Lakhasly

The sound of food being prepared, cooked, served, and eaten influences food preferences and our perception of freshness, as exemplified by the crisp, crunchy sound of an apple. Food texture, felt by the fingertips, tongue, teeth, and palate, is known as mouthfeel.

Sensory testing requires careful control to measure true product differences. The physical setting should minimize subject biases, maximize their sensitivity, and eliminate extraneous variables.

Introduction

Everyone has different taste perceptions, so tasters should understand that there's no "right" answer. During tasting sessions, tasters should refrain from talking, sharing ideas, or looking at each other's expressions. Industry uses tasting booths to prevent these distractions.

Test Room Design

• A circular table is used for consensus-type descriptive analysis, round-table discussion for descriptive analysis ballot development, and training or other descriptive tasks.
• The sample preparation area should be located near, but separate from, the test room.
• A small stainless-steel sink and faucet are mandatory for evaluating mouthwashes, toothpastes, and household items.
• A conference-style room with tables that can be arranged according to the group's size and objective.
• Audiovisual equipment, including an "electronic whiteboard" or projector, for data display.
• Separate facilities for reference samples.
• Storage space for frozen, refrigerated, or room temperature samples.

Entrance and Exit Areas

In large facilities, separate entrance and exit areas prevent information exchange. The exit area often includes a desk for studying identity samples and a "treat" to encourage participation.

Office Facilities

An office within view of the panel booths houses records, storage, computer equipment, and phones/printers at a distance to minimize distractions.

Storage

Space is allocated for storing samples before and after preparation, as well as reference samples and controls.

General Design Factors

• Color and Lighting: Neutral, unobtrusive off-white colors and minimal patterns minimize distractions. Red, green, or blue lighting at low intensity is a common feature.
• Air Circulation, Temperature, and Humidity: Sensory evaluation areas should be air-conditioned at 72°F–75°F and 45%–55% relative humidity.
• Non-odorous: Avoid materials like paper, fabric, carpeting, and porous tile that can harbor odors.
• Color: Use neutral, unobtrusive color schemes.
• Plumbing: Prevent product trapped in pipes from creating distracting odors.

Construction Materials

The preparation area should accommodate the preparation of all possible sample combinations at the maximum required rate.

Preparation Area

• Laboratory benches flush with hatches for sample tray movement.
• Benches, kitchen range, ovens, refrigerators, and freezers.
• Storage for glassware, dishes, trays, and other equipment.
• Dishwashers, disposals, trash compactors, wastebaskets, sinks, and garbage containers.
• Storage for panel member treats.
• Central computer system for tracking products and panelists.

Product Controls

• The product researcher and sensory analyst seek to identify treatment effects such as ingredient changes, processing variations, packaging changes, and storage variables.
• The sensory analyst controls the early handling, preparation, and presentation of each product to prevent extraneous variables.
• The preparation area should be situated adjacent to the test area, with positive pressure feeding into the preparation area and air return and exhaust in the preparation area.

Sample Preparation

• Supplies and Equipment: Scales, glassware, timers, stainless-steel and glass equipment for mixing and storing products. Most plastic cutlery, storage containers, wraps, or bags are unsuitable due to potential volatile transfer.
• Preparation Procedures:
  • Precisely measure product amounts by weight or volume.
  • Precisely measure added ingredients.
  • Monitor preparation time and temperature.
  • Define holding time (minimum and maximum time after preparation).

Sample Presentation

• Container, Sample Size, and Other Particulars: Select equipment and procedures that minimize biases and new variables.
• Order, Coding, and Number of Samples: Balance the order of presentation so that each sample appears in a given position an equal number of times.
• Product Sampling: Determine the amount of product needed for evaluation and understand the product history.

Panel Training or Orientation

• Familiarize panelists with test procedures: amount of sample, delivery system, contact time, disposition, score-sheet design, instructions, terminology, scales, and judgment type.

Panel Control

• The procedure used by a panelist to evaluate a sample.

Product/Time of Day

• Schedule evaluations of certain products at the time of day they are normally used or consumed.
• Avoid tasting highly flavored or alcoholic products early in the morning or immediately after meals or coffee breaks.
• Precondition panelists' skin, hair, nose, or mouth as necessary.

Panelists/Environment

• Control the test environment to avoid biases. Colored lights, high humidity, or enclosed spaces can cause anxiety or distraction.
• Prepare panelists for the test situation, provide orientation and time to feel comfortable, and ensure they understand the protocols.

Factors Influencing Sensory Verdicts

• Treat tasters as variable measuring instruments prone to bias.
• Understand physiological and psychological factors influencing perception.

Physiological Factors

• Adaptation: Decrease in sensitivity to a stimulus due to continued exposure.
• Enhancement or Suppression: Interaction of simultaneously presented stimuli.
• Enhancement: One substance increases the perceived intensity of another.
• Suppression: One substance decreases the perceived intensity of a mixture.

Psychological Factors

• Expectation Errors: Information given with the sample triggers preconceived ideas.
• Error of Habituation: Continuing to give the same response to a series of slowly increasing or decreasing stimuli.
• Stimulus Error: Irrelevant criteria, such as container style or color, influence the observer.
• Logical Errors: Two or more characteristics of the samples are associated in the assessors' minds.
• Halo Effect: Simultaneous scoring of various flavor aspects with overall acceptability produces different results than separate evaluation.

Order of Presentation of Samples

• Five types of bias can be caused by the order of presentation:

  • Contrast Effect: A good-quality sample presented before a poor-quality sample.
  • Group Effect: One good sample presented in a group of poor samples is rated lower than if presented alone.
  • Error of Central Tendency: Samples in the middle of a set are preferred over those at the ends.
  • Time Error/Positional Bias: Attitude changes over a series of tests, from anticipation to fatigue.
  • POOR PHYSICAL CONDITION

• Panelists should be excused from sessions if they have a fever, common cold, skin or nervous system disorders, poor dental hygiene, emotional upset, heavy workload, take medications affecting taste or smell, or are elderly.

• Smokers should refrain from smoking for 30-60 minutes before a panel.

• Strong coffee affects perception for up to an hour.

• Taste and smell dysfunctions are associated with chronic diseases.

The sound of food being prepared, cooked, served and eaten all help to
influence food preferences. The sounds also influence our understanding
of whether they are fresh or ripe, e.g. a crisp, crunchy apple.
Food texture is the way food is felt by the fingertips, tongue, teeth and
palate. When food is placed in the mouth, the surface of the tongue and
other sensitive skin reacts to its surface texture. This sensation is known as
mouthfeel
 Many variables must be controlled if the results of a
sensory test are to measure the true product differences
under investigation.
 The physical setting must be designed
 minimize the subjects’ biases
 maximize their sensitivity
 eliminate variables that do not come from the products
themselves
INTRODUCTION
 Everyone has different perceptions of tastes, so the tasters should
understand that no-one has the ‘right’ answer.

 During a tasting session
 the tasters should not talk or share ideas
 Not look at the expressions on the faces of the other tasters.
 In industry, tasting booths are used to prevent this from happening.
 Test-room environment
 use of booths or a round table
 lighting
 room air
 preparation area
 Entry and exit areas
Controls of test room
Test room design
 Circular table used for consensus-type
descriptive analysis.
 Round-table discussion used for
descriptive analysis ballot development.
 Roundtable used for training and/or other descriptive tasks
 sample-preparation area be located near to, but separate from the test
room.
 Small stainless-steel sink and a water faucet are usually included for
rinsing.
These are mandatory for the evaluation of such products as
mouthwashes, toothpastes, and house- hold items
Test room design cont.
 A conference-style room with several tables that can be arranged as
required by the size and objective of the group.
 Audiovisual equipment, which may include an “electronic white
board” capable of making hard copies of results or a monitor/screen
that projects the data from the panel leader’s computer.
 Separate preparation facilities for reference samples used to illustrate
the descriptors or intensities depending on type, these may include a
 storage space (frozen, refrigerated, or room temperature, perhaps
sealed to prevent odors from escaping)
 holding area for preparing the references
test room design
 In large facilities, it is advisable to separate entrance and exit areas for
assessors to prevent the unwanted exchange of information.
 The exit area commonly contains a desk where assessors can
 study the identity samples
 receive a “treat” to encourage participation
Entrance and Exit Areas
 An office is usually situated within view of the panel
booths, as someone must be present while testing is in
progress.
 convenient to locate records,
 Locate a storage space
 computer equipment in the same area so that the panel
leader’s time may be effectively utilized.
 Equipment such as phones and printers should be at a
sufficient distance to avoid distracting the subjects.
Office Facilities
 Space must be allocated for storage under the appropriate temperature and humidity
conditions
 Samples prior to preparation
 Samples after preparation
 Samples at the time of serving
 Reference samples and controls or standards
Storage
 Colored Lights
 Air Circulation, Temperature, and Humidity
 Construction Materials
 Non-odorous
 Color
 Plumbing
General Design Factors
• Color and Lighting: The color and lighting in the booths should be planned to
permit adequate viewing of samples while minimizing distractions
 A common feature of many panel booths is a choice of red, green, and/or
blue lighting at low intensity obtained through the use of colored bulbs or
special filters
• Air Circulation, Temperature, and Humidity: The sensory evaluation area
should be air conditioned at 72°F–75°F and 45%–55% rela- tive humidity
(RH).
General Design Factors
• Non-odorous: Paper, fabric, carpeting, porous tile, and
so on must be avoided because they are either odor- ous
in themselves or may harbor dirt, molds, and so on that
will emit odor
 Color: A neutral, unobtrusive color scheme using off-
white colors and few patterns provides a background that
is not distracting to panelists
• Plumbing: Product trapped in pipes causes distracting
and confounding odors in a sensory labora- tory.
Construction Materials
 The preparation area is a laboratory that must permit
preparation of all of the possible and foreseeable
combinations of test samples at the maximum rate at
which they are required.
Preparation Area
 Laboratory benches flush with the hatches so that sample
trays will slide through
 Benches, kitchen range, ovens, and so on, for preparation
 Refrigerator and freezer for storage of samples
 Storage for glassware, dishes, glasses, trays, and so on
 Dishwashers, disposals, trash compactors, wastebaskets,
sinks, and so on
 Storage for panel member treats, if used
 Large garbage containers for quick disposal of used
product, and so on
 Central computer system to keep track of products and
panelists
Preparation Area
 equipment used
 way samples are screened
 prepared
 numbered
 coded
 served
Product controls
 Product equipment
 The product researcher and the sensory analyst are looking for
some treatment effect
 effect of an ingredient change
 processing 39 Controls for Test Room,
 Products, and Panel
 Product Controls variable
 packaging change
 storage variable
PRODUCT CONTROLS
 One of the primary responsibilities of the sensory analyst is to control the
early handling,
 The preparation
 The presentation of each product. These controls ensure that extraneous
variables are not introduced and that no real treatment variables are
obscured
 The preparation area should be situated adjacent to the test area.
 The air handling system should be structured so that the test area has
positive pressure that feeds into the preparation area, which in turn
contains the air return system as well as a supplementary exhaust.
PRODUCT CONTROLS
Sample preparation
 Supplies and Equipment In addition to the necessary major appliances, the
controlled preparation of products requires adequate supplies and
equipment,
 Scales, for weighing products and ingredients
 Glassware, for measurement and storage of products
 Timers, for monitoring of preparation procedures
 Stainless-steel and glass equipment, for mixing and storing products
 Most plastic cutlery
 storage containers, and wraps or bags are unsuitable for the preparation and
storage of foods, beverages, or personal care products.
 The transfer of volatiles to and from the plastic can change the aroma and/or
flavor characteristics of a product.
PRODUCT CONTROLS
Preparation Procedures : The controlled preparation of products
requires careful regulation and monitoring of procedures used,
with attention given to
 Amount of product to be used, measured by weight or volume
using precise equipment (volumetric cylinders, gram scales,
etc.)
 Amount of each added ingredient (as above)
 The process of preparation, regulation of time (stopwatch), and
temperature (thermometers)
 Holding time, defined as the minimum and maximum time after
preparation that a product can be used for a sensory test20
Controls to ensure fair testing include:
 all samples served in the same way, at the same temperature (appropriate to
the food);
 a small number of samples presented at one time, otherwise their taste buds
get tired.
 tasters allowed to sip water or eat a plain biscuit in between each tasting to
clear the palate;
• Supplies and Equipment
Scales, for weighing products and ingredients
Glassware, for measurement and storage of products
Timers, for monitoring of preparation procedures
 Stainless-steel and glass equipment, for mixing and storing products
Sample Preparation

1. Container, Sample Size, and Other Particulars:
   The equipment and procedures used for product presentation during the
   test must be carefully selected to reduce introduction of biases and new
   variables


2. Order, Coding, and Number of Samples: As part of any test, the order,
   coding, and number of samples presented to each subject must be
   monitored. The order of presentation should be “balanced” so that each
   sample appears in a given position an equal number of times.


3. Product Sampling: The sensory analyst should determine how much of
   a product is required for evaluation and should know the history of the
   products to be tested
   Sample Presentation
   Panel Training or Orientation
    The test procedures, such as the amount of sample to be tasted at
   one time; the delivery system (spoon, cup, sip, slurp);
    The length of time of contact with the product (sip/spit, short
   sniff, one bite/chew); and
    The disposition of the product (swallow, expectorate, leave in
   contact with skin or remove from skin)
    The score-sheet design, including instructions for evaluation,
   questions, terminology, and scales for expressing judgment must be
   understood and familiar to all panelists.
    The type of judgment/evaluation required (difference,
   description, preference, acceptance) should be understood by the
   panelists as part of their test orientation
   Panel control
   Panel control
   the procedure used by a panelist evaluating the sample
   Product/Time of Day
    With panelists who are not highly trained, it is wise to schedule
   the evaluation of certain product types at the time of day when that
   product is normally used or consumed.
    The tasting of highly flavored or alcoholic products in the early
   morning is not recommended.
    Product testing just after meals or coffee breaks also may
   introduce bias and should be avoided. S
    Some preconditioning of the panelists’ skin, hair, nose or mouth
   may be necessary to improve the consistency of verdicts.
   Panelists/Environment
    The test environment, as seen by the panelist, must be controlled if
   biases are to be avoided.
   such as colored lights, high humidity, or an enclosed testing area
   may cause anxiety or distraction.
    Again, it is necessary to prepare panelists for what they are to expect in
   the actual test situation, to give them the orientation and time to feel
   comfortable with the test protocols, and to provide them with enough
   information to respond properly to the variables under study.
   Factors Influencing Sensory Verdicts
    Good sensory measurements require that we look at the tasters as
   measuring instruments that are somewhat variable over time and
   among themselves and are very prone to bias.
    To minimize variability and bias, the experimenter must understand
   the basic physiological and psychological factors that may influence
   sensory perception.
   Factors Influencing Sensory Verdicts
    PHYSIOLOGICAL FACTORSPSYCHOLOGICAL
    Adaptation
    Enhancement or suppretion
    PSYCHOLOGICAL FACTORS
    Expectation Error
    Error of Habituation
    Stimulus Error
    Logical Error
    Halo Effect
   Physiological factors
    Adaptation: decrease in or change in sensitivity to a given
   stimulus as a result of continued exposure to that stimulus or
   a similar one.
    Enhancement or suppression: involves the interaction of
   stimuli presented simultaneously as mixtures
    Enhancement. The effect of the presence of one substance
   increasing the perceived intensity of a second substance.
    Suppression. The effect of the presence of one substance
   decreasing the perceived intensity of a mixture of two or
   more substances.
   Psychological factors
    Expectation errors: Information given with the sample may
   trigger preconceived ideas.
    can destroy the validity of a test and must be avoided by keeping
   the source of samples a secret and by not giving panelists any
   detailed information in advance of the test.
    Samples should be coded, and the order of presentation should
   be balanced among the participants.
   Psychological factors
    Error of Habituation: is a tendency to continue to give the same
   response when a series of slowly increasing or decreasing stimuli
   are presented.
    Habituation is common and can be counteracted by varying the
   types of product
    for example, in quality control from day to day. The panelist may
   be apt to repeat the same scores and hence to miss any developing
   trends, or even to accept an occasional defective sample.
   Psychological factors
    Stimulus Error: This error is caused when irrelevant
   criteria, such as the style or color of the container,
   influence the observer
    Samples served late in a test may be rated more flavorful
   because panelists know that the panel leader will present
   light-flavored samples first to minimize fatigue.
   Psychological factors
    Logical errors: occur when two or more characteristics
   of the samples are associated in the minds of the
   assessors.
    Logical errors must be minimized by keeping the
   samples uniform and by masking differences with the
   aid of colored glasses, colored lights.
    Example, a darker mayonnaise tends to be stale causes
   the observer to modify his verdict
   Psychological factors
    Halo Effect: Simultaneous scoring of various flavor aspects along with
   overall acceptability can produce different results than if each
   characteristic is evaluated separately.
    Example: in a consumer test of orange juice, subjects are asked not
   only to rate their overall liking but also to rate specific attributes.
   Psychological factors
   Order of Presentation of Samples
    Five types of bias may be caused by the order of presentation.
    All of these effects must be minimized by the use of a balanced or
   randomized order of presentation
    Contrast effect
   Presentation of a sample of good quality just before one of poor
   quality
    Group effect
   One good sample presented in a group of poor samples will tend to be
   rated lower than if presented on its own.
   Psychological factors
    Error of central tendency
   Samples placed near the center of a set tend to be preferred over those placed at the ends.
    Time error/positional bias
   One’s attitude undergoes subtle changes over a series of tests, from anticipation or even hunger for
   the first sample, to fatigue or indiffer ence with the last. O
   POOR PHYSICAL CONDITION
   Panelists should be excused session if
    suffer from fever or the common cold in the case of tasters, and if
   they suffer from skin or nervous system disorders in the case of a
   tactile panel
    suffer from poor dental hygiene or gingivitis
    the case of emotional upset or heavy pressure of work that prevents
   them from concentrating
    take any medications that will interfere with their ability to taste or
   smell
    Additionally, aging affects sensory sensitivity, and elderly people can
   be less sensitive to different tastes and smells
   POOR PHYSICAL CONDITION
    Smokers can be good tasters but should refrain from
   smoking for 30–60 min before a panel
    Strong coffee can affect perception for up to an hour
    Taste and smell dysfunctions are associated with chronic
   diseases