Alfas, Presentation Slide.Spoilage of vacuum packaged meat
•Download as PPTX, PDF•
2 likes•620 views
- Vacuum packaged beef is commonly distributed and sold in Australia, where the meat industry is a major part of the economy. Spoilage can sometimes occur in vacuum packaged meat under refrigeration. - The study aimed to identify microbes responsible for off odors in spoiled vacuum packaged beef. Samples from two spoiled packages were analyzed, with psychrotrophic lactic acid bacteria found to dominate at refrigeration temperatures. - Isolates were characterized and tested for their ability to cause spoilage. Carnobacterium species were identified as off odor producers through gene sequencing of effective spoilage isolates. Carnobacterium was concluded to be one of the microbes responsible for spoilage in vacuum packaged beef under refrigeration conditions.
More Related Content
Similar to Alfas, Presentation Slide.Spoilage of vacuum packaged meat
Similar to Alfas, Presentation Slide.Spoilage of vacuum packaged meat (20)
Alfas, Presentation Slide.Spoilage of vacuum packaged meat
- 1. Spoilage of vacuum packaged meat Alfas Ahmed Siddique Supervisor- Dr. Shane Powell
- 2. Meat in Australian economy • Australia is the 3rd largest meat exporter • >1 million metric ton exported by 2015 • Exporting to Japan, China, Indonesia, USA, South Korea, New Zealand, Saudi Arabia, Hong Kong, United Arab Emirates …. • 61% Australian land for farming and grazing • Beef is vacuum packaged commercially to distribute and sell.
- 3. Vacuum packed meat • Vacuum packaging - Meat in a plastic film or bag - Remove air and oxygen - Sealing Aim is to make meat safer to consume and protect from any contamination.
- 4. Aims • Overall Aims - Determining off odor producing microbes in vacuum packaged beef (numerous and culturable only) - Identification of microbes cause off odor under refrigeration
- 5. Sample Purge
- 6. Previous studies • The condition is anaerobic • Psychotropic Lactic Acid Bacteria (LAB) mostly reported as dominant and off odor producer Brochothrix, Lactobacillus, Leuconostoc, Carnobacteria, Weisellia (a large group of bacteria produce lactic acid) • Clostridia spp. involvement in blown pack. • Enterobacteria in spoilage Serratia spp The LAB become dominant and off odor producer.
- 7. Method Sampling Plate count Isolation and pure culture Characterization Cooked meat growth Potential spoilage microbe Inoculation on irradiated sterile meat Off odor detection Gene sequencing for identification
- 8. Sampling, plate count and pure culture Two spoiled sampled were examined. Up to dilution 4 were spread plated on PCA – Non selective VRBG – Selective for Enterobacteriaceace BHI – Non selective CFC – Selective for Pseudomonas MRS – Selective for LAB STAA – Selective for Brochotrix -Incubation at 4ᵒC, 10ᵒC and 25ᵒC. (PCA-plate count agar, BHI- Brain heart infusion agar, MRS-Man Rogosa Sharpe agar, VRBG-Violet Red Bile Glucose agar, CFC- Centrimide Fucidine Cephalosporin, STAA- Sterptomycin thallous acetate actidione)
- 9. Characterization • Colony morphology • Gram stain • KOH test • Hetero and homo fermentation of LAB X - APT broth (hot loop test). Bubbles – hetero; No bubbles - Homo X - HHD (Blue colony- Hetero; White colony – Homo) - M5 media (Green color change – Hetero; No color change – Homo) media color changes from blue to green by hetero fermentation Isolates with similar colony morphology and gram stain assumed as same microbes.
- 10. M5 media Homo fermentation Hetero fermentation Fig – Homo and hetero fermentation differentiation using M5
- 11. Testing spoilage potential Cooked meat medium - Inoculation and incubation at 4ᵒC, 10ᵒC, 20ᵒC and 25ᵒC. - Off odor detection Sterile irradiated meat inoculation - Potential spoilage isolates were inoculated on irradiated meat - Incubation at 25ᵒC. Gene sequencing -Sequencing of potential isolates.
- 12. Cooked meat Irradiated meat Inoculation
- 13. Results • Psychrotolerant LAB at 4ᵒC • Diverse flora in BHI 0 1 2 3 4 5 6 7 8 PCA BHI MRS LogCFU/gofmeat Media and temperatures 4C 10C 25C Log CFU/G of meat of 1st spoiled sample
- 14. • Psychrotolerant at 10ᵒC • LAB is higher • Higher Log CFU/g 0 1 2 3 4 5 6 7 8 PCA BHI MRS LogCFU/gofmeat Media and temperatures 4C 10C 25C Log CFU/G of meat of 2nd spoiled odor sample
- 15. Characterizations results • 90 isolates • Mesophilic and psychotropic • Psychrotolerant • Gram +ve/-ve cocci/rods in pairs/chains • Cooked meat medium • M5 media (LAB only)
- 16. Isolate no. Media Colony morphology Gram stain Cooked meat broth P10 PCA Dull white, round, smooth, flat, glistering, small in size -ve Short rods chains Sulfurous P15 PCA Transparent, round, smooth, flat, smallest tiny dot like -ve/+ve Coccoid rod/short rod Chains Unpleasant smell P19 PCA Transparent, round, smooth, flat, smallest tiny dot like -ve Rods Sulfurous P20 PCA Watery milky, glistering, round, flat -ve Cocci Chains Unpleasant smell B10 BHIB Whitish, round, transparent, glistering, small -ve cocci Spoil smell B25 BHIB Transparent, round, glossy, flat, glistering, medium size + cocci Unpleasant smell B29 BHIB Dull white, round, flat, opaque, no glistering, smooth +ve cocci Unpleasant smell Short Isolation chart Homo- Hetero differentiation M6 MRS Completely transparent, round, smooth, flat, dot like +ve Cocci Spoil smell APT – Homo M5 – Hetero HHD – Hetero M12 MRS Transparent, round, smooth, flat, smaller size +ve Small Rods No smell APT – No inoculation M5 – Homo HHD – Homo
- 17. Sign of spoilage on radiated meat and compare with sample Discoloration and purge
- 18. Irradiated meat inoculation results Isolates Amount of inoculum cells/cm² Off odor Color change Purge production P10 3x10^6 Yes, Sickly sweet, Greyish + + + P19 3.38x10^6 No or as control - P20 5.8x10^6 Yes, Chunky cheesy, sour and vomit type Greyish + + P27 4.36x10^8 No or as control - - M1 4.02x10^8 No or as control - - M6 3x10^6 No or as control - - M12 5.76x10^8 Yes, Chunky cheesy, sour and vomit type Greyish + B10 6.83x10^8 Yes, Fruity sweet Slightly greyish + + B1 6.63x10^8 No or as control - - B29 4.95x10^8 Yes, Yeasty alcoholic Slightly greyish + B25 5.25x10^8 Yes, Yeasty alcoholic Slightly greyish + ** The red colored ones were analyzed by gene sequencing to identify the microbes
- 19. Gene sequencing results • P10 Carnobacterium spp. • B25 Carnobacterium spp.
- 20. Conclusion One of the off odor producing microbes was Carnobacterium spp. It grows between -1ᵒC to 25ᵒC. Aerobically, Anaerobically and Micro aerobically. Cause spoilage in vacuum packed meat under refrigeration.
- 21. Thank you