Scholar Series: Allison Brown, PhD Candidate in Food Science and International Agriculture and Development
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Description: An interview as part of the Well Tempered Podcast\\u2019s \\u2018Scholar Series\\u2019 (recorded February 2020)
Guest: Allison Brown, PhD candidate at Penn State
Area of study: Food Science and International Agriculture and Development
Allison Brown is a PhD candidate and USDA NIFA (United States Department of Agriculture, National Institute of Food and Agriculture) predoctoral fellow studying a dual-title degree in Food Science and International Agriculture and Development at The Pennsylvania State University. She studies cocoa and chocolate using chemical and sensory analysis to fingerprint the flavor, taste, and mouthfeel of varieties of Theobroma cacao. In addition, she led a consumer research project to understand the importance of chocolate flavor to premium chocolate consumers. For the international agriculture and development portion of her PhD, she studies the impact of an in-country national cocoa sensory panel on cocoa quality, using Honduras as a case study. She draws on professional experience in food science product development, chocolate production, culinary arts, winery cellar work, and winery laboratory work.
Most recently she has published work in The Journal of Sensory Studies, entitled "Flavor and Mouthfeel of Pseudo-Cocoa Liquor: Effects of Polyphenols, Fat Content, and Training Method".
Citation: Hamada, T. Y., Brown, A., Hopfer, H., & Ziegler, G. R. (2019). Flavor and mouthfeel of pseudo-cocoa liquor\\u202f: Effects of polyphenols, fat content, and training method, (June), 1\\u20137. https://doi.org/10.1111/joss.12541 (Note: at the time of this podcast episode\\u2019s release, this article was available to access for free).
Her manuscript about premium chocolate consumer perception of chocolate quality and craft chocolate is currently under review.
UPDATE December 2020: Since release of this podcast episode Allison\\u2019s and her colleagues\\u2019 work \\u2018Understanding American premium chocolate consumer perception of craft chocolate and desirable product attribute using focus groups and projective mapping\\u2019 has been featured in PLoSONE. Their research was also referenced on Penn State\\u2019s news site.
\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\nPodcast RSS\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n\\n \\n\\n \\n \\n \\n\\n \\n\\n \\n\\u201c \\u2026(sensory evaluation) it\\u2019s not actually elite, it\\u2019s for the people. We all have these tools\\u2026we have our mouths. \\u201c - Allison Brown
\\n \\n \\n \\n \\n \\n \\n\\n \\n \\n Allison Brown, PhD Candidate in Food Science and International Agriculture and Development. photo credit: Allison Brown
\\nTopics discussed in this episode:
Part I. We talk about different types of food analyses:
-Chemical analysis: GC-MS, HPLC
-Sensory evaluation: hedonic testing (i.e. do you like this thing?), difference testing (i.e. are these different? triangle test), descriptive analysis testing (i.e. how are these things different?); the 3rd is used in Allison\\u2019s panel.
- Tasting cocoa liquors, creating references to other food products
- Attribute generation = key-in to your senses, looks, smells, tastes like (ensure air is present to volatilize chemical compounds), perceive flavor, then note aftertaste, oral touch
- The 5 basic tastes: bitter, sour, sweet, salty, umami
\\u2014-> Receptors versus ion exchange on our tongue recognize bitter and sour as basic tastes, astringency is an oral touch. Sour can cause a puckering sensation.
\\u2014-> Flavor on the other hand is different from basic taste; taste, smell, touch, burning (such as from capsicum), sound, sensory. A complex perception. The burnt flavor (such as related to burnt toast) falls into this category.
- The \\u2018golden tongue\\u2019
Part II. We also talk about genetics, and how flavor could be linked to genetics (scroll to the bottom for a quick overview of genetics).
- there are 4,000 known accessions of Theobroma cacao in genebanks; lots of diversity. In her project she studied 11 cultivars.
-Mark Guiltinan and Siela Maximova (see here for information about their lab and access some of their publications: https://plantscience.psu.edu/research/labs/guiltinan) are plant biologists who have spent their careers researching the plant, Theobroma cacao. In 2010, they discovered the genome of Theobroma cacao (https://plantscience.psu.edu/research/labs/guiltinan/publications/manuscripts/genome-cacao2010), and use this information to understand how diseases and pests impact growth of this plant.
- In her work, it was necessary to search for a tropical research center that could provide adequate needs of cultivars for sampling; Fundaci\\xf3n Hondure\\xf1a de Investigaci\\xf3n Agr\\xedcola FHIA
Part III. Publications, Projects, and her Panel.
In fall 2019, they published in The Journal of Sensory Studies: Flavor and mouthfeel of pseudo-cocoa liquor: Effects of polyphenols, fat content, and training method. Researchers were: Terianne Y. Hamada, Allison Brown, Helene Hopfer, Gregory R. Ziegler.
In post-conflict Rwanda, high quality coffee began to be produced there (and marketed outward).
\\u2014-> To detect defects in coffee cupping, they introduced the \\u2018Coffee Doctors\\u2019 - who diagnose fermentation issues through sensory training tactics. This can be transferred to cocoa. Read more; article by Jenny Elaine Goldstein (2011): https://www.tandfonline.com/doi/abs/10.1080/07409710.2011.544226
More related coffee links:
Coffee Quality Institute - Rwanda
Transforming Rwanda\\u2019s Coffee Sector by Dan Clay (PPT)
For cocoa:
Examples of USAID work on cocoa liquor tasting panels in-country: African Cocoa Initiative Final Performance Evaluation Report
USAID Grants and the Democracy of Information, from Equal Exchange
Because no one has previously analyzed the impact of an in-country panel on cocoa liquor quality, Allison used exploratory, qualitative methods in Honduras. She conducted interviews with 35 members of the cocoa and chocolate supply chain, including growers, cooperative managers, Honduran chocolate makers, and American chocolate makers.
Fingerprinting taste and flavor of varieties ; do varieties taste different?
\\u2014-> Fingerprinting is determining which chemicals, both volatile and non-volatile, and flavors, tastes, and mouthfeels, are associated with each cultivated variety (cultivar) of theobroma cacao
Convergent validity - Why is this important for scientists?
This is important because it means two different methods tell you the same thing. It means your findings are highly robust.
Allison\\u2019s consumer focus groups:
---> People & Packaging
---> Storytelling
Further links related to this episode:
Dr. Kristy Leissle\\u2019s article on craft.
As well as her writing on the subject via Dandelion Chocolate\\u2019s blog.
PennState\\u2019s Dr. Gregory Ziegler, editor on Steve T. Beckett\\u2019s Industrial Chocolate Manufacture and Use; his work on bound and unbound polyphenols, fat content, and their nuances has informed Allison\\u2019s work
FCCI/FCIA consumer survey mentioned, is only available to members of the FCIA:
Here Karen Bryant offers an overview.
The Professional Manufacturing Confectioners Association (PMCA) conference scheduled for April 20-22, 2020 was postponed this year due to the pandemic.
PennState Department of Food Science Short Courses: such as, Advanced HACCP Workshop, Principles of Sensory Evaluation, Ice Cream 101 \\u2018Introduction to Frozen Desserts\\u2019
(continued from Part II. )
::A brief primer on genetics (as she says, \\u201cfrom someone who isn\\u2019t a plant biologist\\u201d but that \\u201cis still helpful to someone like me,\\u201d says the podcast host without a science degree.)::
-Genes are composed of DNA which is the basic code for the plant.
-Phenotypes are the perceivable traits or characteristics that are coded for by the genotype, but may be impacted by the environment (sun exposure, rain, soil type, etc.).
Some phenotypes are more fixed than others. A human example would be: my genes code for hazel (phenotype) eyes and I have hazel eyes my entire life. A less fixed example would be: my genes code for brown hair (phenotype). However, when it is summertime and my hair is exposed to the sun (environment) regularly, it becomes blond. Think \\u201cnature and nurture.\\u201d
When translated to cacao, seed color (white or purple) is a fixed trait that is coded for by the genes, whereas pod color is also coded for by the genes, but not fixed because it is influenced by shade cover and sun exposure.
Flavor is viewed as a phenotypic trait. To understand this from a genetic perspective, we would take one specific chemical compound, for example, linalool, which is responsible for floral flavor. We would analyze the amount of linalool (phenotype) in a large number of cacao varieties and then match this data with genetic data from the varieties. We could begin to understand what part of the gene regulates the level of linalool, which would help us understand the relationship between genetics and flavor.
Where to find Lauren, host of Well Tempered Media productions and chocolate maker at WKND Chocolate:
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Twitter: @wkndchocolate
Articles, podcasts, chocolate recipes, and Conversations in Cocoa at laurenonthewknd.substack.com