MST-ITD

Skedul ITD No Topic Sub Topic 1 Introduction Scope of meat science and technology; 2 Meat microbiology Principles of microbiology of meat 3 Physical preservation of meat Thermal preservation, dehydration, irradiation 4 Chemical preservation of meat Curing, organic and inorganic acids, carbon dioxide, ozone, antibiotics, and smoking 5 Methods of meat cooking Boiling, frying, roasting, microwave, 6 Technology of meat processing Grinding, mixing, stuffing, heat treatment 7 Ingredients for meat products Filler, binder, gelling, flavouring, emmulsifier, food additive 8 Meat emulsion products Sausages, meat ball, burger, nugget 9 Traditional meat products Abon, jerkey 10 Fermented meat products Fermented sausages 11 Meat and meat products standard Indonesian standard for meat and meat products 12 Meat and meatproducts packaging Packaging materials 13 Meat and meat products packaging Packaging methods. 14 Labeling

References Aberle, E.D., J.C. Forrest, D.E. Gerrard, E.W. Mills, H.B. Hedrick, M.D. Judge, R.A. Merkel, 2001. Principles of Meat Science. 4th ed. Kendall/Hunt Publishing Company, Dubuque, Iowa. Swatland, H.J., 1984. Structure and Development of Meat Animals. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. Soeparno, 2015. Ilmu dan Teknologi Daging. Cetakan ke-6 (Edisi Revisi). Gadjah Mada University Press, Yogyakarta. Soeparno, 2011. Ilmu Nutrisi dan Gizi Daging. Cetakan pertama. Gadjah Mada University Press, Yogyakarta.

Principles of meat microbiology Meat contains high, complete, and balanced nutrients. Such nutrients are a good medium for the growth of microbes. Meat spoilage can be caused by microbiological, chemical, or physical factors.

Microbes in meat Infection in a live animal. Contamination during postmortem handling. Contamination during storage, Contamination during the processing of processed meat.

Contaminant sources in abattoir Water and soil around abattoir Dirt in animal skin The content of digestive tract Equipment used during slaughter Dirt and dust in the air Workers of slaughterhouse/abattoir From workers: Salmonella, Shigella, Escherichia coli, Bacillus proteus, Staphylococcus albus, Staphylococcus aureus, Clostridium walchii, Bacillus cereus. From feces: Staphyloccocus From water and soil: Clostridium botulinum.

Contamination during slaughter Microbes enter blood flow during slaughter. Contamination through the surface of meat during meat preparation (halving the carcass, chilling, freezing, thawing, cutting the carcass/meat, making meat products, packing, preserving, and distributing).

Growth of microbes in meat Lag phase is the phase where there is no growth due to unsupportive environmental condition. Logarithmic growth phase is the growth phase with constant rate. Stationary growth phase is the phase where the number of new cells is the same as that of dying cells. Death phase is the phase where there is a decrease in the number of cells due to the death of cells caused by depletion of nutrients and accumulation of metabolic products or effects of certain preservatives.

Factors affecting the growth of microbes Intrinsic factors: meat nutrients, water content, pH, oxidation-reduction potential, and inhibitor. Extrinsic factors: temperature, relative humidity, oxygen supply, condition of meat Factor of meat nutrients Nitrogen and energy needs for microbes are from amino acids, other non protein nitrogen, peptides and protein. Fungi can make use of protein, carbohydrate and fats better than yeast and bacteria. A number of microbes can synthesize vitamin B for their growth. Factor of water content The water content in meat really determines the growth rate of microbes. The water need for microbes is stated as water activity (Aw).

Factors affecting the growth of microbes Water activity (Aw) is ratio the vapor pressure of solution and that of pure solvent at the same temperature (Aw=p/p0). Aw of fresh meat is usually 0,99 or higher. The relation between Aw and RH is: RH=Awx100. Aw need of bacteria is higher than that of fungi and yeasts. Minimal Aw for Salmonella is 0,94, Minimal Aw for Staphylococcus is 0,86, Minimal Aw for fungi and yeasts is 0,62.

Factors affecting the growth of microbes Factor of pH The ultimate pH value of meat is 5,3-5,7. Most bacteria grow on pH 7. Fungi can grow around pH 2,0-8,0. Yeasts can grow around pH 4,0-4,5. The ultimate pH of meat is beneficial for the growth of yeasts and fungi, except for acidophilic bacterium (pH 5,2). Lactic acid bacteria grows well around pH 5,5-6,0.

Factors affecting the growth of microbes Factor of oxidation-reduction potential Aerobic microbes are microbes which grow well in a high oxidation-reduction potential. Anaerobic microbes are microbes which grow well in the absence of oxygen, in a low oxidation-reduction potential. Facultative anaerobic microbes are microbes which can grow in the presence or absence of oxygen.

Factors affecting the growth of microbes Factor of inhibitor Bacteriostatic is the substance which can inhibit microbial activities. Bactericidal is the substance which can destroy or kill microbes.

Factors affecting the growth of microbes Factor of temperature Based on maximum and minimum temperature, microbes are categorized into: mesophiles, psychrophiles, and thermophiles. Most microbes including mesophiles grow well at the temperature of (15-40oC), with a temperature minimum of 10oC. Psychrophiles are microbes which grow at the temperature of 0oC or lower, with the maximum of 20-30oC. Thermophiles are microbes which grow well at the temperature of 45-60oC.

Factors affecting the growth of microbes Factor of temperature Microbes which survive and grow at pasteurization temperature are called thermoduric microbes. Fungi are the most thermophilic microbes, followed by yeasts and bacteria. The temperature of 5oC is critical temperature during the handling and storage of meat, because it can inhibit the growth of microbes. Psychrophiles in meat: Pseudomonas, Achromobacter, Micrococcus, Lactobacillus, Streptococcus, Leuconostoc, Pediococcus, Flavobacterium, Proteus, and Listeria.

Factors affecting the growth of microbes Factor of relative humidity Higher storage temperature will lead to lower humidity. At the temperature of -1 – 3oC, the humidity is around 88-92%. At a very high humidity, water tends to condense in the surface of meat and lead to the growth of microbes. At a very low humidity, surface water tends to evaporate/dehydrate so it can inhibit the growth of microbes.

Factors affecting the growth of microbes Factor of atmospheric oxygen All fungi and most yeasts growing in meat are aerobic, except bacteria which can grow in aerobic, anaerobic or facultative anaerobic condition. Microbes at the surface of meat are aerobic and facultative anaerobic ones. Microbes in the inside of meat are anaerobic and facultative anaerobic microbes. Vacuum packing or packing can prevent aerobic microbial activities.

Factors affecting the growth of microbes Factor of physical condition of meat Physical condition of meat: carcass size, carcass and meat cut, shape of ground or minced meat, and processing treatment. Grinding has more potential of contamination because: (1) larger surface area, (2) more available nutrients and water, (3) more penetration of oxygen, (4) grinding takes time, (5) more contact with equipment, (6) more even distribution of microbes.

Factors affecting the growth of microbes Effects of microbial activities on meat constituents Carbohydrate metabolism Protein metabolism Fat metabolism

Food Poisoning and Foodborne Infection Food poisoning is disease caused by toxin ingestion on the food consumed . Foodborne infection is consuming food which contains pathogenic microbes. Toxin is produced by bacteria, mycotoxin is produced by fungi (yeasts and fungi).

Microbial of meat Salmonelosis Bacteria that cause: Salmonella Salmonella is facultative and does not form spores. Salmonella can grow on consumers and produce endotoxin (toxin kept within bacterial cells) and may cause illness. Symptoms: headache, vomiting, and diarrhea caused by irritation in the small intestine wall by endotoxin. Infection occurs after the ingestion 1 million of Salmonella. Incubation period: 1 – 3 days (approximately 24-24 hours). The contamination of Salmonella can be from the contamination of carcass and meat during slaughter; contamination during meat processing; or recontamination of meat and other food ingredients. Handling: heating at 65oC for 12 minutes or 60oC for 30 minutes.

Microbial of meat Clostridium perfringens Bacteria causing: Clostridium perfringens Clostridium perfringens is anaerobic and forms spores. Clostridium perfringens consists of pathogenic and non-pathogenic ones. Pathogenic strain produces toxin. Clostridium perfringens grows at the temperature of 10-50oC with an optimum temperature of 45oC. Handling: heating at the temperature of 100oC for 10 minutes will destroy 99% strain causing food poisoning.

Microbial of meat Botulism Bacteria causing: Clostridium botulinum. Clostridium botulinum is anaerobic bacteria which form spores and gas. Clostridium botulinum produces neurotoxin. The incubation period is 24-48 hours after toxic ingestion. Toxin is inactive during heating at the temperature of 85oC for 15 minutes. The spores are spoiled at he temperature of 100oC for 6 hours, 120oC for 4 minutes.

Microbial of meat Staphylococcal Bacteria causing: Staphylococcus aureus Staphylococcus aureus is facultative bacteria which do not form spores. Staphylococcus aureus produces enterotoxin which is very heat-resistant. Toxin is inactive at the temperature of 121oC for 30 minutes. Staphylococcus aureus can be destroyed by heating at the temperature of 66oC for 12 minutes.

Microbial of meat Parasitic Infections Trichinosis is caused by small nematode worm (Trichinella spiralis). Infections by tapeworms (Taenia saginata and Taenia solium). Infections by liver flukes (Faciola hepatica). Handling of parasitic infections: heating at the temperature of 100oC for 30 minutes.

Microbial of meat Infections by Tapeworms Infections by tapeworms (Taenia saginata in beef and Taenia solium in pork). Tapeworms can be found in intramuscular connective tissues. Embryonic egg hatches in the intestines then migrates to intramuscular connective tissue, and undergoes metamorfose into cysticercus. Cysticercus consumed by human in the intestinal wall will grow to be adult tapeworms and leads to infections on human.

Microbial of meat Infections by Liver Flukes Infections by liver flukes (Faciola hepatica). Infection is due to consuming liver infected by liver fluke.

References Aberle, E.D., J.C. Forrest, D.E. Gerrard, E.W. Mills, H.B. Hedrick, M.D. Judge, R.A. Merkel, 2001. Principles of Meat Science. 4th ed. Kendall/Hunt Publishing Company, Dubuque, Iowa. Swatland, H.J., 1984. Structure and Development of Meat Animals. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. Soeparno, 2015. Ilmu dan Teknologi Daging. Cetakan ke-6 (Edisi Revisi). Gadjah Mada University Press, Yogyakarta. Soeparno, 2011. Ilmu Nutrisi dan Gizi Daging. Cetakan pertama. Gadjah Mada University Press, Yogyakarta.