Potential of Lactobacillus in Northern European cheeses

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Potential of LactobacillusinNorthern European
cheeses

• Symposium in Tallinn, Estonia23-25 April 2007

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Session A Lactobacillus in Nordic cheese

• Lactobacillus helveticus enhance flavour
  production in cheese
• NSLAB well characterised in many Northern
  European cheeses
• The metabolism of Lb. plantarum (most probably
  the majority of NSLABs) in cheese is influenced
  by the starter used
• In cheeses with added Lb. helveticus 16 key aroma
  compounds has been identified
• The proportions and numbers of NSLAB are
  dynamically changing during ripening of Estonian
  cheeses. Most of the isolates were Lb. paracasei,
  Lb. curvatus and Lb. danicus and some have good
  resistance to acid and bile salts.

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Session A Lactobacillus in Nordic cheese

• Lb. rhamnosus, Lb. casei and Lb . fermentum was
  found in finish Emmental during ripening, with
  the first one dominating.
• The microflora of a Swedish hard cheese was
  dominated by NSLAB (Lactobacillus) after 3 weeks
  of ripening and a correlation between diversity
  and aroma was indicated.
• 6 different aminopeptidases were found in Lb.
  paracasei, specific for Leu-pNA, Lys-pNA and
  Gly-Pro-pNA

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SPA EVENING

• Thalasso sauna
• perfect negotiation arena
• Massage - ahh!
• Salt chamber
• did you fell asleep?
• Swimming pool
• exercise of the week?
• Infrared sauna

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Session B Lactobacillus as cheese ripening
cultures

• NSLAB do impact on flavour but they are not key
  drivers
• NSLAB cocktails
• Remember the potential of NSLABs for functional
  foods
• Lb. paracaseis does not lyse very much,
• Survive at least 3 h at pH 3 and were resistant
  to bile salt, but only few survived at pH 2.
• Many of them metabolise citrate and reduce pH in
  milk.
• Lb. helveticus strains isolated from cheese grew
  better than the Laboratory strains, and they
  showed no degradation of peptides in a cheese
  extract
• Calorimetric measurements showed that Lb.
  paracasei and St. thermophilus grew better in
  pasteurised milk than in UHT treated milk and
  reconstituted milk

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Session C Improving bioactivity of cheese

• Focus on the functional properties of cheese for
  health
• Vehicle for probiotic bacteria
• CLA
• Bioactive peptides
• Lactococcus strains were more inhibited by spice
  ethanol extracts than Lactobacillus strains with
  clove ethanol extract being the most inhibitive.
• H2O2 addition to milk 1 h before starter
  inoculation influenced the growth of the starter
  and the rheological characteristics of the milk
  gels.

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Session C Improving bioactivity of cheese

• Addition of heat-treated Lb. helveticus
  accelerated breakdown of phospopeptides in
  cheese but did not remove them
• Acetone extracts of rosemary, curcuma and savoury
  had antibacterial effect against lactic acid
  bacteria and pathogenic and spoilage bacteria,
  but were more inhibitive to the lactic acid
  bacteria.
• Amino acids and hydrophilic peptides contribute
  to savoury flavour in cheese and the presence of
  thermophilic Lactobacillus increases the level of
  these components

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Estonian Spring Experience

• City tour with one English and Swedish speaking
  guides
• Now we know the Estonians?
• Dinner at Eesti Maja, a traditional Estonian
  restaurant
• No reason to visit Mc Donalds!

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Session D Application of genomics data for
Lactobacillus in the production of cheeses

• We are impressed by the possibility of
  transcriptomics to study the up and down
  regulation of the microorganisms, we started to
  realise which opportunities we have in the
  future. We started to realise that the amount of
  frustrations in the future will be reduced!
• New nomenclature for the Lb. casei complex has to
  come.
• LTA Lipoteichoic acids
• Low D-alanylation LTAs allows LTA to function as
  an active phage receptor for phage LL-H in Lb.
  delbrueckii subsp. Lactis.
• High D-alaynalated LTAs - immunostimulary
  activities.
• Ca2 and or Mg2 binding
• Inhibition of enzyme activities
• Antigenic
• Lactobacillus paracasei strains showed inhibition
  towards several moulds and Clostridia. Danish
  strains more inhibitive towards clostridia than
  Czech strains

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NordOst

• www.umb.no/nordost
• PhD course
• Final Progress of the NordOst network
• Travel Claim Form
• Proceedings
• 5th IDF Conference on Cheese Ripening
• www.cheese2008.ch