Students

OVIFT Awards Student Scholarships

Continuing the tradition and dedication to supporting student success, OVIFT has awarded two scholarships, $1,000 each to Yutong Li and Jerish Janahar at Ohio State. Meet our scholarship winners below, and make sure to read their prize-winning essays later in the newsletter. Look forward to more student essays to be featured in future newsletter editions.

Yutong Li

I’m Yutong Li, a second year PhD student in Dr. Hua Wang’s lab at the Ohio State University. Our lab focuses on antibiotic resistance gene pool in foods and oral antibiotics as a key driver for gut microbiota disruption. My long-term goal is to investigate the impact of drugs and diet on gut microbiota, and to develop targeted strategies to minimize and repair antibiotic-induced damages.

Jerish Janahar

Jerish Joyner Janahar is a PhD candidate in Department of Food Science and Technology – The Ohio State University, working under the supervision of Dr.V.M.Balasubramaniam. Jerish’s research focus is on process engineering characterization of a continuous high pressure processing method, referred as ultra shear technology (UST). He uses multi-disciplinary approach to investigate the influence of different process parameters and their interactions during UST processing on quality changes in different food matrices.

Student Essay: Antibiotics and Consequences for the Gut Microbiome. 

By: Yutong Li

We all know a balanced diet is important for human health. Meanwhile, a balanced and diverse gut microbiota is essential for maintaining proper function of not only the gut but also many other organs and the whole immune system. It is now recognized that disrupted gut microbiota is associated with many modern diseases such as diabetes, obesity, cardiovascular diseases, brain disorders and even cancers. Severity of COVID-19 was also found to be associated with disrupted patient gut microbiota. Thus, protecting healthy gut microbiota is of critical importance to public health and requires urgent attention. 

For decades, antibiotics have been blamed by the public for causing antibiotic resistance. However, using animal models, Dr. Wang’s lab has discovered since 2011 that instead of the applications of antibiotics, the mainstream oral administration of drugs has been the real driver for the unintended damages to gut microbiota. In order to find out what exact damage could be posed to patient gut microbiota by oral antibiotic treatment, I conducted a clinical case study since joining the Wang team in 2019. I found that oral antibiotics have immediate drug-specific impact on gut microbiota composition, decreasing the richness of the community and changing the abundance of beneficial organisms and some pathogens. More importantly, many of those damages cannot recover naturally even 10 months post-treatment (2021 Hayes forum, 2021 OARDC research meeting).

According to the CDC (Centers for Disease Control and Prevention), annually about 250-350 million total outpatient antibiotic prescriptions were given in the US alone. The US population is only 310 million in 2020. Thus, on average, every American received one complete course of antibiotic every year. Therefore, the general public have already suffered from severe gut microbiota damage due to oral antibiotics in treating infections. Properly addressing this massive public health challenge has thus become a stressing need. While Dr. Wang is leading the global initiative to minimize such damages by changing the mainstream practice of oral antibiotic administration at the policy level, developing practical approaches to repair the already damaged gut microbiota in the general public has also become an urgent need.

While microbiota transplantation has been a popular approach for gut microbiota repair, the treatment itself introduces various risk factors such as fatal antibiotic-resistant infections. Currently, there are two potential strategies to repair gut microbiota damages, functional foods and next generation probiotics. Therefore, my long-term goal is to investigate the impact of drugs and diet on gut microbiota, and to develop targeted strategies to minimize and repair antibiotic-induced damage with optimized drug administration, functional foods and next generation probiotics.

Now, I have already established an animal model to investigate the impact of antibiotic-induced disrupted gut microbiota on brain health disorder. I will use this model to further screen and develop functional foods that can be used to repair damaged gut microbiota. I hope my hypothesis-driven study can advance fundamental understanding in host-gut microbiota interaction and point out new directions for novel functional food development in the future.

Student Essay: Ultra Shear Treatment of Low Acid Liquid Foods

By: Jerish Janahar

These days, food is consumed not only to satiate hunger but also to promote health and well-being. There has been increasing awareness towards ‘clean label’ foods. Articles in ‘Food Technology Magazine’ of IFT has cited the term ‘clean label’ 2, 18 and 77 times in 2000, 2011 and 2016 respectively, showcasing the increasing importance of the term over decades (Asioli et al., 2017). Global sales of clean label food products were estimated at about $180 billion in 2020 by Euromonitor International. This trend necessitates use of minimal processing technologies, such as high pressure processing (HPP), which enable clean label products. Batch HPP is commercially used to process a variety of juices and beverages. This prompted the industry to seek continuous HPP methods, which led to the introduction of a continuous high-pressure processing system for liquid foods, referred to as Ultra Shear Technology (UST).

During UST treatment, the fluid food is pressurized upto 400 MPa and subsequently passed through a tiny clearance in a shear valve. As the fluid passes through the clearance, the instant pressure drop leads to conversion of pressure energy into intense physical forces such as shear, turbulence etc. and temperature rise. The process temperature is a function of flow rate, initial fluid temperature and pressure. The interaction of process parameters like pressure, shear and temperature in UST enable performing useful functions such as particle size reduction, mixing, emulsification, microbial inactivation, texture modification etc. in foods.

It is essential to understand the influence of individual process parameters and their interaction during UST treatment on the quality and safety of foods. Therefore, for my doctoral research, I focused on characterizing UST process parameters on quality attributes of a liquid product-raw milk (Janahar et al., 2021). Using a custom-made UST equipment, I investigated the relative impact of pressure, temperature, shear, and interactions on various milk quality attributes (Figure 1). It was observed that pressure- only (HPP) treatment did not cause apparent fat-protein particle size reduction and thermal-only treatment induced slight reduction in particle size as compared to raw milk. However, the pressure-associated shear action in UST treatment at 35 °C reduced the diameter of fat-protein particles from 3511.76 nm (raw milk) to 291.45 nm and kept milk stable by preventing creaming. The findings revealed the differential effects of pressure, shear, temperature, and their interactions and helped to improve the understanding of underlying physics behind UST technology.

Further, I investigate the influence of UST process parameters and different shear valve geometries on inactivation of Lactobacillus brevis and Bacillus cereus spores. This research is anticipated to provide useful insights on mechanisms responsible for microbial inactivation during UST treatment.

My research findings help UST engineers to design equipment parts, food processors to develop UST process conditions, and regulators to understand the critical process considerations to ensure food safety. Further, the knowledge on UST-induced micro and macro molecular changes in foods will enable food processors to develop novel ‘clean label’ liquid foods and beverages with no or minimal synthetic additives.

References

Asioli, D., Aschemann-Witzel, J., Caputo, V., Vecchio, R., Annunziata, A., Næs, T., & Varela, P. (2017). Making sense of the “clean label” trends: A review of consumer food choice behavior and discussion of industry implications. Food Research International, 99, 58-71.

Janahar, J. J., Marciniak, A., Balasubramaniam, V. M., Jimenez-Flores, R., & Ting, E. (2021). Effects of pressure, shear, temperature, and their interactions on selected milk quality attributes. Journal of Dairy Science, 104(2), 1531-1547.Con