Fat and Sugar Substitutes - Sensory Perception of Foods

Question 1

Give three scenarios where sweeteners could be beneficial in a food product.

Answer 1

Excessive caloric consumption along with a sedentary lifestyle are risk factors for obesity and other health problems.

Some sweeteners have been developed to allow consumers to enjoy sweet products without an excessive caloric intake

Some sweeteners are non- or even anti-cariogenic (do not promote tooth decay)

Some sweeteners are acceptable for diabetics based on their glycemic response rating

Question 2

How many types of fat substitutes are there?

Answer 2

Protein based (eg simplesse)

Carbohydrate based (eg maltodextrin)

Fat based (eg olestra)

Question 3

What is simplesse?

Provide possible applications.

Answer 3

Fat substitute based on soy, milk or egg white protein.

The protein is partially coagulated by heat, creating a micro dispersion, in a process known as microparticulation. The spheroidal particles in this dispersion are very small (0.01-3 microns)!

Due to the small particle size of the protein, we perceive the dispersion as a fluid with similar creaminess and richness of fat.

Simplesse is digested as a protein, but due to the micro dispersion formed, produces only 1.0-1.3 Cal/g

Applications include: Ice cream, yogurt, cheese spread, salad dressings, margarine, mayonnaise, coffee creamer, soups and sauces.

Question 4

What is maltodextrin?

Provide possible applications.

Answer 4

Fat substitute derived from carbohydrate sources such as corn, potato, wheat and tapioca.

It produces a smooth mouthfeel and bland flavour

Maltodextrin is fully digestible, yielding 4 Cal/g (whereas fat yields 9!)

Other carbohydrate based fat replacers are available that range from non-digestible to partially digestible (0-2 Cal/g)

Applications include: Margarine, salad dressings, frozen desserts, frostings, processed meat.

Question 5

What is olestra?

Provide possible applications.

Answer 5

Fat substitute made from a sucrose molecule and 6-8 long-chain edible fatty acids forming a sucrose polyester.

Unlike other fat substitutes, Olestra can withstand high temperatures (e.g. frying), and gives the rich taste and creamy texture of characteristic of fat because it is made primarily from fat.

Enzymes that breakdown ordinary fat can not break down Olestra, therefore it passes through the body ‘unchanged’ (Olestra is not metabolized and not absorbed by the human body), contributing to 0 Cal/g.

Products containing Olestra must mention that vitamins A, D, E and K have been added (see below)

Olestra was approved in the U.S.A. in 1996. Currently it is not approved for use in Canada.

Applications include: Salty, savory snacks and crackers

Question 6

What is a sweetener?

Provide examples.

Answer 6

In Canada, Section B.01.001, of the Food and Drug Regulations (FDR), defines sweetener as “any food additive listed as a sweetener in Table IX to B.16.100.”

Examples of sweeteners are: aspartame, sucralose, sorbitol, and maltitol.

Question 7

What is a sweetening agent?

Provide examples.

Answer 7

In contrast, the FDR defines Sweetening agent as “any food for which a standard is provided in Division 18 of the FDR, but does not include those food additives listed in the table to Division 16 [B.01.001]”.

Examples of sweetening agents are: sugar, honey and molasses.

Question 8

Who might sweeteners be preferred or necessary for?

Answer 8

Individuals with diabetes, those concerned with high caloric intake, and consumers trying to reduce the risk of tooth decay (cavities).

Question 9

What are low calorie sweeteners?

Answer 9

Aspartame and sugar alcohols

Question 10

What is aspartame?

Give applications.

Answer 10

A methyl ester of a dipeptide composed of 2 amino acids (phenylalanine and aspartic acid).

It is metabolized as proteins (amino acids), contributing to 4 Cal/g.

Aspartame is 180-220 times sweeter than sucrose, which allows for very small amounts to be used (thus, a low-calorie sweetener).

Aspartame undergoes degradation reactions at high temperatures (can not be used on baked goods), and eventually degrades overtime into DKP (diketopiperazine). A best before date is necessary on products with aspartame.

Applications include: Acidified beverages, desserts, frozen products, breakfast cereals.

Question 11

Who must avoid aspartame?

Answer 11

people suffering from the rare metabolic disorder known as “PKU” (phenylketonuria) must avoid aspartame.

Question 12

What are the sugar alcohols?

Answer 12

maltitol, sorbitol, mannitol, isomalt, xylitol

Question 13

What is sensory evaluation?

Answer 13

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.

Question 14

Where are sugar alcohols found?

Answer 14

Found naturally in a wide variety of fruits and berries, and also commercially produced by hydrogenating sugars.

Question 15

How are sugar alcohols used in food products?

Provide examples.

Answer 15

Mainly used as a “Bulk sweetener” (can be used cup-for-cup [volume-for-volume] in the same amount as sugar).

They are also responsible for the cool-refreshing (menthol-like) sensation perceived from products like chewing gum and toothpaste.

Unlike the other sweeteners, sugar alcohols are less sweet than sugar (e.g. sorbitol is 60% as sweet as sucrose).

Do not promote tooth decay as they are not fermentable by the bacteria in our mouth.

Sugar alcohols also do not increase blood glucose or insulin levels. They are absorbed slowly in the large intestine, thus contributing 1.5-3.0 Cal/g. This ‘slow absorption’ can lead to a laxative effect when excess consumption occurs.

Applications include: Chewing gums, candies, frozen desserts, cookies, cakes, icings and fillings as well as oral care products(including toothpaste and mouthwash).

Question 16

Provide examples of non-caloric sweeteners.

Answer 16

Acesulfame-k

Sucralose

Steviol glycoside

Question 17

What is acesulfame-k?

Provide applications.

Answer 17

A non-caloric sweetener.

Can provide a synergistic sweetening effect when combined with other sweeteners (e.g. used with Aspartame in soft drinks).

It is heat stable. It has a high degree of stability over a wide range of pH and temperature storage conditions.

Acesulfame-K is 200 times sweeter than sucrose and not metabolized by the body (contributes to 0 Cal/g). It is not fermented by oral bacteria, so it does not contribute to the development of cavities

Applications include: Baked goods, candies, canned goods, chewing gum dry foods. Also used in oral hygiene and pharmaceutical products

Question 18

What is sucralose?

Provide examples.

Answer 18

A non-caloric sweetener.

Sucralose is a chlorinated molecule in which 3 hydroxyl groups(OH) of the sucrose molecule are replaced by chlorine. It tastes similar to sugar but it is 600 times sweeter than sucrose. Sucralose is not metabolized by the human body, passing through unchanged (contributes to 0 Cal/g).

Sucralose is heat stable. It retains its sweetness over a wide range of temperature and storage conditions and in solutions over time. It has no effect in carbohydrate metabolism and does not increase blood glucose or insulin levels. It also does not support the growth of oral bacteria (does not promote tooth decay).

Applications include: Canned fruit, fruit drinks, baked goods, chewing gum, tabletop sweeteners, maple syrup, apple sauce.

Question 19

What is steviol glycoside?

Answer 19

Steviol glycoside is derived from the leaves of the South American Stevia plant where it has been used by indigenous people for centuries.

The steviol glycosides are 100-150 times sweeter than sucrose and provide 0 Cal (due to the intense sweetness), and do not increase blood glucose or insulin levels and does not promote tooth decay.

Stevia also remains stable under acidic conditions and high temperature does not destroy its sweetening properties.

Question 20

What are the basic criteria for accepting a food item?

Answer 20

Appearance

Smell

Texture

Flavour

Question 21

What is sensory evaluation of foods widely used in the food industry for?

Answer 21

Sensory evaluation of foods is widely used in the food industry as an important tool for: new product development, product matching, shelf-life studies, product reformulation, quality control, and consumer preference, among others.

Question 22

What is our perception of the appearance of a food governed by?

Answer 22

A number of factors such as size, shape, colour, gloss, consistency, and presence of defects (e.g. mould on an orange; bruises on an apple).

Question 23

Textural parameters are often used in food selection and in food quality measurement. Provide four examples of textural parameters.

Answer 23

Cutting

Compression

Tensile Strength

Shearing

Question 24

When we have a cold, why does food seem bland?

Answer 24

When you have a cold and your sinuses are congested, food often has a bland flavour, basically being a combination of saltiness, sourness, sweetness and bitterness, which are the basic tastes.

Because your sinuses are congested you do not detect odour or only detect a very small amount of odour when consuming the food and thus it appears to be bland.

Question 25

What is flavour?

Answer 25

A sensation made up of a combination of two senses: FLAVOUR = TASTE + AROMA (SMELL).

In order to perceive a full bodied flavour, we need both the perception of TASTE and AROMA.

Question 26

What are the requirements to elicit a taste sensation?

Answer 26

A substance must be water-soluble and it must interact with the appropriate sensory receptors on the tongue.

Taste is detected in the mouth and primarily on the tongue.

Question 27

What are the requirements to elicit aroma?

Answer 27

Substances must be fat soluble and volatile in order for them to interact with the odour or aroma receptors in the olfactory region of our nasal passages.

Question 28

What are aromas?

Answer 28

Aromas of foods are a complex mixture of chemicals, which are often present in foods in very low concentration.

Aroma constituents are a very important part of foods in relation to our perception of food quality.

Question 29

What are the four recognized taste sensations?

What is an honourable mention?

Answer 29

There are four recognized taste sensations: sweet, salty, sour and bitter. Some researchers recognize a fifth taste, called “umami”.

Question 30

What will elicit a sweet sensation?

Answer 30

Simple sugars, especially monosaccharides; the sweetness of oligosaccharides decreases as the number of sugar residues increases.

Some amino acids such as glycine are sweet. Some peptides (composed of two or more amino acids) are sweet; a notable example is Aspartame.

Other sweeteners include the synthetic compounds such as cyclamate and saccharin, which are neither amino acids nor carbohydrates.

There are other compounds such as chloroform and lead acetate, which are sweet but not used as sweeteners!

Question 31

What will produce a salty taste?

Answer 31

Sodium chloride.

Compounds such as potassium chloride, often an ingredient in salt substitutes, produces a salty as well as a bitter taste.

This is one of the reasons why it has been very difficult to formulate a palatable salt substitute for individuals on low sodium diets.

It is not the sodium portion or the chloride portion of sodium chloride that elicits the salty taste. It is the ionized molecule of sodium chloride that it required for the production of a salty taste.

Question 32

Compare flavours of sodium sulphate, calcium chloride, cesium chloride, and sodium chloride.

Answer 32

Sodium sulphate is bitter but only slightly salty while calcium chloride is very bitter and cesium chloride is sweet.

Sodium chloride is salty and not bitter.

Question 33

What produces a sour taste?

Answer 33

Protonated organic and inorganic acids.

Citric, tartaric, malic, lactic, fumaric, acetic and phosphoric acids produce a sour taste and are commonly found naturally in many acidic foods and are also used as acidulants in foods.

The acid taste of vinegar is due to acetic acid. You can probably recall many instances where you use vinegar to impart an acid taste to a food.

Question 34

What compounds will be bitter?

Answer 34

Compounds that are bitter are typically alkaloids such as caffeine (in coffee and tea), theobromine (in chocolate) and solanine (a naturally occurring toxicant in green potatoes).

Some salts such as sodium sulphate and calcium chloride are bitter, as are some amino acids and peptides.

“Bitter peptides” contribute to the sharpness and bitterness of aged Cheddar cheese.

Question 35

What are flavour enhancers?

Answer 35

Flavour enhancers are compounds that elicit no taste of their own at low concentrations, but can modify the perceived intensity or quality of the taste produced by another.

(eg - MSG)

Question 36

What is umami?

Answer 36

Umami is described as a “savoury” and “delicious” sensation, and is associated with compounds known as “Flavour Enhancers or Potentiators”.

Question 37

What does MSG do in a food product?

Answer 37

It apparently binds to the taste receptors in the tongue and causes an enhancement of taste sensations. Other flavour enhancers are the 5’-nucleotides such as inosine 5’-monophosphate, which enhances meaty flavour.

MSG has no effect on the aroma of a food. It enhances meat and vegetable flavours but does not enhance the flavour of acidic foods such as fruit, bakery products or sweet products.

Enhancement of meaty flavours occurs at MSG concentrations below the level where MSG itself produces a typical taste sensation.

MSG suppresses hydrolysed vegetable flavours (bitter) and sulfur or burnt cabbage flavour notes in foods.

Question 38

What is maltol?

Answer 38

A flavour enhancer.

It modifies the flavours of soft drinks, fruit drinks, jams and other high carbohydrate foods.

However, it does not elicit an “umami” (savory) sensation!

Question 39

What is astringency?

Answer 39

A sensation perceived by the mouth/tongue

More of a “physical” sensation described as puckering in the mouth; it is most often attributed to tannins or polyphenols of high molecular weight.

Question 40

What is pungency?

Answer 40

term used to describe the sensation of “spicy heat” in the oral cavity.

A well known example of pungent substances is the capsaicinoid family of molecules, such as capsaicin, found in chili peppers.

Question 41

What is coolness?

Answer 41

In contrast, the sensation of coolness is a familiar one to you if you like to chew gum.

Key compounds responsible for the cooling effect are menthol and its isomers.

Various sugar alcohols such as xylitol and sorbitol also produce a cooling effect.

Question 42

What is sensory evaluation used for?

Answer 42

new product development, product matching, shelf-life studies, product reformulation, quality control, and consumer preference, among others.

Question 43

What are the 3 main types of sensory tests?

Answer 43

Discriminative and Descriptive analyses (both of which are product-oriented and analytical), and the Hedonic/Preference/Acceptability tests (which are people-oriented and considered as “affective”).

Question 44

What is a discrimination test?

Answer 44

Used to determine whether a difference exists between samples.

The difference can be defined or it may not.

These tests would be used to evaluate if a new processing treatment, yeast type or aging treatment has changed the character of the food product.

Panelists’ personal likes and dislikes are not a concern.

Difference tests are the backbone of sensory analyses. They allow the experimenter to document the presence of perceived differences among samples for quality control, product development and/or research and development purposes.

Question 45

What is descriptive analysis?

Answer 45

Requires detection, description and quantization of the sensory aspects of a product.

It is used only with trained panelists.

These trained panelists must be trained for several weeks in order to be able to be “calibrated” and accurately detect, describe and rate the intensity of each attribute (whether it is appearance, aroma, flavour, mouth feel, etc.).

Examples of descriptive analysis tests include: Flavour profile method, quantitative descriptive analysis (QDATM), and free-choice profiling.

Question 46

What is a hedonic preference test?

Answer 46

Also known as consumer tests.

The objective of these tests is to evaluate a personal (subjective) response to a product.

Consumers can give their preference between products, degree of liking of a product, or their overall acceptance of a product.

Preference tests require a large number of panelists (100s to 1000s) in order to represent the target population for the product being tested.

Examples of preference tests include: Paired-preference, ranking and hedonic scales.