Microbial Profile of 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,

organic hummus made with sustainable and locally grown ingredients and without the

use of artificial preservatives.

Problem: Shelf lifeQuestion: 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

2530

Original Bell Pepper Pura Vida

week 1

60

4029 27

11

Original Bell Pepper Pura Vida

Results.

week 2

180

10039 18 15

Original Bell Pepper Pura Vida

Results.

Problems with autoclave

week 3Results.

week 4

40

10

90

5 7

Original Bell Pepper Pura Vida

Results.

Results.

Categorizing of Bacteria.Gram Staining Results of Original APC ColoniesColony appearance

A - perfect circle, creamy, rings, uniform colorB - spheres, creamy, flatC - circular and jagged edgesD - cloudy, circular

Gram Stain Results

A - Gram negative and positive bacillus possibly encapsulatedB - Gram negative diplobacilliC - Gram positive streptococciD - Gram positive diplococci

Identification of Bacteria.Current Results: Microbacterium barkeri

Family: Microbacteriaceae is a family of bacteria of the order Actinomycetales.

Genera: MicrobacteriumThey are Gram-positive rods.

Frequently isolated from soil.

Identification of Bacteria.Current Results: Micrococcus lylae

Family: Micrococcaceae is a family of bacteria of the order Actinomycetales

Genera: MicrococcusThey 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○ outcompeting 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