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At least 19 recordsLinked to original sources
PubMedDate not supplied

Safety aspects of food preservatives.

The use of food preservatives, such as benzoic acid, nitrites, and sulphites, as antimicrobials, and butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), ascorbic acid and tocopherols, as antioxidants, has probably changed food production patterns and eating habits more than has the use of any other class of food additive. These food preservative chemicals confer substantial benefits on man, not only by the preservation and increased palatability of food, but also by affording protection against the pathological effects of reactive oxygen species (ROS) which are associated with cancer, cardiovascular disease and aging. Nevertheless, although most preservatives are now considered to be without potential adverse effects and are classified as GRAS, there have been problems concerning the safety of some of these chemicals, including the possibility of allergies from benzoic acid and sulphites, the formation of carcinogenic nitrosamines from nitrites, and the possible rodent carcinogenicity of BHA and BHT. The mechanisms of this toxicity at high dosage, the roles of the cytochromes P450, and the generation and scavenging of ROS in the toxicity of these chemicals, are reviewed and discussed.

Animals↗
PubMedDate not supplied

Nutritional aspects of food preservatives.

Despite the benefits attributed to food preservatives, some concern still remains regarding their safety and possible influence on nutrients. Surprisingly, there is quite a lack of scientific knowledge in this field. In order to describe a few examples, the effects of the extensively used sulphite on thiamine, folates, pyridoxal and other nutrients have been reported. Among its antibrowning effects, inhibition of ascorbic acid browning is also considered. As far as sorbic acid is concerned, notwithstanding its easy reaction with protein, probably the acid environment of the stomach determines the breakdown of the sorbic-protein adducts. Detoxication of nitrite by tocopherol and ascorbic acid leads, in the last case, to dehydroascorbic acid and its oxidative products with loss of vitamin activity. Any oxidizing substance destroys ascorbic acid, vitamin E and free vitamin A. Phosphates are largely used with different aims, including preservation, in food processing. Their antimicrobial activity is due to both a direct effect and an interaction with other antimicrobials. Sequestering capacity of phosphates and its nutritional implications are discussed. Also mechanisms of action of organic acids are reported, focusing on sorbic acid effects on single amino acids and proteins. Finally, the little information available about the potential impact of food preservatives on nutritional functions is presented.

Animals↗
PubMed2026

Cationic porphyrin covalent organic framework reinforced hydroxypropyl methylcellulose films for photodynamic-photothermal sterilization and food preservation.

Microbial contamination in food necessitates effective antimicrobial packaging. While cellulose-based packaging materials suffer from limited antimicrobial efficacy, lack of active functionality, and susceptibility to inducing microbial resistance. To address these challenges, this study synthesized a cationic porphyrin-based covalent organic framework (Por-ICOF) as a multimodal photosensitizer. Por-ICOF was uniformly dispersed via non-covalent interaction within hydroxypropyl methylcellulose (HPMC), creating an HPMC/Por-ICOF composite film. This integration enhanced mechanical strength (increased by 26%), hydrophobicity (WCA 71°), and gas barrier properties (OP reduced by 42%, WVP reduced by 36%). Under visible light, the HPMC/Por ICOF film superior absorption generated reactive oxygen species (ROS) and photothermal effects, inactivating 99.2% of Escherichia coli and 99.95% of Staphylococcus aureus within 20 min. The composite film exhibited excellent biocompatibility and effectively extended the shelf life of strawberries. This cationic modification strategy for cellulose-based films offers a novel avenue for the design of high-performance antimicrobial food packaging materials.

Food Preservation↗
PubMed1985

[Chemical preservation of food].

Preservation of foodstuffs has always been a necessity for a number of reasons: the durability of food is limited, numerous foodstuffs are only available during a short harvesting season, the transport routes of food or raw materials from the production site to the consumers are continuously increasing in length and the consumers in modern society characterized by division of labor and changed shopping habits increasingly insist on buying durable products. Beyond this, there are medical-hygienic efforts aimed at inhibiting the growth of micro-organisms in food. The hazard to health which many bacteria carry, has been long known. Recently, a number of fungi have been shown to form toxins during their growth on foodstuffs. There are two methods of food preservation: the physical and the chemical. The greater proportion of foodstuffs is rendered durable by physical procedures: drying, cooling, deep-freezing and heating. But chemical preservation also plays a prominent role. The use of preservatives is often combined with physical methods. The application of preservatives has a long history, such as the use of common salt, smoke or sulfur dioxide. Some of these agents, such as benzoic acid, are achievements of the last century. Others, such as propionic acid and sorbic acid, result from research during the last few decades. The preservatives now in use have been thoroughly tested for their toxicological properties. Their use in the food industry is subject to stringent legal regulations. The consumer can be certain of not running any risk by partaking foods which contain preservatives.

Benzoates↗
PubMed2025

Common food preservatives induce an oxidative stress response in Salmonella enterica serovar Typhimurium.

Despite their frequent use, the mechanisms of action of common food preservatives are poorly understood. As there is a drive to develop alternative preservatives, understanding the mechanisms of action of current preservatives can inform the development of novel food preservatives to ensure their efficacy. Here, we used TraDIS-Xpress, a large-scale, genome-wide unbiased screen to determine the mechanisms of action of common food preservatives by determining the genes that affect preservative susceptibility in Salmonella enterica serovar Typhimurium. We identified genes associated with central metabolism and oxidative stress responses that were important for all four preservatives. Formate dehydrogenase activity and synthesis was crucial for survival in the presence of both sodium chloride and potassium chloride. We found some preservative-specific effects on pathogen susceptibility, for example, LPS synthesis which improved survival upon exposure to sodium nitrite but harmed survival when exposed to sodium chloride or potassium chloride. This research expands our understanding of how some current preservatives act and can inform the effective use of preservatives in current and emerging food products to ensure high standards of food safety.

Salmonella typhimurium↗
PubMed1991

Epstein-Barr virus activators, mutagens and volatile nitrosamines in preserved food samples from high-risk areas for nasopharyngeal carcinoma.

Representative samples of preserved foods collected from high-risk areas for nasopharyngeal carcinoma were assayed for capacity to induce Epstein-Barr virus (EBV) by measuring induction of the DR promoter gene or of genes for early antigens in Raji cells. The two assays gave concordant results, but the DR induction assay detected EBV-inducing substances at lower concentrations and more reproducibly. Three of 17 preserved food items were active in both assays; they were also weakly mutagenic in the SOS chromotest and contained low or moderate levels of volatile N-nitrosamines. After in-vitro nitrosation, the levels of mutagens and nitrosamines increased, whereas EBV-inducing activity was unchanged or decreased. Thus, EBV inducers appear to be a different class of substances from mutagens and volatile N-nitrosamines but could act with them in the etiology of nasopharyngeal carcinoma.

Food Analysis↗
PubMed1977

[Distribution of Cl. perfringens in preserved food and the lecithinase activity of isolated strains].

This is a study of 414 different foodstuff types for Cl. perfringens presence determination. Of the meat products are with the highest contamination - 32 per cent, next ranking seasoning spices ond condiments, and auxiliary materials - 10.9 per cent. In milk, dairy and confectionary products it is isolated in 3.8 per cent of samples, while in tinned foodstuffs - in 1.8 per cent. Lecithinase production of the isolated strains in Kitt-Tarozi bouillon, Following 18-20 hour-long cultivation at 37 degrees C is studied, and dosed within limits ranging from 5 to 100 DMO. In meat food - pork in its own sauce, the development and lecithinase activity of some strains with different doses lecithinase in the enriching bouillon is studied after cultivation of the same at room temperature for 18-20 hours. Under the conditions outlined it is established that the growth of the strains is analogical to that of the bouillon, whilst their lecithinase activity shows a several-fold increase, and is dependent on the individual characteristics of the strains, and on their adaptive properties. The produced quantity of lecithinase does not affect the toxicity of strains upon oral infection of the animals experimented.

Animals↗
PubMed1988

Preserved foods and nasopharyngeal carcinoma: a case-control study in Guangxi, China.

One hundred twenty-eight mothers of nasopharyngeal carcinoma (NPC) cases under age 45 in Yulin Prefecture, China and 174 mothers of population controls were interviewed as part of an epidemiological study to examine childhood exposures in relation to the development of NPC. Exposure before age 2 years to a number of fermented foods was a risk factor for NPC. During weaning, intake of salted fish [relative risk (RR) = 2.6, one-sided P (P) = 0.01], salted duck eggs (RR = 5.0, P = 0.03), salted mustard green (RR = 5.4, P = 0.03), and chung choi (RR = 2.0), P = 0.003), a kind of salted root, was significantly related to an increased risk of NPC. Between ages 1 and 2 years, intake frequency of dried fish [P for linear trend test (linear trend P) = 0.002], fermented black bean paste (linear trend P = 0.0009), and fermented soy bean paste (linear trend P = 0.007) was also positively associated with NPC. A multivariate analysis of these different foods showed all except fermented black bean paste to be independently related to NPC.

Animals↗
PubMedDate not supplied

Effect of some food preservatives on aflatoxin production.

The effect of some food preservatives, such as sorbic (SA) and propionic (PA) acids, on aflatoxin production in synthetic media or in moistened (20%) wheat seeds, was investigated. The preservatives tested, added to synthetic media at sublethal concentrations both at the inoculum and after 5 days of incubation, stimulated aflatoxin production by Aspergillus parasiticus. Sorbic and propionic acids are metabolized by the fungus in vivo and in vitro. Lower concentrations of PA and SA (0.05 to 0.1% w/w) in wheat seeds are ineffective against both fungal growth and aflatoxin production, whilst the combined use of butylated hydroxy toluene (BHT), and PA or SA was more effective in controlling aflatoxin production than their use as single components.

Aflatoxins↗
PubMed1989

Effects of food preservatives and local anesthetics on synthesis of outer membrane proteins in Vibrio parahaemolyticus.

The effects of seven food preservatives including salicylate, benzoate, dehydroacetate, sorbate and propionate, and two local anesthetics, phenethyl alcohol and procaine, on the synthesis of major outer membrane proteins in Vibrio parahaemolyticus strain 3283-61 were investigated. The synthesis of the outer membrane proteins a, b, c and e was remarkably inhibited by all the food preservatives except propionate and two additional outer membrane proteins with respective molecular weights of about 35,000 (protein b') and 32,000 (protein c') were induced. Similar effects were encountered by the local anesthetics except that the synthesis of protein e was only weakly depressed.

Anesthetics, Local↗
PubMed1988

The chemistry of lysozyme and its use as a food preservative and a pharmaceutical.

The chemistry and use of lysozyme as a food preservative and a pharmaceutical are reviewed. Lysozyme inhibits the growth of deleterious organisms, thus prolonging shelf life. Chemicals used to improve the preservative effect of lysozyme and those that inhibit the enzyme are discussed, along with the stability of lysozyme in various chemical environments. Lysozyme has been used to preserve fresh fruits and vegetables, tofu bean curd, seafoods, meats and sausages, potato salad, cooked burdock with soy sauce, and varieties of semihard cheeses such as Edam, Gouda, and some Italian cheeses. Lysozyme added to infant-feeding formulas makes them more closely resemble human milk. Lysozyme has been used clinically in the treatment of periodontitis, administered in chewing gum, and implemented to prevent tooth decay. It has also been administered to patients suffering from cancer for its analgesic effect and has been used as a potentiating agent in antibiotic therapy.

Amino Acid Sequence↗
PubMedDate not supplied

[Adverse reactions to food preservatives].

We relate our experiences about the number of exacerbations that certain food preservatives such as sorbic acid, benzoic acid, sodium benzoate, metabisulfite and sodium nitrate can provoke in 62 patients affected with ASA-triad in steroid dependent intrinsic asthma with nasal polyps and acute bronchospasm caused by aspirin ingestion, and in 80 patients with chronic urticaria (C.U.) as well as the first assays of the possible usefulness of the HRT (Histamine release test automatized using whole blood) for the etiologic diagnosis process. In the cases of ASA-triad, and after the ingestion of aspirin (alternating with lactose in identical capsule), we consider the result as positive when the reduction of FEV1 is superior to 20% from its baseline value. Regarding the cases of C.U., the symptoms always exacerbate twice as much with the same substance within 24 hours of its administration. We have performed the HRT on 59 patients (14 with ASA-triad, 11 with steroid dependent intrinsic asthma; 20 with C.U. were negative to oral intake of analgesics/additives and 14 with C.U. showed positive results). Successive dilutions were incubated for 30 minutes using: pyrazolones, acetylsalicylate of lysine, sodium salicylate, sodium benzoate and 4-hydroxybenzoic acid which did not produce liberation of histamine in 100 controlled individuals. All the determinations were done in duplicate, considering positive those superior to 20% of the difference between total and basal histamine. We have not observed any significant descent of the FEV1 with benzoate and salicylate in our group of 62 patients with ASA-triad, nor any manifestations presented with sodium metabisulfite, sodium nitrate and sorbic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1979

Preserved foods as possible cancer hazards: WA rats fed salted fish have mutagenic urine.

Six batches of food traditionally and commonly consumed by southern Chinese, including two samples of dried shrimps and four samples of different species of salted fish, were tested for mutagenic properties using Salmonella typhimurium TA98 and TA1000. Mutagenic activities toward both tester strains were found in all preparations. In most cases, these activities were enhanced by liver microsomal activation. Urine collected from experimental rats regularly fed salted fish also showed mutagenic activity. The level of this activity decreased markedly when the experimental rats were transferred from a salted fish diet to Purina rat chow. Our data suggested the presence of mutagenic/carcinogenic substances in some local preserved foods and at least one of them, salted fish, has been suspected on epidemiological and experimental evidence to be a possible co-carcinogenic factor in the development of nasopharyngeal carcinoma in southern Chinese. Our finding is compatible with this hypothesis.

Animal Feed↗