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THE EFFECT OF HIGH HYDROSTATIC PRESSURE ON THE QUALITY OF CAMEMBERT TYPE CHEESE
DANTON BATTYADVISED BY DR. JOY WAITE-CUSIC AND DR. LISBETH GODDIK
A little about me
• Grew up in The Dalles, OR
• B.S. in Food Science & Technology from OSU (2016)
• Completing M.S. program this spring
• Involved in IFTSA, ADSA GSD, and BUILD dairy
• Previous experience: cheese maker at OSU (2014-2016) and internships in yogurt, ingredient, and cheese manufacture
• Career interest in applied research and technical operations
OREGON STATE UNIVERSITY 1
Project overview
• Characterize Camembert type cheeses
• Screen Camembert cheese varieties for resistance to high hydrostatic pressure (HPP)
• Determine the effect of HPP on cheese quality
• Evaluate HPP for the reduction of E. coli and Listeria monocytogenes
OREGON STATE UNIVERSITY 2
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Camembert type cheese
OREGON STATE UNIVERSITY 3
• Soft surface-ripened cheese that originated in France
• Surface yeasts and molds are required for the expedited ripening
• Multiple varieties exist (lactic curd, washed curd, stabilized curd, ect.)
• Different varieties result in variable shelf-life and rate of softening
• High risk of contamination by environmental pathogens (Listeria monocytogenes)
• We expect that the manufacturing procedures and recipe will dictate the effect of HPP on the cheese quality
https://www.nytimes.com/2009/12/30/dining/30curi.html
Paste stability 50 days post manufacture
OREGON STATE UNIVERSITY 4
Lactic curd
Washed curd
Blended culture
Stabilized curd
Sweet curd low pH
7 weeks in to ripening at room temperature for 1 hour.
*Previous work done to characterize cheese recipes.
High hydrostatic pressure processing
OREGON STATE UNIVERSITY 5
• Currently used on many foods with little effect on quality
• Principle: High pressure (up to 100,000 PSI) is transferred through a food product sitting in a liquid chamber
• Kills bacteria (pathogens & spoilage organisms) without heat
• Applied to food in final packaging (no risk of recontamination)
http://canigivemybaby.com/deli-meat/ https://www.bbcgoodfood.com/howto/guide/should-i-still-drink-fruit-juicehttps://www.marthastewart.com/1004485/creamy-avocado-dip
Objectives of the experiment
OREGON STATE UNIVERSITY 6
• Identify a treatment time for Camembert type cheese to retain quality• Scenario 1: before surface mold growth (day 3)
• Scenario 2: after mold growth prior to theoretical distribution (day 11)
• Scenario 3: at the end of shelf life (day 45)
• Determine how different Camembert recipes withstand the HPP process
• For this presentation just the traditional and stabilized varieties will be compared
Experiment methodology
OREGON STATE UNIVERSITY 7
• Each has varying pH, composition, and shelf life
Manufacture 3 cheese types
• 550 MPa (10 min at 25° C)
• Experiment with treatment time (3, 11, and 45 days post manufacture)
HPP treat
• Appearance (color)
• Texture
• Microbiology (yeasts and molds from rind)
Analyze for key quality metrics
Results – texture
OREGON STATE UNIVERSITY 8
Control
3 day
11 day
45 day
Stabilized
a
a
a
b
b
b
bb aa
bbbb b
Control
3 day
11 day
45 day
Traditional
ab
b
a
a
a
bb
ba
aab
Results – microbiology
OREGON STATE UNIVERSITY 9
Control
3 day
11 day
45 day
Traditional
Result below detection limit (< 10 CFU/g)
b
a
a
b
a aa
b
aa
b
c
Control
3 day
11 day
45 day
Stabilized
c
bb
a aa
a
a a
b
a
b
Appearance 50 days post mfg (traditional variety)
OREGON STATE UNIVERSITY 10
3 day treatment
45 day treatment
Control11 day treatment
Appearance 50 days post mfg (stabilized variety)
OREGON STATE UNIVERSITY 11
3 day treatment
45 day treatment
Control11 day treatment
Summary of findings
OREGON STATE UNIVERSITY 12
• Treatment time has a greater impact on quality than variety of Camembert
cheese
• HPP has little impact on texture by the end of ripening (50 days)
• The surface flora that makes up the rind is negatively impacted by HPP
• Penicillium camemberti mycelium is lysed and survival is declined
• The color of the cheese surface is negatively impacted by HPP
• Good news: HPP can be effectively used on soft ripened cheese with little impact on texture
Thank you for your time!
OREGON STATE UNIVERSITY 13
Special thanks to:
Dairy Management Inc. Eckelman Memorial Fellowship
Arbuthnot Dairy CenterOSU Dairy Processing Group
Waite-Cusic Lab Alex Emch
Danica Berry Cornell HPP Validation Center
OSU Seafood Lab
Additional questions? Contact me at: