Food quality: Color

People accept food on the basis of certain characteristics that they define and perceive with their senses.

Food color has been usually related to the product quality and influences the perception of other attributes such as flavor, sweetness and saltiness. Food color is governed by the chemical, biochemical, microbial and physical changes which occur during growth, maturation, postharvest handling and processing.

Color is the first characteristic that consumers rely on when making food choices, and even the slightest changes can deter a potential buyer and alter the consumer’s perception of product quality.

Color changes are accompanied by undesirable changes in texture, taste, or odor. Overage cheese, beer, meat, and fish all develop off-color, which the consumer recognizes as being associated with poor flavor quality.

Color is one of the most important quality components of fresh fruit and vegetables. Fruit ripening is a complex, genetically programmed process that culminates in dramatic changes in texture, color, flavor and aroma.
Food quality: Color

Food quality: Food appearances

Many experts suggest that investigated consumers most frequently use freshness, taste, and appearance to evaluate food quality. The first impression of a food is usually visual, and a major part of customer willingness to accept a food depends on its appearance.

Appearance of the products including appearance, color, size, and shape. Appearance is determined by physical factors including the size, the shape, the wholeness, the presence of defects (blemishes, bruises, spots, etc.), finish or gloss, and consistency. Size and shape may be influenced by cultivar, maturity, production inputs, and the growing environment.

The most important attribute of any food's appearance is its color, especially when it is directly associated with other food-quality attributes, for example the changes that take place during the ripening of fruit or the loss in color quality as food spoils or becomes stale.

An important problem is discoloration or the fading of the colors of various raw and processed fruits and vegetables. In some cases, color changes are accompanied by undesirable changes in texture, taste, or odor. Overaged cheese, beer, meat, and fish all develop off-color, which the consumer recognizes as being associated with poor flavor quality.

Color plays an essential role in food appearance and acceptability. Synthetic or artificial colors, i.e., coloring agents that are not nature-identical and have been obtained by chemical synthesis, are routinely added to food products to impart desirable sensory characteristics.

Color is derived from the natural pigments in fruits and vegetables, many of which change as the plant proceeds through maturation and ripening. The primary pigments imparting color quality are the fat-soluble chlorophylls (green) and carotenoids (yellow, orange, and red) and the water-soluble anthocyanins (red, blue), flavonoids (yellow), and betalains (red).
Food quality: Food appearances

The appearance of food spoilage

During storage and distribution, foods are exposed to a wide range of environmental conditions. Food spoilage occurs when products develop undesirable odors, flavors and appearances due to microbial growth.

Quite often, the evidence of microbial growth is easily visible as in the case of slime formation, cotton-like network of mold growth, iridescence greening in cold cuts and in cooked sausage, and even discrete large colonies of bacteria. Food spoilage also produces undesirable aromas and color defects.  

In liquid such as juice, microbial spoilage is often manifest by the development a cloudy appearance or curd formation.

Spoiled food, such as moldy bread, soured milk or bad fish may not cause any harm or illness if consumed.

On the other hand, if food is contaminated with pathogenic bacteria then a potentially dangerous food poisoning may occur.
The appearance of food spoilage 

Food appearance related to quality

Consumers are interested in many aspects related to the quality of food, such as appearance, freshness, taste, nutritional value and food safety.

The appearance of a food includes its size, shape, color, structure, transparency or turbidity, dullness or gloss and degree of wholesomeness or damage. Appearance includes all visible attributes and derives from the interactions between a substance or object and its environment as perceived by the human observer.

While selecting a food and judging its quality, a consumer takes these factors into account as they are indeed an index of quality.

Surface characteristics of food products contribute to the appearance. Appearance often has become the customer’s only consideration when evaluating the quality of meat.  Consumers look for color and fluid retaining characteristics in the hope that these will indicate the potential eating quality.

The most important qualities for meat appear to be color, freshness, visible fat price and presentation. Quality perception increases with attractive appearance and freshness and decreases with amounts of visible fat.

Appearance combines the visual information contained in reflected, transmitted and scattered light, and the color of that light.

The color of a fruit indicates how ripe it is, and color is also an indication of strength as in tea or coffee, degree of cooking, freshness or spoilage.

Interior appearance can also be evaluated. Lumps in a pudding or gravy which are not desirable can be judge by the eye.
Food appearance related to quality

Perception of quality: Appearance

Perception of quality: Appearance
In one survey of consumer attitudes towards fresh fruits and vegetables, 96% of the respondents cited ripeness and freshness as important selections criteria, while an equal percentage cited “taste”. In addition, 94% indicate d the importance of appearance and conditions, while 66% used nutritive value and 63% used price as a guide. Two factors enters into the purchase decision of fresh produce

1. Competition of different items on display shelf.

2. The acceptability of particular items in reference to a consumer’s standard for that item.

“Taste” nutritive value and expected price level provide differentiation between items. Freshness/ripeness, appearance/condition, and current price are more likely to be factors in evaluating specific items against the standards at the point of purchase.

Appearance factors include size, shape, gloss, color, and absence of defects. Crop production, harvesting and handling conditions affect general product appearance. For many items, a premium is paced on size, with the greater size commanding a higher prize per pound, but oversize items may be associated with objectionable traits such as being too tough, overripe, or inconvenient to handle.

Visual defects may be caused by insects damage, disease of the plant prior to harvest or of the detached organ after harvest, damaged incurred by adverse weather conditions, physiological disorders due to inadequate plant nutrition or improper handling, and mechanical damage incurred during harvesting or handling, resulting in bruising or breaking of the protective peel and rind. When given a choice, most consumers appear to prefer a predictable uniformity in their produce and an absence of defects.
Perception of quality: Appearance