Microbial Profile of Hummus. Categorizing and identifying - - PowerPoint PPT Presentation

Microbial Profile

• f

Hummus.

Brittany Richards Maren Clark Nelssie Flores Ya Ya Wong

Categorizing and identifying microflora

Happy Monkey Hummus is a local company dedicated to the creation of wholesome,

• rganic hummus made with sustainable and

locally grown ingredients and without the use of artificial preservatives. Problem: Shelf life Question: Microbial flora present in hummus? A series of microbial tests were performed with the objective of categorizing and identifying microflora

Our Project.

Method - Enumeration.

• Samples

○ A: Original ○ B: Fire Roasted Bell Pepper ○ C: Pura Vida

• Tests

○ Coliform ○ Yeast and Mold ○ Aerobic Plate Count (APC) ○ Mesophilic Aerobic Spore (MAS) Test

• Mesophilic Aerobic

Spore Test (MAS)

○ Tryptone glucose extract (TGE) agar ○ Flasks held in water bath (80˚C) for 30 minutes ■ activates spores ○ Pour plates

Method - Enumeration.

Method - Identification.

Colonies from APC (4)

Categorized

Gram Stain Morphology

Colonies from TGE (2)

Identification

• Dr. Robison’s Lab

Microbial identification system (MIS)

whole cell fatty acid analysis via gas chromatography (This method was also used in Dr. Steele’s paper on corn masa)

Results.

week 0

20 20 10 17 25 30

Original Bell Pepper Pura Vida

week 1

60 40 29 27 11

Original Bell Pepper Pura Vida

Results.

week 2

180 100 39 18 15

Original Bell Pepper Pura Vida

Results.

Problems with autoclave

week 3

Results.

week 4

40 10 90 5 7

Original Bell Pepper Pura Vida

Results.

Results.

Categorizing of Bacteria.

Gram Staining Results of Original APC Colonies

Colony appearance

A - perfect circle, creamy, rings, uniform color B - spheres, creamy, flat C - circular and jagged edges D - cloudy, circular

Gram Stain Results

A - Gram negative and positive bacillus possibly encapsulated B - Gram negative diplobacilli C - Gram positive streptococci D - Gram positive diplococci

Identification of Bacteria.

Current Results: Microbacterium barkeri

Family: Microbacteriaceae is a family of bacteria of the

• rder Actinomycetales.

Genera: Microbacterium They are Gram-positive rods. Frequently isolated from soil.

Identification of Bacteria.

Current Results: Micrococcus lylae

Family: Micrococcaceae is a family of bacteria of the

• rder Actinomycetales

Genera: Micrococcus They are Gram-positive spheres. Frequently isolated from soil, water, and dust.

• Competition
• pH

○ <4.0

• Process temperature

○ Cook beans, add dry ingredients held 180˚F for 10-15 minutes.

Discussion-

Coliforms, Yeast and Mold

Discussion - APC.

• Most growth in Sample A

(Original)

○ Least ingredients ○ Antimicrobial effects of red bell peppers (Sample B) ○ Antimicrobial effects of spices (Sample C)

• Sample A and B growth starts to

decline at week 4

○

• utcompeting of microorganisms

○ liquefying gel of Petrifilm APC plates

■ inaccurate count

• Tahini
• from sesame
• sesame grow close to

the soil

• made in developing

countries (Jordan)

• Why decreased?
• reverting of the activated spores to

dormant form under 40 ˚F

Discussion -

Mesophilic Aerobic Sporeformers

• Why increased?

superdormant Bacillus spores

• higher moist-heat resistance
• recover from heat stress injuries

during refrigeration

Conclusion.

• Inhibitory effects of various spices was

efficient

• Using our research and identifications,

company can further determine shelf life

• More research to be done

References.

2010-03, Hazard Analysis and Critical Control Point Generic Models for Some Trad Allahghadri, T., Rasooli, I., Owlia, P., Nadooshan, M. J., Ghazanfari, T., Taghizadeh, M. and Astaneh, S. D. A. (2010), Antimicrobial Property, Antioxidant Capacity, and Cytotoxicity of Essential Oil from Cumin Produced in Iran. Journal of Food Science, 75: H54–H61. doi: 10.1111/j.1750-3841.2009.01467.x Rodriguez-Palacios, A., LeJeune, T.J. (2011), Moist-Heat Resistance, Spore Aging, and Superdormancy in Clostriduim difficile in American Society for Microbiology, May 2011 vol. 77 no. 9 3085-3091 Amaeze, N.J. (2013), Effect of different fruit components, aeration and cold storage at 5°C on the germination of ascospores of Neosartorya fischeri. Letters in Applied Microbiology, 56: 443–448. doi: 10.1111/lam.12072 Ghosh S., Setlow P. 2009. Isolation and characterization of superdormant spores of Bacillus species. J. Bacteriol. 191: 1787–1797.

Questions?

Thank you