical
 Chemical
 Packaging materials

6. PHYSICAL AND RHEOLOGICAL PARAMETERS
Refraction
Sieve test
Flour
Insect infestation
Visual observation
Cereals, pulses
Admixture
Visual observation
Cereals, pulses
Colour on Lovibond scale
Lovibond Tintometer
Oil, fat,
Bellier turbidity temperature
Visual
Oils
Optical rotation
Polarimeter
Sugar, Syrup, Oil & fat

7. CHEMICAL PARAMETERS
Moisture
Hot air oven
Vacuum oven
Karl Fischer titer
Dean & Stark
Most of the food products, Animal
feeds
Fat or oil
Chemical
Most of the food products, Animal
feeds
Protein
Chemical
Most of the food products, Animal
feeds
Starch
Chemical
Starch containing products

8. PACKAGING MATERIALS
Tin, Chromium
AAS
Tin plate
Sulphide stain
Chemical
Food cans
Laquer
Physical Chemical
Tin cans
Migration tests
Chemical
Food grade plastics
Heavy metals like Pb, As, Cd, Se, AAS
Ba,
Coloured plastics
Water vapour permeability
Plastics
Humidity chamber

9. BENEFITS OF FOOD QUALITY PARAMETERS
 Benefits
of food processing include toxin
removal, preservation, easing marketing
and distribution tasks, and increasing food
consistency.
 To increases yearly availability of many
foods, enables transportation of foods
across long distances and makes many
kinds of foods safe to spoilage and microorganisms.
 To reduce the incidence of food borne
disease.

10. CONTINUE;
 To
improve the quality of life for people with
allergies, diabetics, and other people who cannot
consume some common food elements.
 To add extra nutrients such as vitamins.
 To offer products that fulfill many different needs:
for example fully prepared ready meals that can be
heated up in the microwave oven within a few
minutes.

11. INSTRUMENTAL TECHNIQUES USED FOR
ASSESSMENT OF FOOD QUALITY
Classical approach in evaluation of organoleptic quality
of food products is the only method used on this purpose.
 Classical methods are mainly based on the sensory
analysis. This analysis is a perfect tool in carrying out
marketing tests of consumers but the limitation is a good
complement in the evaluation of organoleptic food
properties in instrumental analysis.
 The use of appropriate instrumental methods allow for
identification of the volatile compounds which influence
on the flavor composition of food products.


12. GAS CHROMATOGRAPHY-OLFACTOMETRY (GCO)

GC-O is a technique based on sensory evaluation of the
eluate from the chromatographic column by trained
assessor or group of assessors.

Identification of aroma active compounds is possible on
the basis of simultaneous use of second detector.
Mostly, second detector function performs mass
spectrometer (MS) or flame-ionization detector (FID).

13. SCHEMATIC DIAGRAM OF GC-O

Fig. 1. Scheme of gas chromatograph coupled with
olfactometric detector

14. METHODS OF GC-O

15. ELECTRONIC NOSE

Electronic nose is a device consisting of a set (matrix) of
electrochemical sensors, selective for certain volatile
compounds.

The instrument is equipped with appropriate system of
pattern recognition capable of identification of simple
and complex odors.

16. SCHEMATIC DIAGRAM
ELECTRONIC NOSE

18. 
For the odor of a tested product responsible are not only
single aromatic compounds but also their complex mixtures.
They give a resultant aromatic effect which is present in
perfumes.
It has a number of gas sensors that form matrix . These
sensors act as sensory neurons and Artificial Neural
Networks (ANN) constitute its main part . Microprocessor or
computer play a role of a brain.
 There is a resultant signal from all the sensors collected in
the computer and an electronic pattern of the odor is
created.


Practical applications of electronic nose in food industry

20. FEATURES AND DISADVANTAGES OF THESE
TECHNIQUES





Both presented techniques are better than classically
applied in the industry. However, more promising seems
to be e-nose. It is due to the following features:
Short time of analysis, high sensitivity and
reproducibility, objective, identification of odors, possible
in situ analysis (portable devise).
E-nose system has also a few disadvantages,
Ageing material of sensors, possibility of sensors
poisoning, in some cases humidity influence to sensor
responses.
The use of these methods also allow for discrimination
raw material used in the production.

21. DRAWBACKS
Food quality parameters includes the following
drawbacks,
 To
affect its nutritional density, the amount of
nutrients lost depending on the food and method of
processing.
 Vitamin C, is destroyed by heat and therefore canned
fruits have a lower content of vitamin C than fresh
ones.
 Large mixing, grinding, chopping and emulsifying
equipment, inherently introduce a number of
contamination risks.
 Large food processors will utilize many metal within
the processing stream, metals may be dangerous for
our health.
