1. TEXTURE ANALYSIS OF FOOD
Submitted to:- Submitted by:-
Dr. Shagun Sharma Sandesh Choudhary
201190016
Anupam Kumar
201190004
2. CONTENT:-
• Introduction
• Terminology
• Instrumentation
• Instrumental Methods & Analysis
• Texture profile analysis
• Sensory vs. instrumentation
• Correlations between sensory and instrumental
measurements of texture
• References
3.
4.
5.
6. INTRODUCTION
• Texture of food products is defined as all the rheological,
mechanical and structural attributes of the product
perceptible by means of mechanical , tactile, visual as well as
auditory receptors.
• Attribute of a substance resulting from a combination of physical
properties and perceived by the senses of touch, sight, and
hearing.
• Can be determined either by sensory or instrumental methods.
• Physical properties may include size, shape, number, nature,
and conformation of constituent structural elements.
7. Cont.
• Comprises those properties of a foodstuff, apprehended by
the eyes and by the and muscle senses in the mouth,
including roughness, smoothness, graininess, etc.
• Texture is an important aspects of food quality ,
sometimes even more important than flavor and colour.
8. Terminology used in texture analysis
Primary parameters
• Hardness/ Firmness
• Cohesiveness
• Elasticity
• Adhesiveness
• Viscosity
Rheological properties of
food:-
• Density
• Flow rate
• Heat capacity
• Shear stress
• Thermal conductivity
• Shear rate
Secondary parameters
• Brittleness, crunchiness and crumbliness
• Chewiness, Tenderness or toughness
• Gumminess
Other physical properties:-
Wet ability, phase changes, Surface-tension,
Mastication/anatomy/physiology
• Sensory evaluation of food
texture by touch includes the use
of fingers , lips, tongue, palate
and teeth.
13. INSTRUMENTATION:-
• Textural properties are measured with instruments
commonly known as texture analyzers that can compress
or stretch food materials.
• Can be carried out under defined and controlled
conditions .
• Applying controlled forces to the product.
• Recording the response in the form of force, deformation
and time.
• More sensitive than subjective sensory evaluation.
• A number of instruments are available that offer a range
of force measuring capability
14. Basic requirements of
instrumentation
• Instrumental methods of assessing food texture can be carried
out under more defined & controlled conditions.
• Analysis should give consistent results, if analyzed in constant
conditions.
• equipment capable of driving a probe for a given distance
into a sample at a fixed speed.
• Continuously log the force required to maintain this speed
• Respond to a trigger force (signal to start of test)
• Detect initial height of the sample
• Compress it to a fixed portion of this height (% strain)
• Thus improving the accuracy obtained from the test method.
15. Instrumental Method Of Texture
Measurement
May Be Classified Into Three Groups:
1. Fundamental Method.
Based on measurement of physical properties such as stress and strain and
rheological properties such as viscosity and elasticity.
2. Empirical Method
• Measures parameters which are often poorly defined.
• Appear to relate to textural quality as in the case of measurement of texture
using penetrometers and shearing instruments.
• widely used in the food industry.
3. Imitative Method
• Stimulates the conditions to which materials are subjected in practice using
Squeezometer and Farinograph.
16. Penetrometer
• An instrument for determining the consistency or hardness of a
substance by measuring the depth or rate of penetration of a rod
or needle driven into it by a known force.
• Measure the force required to move a plunger a fixed distance
through a food material.
17. Succulometer
• An instrument for measuring the moisture content of a fresh
or processed vegetable product such as sweet corn.
• Uses compression to squeeze juice out of food as a measure
of succulence.
18. Tenderometer
• A device for determining the maturity and tenderness of
samples of fruits & vegetables.
• Applies compression and shear to measure the tenderness of
foods.
19. Compression test
• Tests are performed by compression to a given force.
• In this test method sample is placed n the flat base of the
instrument .
• The platen should be bigger than the sample being tested.
• one of the most common tests carried out on food products.
20. Penetration/Puncture tests
• This test is commonly used for puncturing the sample to defined
distance and recording the force required to giving parameters
such as hardness.
• similar to compression testing but probe is typically much smaller
than the dimensions of the sample.
• Various types of probes can be use such as cones and cylinders for
measure the products such as gel, pectin, butter and margarine.
21. Shearing test
• Shear testing is important for check the shear strength of food
• Various shear testing apparatus (razor blades , V shaped blades,
rounded blades ,straight blades ) are used.
• Warner-Bratzler shear force test are widely used in the meat
industry and to measure the tenderness of meat.
• Consists of a stainless steel blade in which cylindrical piece of meat
is placed between the notch of the blade.
23. Texture Profile Analyzer
• widely used test based on double
compression of a material between two
flat plates.
• For determining the textural
properties(hardness, cohesiveness,
adhesiveness, gumminess, chewiness) of
foods.
• Widely used in bread because it mimics
the biting and chewing action of the jaw
by compressing the sample.
• Known as the two bite test.
• This test also suitable for measuring
changes in firmness (staling) during
storage by testing at different time
points.
24. Cont..
• This test appears as two peaks and representing the two compressions.
• Second peak is typically smaller than the first peak .
• Gap between the two peaks represents the time when the probe is
stationary between the two compressions.
• Height of the first peak related to the firmness or hardness of the bread.
• Resilience, Cohesiveness, Springiness are also measured by this method.
28. Bulk analysis methods
• where a large amount of a product is tested at once
so these methods giving an average value of the
textural properties.
• such as with expanded rice grains or breakfast
cereals
29. 1. Kramer shear cell
• Consists of a set of blades that
move down through a
containment box that holds the
sample under test
• Test combines compression,
extrusion and shear
▪ Applicable to a wide variety
foods, such as grains, cereals,
pulses,pasta, fruits and
vegetables .
30. Breaking or bending tests
3 point bend
• it provides information about
the strength of the internal
structure of the food.
• The braking force and
flexibility is measured.
• Usually a plate with a rounded
edge, comes down to apply the
bending force
• distance between the two
parallel bars can be adjusted to
accommodate different sized
samples
• Chocolate, Biscuits and crackers
are often tested using this test.
31. Tests of Hard Brittle Foods
• Examples of hard brittle foods include crisps, snacks, biscuits,
crackers, breadsticks (bread crusts), pastry.
• physical measurements:-
• sound made by a hard brittle food is recorded.
• intensity of the sound is recorded relating to crispiness or
crunchiness. This correlates with the force required to crush
food between the teeth.
• Hardness of these products is determined by the maximum
force on the force-distance graph.
33. Sensory Vs Instrumental analysis
• Sensory analysis Done using fingers, lips, tongue, palate and
teeth.
Mouth feel: how a food feels in your mouth (sticky, smooth,
tender) & Tongue & Palate evaluate feelings such as
sweetness, grittiness, sandiness of food.
Pressure between teeth & jaws determines Hardness ,
Chewiness, gumminess of food.
Fingertips and thumb help in determining Stickiness,
Elasticity, Sponginess, Brittleness of food.
34. Cont.
• Instrumental methods of assessing texture can offer
advantages over sensory analysis as they are Economic,
rapid & Objective.
• can be carried out under strictly defined and controlled
conditions.
• offer a potential ease of standardization
• when developing new products where specific sensory
parameters required for check the product quality.
35. Correlations between sensory and
instrumental measurements of
texture
• Finding instruments to measure quality control of food in
industries.
• Predicting consumer response, as the degree of liking and
the overall acceptance of a new product.
• Understanding what is being sensed and perceived in the
mouth during sensory assessment of texture.
• Improving or optimizing instrumental methods to
complementary the sensory evaluation.