FOOD SAFETY AND PRESERVATION
National center for home food preservation website at http://nchfp.Uga.Edu/site includes science-based information on home food preservation, publications and links to other extension sites. The center was established with funding from the cooperative state research, education and extension service, u. S. Department of agriculture (csrees-usda) to address food safety concerns for those who.
About us the national center for home food preservation is your source for current research-based recommendations for most methods of home food preservation. The center was established with funding from the cooperative state research, education and extension service, u. S. Department of agriculture (csrees-usda) to address food safety concerns for those who practice and teach home food preservation and processing methods. Read more.
The uc master food preserver mission statement is “to teach research-based practices of safe home food preservation to the residents of california. “this website is devoted to sharing information about food safety and safe ways to preserve food at home. It provides links to many of the other related resources available to you. If you cannot find what you’re looking for on this website, use our mfpoc helpline to contact the ucce master food preservers of orange county.
Food preservation is one of the most important inseparable parts of human life. Historically people would build their own root cellars to preserve their food. To increase the shelf-life of the food products, application of various methods such as drying, storage in vinegar under acidic condition, canning, freezing, fermenting, dry salting, curing, smoking, and sealing have been suggested. Although the traditional methods of food preservation guarantee its safety, application of these methods in food systems promotes the loss of temperature sensitive compounds, denaturation of proteins, alteration of food structures, change of color and taste of the products, and formation of new undesirable substances. Thus today there is a growing interest in using nonthermal processing methods for preservation of food products.
Some of the future methods of food preservation are irradiation and chemical additives. Although these methods are currently in use, they are expected to expand and develop further. Irradiation of food is the process of exposing food to ionizing radiation. This process can alter the bacteria, microorganism or virus’ dna, without harming the food. Irradiation is attractive because of its selective targeting. It is already used on non-food items. “the molecular bonds in the microbial dna are the main targets of the irradiation, but dna and rna synthesis, denaturation of enzymes and cell membrane alterations may also be affected”(1). The process of irradiation opens the possibility to process a large number of foods in great quantities, however it can be expensive. The buildings for such a process require specific infrastructure and construction that is both expensive and time consuming. “the food and agriculture organization (fao), the international atomic energy agency (iaea), and world health organization (who) concluded in their report, that any food irradiated up to a maximum dose of 10 kgy is considered safe and wholesome”(1). Essentially three things were concluded in their report: 1. It won’t lead to toxicological changes in the food that will negatively affect our health, 2. The technology won’t increase the microbial risk of the consumer, and 3. Irradiation won’t lead to nutritional losses. However, most consumers are still radiation-phobic despite these positive results. They aren’t willing to buy something that has, in their mind, been radiated and burned to safety.
Food preservation has been practiced for centuries, with salting generally recognized as the earliest form of preservation. Several intrinsic and extrinsic factors associated with foods serve to promote preservation, the most important of which include: water activity (aw), temperature (low or high), preservatives (i. E. , nitrite), acidity (ph), competitive microorganisms (i. E. , lactic acid bacteria), and redox potential (eh). These extrinsic and intrinsic factors are limited when applied singly. However, when combined with one another in a sequence or applied simultaneously, the activity of each is considerably enhanced. This effect is likened to a series of hurdles that become increasingly harder to overcome the more hurdles that are utilized. The result is synergistic food preservation referred to as a hurdle effect. To fully understand the effects of these hurdles on microbial populations, extensive research has focused on defining the critical limits for growth, survival, and death of the most significant microorganisms associated with the food supply. This information has provided a foundation for designing effective food preservation strategies. Thus, the term hurdle technology represents the intentional combination of hurdles, without necessarily listing them, at independently sublethal levels to preserve novel and traditional foods. Hurdles can be strategically combined such that it is possible for a food to become increasingly economical, have improved microbial safety and stability, as well as enhanced nutritional and sensory characteristics. The overall goal is for the hurdles to control the naturally occurring microbial population by either inhibiting growth or inactivating the microorganisms.
A Note On Food Safety
Food preservation, volume six, the latest in the nanotechnology in the agri-food industry series, discusses how nanotechnology can improve and control the growth of pathogenic and spoilage compounds to improve food safety and quality. The book includes research information on nanovesicles, nanospheres, metallic nanoparticles, nanofibers, and nanotubes, and how they are capable of trapping bioactive substances to increase and maintain the stability of compounds often sensitive under typical food processing and storage conditions. This book will be useful to a wide audience of food science research professionals and professors and students doing research in the field.
Describes the effective utilization of nanostructured antimicrobials in toxicological studies and real food systems offers research strategies for understanding opportunities in antimicrobial nanostructures and the potential challenges of their toxicity presents diverse applications of nanostructured antimicrobials in food preservation covers the potential benefits of nanotechnology and methods of risk assessment that ensure food safety.
Food Safety & Processing
In the united states, as elsewhere, the food and drug administration requires thermal processing to be carried out under what is known as good manufacturing practices (gmps) to help assure food safety and wholesomeness. Among these gmps are specific regulations pertaining to low-acid canned foods (foods that are thermally processed, have ph values greater than 4. 6 and water activity greater than 0. 85, are packaged in hermetically sealed container, and are not stored under refrigeration).
Food preservation techniques have relied heavily on heat in diverse forms and levels to destroy microorganisms and extend shelf life. The inactivation of the pathogenic and spoilage microorganisms present in foods is the main purpose of food preservation. Heat-processing technologies are quite efficient in controlling microbial growth in different foodstuffs, but they also can affect their biochemical composition, causing damage in some of their sensory and nutritive attributes. With increasing demand by consumers to obtain processed foods with better attributes than have been available to date, food researchers have pursued the discovery and development of improved preservation processes with minimal impact on fresh taste, texture, and nutritional value of food products. Both improved heating and nonthermal processing technologies have been investigated for their effects on food freshness, nutrition, and safety. Over recent years, several technologies have been the object of rapid developments in scientific understanding as well as equipment design. These efforts have helped to eliminate many of the barriers to commercial applications of novel or nonconventional food preservation techniques.
Food preservation and the insurance of microbiological safety are based firstly on the delay or prevention of microbial growth and must therefore operate through those factors that most effectively influence the growth and survival of microorganisms. These include a number of physical factors, some predominantly chemical ones, and some that are essentially biological. These factors have been categorized in a number of ways, but the most widely quoted are those of icmsf (1980), mossel (1983) and huis in’t veld (1996). These identify ‘intrinsic factors’, ‘processing factors’, ‘extrinsic factors’ and ‘implicit factors’ and, additionally, ‘net effects’ that take into account the fact that many of the other factors strongly influence the effects of each other, so that the overall influence of combinations of factors may not be obviously predictable, but may be derived from modern predictive modelling studies (mcmeekin et al. , 1993; mcclure et al. , 1994; mcmeekin and ross, 1996), and may be of greater efficacy than the perceived effects of single factors would lead one to expect.
Fda has issued a number of regulations for low-acid foods. Additional regulations for acidified foods have also been released. The primary purpose of these regulations is to describe safe procedures for manufacturing, processing, and packing of foods that could otherwise support the growth of and toxin production by clostridium botulinum. The safety of low-acid and acidified foods is further ensured through the emergency permit control regulations, which require manufacturers to register their processing plants and file their processes with the fda. These regulations also require firms to adhere to their filed and approved processes, to maintain detailed records, and to make these records available to authorized fda personnel. Since differences in processing equipment, operating conditions, container type or size, kind of food, and food form constitute different processes, presently over 100,000 processes have been filled with the fda under these regulations.
Heat processing of foods is designed to result in a specific reduction in numbers of foodborne pathogens or elimination of food spoilage organisms in the target product, thus ensuring microbiological safety and increased shelf life. Microbial heat resistance is described via d- and z-values; d-value equates to the heating time required at a specific temperature to destroy 90 per cent of the viable cells or spores of a specified organism. The z-value represents the change in temperature needed to change the d-value by 1 log cycle, thereby giving an indication of the relative heat resistance of an organism. Increasing heating temperatures will reduce the time required at that temperature to achieve the required lethal effect. Typical d-values for salmonella spp are one to 10 minutes at 60°c, and 0. 1-0. 2 minutes for c. Botulinum spores at 121°c.
Whether canning, freezing or dehydrating — preserving foods at home is a great way to use up produce, build food storage and even launch a business. Msu extension can help you learn how to be safe by following research-based recipes and processing methods. Newsletter sign-up ask an expert preserving food at home may be a practice that goes back for generations, but it is critical for anyone preserving and processing foods to have the most reliable and current information available about food safety and quality. Michigan state university extension is a trusted source for research-based information and education on proper canning methods and approved recipes.