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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↗
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↗
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↗
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↗
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↗
PubMed1975

Acute cytogenetic effect of 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2, a food preservative) on rat bone marrow cells in vivo.

The cytogenetic effects of 2(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2), a food preservative used in Japan, on rat bone marrow cells in vivo were studied. The aberrant metaphase cells in the bone marrow increased and reached the peak level 6 h after intraperitoneal injection of 240 mg/kg body weight of AF-2 and returned to the normal level within 24 h. A dose-response relationship was obtained using 4-240 mg/kg of AF-2. Chromosome aberrations were also induced after oral administration of 30-240 mg/kg. The aberrations were mostly chromatid breaks and the distribution among and within chromosomes was similar to those induced by a carcinogen, 7, 12-dimethylbenz(a)anthracene (DMBA). The present results provide the first evidence of in vivo cytogenetic effects of AF-2 on mammalian cells and, together with the evidence of mutagenicity already proved in other organisms, warn of the possible genetic hazards to cells exposed to this compounds.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1976

Effectiveness of various food preservatives in controlling the outgrowth of Byssochlamys nivea ascospores.

Potassium sorbate, sodium benzoate, sulfur dioxide, and diethylpyrocarbonate (DEPC) were tested for their effectiveness in preventing the outgrowth of Byssochlamys nivea Westling ascospores. Sulfur dioxide was the most inhibitory of the test antimycotics, complete inhibition of colony formation occuring in acidified (pH 3.5) potato dextrose agar containing 50 ppm of the preservative. Complete inhibition of B. nivea ascospore outgrowth in grape juice stored for 60 days was noted in the presence of 300 ppm sulfur dioxide, 400 ppm potassium sorbate, and 600 ppm DEPC. Growth was observed in grape juice containing 1000 ppm sodium benzoate. The presence of up to 100 ppm potassium sorbate in grape juice during heat activation appears to have a stimulatory effect on breaking dormancy, while the other test preservatives at this concentration decrease the heat resistance of B. nivea ascospores. The time elapsed between heat shock and exposure to DEPC or sodium benzoate is critical with respect to the sensitivity of ascospores to these preservatives.

Ascomycota↗
PubMed1979

Determination of food preservatives and saccharin by high-performance liquid chromatography.

The quantitative analysis of benzoic and sorbic acid, methyl, ethyl and propyl esters of p-hydroxybenzoic acid and saccharin in foodstuffs is described. These compounds are quantitatively extracted with disposable clean-up columns packed with Extrelut and simultaneously determined by high-performance liquid chromatography on reversed-phase columns. Complicated matrices such as cheese, cake, ketchup and chocolate were tested and recoveries were generally better than 95% in the concentration ranges normally used in the food industry.

Benzoates↗