Sensory evaluation of foodSensory evaluation of food

Introduction to sensory

evaluationevaluation

At the end of this chapter, you will be able

to:

Understand the definition of sensory.

Sensory evaluation in product development.

Sensory evaluation in food industry. Sensory evaluation in food industry.

A Physiological and Psychological

Perspective

WHAT IS SENSORY EVALUATION?

Sensory evaluation is a scientific discipline used to

evoke, measure, analyze and interpret reactions to

those characteristics of foods and materials as they

are perceived by the senses of sight, smell, taste,

touch and hearing.

Eating quality parameters

We, as consumers, eat only that food which is palatable and

enjoyable.

Palatability

The quality of food should be appealing and appetizing and we

crave for more.

Other quality parameters, such as nutrition and wholesomeness are secondary.

For the consumers the eating quality attributes are:

aroma, taste, aftertaste, tactual properties and appearance are

the deciding factors in food acceptance.

Thus quality is that which the consumer likes bestand the grades of

quality are understood more by the degree of desirable attributes and

absence of undesirable characteristics.

The importance of sensory evaluation

1. Determination of consumer preferences

Todays consumers are discerning, demanding, and

more knowledgeable about food and expect products

which are safe, good value, and of high sensory

quality. Therefore, knowing consumers preferences

and perceptions of the sensory characteristics of and perceptions of the sensory characteristics of

food/drink products is very important to food

manufacturers and retailers alike (FIF, 2005).

2. Market testing of new or modified productsUnderstand how their product performs against competitors

products in relation to consumer perceptions and/or sensory

characteristics;

Determine whether or not consumers can detect differences

between products, e.g., me too products, or changes in the between products, e.g., me too products, or changes in the

product due to recipe modifications

Sensory evaluation helps customers to reduce risks, improve their

products consumer appeal and enhance quality of outcomes.

3. Assisting with product development

According to a survey more than 90%of the new

products developed result into failure mainly because

of poor sensory attributes and rejection by the

consumers.

The adoption of appropriate sensory methods during The adoption of appropriate sensory methods during

new product development is thus inevitable.

4. Quality control The modern day concept of Total-Quality-Control (TQM)

involves sensory evaluation at all stages of product flow.

This includes, not only the sensory quality of raw material,but

also quality of product during processing and storage.

The changes in product quality in terms of colour, flavour and

texture during processing and storage has to be regularly

monitored using sensory techniques.

5. Selection of Packaging Material:

Now the consumers have become very quality conscious and

prefer to buy properly packaged processed food.

This has resulted into development of various types of packaging

materials for food applications.

The suitability of these films for packaging a particular dairy The suitability of these films for packaging a particular dairy

product in respect of containment of product, its non-

reactiveness with food ingredients and compatibility to storage

conditions has to be examined adopting sensory analysis along

with some chemical/ instrumental method.

6. Cost Reduction In addition to eating quality of a dairy product, the

cost is also an important consideration for selection of the

product by consumers.

Hence, dairy product manufacturers always try to reduce

the cost by either using low cost ingredients or adopting

good management skills.

The use of low cost or alterative ingredients may The use of low cost or alterative ingredients may

adversely influence the sensory characteristics of the

product and may not find good acceptability.

The sensory evaluation of product during these

modifications is, therefore, highly advantageous.

7. Shelf Life Studies

Dairy products during storage undergo many types of

changes, for example, chemical, bacterial, enzymatic, physical,

etc.

All these alter the sensory properties, such as taste, colour,

flavour, texture and appearance.

Application of sensory evaluation not only monitors these Application of sensory evaluation not only monitors these

changes but also determine the nature and extent of the

defects in dairy product during storage so that corrective

measures can be adopted.

The expiry date has to be determined by using chemical and

sensory techniques together.

8.Establishing Analytical/ Instrumental/

Sensory Relationships

Such relationships are highly useful for quick evaluation of the product

quality and for designing new equipment for product manufacturing.

Some relationships between sensory properties of milk and dairy products

with that of analytical or instrumental techniques have already been

established.

For example,

the titratable acidity of fresh milk ranges between 0.14 to 0.16%, and at

0.17% and above it may impart sour flavour.

the free fatty acid (as oleic acid) in ghee of good quality (no rancidity)

should be less than 2.8%.

Relationship between sensory textural attributes, hardness, stickiness,

chewiness, gumminess and elasticity/ sponginess with that measured by an

instrument can also be established. (For example : Texture Analyzer)

Role of Sensory evaluation in product

development.

Sensory evaluation techniques are mostly quantitative in

design and can be used to:

1. test concepts and -prototypes,

2. compare competitive products,

3. determine the effects of ingredient substitution, -3. determine the effects of ingredient substitution, -

process changes and -shelf life on prototypes and

existing products.

Qualitative tests (such as focus groups and brainstorming) can

also be used to:

1. generate descriptive terminology,

2. address the validity of questionnaires,

3. indicate what would make a product different or special,

4. understand what would make consumers buy the product, 4. understand what would make consumers buy the product,

and

5. provide greater insight into evaluation results and consumer

opinion.

Additional info;

Sensory analysis is increasingly becoming

an integral part of the product

development process.

If a product does not taste good,

consumers will not make repeat consumers will not make repeat

purchases.

Sensory evaluation in food

industry.

Nowadays, sensory evaluation becomes a tool irreplaceable in food industry while interacting with the key sectors in food production (Fig. 1).

When a consumer buys a food product, they can buy nutrition, convenience, and image. Nevertheless, most nutrition, convenience, and image. Nevertheless, most importantly consumers are buying sensory properties/performance and sensory consistency.

Therefore, sensory evaluation should be an integral part in defining and controlling product quality.

As a way to reduce risk and uncertainly in

decision making.

When a product development manager asks

for a sensory test, it is usually because

there is some uncertainly about exactly there is some uncertainly about exactly

how people perceive the product.

.

Fig. 1: Sensory evaluation in relation with different sectors of food production

A Physiological and Psychological

Perspective

From study of the physiology and anatomy

of the systems, each sense modality has

its own unique receptors and neural

pathways to higher and more complex

structures in the brain.structures in the brain.

products are a complex source of

stimulation and that stimulation will not be

exclusive to a single sense, such as vision

or taste.

Consider an evaluation of a strawberry jam

that has visual, aroma, taste, and textural

properties. Requiring subjects to respond only

to textural attributes (and ignore all other

stimuli) will lead to partial or misinformation

about the products, at best. Whyyy????about the products, at best. Whyyy????

Response to all other stimuli will be embedded in

the textural responses which, in turn, leads to

increased variability and decreased sensitivity.

BASIC PRINCIPLES OF SENSORY

EVALUATIION