Color as a factor on food acceptance

The color of natural foods has evolved first through optimization of plant life to prevailing geographical, geographical and climatologically conditions and second, through co-evolution with insect and animal visual characteristics.

Color plays a key role in establishing consumer acceptability of food. Of the three sensory properties of foods; food scientists tell that color is more important than flavor and texture in the initial food selection process.

In addition, the colors of food contribute significantly to people to enjoy their meals. For this reason it is desirable to maintain as much of the natural color of fresh and processed foods as possible.

However, inappropriately colored foods have a negative effect on acceptance. This is true for foods that have colors normally associative with spoilage (brown meat, green bread, black tomatoes) as well as for impropriate colors not associated with spoilage (blue steak, red peanut butter etc).

Color is a characteristic of a particular food material and is vital to its identification and judgment of quality. The food processer makes every effort to retain good color characteristics of his/her food products because he or she understands the importance of this property in promoting his/her sales.
Color as a factor on food acceptance

Color affecting on flavor

Color is the perception in the brain that results from the detection of light after it has interacted with an object. Color plays a central role in the evaluation of food. It not only influences the senses of taste and smell, but also they acceptability of a food product.

Intensity of color affects flavor perception. Color can have a halo effect that modifies subsequent flavor perceptions.

A stronger color may cause perception of a stronger flavoring in a product, even if the stronger color is simply due to the addition of more food coloring.

Color-flavor association can modulate flavor discrimination abilities even in the case of familiar food products such as sugar-coated chocolates.

In fruit-flavored yoghurts it has been found that, even with the same content for each fruit flavor (such as strawberry, orange and fruit of the forest) and sugar, the greater the concentration of colorant the greater the perceived flavor intensity.

In market research studies it has been determined that 60 percent of acceptance or rejection of a product is based on its color. That decision is also made very quickly. Within 90 seconds, a person will make a choice to accept or reject a purchase.
Color affecting on flavor

Flavor and color of alkaline noodles

Alkaline noodles are made from flour, other ingredients and alkaline salts such as sodium or potassium carbonates and less commonly sodium hydroxide.

Inclusion of alkaline salts in noodle formulas imparts a characteristic aroma and flavor, and a yellow color.

The flavor of the cooked product is typical of an alkaline odor and influences its acceptance to consumers.

The yellow color is associated with naturally occurring flavones in flour, which are colorless at acidic pH but turn yellow at the high pH of alkaline noodles.

The desired characteristics are a bright, light yellow appearance; free of any darkening or discoloration; a firm clean bite; a chewy and elastic texture with some degree of springiness; and a satisfactory al dente reaction of biting.
Flavor and color of alkaline noodles

Caramel as food additive

Caramel is a complex mixture of brown flavoring/coloring substances produced when sugars are heated above their melting point during caramelization. During heating, the compounds breakdown and reassemble to form hundreds of different molecules that add flavor and aroma to foods.

Caramel is also used in flavorings and flavor enhancers for a wide range of foods, including caramels, cakes, and biscuits.

There are four classes of caramel used as food additives and they are defined by the reactant added to the carbohydrate during production.
*Plain caramel
*Caustic caramel
*Ammonia caramel
*Sulfite ammonia caramel

Caramel colorant must be compatible with food products in which they are used, which usually means the absence of flocculation and precipitation in the food.

Caramel is made up from the following food-grade carbohydrate: dextrose, invert sugar, lactose, malt syrup, molasses, starch hydrolysates, and fraction thereof and sucrose, by carefully controlled heat treatment. A large amount of commercial caramel is produced from liquid corn syrup or glucose syrup.

Caramel coloring is freely soluble in water and insoluble in most organic solvents. In concentrated form the colorant has a distinctive burned taste that is unnoticeable at the typical levels of use.

Caramel colors are the most widely used food coloring agents, contributing about 90% by weight of the total coloring agents supplied in the UK food industry. World-wide 80% has been quoted.

Caramelization is done in the industry with different catalysts to produce either flavor or color.

For flavor purposes, sucrose is caramelized in concentrated syrup. The caramel aroma is mainly due to a group of cyclic alkylenolones, dihydrofuranones, and pyrones.
Caramel as food additive

Protein as a color in food

The role of protein in color of foods is not clear cut. In most instances it may either play a role through its interaction or as part of a complex molecules.

The brown color produced during the heating of many different foods comes, in part, from the Maillard reaction.

Maillard Reaction is a browning reaction between an amino group and a reducing group of a carbohydrate.

This reaction contributes to the golden crust of baked products, the browning of meats and the dark color of roasted coffee.

Proteins are directly involved in the color of the protein happens to be a pigment. Selected color pigments, such as chlorophyll are bound in the chloroplasts in a protein lipid matrix.

The meat turn grayish brown during cooking when protein holding the pigment becomes denatured. While milk appears white as light reflects odd the colloidal dispersion of milk protein.

The color of raw salmon flesh is a translucent deep pink red, which on smoking turns a more opaque light pink, as the conformation of the protein changes during processing light scattering within the fish increases.

The visible light range is only a small portion of the electromagnetic energy spectrum which ranges from wavelengths of 60 m for radio waves to 0.0001 nm for gamma waves.

Protein as a color in food

Color of Food

Color of Food
Color is important to many food, both those that are unprocessed and those that are manufactured.

Together with flavor and texture, color plays an important role in food acceptability.

In addition, color may provide an indication of chemical changes in a food, such as browning and caramelization.

For a few clear liquid foods, such as oils and beverages, color is mainly a matter of transmission of light.

Other foods are opaque - they derive their color mostly from reflection.

Some hues occur frequently in foods provided by nature. Green, red, pink, orange, yellow and purple are common. Blue green is rare and no blues exist at all.

It is instructive to consider the fundamental natural rules governing the colors of the world around us and the food we eat.

Color is the general name for all sensations arising from the activity of the retina of the eye. When light reaches the retina, the eye’s neural mechanism responds, signaling color among other things.

Light is the radiant energy in t wavelength range of about 400 to 800 nm. According to this definition color cannot be studied without considering the human sensory system.

The color perceived when the eye views an illuminated object is related to the following three factors: the spectral composition of the light source, the chemical and physical characteristics of the object and the spectral sensitivity properties of the eye.

To evaluate the properties of the object we must standardize the other two factors. Fortunately, the characteristics of different people’s eyes for viewing colors are fairly uniform; it is not too difficult to replace the eye by some instrumental sensor or photocell that can provide consistent results.

There are several systems of color classification; the most important is the CIE system (Commission International de I’Eclairage –International Commission on Illumination. Other systems used to describe food color are the Munsell, Hunter and Lovibond systems.

Added colorants in foods dates from at least 3,700 BC when Egyptians were coloring their candy.

Sugar imported into Europe from Alexandra in the twelfth century was colored with madder and kermes, but the use of cochineal probably predates this.

Awareness of browning would have predated the use of color additives. For an extended shelf life in fresh fruits and vegetables, enzymatic browning must be eliminated.

Foods depending on enzymatic browning for their quality include black tea, dates, prunes and raisin, Non enzymatic browning provides many of the flavors of baking and cooking.
Color of Food