IRRADIATION AS A MEANS OF PRESERVATION IN THE FOOD INDUSTRY

IRRADIATION AS A MEANS OF PRESERVATION IN THE FOOD INDUSTRY

CHAPTER ONE

1.1INTRODUCTION

Food irradiation is the process of exposing food to ionizing radiation in order to disinfect, sanitize, sterilize, preserve food, or provide insect control. (wikipedia.org)

To emphasize the process’s similarity to pasteurization, food irradiation is sometimes referred to as cold pasteurization or electronic pasteurization. Ionizing radiation, like pasteurization of milk and pressure cooking of canned foods, can kill bacteria and parasites that would otherwise cause food borne diseases. (www.cdc.gov; wikipedia.org)

Depending on the dose, irradiating food kills some or all of the microbes, fungi, viruses, or insects present. In cases where microbial spoilage is the limiting factor in shelf life, this extends the life of the food. Some foods (for example, herbs and spices) have been irradiated at such high doses (5kGy).

that they show microbial counts reduced by several orders of magnitude. It has also been demonstrated that irradiation can postpone the ripening or sprouting of fruits and vegetables, thereby eliminating the need for pesticides.

According to studies, when Irradiation is used as approved on foods:

Germs responsible for disease are reduced or eliminated.

It is not possible for food to become radioactive.

Food does not contain any dangerous substances.

The nutritional value of the food has remained essentially unchanged. (www.cdc.gov)

Radurization, Radicidation, and Radappertization are three types of radiation treatments used in the food industry. However, three different irradiation technologies are used in the actual process of irradiation: gamma irradiation, electron-beam irradiation, and x-ray radiation. (www.cdc.gov)

Irradiation dose is typically measured in a unit known as

The Gray, shortened (Gy). This is a measurement of the amount of energy transferred to the irradiated food, microbes, or other substances. Photographic film is exposed to irradiation at the same time to measure the amount of irradiation something is exposed to.

D-values are used to quantify the killing effect of irradiation on microbes. One D-value represents the amount of irradiation required to kill 90% of that organism. For example, 0.3 kGy is required to kill 90% of Escherichia coli, so E.coli’s D-value is 0.3 kGy. (www.cdc.gov).

To identify irradiated products on food packaging, a distinctive logo has been developed. This symbol, known as the “radura,” is used internationally to indicate that the food in the package has been cooked.

irradiated. (www.cdc.gov) (www.cdc.gov)

1.2DEVELOPMENTS IN FOOD IRRADIATION

The gap between population growth and food production is widening in Africa, Asia, and Latin America’s less developed countries (LDCs). Nonetheless, in LDCs, more than a quarter of harvested food is lost due to waste and spoilage. In Nigeria, very high food losses occur during the time lag between harvest and consumption, as well as during storage, especially for highly perishable foods such as fish, fruits, vegetables, and some dietary staples such as yam, maize, millet, and sorghum. As a result, these countries must make better use of the available appropriate food preservation technologies (Aworh, 1986).

Food irradiation is a new technology that has emerged in the last three decades that has the potential to revolutionize the food industry.

reducing food waste in LDCs (Aworh, 1986).

Food irradiation research dates back to the turn of the twentieth century. In 1905, the first US and British patents for using ionizing radiation to kill bacteria in foods were issued. Food irradiation gained traction in 1947, when researchers discovered that high-energy sterilization of meat and other foods had the potential to preserve food for military troops in the field. In the early 1950s, the United States Army began a series of experiments with fruits, vegetables, dairy products, fish, and meat to determine the safety and effectiveness of the irradiation process. (www.ccr.uc davis.edu).

Under the Food Irradiation Act of 1958, Congress delegated authority over the food irradiation process to the FDA.

The Food, Drug, and Cosmetic Act was amended in 1958 to include food additives. Wheat, potatoes, pork, spices, poultry, fruits, vegetables, and red meat have all been approved for food irradiation by the FDA (www.ccr.uc davis.edu).

The United Nations recognized food irradiation and established the Joint Expert Committee on Food Irradiation. Their first meeting took place in 1964. The committee concluded in 1980 that “irradiation of foods up to the dose of 10kGy introduces no special nutritional or microbiological problems”. (www.ccr.uc davis.edu).

The World Health Organization determined in 1999 that the dose limitation at very high doses is palatability, among other things. Irradiation should be treated similarly to cooking in terms of safety. (www.ccr.uc davis.edu).

In the last few decades, enormous progress has been made in the design and construction of Radiation accidents are now extremely unlikely, provided that personnel have been properly trained in the operation of radiation facilities (Aworh, 1986).