The effect of food additives on sensory value of food

Food additives preserve the freshness and appeal of food between the times it is manufactured and when it finally reaches the market. Additives may also improve nutritional value of foods and improve their taste, texture, consistency or color.

Color, odor, taste and consistency or texture, which are important for the sensory value of food, may decreases during processing and storage. Such decreases can be corrected or readjusted by additives such as pigment aroma compounds or flavor enhancers.

When the food is to be stored for a prolonged period, use of additives and preservatives is essential in order to maintain its quality and flavor. Development of “off flavor” for instance, derived from fat or oil oxidation, can be suppressed by antioxidants. Food texture can be stabilized by adding minerals or polysaccharides, and by many other means.

A flavour additive is a single chemical or blend of chemicals of natural or synthetic origin that provides all or part of the flavour impact of a particular food. These chemicals are added in order to replace flavour lost in processing and to develop new products. Flavourings are the largest group of food additives, with more than 1,200 compounds available for commercial use.

Some artificial colors are also added to the foods to give them an appealing look. These coloring substances are erythrosine (red), cantaxanthin (orange), amaranth (Azoic red), tartrazine (Azoic yellow) and annatto bixine (yellow orange). Colorants are often necessary to produce a uniform product from raw materials that vary in colour intensity. Colorants used as food additives are classified as natural or synthetic.

Additives and preservatives maintain the quality and consistency of the foods. They also maintain palatability and wholesomeness of the food, improve or maintain its nutritional value, control appropriate pH, provide leavening and color, and enhance its flavor.
The effect of food additives on sensory value of food

Effect of canning on vegetables

From the textural standpoint, vegetables may be divided into those that are eaten raw and valued primarily for their crispness, those that are eaten cooked and valued for their softness and those that can be consumed in either form such as cauliflower and carrots.

Vegetables like peas, beans, greens are sometimes canned. The retention of original color is of great importance effecting the marketability and consumer response.

In the process of canning, vegetables are heated to destroy spoilage disease causing microorganisms.

Such heat treatments also produce a number of of undesirable chemical and textural changes in the vegetables. The textural changes are due to partial destruction of the cell wall and cell membrane.

Blanching, plus the strong heat treatments applied to nonacid vegetables, appears to be responsible for the large vitamin losses in canning.

Heat treatments also cause chemical alteration of the green pigment chlorophyll, thus resulting in a processed vegetable with less green color.

During canning chlorophyll gets converted to pheophytin due to the high temperature used. Sometimes to retain the color and to neutralize the acid, alkali is added.
Effect of canning on vegetables

Effects of microorganisms on food

Foods undergo deterioration to varying degrees in organoleptic properties, nutritional value, safety and esthetical appeal.  The term food deteriorations, is often associated with advanced spoilage.

Bacteria, molds and yeasts are the main causes of the spoilages of unpreserved foods, with bacteria playing the major role in the spoilage of meats, poultry, dairy, and fish products.

Mold and yeast play the major role in the spoilage of fruits and vegetables. The changes in foods due to microbial action can be classified into two types: undesirable changes and desirable changes.

These microorganisms do not cause disease but they spoil food by growing in the food and producing substances which alter the color, texture and odor of the food, making it unfit for human consumption.

All bacteria associated with foods are small. Most are of the order of one to a few micrometers in length and somewhat smaller than this in diameter. All bacteria can penetrate the smallest openings; many can pass through the natural pores of an egg shell once the natural bloom of the shell is worn.

Yeasts are somewhat larger, of the order of 20 um or so in individual cell length and about a third this size in diameter.

Typically, the effects of temperature, pH, and the acidulants, water activity and the humectants, oxygen availability, redox potential and identity and concentration of inhibitory agents are among the variables that must be considered when assessing whether microorganisms will pose a problem in particular food system.
Effects of microorganisms on food

Salt and health effects

Salt has been used as a preservative for thousands of years. By killing bacteria life in a food, salt is able to slow the natural decomposition of that food. However today, with refrigeration, freezer and canning technology, there really is no reason anymore for adding salt to food for preservation.

But large amount of salt are still commonly added.

Salt also draws water from the bloodstream, causing the body to experience excessive thirst.

Studies on human populations around the world showed evidence that eating too much salt is connected with high blood pressure. In countries where peop0le eat a lot of salt there is high blood pressure, and where they do not eat a lot of salt high blood pressure is not a problem.

According to the Committee on Diet and Health, diets containing more than 6 g of salt per day are associated with elevated blood pressure.

There is also evidence that salt is problematic in ‘salt sensitive’ people even in the absence of high blood pressure. They risk of dying from cardiovascular problems.

A high salt intake is associated with atrophic gastritis in epidemiologic and animal studies and there is also epidemiologic evidence that a high salt intake and frequent consumption of salt-cured and salt-pickled foods is associated with an elevated incidence of gastric cancer.
Salt and health effects