Dr. Chrysoula TassouBiologist-Food Microbiologist
Research Director
Hellenic Agricultural Organisation – DEMETERInstitute of Technology of Agricultural Products
(ITAP)S. Venizelou 1, Lycovrissi, 141 23 Attica, Greece
tel: 210-2845940, fax: 210-2840740e-mail: [email protected]
“Microorganisms of Table Olives.
Contribution to Safety and Beneficial Activity”
Since ancient times olives have been a key element in the nutrition of the people of the Mediterranean basin
Table olives & olive oil
Today olives are the most economically important, fermented
product in the Western world.
Table olives in the Mediterranean diet
Important commercial types of olives after processing:
➢ Natural olives in brine (Greek type olives)
➢ Green olives in brine (Spanish type)
Raw olive fruits are not edible and need processing……
In both types, the fermentation is the critical processing step
Natural ripe (black) olives
Harvesting
FERMENTATION in brine
Gradual debittering - ripening
Green Spanish style
Harvesting
Debittering with ΝaΟΗ
Washing with H2O
FERMENTATION in brine
green na
tural olive
s
Table olive fermentation
• Basic process for the preparation of natural black or green table olives.
• The microorganisms of raw olives are responsible for the fermentation.
• Yeasts-fungi 5.4 (log10cfu/g)
• Lactic acid bacteria 4.0
• Enterobacteriaceae 2.5
• Pseudomonas spp. 3.5
Tassou, C. (1993) Microbiology of olives with emphasis on the antimicrobial activity of phenolic compounds. PhD Thesis Univ. of Bath, UK
putida
cepacia
fluorescens
luteola
Microorganisms of raw olive fruits
Yeasts
Pichia
Rhodotorula
Candida
Saccharomyces
Trichosporon
Debaryomyces
Bacteria
Aerobacter
Achromobacter
Pseudomonas
Serratia
Escherichia
Micrococcus
Bacillus
Based on Vaughn (1949), Balatsouras & Vaughn (1958), Gonzalez Cancho (1957), Borbolla y Alcala et al. (1958)
Microorganisms of raw olive fruits*
* isolated from stored olives or oviposition sites of Dacus oleae
Moulds
Aspergillus
Fusarium
Penicillium
Alternaria
Rhizopus
Cladosporium
Geotrichum
Pullularia
Brettanomyces
Cryptococcus
Candida
Rhodotorula
Saccharomyces
Pichia
Debaryomyces
Hanseniaspora
Hansenula
Schizosaccharomyces
Kloeckera
Kluyveromyces
Sporobolomyces
Trichosporon
Lactobacillus
delbrueckii
leichmannii
helveticus
acidophilus
casei subsp. alactosus
casei subsp. rhamnosus
xylosus
plantarum
curvatus
coryniformis
fermentum
brevis
higardii
Based on Pelagatti (1978-80).
Yeasts genera Lactic acid bacteria
Microorganisms of raw olive fruits
Microorganisms of raw olive fruits (yeasts)*
Based on Hernandez et. al. 2007, Romo-Sanchez et al. (2010).
* Identified by molecular techniques
Olive fruits*Pichia holstii
Kluyveromyces thermotolerans
Crushed olives* Pichia caribbica
Pichia mississippiensis
Lachancea sp.
Lachancea thermotolerans
Kluyveromyces thermotolerans
Zygosaccharomyces fermentati
Pichia holstii
Candida thermophila
Olive fruits
Pichia guilliermondii
Candida maris
Candida humicola
Klyveromyces marxianus
Cryptococcus laurentii
Rhodotorula glutinis
Table olive fermentation
• By placing in the brine, part of the microorganisms
migrates to the brine and ferments the sugars derived from the olive
flesh.
• The anaerobic conditions, the salt and the gradual reduction of pH, exert
selective action on microorganisms.
• Under normal conditions, lactic acid bacteria and yeasts dominate.
• Basic metabolic products: lactic acid, acetic acid, ethanol.
• The temperature, the nutrient availability and the phenolic
compounds, the salt and the pH are critical factors for the course of
fermentation
• Stage Ι
(48-72 hours)
Enterobacter cloacae, Citrobacter freudii, Enterobacter aerogenes,
Escherichia coli, Aeromonas hydrophila, Flavobacterium diffusum, F.
balustinum, Pseudomonas spp. (Gram -)
Bacillus spp., Micrococcus spp., Clostridium spp. (Gram +)
• Stage ΙI
(14-15 days)
•
Gradual dominance of Pediococcus spp. & Leuconostoc spp. (cocci)
Reduction of Gram (-) bacteria
Microbiology of table olive fermentation – Stages of fermentation
• Stage ΙΙΙ
(main fermentation stage)
Dominance of Lactobacillus spp and specifically of L. plantarum, L. pentosus
Other species: L. brevis, L. fermentum, L. cellobiosus, L. casei
End of stage: pH 4,0 or lower
Microbial evolution during naturally black olive fermentation at25°C
•-□- lactic acid bacteria, -O- yeasts, -- enterobacteria -➢ pseudomonads
Tassou, C.C., Panagou, E.Z. and Katsaboxakis, K.Z. (2002), Food Microbiology 19:605-615.
Nychas, G., Panagou E.Z.,….. Tassou C. (2002) Microbial colonization of naturally black olives during fermentation and associated biochemical activities in the cover brine. Lett. Appl. Microb. 34:173-177
Microbiology of table olive fermentation
Nychas, G., Panagou E.Z.,….. Tassou C. (2002) Microbial colonization of naturally black olives during fermentation and associated biochemical activities in the cover brine. Lett. Appl. Microb. 34:173-177
Microbiology of table olive fermentation
Microbiology of table olive fermentation
•
The fermentation is considered complete and successful when:
• The desired microbiota,
• the physicochemical characteristics (pH, acidity, salt) and
• the organoleptic characteristics of olives have been developed.
Microbiology of fermentation -Lactic acid bacteria
Bonatsou S., Tassou C., Panagou E. Nychas GJ. (2017) Microorganisms 5: 30
Microbiology of fermentation -Yeasts
Bonatsou S., Tassou C., Panagou E. Nychas GJ. (2017) Microorganisms 5: 30
Microbiology of fermentation -Yeasts
Bonatsou S., Tassou C., Panagou E. Nychas GJ. (2017) Microorganisms 5: 30
Cluster analysis of PFGE ApaI digestion fragments of the different lactic acidbacteria strains recovered from olives and brine calculated by the unweightedaverage pair grouping method. The distance between the pattern of eachstrain is indicated by the mean correlation coefficient (r%).
71 different strains of lactic acid bacteria isolated from fermented olives of Greek
varieties
and identified using molecular tools
13 Lactobacillus plantarum
37 Lb. pentosus
1 Lb. paraplantarum
2 Lb. casei group (Lb. casei, Lb. paracasei)
17 Leuconostoc mesenteroides
1 Ln. pseudomesenteroides
Lb. pentosus 606
Ln. mesenteroides B275
Ln. mesenteroides B276
Ln. mesenteroides B265
Ln. mesenteroides B267
Ln. mesenteroides B273
Ln. mesenteroides B259
Ln. mesenteroides B269
Ln. mesenteroides B274
Ln. mesenteroides B260
Ln. mesenteroides B264
Ln. mesenteroides B271
Ln. mesenteroides B266
Ln. mesenteroides B268
Ln. mesenteroides B263
Ln. mesenteroides B262
Ln. mesenteroides B270
Lb. pentosus B279
Lb. pentosus E129
Lb. pentosus E83
Lb. pentosus E84
Lb. pentosus E182
Lb. pentosus 612
Lb. pentosus E141
Lb. plantarum E45
Lb. pentosus E43
Lb. plantarum E10
Lb. plantarum E50
Lb. pentosus E130
Lb. plantarum E68
Lb. plantarum E79
Lb. plantarum E73
Lb. plantarum E66
Lb. plantarum E77
Lb. plantarum E4
Lb. pentosus E128
Lb. pentosus E139
Lb. pentosus E108
Lb. pentosus E111
Lb. pentosus E121
Lb. plantarum E131
Lb. pentosus E105
Lb. pentosus E101
Lb. plantarum E69
Lb. pentosus 609
Lb. pentosus 632
Lb. pentosus E96
Ln. mesenteroides B261
Lb. pentosus 390A
Lb. pentosus 625A
Lb. pentosus E100
Lb. pentosus B283
Lb. plantarum E71
Lb. plantarum B282
Lb. pentosus E119
Lb. pentosus E120
Lb. pentosus 637
Lb. pentosus E110
Lb. pentosus E97
Lb. pentosus E106B
Lb. pentosus E89
Lb. pentosus E104
Lb. pentosus B278
Lb. pentosus B281
Lb. paraplantarum B280
Lb. pentosus B284
Lb. pentosus B285
Ln. pseudomesenteroides B277
Lb. pentosus E95
Lb. casei group E93
Lb. casei group E94
10080604020
Microbiology of fermentation – Lactic acid bacteria
National and European Research projects on table olive fermentation implemented in NAGREF-ITAP since 1987
NATIONAL AGRICULTURAL
RESEARCH FOUNDATION
NAGREF
1. Study of the microbiology of olive fruit (GSRT) (1987-1989)
2. Ιmprovement of texture characteristics of some European olive fruit varieties suitable for table olive purposes (ΕU,FAIR-CT97-3053) (1997-2000)
3. Biocontrol of olive fermentation; Microbiological and organoleptic studies for the improvement of safety, quality andacceptance of the final product (ΕU, FAIR-9526) (1997-1999)
4. Technological improvement of the fermentation and preservation of green olives (GSRT-PAVE 99) (1999-2001)
5. Technological improvement of the fermentation and preservation of natural black olives and new productdevelopment (GSRT-PAVE 99) (1999-2001)
6. Natural fermentation of green olives with selected strains of lactic acid bacteria resistant to phenolic substances(NAGREF-British Council) (2000-2002)
7. Setting-up a network of Technology Dissemination Centres to optimise SME’s in the olive and olive oil sector (TDC-OLIVE) (ΕU, FOOD-CT-2004-505524) (2004-2006)
8. Improvement of green olive fermentation using probiotic lactic acid bacteria as starters (GSRT-PENED) (2005-2008)
9. Green olive fermentation with probiotic lactic acid bacteria (NAGREF-Tunisia) (2006-2008)
10. Study of the parameters related to processing, preservation and distribution of table olives. Application of improvedtechniques at industrial level for the quality improvement and minimization of environmental impact Reg. (ΕC)2080/05 (12/06-3/08)
11. Preservation of green Kalamata table olives with P. Stathopoulos company.
12. Training of the sensory panel on the organoleptic characteristics of table olives according to the method of Intern.l Olive Council (COI/OT/MO No1/Rev.2 - 2011 ‘Sensory analysis of table olives’) Reg.(ΕC)867/08 (4/2012-3/2015)
13. Table olive fermentation with selected probiotic bacteria. Towards a functional food “PROBIOLIVES”(EU, FP7-SME-2008) (2010-2013)
Cluster analysis of PFGE ApaI digestion fragments of the different lactic acidbacteria strains recovered from olives and brine calculated by the unweightedaverage pair grouping method. The distance between the pattern of eachstrain is indicated by the mean correlation coefficient (r%).
Lactic acid bacteria71 different strains of lactic acid bacteria isolated from fermented olives of Greek
varieties
13 Lactobacillus plantarum
37 Lb. pentosus
1 Lb. paraplantarum
2 Lb. casei group (Lb. casei, Lb. paracasei)
17 Leuconostoc mesenteroides
1 Ln. pseudomesenteroides
9 of them showed PROBIOTIC POTENTIAL IN VITRO
Lb. pentosus 606
Ln. mesenteroides B275
Ln. mesenteroides B276
Ln. mesenteroides B265
Ln. mesenteroides B267
Ln. mesenteroides B273
Ln. mesenteroides B259
Ln. mesenteroides B269
Ln. mesenteroides B274
Ln. mesenteroides B260
Ln. mesenteroides B264
Ln. mesenteroides B271
Ln. mesenteroides B266
Ln. mesenteroides B268
Ln. mesenteroides B263
Ln. mesenteroides B262
Ln. mesenteroides B270
Lb. pentosus B279
Lb. pentosus E129
Lb. pentosus E83
Lb. pentosus E84
Lb. pentosus E182
Lb. pentosus 612
Lb. pentosus E141
Lb. plantarum E45
Lb. pentosus E43
Lb. plantarum E10
Lb. plantarum E50
Lb. pentosus E130
Lb. plantarum E68
Lb. plantarum E79
Lb. plantarum E73
Lb. plantarum E66
Lb. plantarum E77
Lb. plantarum E4
Lb. pentosus E128
Lb. pentosus E139
Lb. pentosus E108
Lb. pentosus E111
Lb. pentosus E121
Lb. plantarum E131
Lb. pentosus E105
Lb. pentosus E101
Lb. plantarum E69
Lb. pentosus 609
Lb. pentosus 632
Lb. pentosus E96
Ln. mesenteroides B261
Lb. pentosus 390A
Lb. pentosus 625A
Lb. pentosus E100
Lb. pentosus B283
Lb. plantarum E71
Lb. plantarum B282
Lb. pentosus E119
Lb. pentosus E120
Lb. pentosus 637
Lb. pentosus E110
Lb. pentosus E97
Lb. pentosus E106B
Lb. pentosus E89
Lb. pentosus E104
Lb. pentosus B278
Lb. pentosus B281
Lb. paraplantarum B280
Lb. pentosus B284
Lb. pentosus B285
Ln. pseudomesenteroides B277
Lb. pentosus E95
Lb. casei group E93
Lb. casei group E94
10080604020
Microbiology of fermentation
Test
Strains Low pH
(SR%)a
Bile salts
(SR%)b
Bile salts
hydrolysis
Haemolytic
activityd
Antibiotic
resistance eCaco-2
(Adherence%
)
Lb. pentosus B281 95.64 94.78 0 c α K, C, S 37.21
Lb. pentosus E97 89.69 96.79 0 γ K, C, S 39.76
Lb. pentosus E104 92.52 97.64 0 γ K, G 33.72
Lb. pentosus E108 91.08 100.59 0 γ K, A 60.78
Lb. plantarum B282 87.79 100.09 1 γ K, G, E 68.94
Lb. plantarum E10 89.95 98.67 1 γ K, G 44.75
Lb. plantarum E69 98.36 100.02 0 γ K, G 30.51
Lb. paracasei subs. paracasei
E93
89.41 96.55 0 γ K, G, S 41.92
Lb. paracasei subs. paracasei
E94
82.75 88.80 0 γ K, G, S 74.02
Lb. casei Shirota 82.83 100.20 0 γ S, E, P, T, C 31.41
Lb. rhamnosus GG 64.02 100.61 0 γ K, A, P 34.00
•a survival rate after 3h in low pH, b survival rate after 4h in bile salts, c 0, no hydγrolysis; 1, partial hydrolysis.
•d a-haemolysis, γ-haemolysis, e A: ampicillin, V: vancomycin, G: gentamycin, K: kanamycin, S: streptomycin, P: penicillin,
E: erythromycin, T: tetracycline, C: chloramphenicol
Assessment of probiotic potential by in vitro tests (Lb. casei Shirota & Lb. rhamnosus GG used as reference strains)
Definition of probiotics
“live microorganisms which, when consumed in adequate amounts, confer a health benefit on the host (FAO/WHO, 2002)
• In the early 1930's, in Japan, Minoru Shirotamade a probiotic yoghurt type product, Yakult, from fat-free fermented milk with the strainLactobacillus casei shirota.
• The term "probiotic" was introduced in 1965 by Lilly & Stillwell.
• Pro- + bios = Life (promotes life)
➢ They are mainly lactic acid bacteria but also yeasts.
➢ They are used mainly in fermented dairy foods but also as food supplements.
➢ To exert their beneficial action, consumption of at least 106-107
cfu/g is needed
Probiotic microorganisms
Known probiotic strains
Lactobacillus species• L. acidophilus• L. plantarum• L. casei subspecies rhamnosus• L. brevis• L. delbreuckii subspecies bulgaricus
Bifidobacterium species• B. adolescentis• B. bifidum• B. longum• B. infantis
• B. breve
•
Other:
• Streptococcus salivarius ssp. thermophilus
• Lactococcus lactis ssp. lactis
• Lactococcus lactis s ssp. cremoris
• Enterococcus faecium
• Leuconostoc mesenteroides ssp. dextranicum
• Propionibacterium freudenreichii
• Pediococcus acidilactici
• Saccharomyces boulardii
Minimum requirements for characterization as probiotics
✓ Identification (genus, species, strain)
✓ In vitro tests for selection: eg. resistance to gastric acidity, digestive enzymes, bile salts, antimicrobial action on pathogens
✓ Safety test: that the probiotic strain is safe and free of contamination in the form administered
✓ In vivo studies to document action on health
Beneficial actions of probiotics
• Antimicrobial actions (inhibition of pathogenic microorganisms)
• Biochemical actions (relieving lactose intolerance, lowering cholesterol, antihypertensive action, etc.)
• Physiological actions (stimulation of the immune system, treatment of allergies, etc.)
Mechanisms of action
• Lactic acid production - pH reduction in the GIT and pathogen inhibition eg. Clostridium, Salmonella, Shigella, E. coli, etc.
• Reduction of toxic and carcinogenic metabolites production.
• Increased acidity in the intestine helps in the absorption of trace elements, especially calcium.
• Production of β-D-galactosidase enzyme for lactose degradation.
• Production of antimicrobials such as Bacteriocins and Vitamins (B & K vitamins)
• Inhibition of pathogen adhesion to the intestinal epithelium.
Suggested probiotic consumption
• Minimum intake:
100g of a probiotic food with 107 cfu/g.
• Most probiotics do not permanently adhere to the
epithelium but exhibit their action with their
increase and metabolism in their passage through
the intestine.
• Daily intake of these bacteria is the best way for
their activity and effectiveness.
Poly-probiotics
1. Lactobacillus gasseri PA16/8, Bifidobacterium bifidum MF20/5, Bifidobacterium longum SP07/3
2. Lactobacillus acidophilus, Bifidobacterium longum
3. Lactobacillus acidophilus, Bifidobacterium bifidum, Bifidobacteriumlongum
4. Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus Casei, var. Rhamnosus, Enterococcus faecium
Food is the best way to take probiotics….
There is a synergistic effect between the components of the food (prebiotics) and the probiotic cultures.
The natural balancing of the acid environment in the stomach by the food also increases the stability of probiotics.
The fermented foods provide:
• a traditional preservation method desired by consumers
• components valuable to health eg. antioxidants, vitamins, fibre present in fruits & vegetables
• the occurence of beneficial microorganisms and their enrichment with probiotic bacteria may add value to them.
Traditional fermented foods as probiotic carriers
Table olives are a high nutritional food that provides essential fatty acids, fibers, vitamins and trace minerals, mainly calcium, iron, potassium, magnesium, phosphorus and iodine.
They contain a very high percentage of unsaturated fatty acids, especially oleic acid.
They also contain polyphenols and flavonoids that have anti-inflammatory action.
Their enrichment with probiotic bacteria will add value to the product.
The suggested daily intake for adults is 20-25 g olives/day, or 5-7 olives.
Table olives as a functional probiotic food
Probiotic lactic acid bacteria isolated from olive microbiota, were used successfully as starters in lab and pilot scale green olive fermentations
1) Lb. pentosus B281 x2
2) Lb. plantarum B282 x2
3) Cocktail B281+B282 x2
a) 8% (w/v) NaCl
b) 10% (w/v) NaCl
Probiotics from and for olives
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90 100 110 120
Time (d)
Lo
g c
fu/m
l AL
AH
AL
AH
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90 100 110 120
Time (d)
Lo
g c
fu/m
l BL
BH
BL
BH
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90 100 110 120
Time (d)
Lo
g c
fu/m
l SL
SH
SL
SH
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90 100 110 120
Time (d)
Log
cfu/
ml CL
CH
CL
CH
The probiotic lactic acid bacteria were maintained at high levels during fermentation
(3 months) regardless of the salt level
•L: Low salt, H: High salt ▪,●: Brine, ▫,◦: Olives
•Lb. pentosus B281 •Lb. plantarum B282
•Lb. pentosus B281 & Lb. plantarum B282 •Control
Brine 8% NaCl Brine 10% NaCl
Inoculated Strain
Fermentation time (d)
Survival rate (PFGE)
Fermentation time (d)
Survival rate (PFGE)
Lactobacillus pentosus B281
1 100% 1 100%
30 100% 30 100%
107 94.7% 107 100%
Lactobacillus plantarum B282
1 100% 1 100%
30 100% 30 100%
107 55% 107 58.8%
Mixed culture (B281+B282)
1 46.67%B281 / 53.33%B282
1 43.75%B281 / 56.25%B282
30 100%B281 30 42.86%B281 / 57.14%B282
107 100%B281 107 100%B281
Survival of probiotics at the end of fermentation (PFGE)
•B
2
8
1
•B
2
8
2
Packaging and storage
1) Autochthonous fermentation Control)
2) With Lb. pentosus B281
3) With Lb. plantarum B282
4) With Cocktail B281+B282
Storage at 4 °C and 20 °C
Packaging in MAP: 70% N2: 30% CO2 or in brine
0
1
2
3
4
5
6
7
8
9
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Time (d)
log
cfu
/g
0
1
2
3
4
5
6
7
8
9
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Time (d)
log
cfu
/g
0
1
2
3
4
5
6
7
8
9
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Time (d)
log
cfu
/g
0
1
2
3
4
5
6
7
8
9
0 20 40 60 80 100 120 140 160 180 200 220 240 260
Time (d)
log
cfu
/g
Survival of probiotics at high levels (105-106 cfu/g) after 6 months of storage
•■: 20 °C ♦: 4 °C
•Lb. pentosus B281 •Lb. plantarum B282
•Lb. pentosus B281 & Lb. plantarum B282 •Control
Survival of probiotic strains at the end of storage (detected by PFGE)
4oC 20oC
Inoculated strain Fermentation time (d)
Survival rate Survival rate
L. pentosus B281 1 90%
56 * 92.86% 93.33%
196 100% 20%
L. plantarum B282 1 87.5%
56 * 40% 46.66%
196 96% 10%
Mixed inoculum(B281 & B282)
1 90% B281 / 0% B282
56 * 73.33% B281 / 0% B282
40% B281/0% B282
196 100% B281/0% B282
60% B281/6.66% B282
Sensory evaluation – end of fermentation
The product “Probiotic olives” submitted by Agric.
Univ. Athens, received the 2nd prize at the
ECOTROPHELIA 2012 Innovative Food Competition
Patent No. 20110100600 «Functional table olives
fermented with lactic acid bacteria with probiotic
properties» PROBIOTIC OLIVES (OBI 14-10-2011)
by PEMETE
Distinctions
Lactic acid bacteria as bioprotective cultures
• Bioprotection is the enrichment of a foodstuff with bio-protective cultures of bacteria capable of inhibiting the growth of spoilage and pathogenic microorganisms.
• It helps to extend the shelf life and maintain food safety.
• Bioprotective cultures can be used with the fermentation cultures or as culture adjuncts.
Lactic acid bacteria as bioprotective cultures
➢ Τhe activity of lactic acid bacteria during fermentation, results in the
production of a variety of metabolic compounds, in which lactate and acetate
predominate, lowering the pH of the brine and decreasing thus the presence of
pathogenic microorganisms.
Lactic acid bacteria as bioprotective cultures
Safety of table olives
➢ In addition, antimicrobial compounds (e.g. ethanol, bacteriocins) produced by
certain strains of lactic acid bacteria contribute to a better preservation effect of
the final product.
➢ For this reason, fermented foods have been generally considered less likely to
cause foodborne infection or intoxication.
• A survey was carried out in Greece involving 69 different commercially available
table olive preparations, including Spanish-style green olives, naturally black olives
and dry-salted olives.
• No enterobacteriaceae, pseudomonads, B. cereus, or Clostridium perfringens were
detected in any of the samples analyzed given the physicochemical characteristics
found (average pH, 3.9–4.3; salt content, 6.2–7.3).
•Absence of Salmonella spp., L. monocytogenes, E. coli, Bacillus cereus and C. perfringens reported by Grounta, Nychas Panagou (2013) Int. J. Food Microb. 161: 197-202
•Similar observations in Spain and Italy
Safety of table olives
Safety of table olives
•Inoculation (107 cfu/ml)
•Escherichia coli O157:H7,
•Listeria monocytogenes
•Salmonella Enteritidis
•Fermented Olives
•Removal of brine
•Fresh brine addition(NaCl 6% w/v)
•Packaging 70% N2:30% CO2
•Storage at 4ο & 20°C
Safety of table olives
(a)
0
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40
Time (days)
Lo
g c
fu/m
l
•Escherichia coli O157:H7
(a)
0
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40
Time (days)
Lo
g c
fu/m
l
•Salmonella Enteritidis
(a)
0
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40 45 50
Time (days)
Lo
g c
fu/m
l
•Listeria monocytogenes
8 ημέρες 17 ημέρες 14 ημέρες 22ημέρες
Salmonella Enteritidis PT4Bacillus cereus
Safety of table olives
Panagou E., Tassou C., ….Nychas GJ. (2008) J. Food Protection 71: 1393-1400
Panagou E., Nychas GJ. Sofos J. (2013) Food Control 29:32-41
• Recently, Grounta et al. (2013) demonstrated also that Salmonella, E. coli O157:H7, L. monocytogenes and S. aureus did not survive on natural black olives stored under aerobic conditions.
Therefore the results indicate that:
Fermented olives can be a probiotic, functional food of high
added value,
Fermented olives are safe, since they are not a favorable
environment to support the growth of foodborne pathogens.
Organoleptic evaluation of table olives
The first National Taste panel has been trained according to the method
COI/T.20/Doc.No 6/Rev.1 (Sept.2007) by Dr. Tertivanidis and Assoc. Prof. Panagou at
the laboratory of ITAP and is provided to interested companies.
Thank you for your attention!
NATIONAL AGRICULTURAL
RESEARCH FOUNDATION
NAGREF
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