Antimicrobial Agents

provender saving has long been in effect(p) since the olden times with formes much(prenominal)(prenominal) as heating , drying, excitement and refrigeration. In wound of this, physical methods be not adequacy to eliminate in all microorganisms found in nutritions. Therefore, anti microbial instruments be needed to undo these alimentborne pathogens, so that the f atomic number 18 will wee-wee a interminable shelf-life. As engineering progresses, improvements in the treat procedure and furtherance systems considerably devote to the preservation of sustenance. thus far so, antimicrobic agents silent play an all important(predicate) role in protecting the sustenance supply. germicide agents ar chemical immixs biosynthetically or synthetically produced which all destroy or ingestionfully trounce the growth or transfiguration of a variety of microscopical or submicroscopic forms of life. 2. Factors modify the Selection of healthful agents 2. 1 Antimicrob ial activity against varied organisms It is desirable to occasion an antimicrobic agent that can interdict a ample range of spoilagecausing microorganism.A good savvy of the chemicals mode of execute is overly recyclable in selecting a preservative.2. 2 microbial load of the food product . The food moldiness be of the juicyest microbiological quality initially. Food should always be processed beneath the well-nigh precise sanitary conditions to understate contamination. A graduate(prenominal) microbial existence would require higher(prenominal) doses of disinfectant agents. engage of healthful agents should not be viewed as a succour for good sanitation. 2. 3. chemical substance and physical properties In choosing an antimicrobial agent, properties such as solvability, turn head teacher, and dissociation argon mportant. Water solubility is important since microbial growth requires piss. 1 Volatile preservatives ar easily lost(p) if the food is heat during processing. Dissociation of sorbic pane of glass has an important thrill on its military capability in inhibiting pestilential microbes. Most compounds are rough-and-ready in their undissociated form.Stability Constituents in food such as protein and theatrical role can pit with the preservative and sicken its potentness. For this reason, the stability of antimicrobial agents during store is very important. 2. Processing and storage conditions The conditions of storage and interactions with other processes must be evaluated to ensure that the antimicrobial will wait functional all over time. 2. 6 smack The addition of the antimicrobial agent should not interfere with the aroma of the food product, or rather call down it. 2. 7 address The choice of antimicrobial should be efficient and suited to the food product. 2. 8 safety device and legality Antimicrobials agents must not be toxic to humanness. The affair of antimicrobial agents is oftentimes strictly reg ulated. As a processor, it is inbred to intake chemicals as prescribed by the regulations. 3. Types of Antimicrobial agents and their Functions 3. 1 benzoic stifling and sodium Benzoate ? expression Fig 1. Structures of benzoic sulphurous and atomic number 11 Benzoate (Image from Wibbertman,Mangelsdorf Melber, 2000) ? Sources o benzoic caustic occurs of course in some(prenominal) plants and resins such as cranberries, plums, prunes, cinnamon. However, benzoic savage can be produced commercially by the reaction of methylbenzene with oxygen at temperature around 200C in the liquid phase. The process is catalyzed by carbon monoxide or atomic number 25 salts. Fig. 2 business of benzoic sulfurous (Image from Wikipedia. rg) o atomic number 11 benzoate atomic number 11 benzoate is produced by the neutralization of benzoic unpleasant with sodium hydroxide. ? Properties Benzoic bitter is a duster solid that starts to change at one hundredC, with a melt point of 122C and a stewing point of 249C. Its solubility iin pee is unhopeful (2. 9 g/ lambert at 20C). 3 The undissociated form of benzoic pane (pKa=4. 2) is the about effective antimicrobial agent. It was inform that the compound was 100x as effective in sulphurous solutions as in neutral solutions. Sodium benzoate is a washrag crystalline disinteg place with a syrupy astringent taste.It has a melting point above three hundredC. It is very disintegrable in water (550-630 g/litre at 20. Benzoates are most effective at pH 2. 5-4. 0and least(prenominal) effective at pH 4. 5. ? radical use Benzoic acid and its salts are used as antimycotic agents against yeast and molds, such as Saccharomyces cerevisae and genus Aspergillus parasiticus. ? Mechanism/s of action o Formation of benzoic acid-oxidase complex Benzoic acid inhibits aminic acid intake in molds and bacteria. Benzoates also inhibit enzymes in the bacterial kiosk such as those controlling acetic acid metabolism and oxidative ph osphorylation.Klein and Kamin (1940) reported that the activity of the d-amino acid oxidase was decreased by benzoic aci ( e. g. , the rate of oxidation of 1 mg. of d(-)-alanine by preparations of the oxidase was decreased about 60 per cent by benzoic acid). They suggested that the repressing effect of benzoic acid is collectable to the formation of a benzoic acid- oxidase complex. o Inhibition via low of internal pH of the cell ? Applications Sodium benzoate is used in carbonated and dumb beverages, margarine, soy sauce, jams and jellies, storage of vegetables, fish preserves, proceeds salads, and other high acid foods. ? regulative Status GRAS, up to a supreme of 0. 1%. Toxicology subaltern order of toxicity for animals and humans. The reason is because humans and animals have an effective detoxification mechanism for benzoates. 4 3. 2 Sorbic Acid and Sorbates ? Structure Fig. 3 Sorbic Acid (Image from caper Wiley Sons, 2000) ? Sources Sorbic acid, which is also cogni ze as 2,4-hexadienoic acid, was kickoff isolated from rowanberry (berries of the fortune ash tree) decades past by A. W. train Hoffman, a German chemist.It is now lively for industrial use via condensation of malonic acid and crotonaldehyde Fig. 4 implication of Sorbic acid (Image interpreted from Lookchem. com/Chempedia) ? Primary use Sorbic acid and its salts targets yeasts, molds, and bacteria. both(prenominal) of these include species Candida, Oospora, Fusarium, Mucor and Trichoderma. ? Properties Sorbic acid is a black-and-blue crystalline grind and is slightly soluble in water (0. 16g/100mL).