Processed Meats and Seafoods. Doç. Dr. Arzu Çağrı Mehmetoğlu

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1 Processed Meats and Seafoods Doç. Dr. Arzu Çağrı Mehmetoğlu

2 PROCESSED MEATS Processed meats are those meat products that are cured, smoked, or cooked. processed meats stored under vacuum or modified atmospheres

3 Curing Major İngredients: NaCl, nitrite or nitrate, and sugar (sucrose or glucose) Miner ingredients: phosphates, sodium ascorbate or erythorbate, potassium sorbate, monosodium glutamate, hydrolyzed vegetable proteins, lactates, or spices. In dry curing, no water is added to the NaCl, nitrite or nitrate, and sugar mixtures. In pickle curing, these ingredients are added to water to form a brine. Salt serves to prevent microbial growth during and after curing, and up to 2.5% may be found in finished products. Nitrite or nitrate stabilize red meat color, contribute to cured meat flavor, retard rancidity, prevent the germination of clostridial spores.

4 All curing ingredients may be expected to contain microorganisms

5 Smoking primary purposes of smoking meat : (1) Development of aroma and flavor, (2) preservation, (3) creation of new products, (4) development of color, (5) formation of a protective skin on emulsion-type sausages, and (6) protection from oxidation.

6 Smoking Smoke, whether directly from wood or in liquid form, contains phenols, alcohol, organic acids, carbonyls, hydrocarbons, and gases. The antimicrobial properties of smoking : heat (wood smoking) the smoke ingredients Liquid smoke contains all of the essential ingredients of wood smoke, but it is free of the carcinogen benzopyrene.

7 Processed meats Sources of organisms: the meat components, the seasoning formulation ingredients The biota of frankfurters: Gram-positive organisms : micrococci, bacilli, lactobacilli, microbacteria, enterococci, and leuconostocs along with yeast.

8 The biota of vacuum-packaged sliced cured meat contains catalase-positive cocci- micrococci coagulase-negative cocci- staphylococci catalase-negative bacteria of the lactic acid types, lactobacilli, leuconostocs, pediococci, and enterococci The biota in cooked salami consist mostly of lactobacilli.

9 Spoilage three types: sliminess, souring, and greening. Slimy spoilage occurs on the outside of casings, especially of frankfurters Yeasts, lactic acid bacteria of the genera Lactobacillus, Enterococcus, Weissella, and B. thermosphacta, may be isolated from the slimy material. W. viridescens produces both sliminess and greening. Slime formation is favored by a moist surface hot or warm water removes this material

10 Souring takes place underneath the casing of these meats results from the growth of lactobacilli, enterococci, milk solids is the sources of these organisms The souring results from the utilization of lactose and other sugars by the organisms and the production of acids. Sausage usually contains a more varied biota than most other processed meats due to the different seasoning agents employed, all contribute their own biota. B. thermosphacta has been found by many investigators to be the most predominant spoilage organism for sausage.

11 Although mold spoilage of these meats is not common, it can and does occur under favorable conditions. When the products are moist and stored under conditions of high humidity, they tend to undergo bacterial and yeast spoilage. Mold spoilage is likely to occur only when the surfaces become dry or when the products are stored under other conditions that do not favor bacteria or yeasts.

12 greening Two types of greening occur on stored and processed red meats: 1. caused by H 2 O 2 2. Caused by H 2 S. Greening by H 2 O 2 occurs commonly on frankfurters as well as on other cured and vacuum packaged meats. It generally appears after an anaerobically stored meat product is exposed to air. Upon exposure to air, H 2 O 2 forms and reacts with nitrosohemochrome to produce a greenish oxidized porphyrin H 2 O 2 may accumulate when heating if nitrite destroys catalase, and the peroxide reacts with meat pigments to form choleglobin, which is green. Weissella viridescens is the most common organism in this type of greening, but Leuconostocs, Enterococcus faecium, and Enterococcus faecalis are capable of producing greening of products. Greening can also be produced by H 2 O 2 producers such as Lactobacillus fructivorans and Lactobacillus jensenii. W. viridescens is resistant to >200 ppm NaNO2, and it can grow in the presence of 2 4% NaCl but not in 7%.

13 Iron Binds with Common Location or Cause Colo r Chemical Name Water Interior of raw meat deoxymyoglobin Oxygen(:O 2 ) Surface of meat in air oxymyoglobin Hydroxide (- OH) Nitric Oxide (:NO) Carbon Monoxide (:CO) Low air package or below surface Cured meat, or heated meat and smoke ring Smoke ring or poison Cooked above ~160F metmyoglobin nitrosomyoglobin, or nitrosylhemochromogen, or denatured hemochrome family carboxymyoglobin denatured globin hemichrome Cyanide (-CN) Poison cyanmetmyoglobin Hydrogen Sulfide (-HS) Hydrogen Peroxide (- H 2 O 2 ) Poison Poison sulfmyoglobin choleglobin

14 Greening The second type of greening occurs generally on fresh red meats that are held at 1 5 C and stored in gasimpermeable or vacuum-packaging containers; it is caused by H 2 S production. H 2 S reacts with myoglobin to form sulphmyoglobin This type of greening does not usually occur when meat ph is below 6.0 The organism responsible Pseudomonas mephitica The lactobacillus can also produce H 2 S only in the absence of O 2 and utilizable sugars

15 Vacuum-packaged luncheon-style meat A yellow discoloration of vacuumpackaged luncheon-style meat is caused by Enterococcus casseliflavus. The discoloration appears as small spots on products stored at 4.4 C, it fluorescent under long-wave ultraviolet light 3-4 weeks require for the condition to develop The responsible organism can survive 71.1 C for 20 minutes In addition to 4.4 C, it occurred also at 10 C but not at 20 C or above.

16 Summary of Some Microbial Spoilage Conditions of Processed Meats Condition Products Affected Greening Vacuum-packaged bologna C. viridans Greening Vacuum-packaged beef L. sakei Greening Fresh red meats P. mephitica, S. putrefaciens Greening DFD meats S. purefaciens Greening/sliminess Wieners, bologna W. viridescens Yellowing Vacuum-packaged luncheon meats E. casseliflavus Black spot Cured meats C. nigrificans Souring Sausage B. thermosphacta Blown pack Vacuum-packaged meats C. frigidicarnis, C. gasigenes General spoilage Vacuum-packaged meats L. algidus; L. fuchuensis

17 Pastrami brining and seosoning coating, make them relatively insusceptible to spoilage by most bacteria. The most common form of pastrami spoilage is moldiness, which may be due to Aspergillus, Alternaria, Fusarium, Mucor, Rhizopus, Botrytis, Penicillium, and other molds. The high fat content and low aw make it somewhat ideal for this type of spoilage. Bacteria of the genera Enterococcus, Lactobacillus, and Micrococcus are capable of growing well on certain types of pastırami

18 Jambon Curing solutions pumped into jambons contain sugars that are fermented by the natural biota of jambon and also by those organisms pumped into the product in the curing solution, such as lactobacilli. The sugars are fermented to produce conditions referred to as sours of various types, depending on their location within jambon. the cause of sours : Acinetobacter, Bacillus, Pseudomonas, Lactobacillus, Proteus, Micrococcus, and Clostridium

19 Fish the inner tissues of a healthy fish are sterile. With fish, the microbial biota is found generally in three places: the outer slime, gills, and the intestines of feeding fish. Fresh or warm-water fish - more mesophilic Grampositive bacteria cold-water fish- largely Gram negative

20 Microorganisms overall sanitary quality of the waters - the overall microbial quality of finished products. microbes are picked up at various processing steps such as peeling, shucking, evisceration, breading, and the like.

21 SPOILAGE OF FISH Both saltwater and freshwater fish contain comparatively high levels of proteins and other nitrogenous constituents the nonprotein nitrogen compounds are the free amino acids, volatile nitrogen bases such as ammonia and trimethylamine; creatine, taurine, the betaines, uric acid, anserine, carnosine, and histamine. Fresh iced fish are always spoiled by bacteria, whereas salted and dried fish are more likely to undergo fungal spoilage. The bacterial biota of spoiling fish is found to consist of asporogenous, Gram-negative rods of the Pseudomonas, Flavobacterium and Acinetobacter-Moraxella types. Many fish-spoilage bacteria are capable of good growth between 0 C and 1 C

22 The most susceptible part of fish is the gill region, The earliest signs of organoleptic spoilage in the gills for the presence of off-odors.

23 Spoilage If feeding fish are not remove the guts immediately, intestinal bacteria soon make their way through the intestinal walls and into the flesh of the intestinal cavity. This process is believed to be aided by the action of proteolytic enzymes, which are from the intestines and may be natural enzymes inherent in the intestines of the fish, or enzymes of bacterial origin from the inside of the intestinal canal, or both. Fish-spoilage bacteria apparently have little difficulty in growing in the slime, and on the outer layer of fish.

24 Slime Composed of mucopolysaccharide components, free amino acids, trimethylamine oxide, piperidine derivatives

25 Trimethylamine oxide, creatine, taurine, anserine, and related compounds along with certain amino acids decrease during fish spoilage with the production of trimethylamine, ammonia, histamine, hydrogen sulfide, indole, and other compounds.

26 Off odor H3C Trimethylamine-N-oxide N CH3 H3C Trimethylamine

27 Histidine Histamine Decarboxylase Histamine, diamines, and total volatile substances are used also as fish-spoilage indicators. Histamine is produced from the amino acid histidine by microbially produced histidine decarboxylase Histamine is associated with scombroid poisoning

28 Tyramine is produced by some fish-spoilage organisms, and its production by Carnobacterium piscicola and Weissella viridescens from isolates of vacuum-packaged sugar-salted fish Tyramine results from decarboxylation of the amino acid tyrosine

29 Color Change Greenish yellow color-p. fluorecesens Yellow color- Micrococcus Red or pink color-bacillus, sarcinia, mold and yeast Chocolate brown- yeat and molds