Meat, organic acids

Organic acids may exhibit other sensory properties. For example, citric acid possesses sweet-and-sour sensory notes, and succinic acid has a salty-bitter taste. On the other hand, the typical taste and flavor of Emmental cheese can be ascribed to the propionic acid and a few other compounds, such as proline. In fact, taste and flavor result from the combination of different food constituents in definite proportions. Raw meat smells much like lactic acid, which arises from postmortem anaerobic glucolysis and determines the pH of meat, its final properties, and microbial stability. This same organic acid has been related to the inhibition of certain pathogenic bacteria in yogurt (3). Table 1 lists the reported threshold concentrations for various organic acids in different media (4-6). 

Organic acids were separated on a LiChrosorb RP-18 (250-mm X 4.6-mm-ID) column, using the mobile phase 0.005 M ammonium acetate-acetic acid-acetonitrile, at a detection wavelength of 225 or 232 nm. This method can be used for vegetable oils, meat salads, jams, mayonnaise, and mustard (69). After derivatization (benzoylation), it is possible to separate EsHBA with either normal-phase or reverse-phase columns. The normal-phase method showed high efficiency and sensitivity at a detection limit of 0.2 ppm. The preservatives were separated on a LiChrosorb Si 60 column and eluted with isoacetate-diethyl ether-acetonitrile (500 35 0.3). On an RP-18 column, a methanol-water mobile phase was used. Eluents were monitored at 240 nm (70). 

Five species of common edible crabs were used. They were cooked in boiling water containing 3% NaCl for 20 minutes according to commercial practice. After cooling, the leg meat was removed from the crabs of both sexes and extracted with hot water. The extracts were then deproteinized with 80% ethanol and analyzed for free and combined amino acids, nucleotides and related compounds, quaternary ammonium bases, sugars, organic acids, and inorganic ions. 

The organic acids are added according to the general sdxeiuo to form the mixed anhydride < with excess of carboxylic acid, rearntngi meat and decomposition occur ... 

Samelis, J., Sofos, J.N., Kendall, P.A., and Smith, G.C. 2002. Effect of acid adaptation on survival of Escherichia coli 0157 H7 in meat decontamination washing fluids and potential effects of organic acid interventions on the microbial ecology of the meat plant environment. Journal of Food Protection 65 33M0. 

Doyle, E.M. 1999. Use of organic acids to control Listeria in meat. American Meat Institute Foundation. 

Theron, M.M. and Lues, J.F.R. 2007. Organic acids and meat preservation A review. Food Reviews International 23 141-158. 

In 1970 findings were reported that treating meat with organic acids can provide other means of extending the distribution and visual attraction of fresh meat (Bauernfeind and Pinkert, 1970 Barker and Park, 2001 Huang, Ho, and McMillin, 2005). 

In Table 3.1 some factors are stipulated that should be considered in the decontamination of meat (European Union, 1996). Spraying with 1.5-2.5% organic acids such as acetic or lactic acid is effectively applied on red meat carcasses (Canadian Food Inspection Agency, 2004). Lactic and acetic acid solutions are commonly used by the red meat slaughtering industry as an antimicrobial spray wash on freshly slaughtered beef carcasses. These spray washes are used in the early steps of beef carcass processing, usually applied to carcasses after hide removal, before and after evisceration, but before chilling (Berry and Cutter, 2000). 

It is necessary to use organic acids to disinfect the carcasses in an environmentally friendly way and still produce the maximum shelf life for fresh meat. These methods must, therefore, be simple, long-lasting, and with a minimal effect on the sensory, chemical, and physical characteristics of the meat, and be inexpensive (Ogden et al., 1995). 

In decontamination of red meat carcasses the use of 1.5-25% of the following organic acids is permitted Acetic acid Lactic acid Citric acid Application/description... 

Table 3.3 Factors That Determine the Selection of Organic Acids in Meat Decontamination...

Increased effectiveness of organic acids may be achieved when used in lower concentrations, but in combination with additional inhibitors. For example, combining nisin with reduced organic acid concentrations may decrease potential flavor flaws in meat products (Samelis et al., 2005). Citric and ascorbic acids, in combination, are effective in inhibiting growth and toxin production of C. botulinum type B in vacuum-packed foodstuffs (Barbosa-Canovas et al., 2003 Samelis et al., 2005). In other studies, a combination of equal amounts of ascorbic acid and citric acid did not have additional benefits, compared with using ascorbic acid alone (Mancini et al., 2007). 

In carcass decontamination dilute solutions of organic acids (1-3%) normally do not have any effect on the sensory properties of meat. However, it is known that lactic and acetic acid can produce unfavorable sensory changes if applied directly to meat cuts, which may be irreversible. Salts of organic acids are approved for use as food ingredients such as emulsifiers, color and flavor enhancers, and humectants. They are also used to enhance the quality of cooked or cured meat products and to control the pH (Smulders and Greer, 1998). Sodium lactate is approved for use as (1) a flavor enhancer, (2) humectant, and (3) pH control agent (Lemay et al., 2002). 

Feed with formic and propionic acids has been found to reduce Salmonella colonization in broilers (Thomson and Hinton, 1997), whereas decontamination of chicken carcasses with acetic or lactic acid reduced Campylobacter on carcasses or meat (Van Netten et al., 1994 Chaveerach et al., 2002). Organic acids, when added to feeds, should be protected to avoid dissociation in the crop and in the intestine that are known to possess higher pH and to reach far into the GIT, where the targeted bacterial population is situated (Gauthier, 2005). 

Ahvenainen, R. 1996. New approaches in improving the shelf life of minimally processed fruits and vegetables. Trends in Food Science and Technology 7 179-186. Aktas, N. and Kaya, M. 2001a. Influence of weak organic acids and salts on the denaturation characteristics of intramuscular connective tissue. A differential scanning calorimetry study. Meat Science 58 413-419. 

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