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Federico Harte, Ph.D.

  • Associate Professor of Food Science
Federico Harte, Ph.D.
331 Rodney A. Erickson Food Science Building
University Park, PA 16802
Email:
Work Phone: 814-867-5689

Areas of Expertise

  • Dairy Processing
  • Food Rheology
  • Food Engineering

Education

  1. B.S., University of Uruguay. Agricultural Engineering.
  2. Ph.D., Washington State University. Biological Systems Engineering.

Teaching

Dairy Foods processing
Food Rheology
Food Engineering

Current key members

Dr. Charith Hettiarachchi (Postdoctoral Research Associate)
Dr. Ehsan Mahdinia  (Postdoctoral Research Associate)
Grace Lewis (MS student)                          

Research Focus

Research focuses on processing interventions that strongly affect protein functionality and overall food physical properties. As we continue to seek for ‘minimally processed’ and ‘clean’ label foods, understanding the effect(s) of processing operations on the functionality of proteins, fats and carbohydrates becomes critical.

Recent projects have focused on:

  • Caseins as natural emulsifiers and foaming agents
  • Functionality of lecithin phospholipid fractions beyond emulsification
  • Cryo-electron microscopy to elucidate the structure of casein micelles
  • Analytical methods to separate glycosylated casein proteins
  • The emulsifier-free and stabilizer-free ice cream
  • High pressure jet processing to dissociate protein quaternary structures
  • Effect of ionic environment on protein integrity

Strong emphasis is given in the following areas:
Dairy Processing and the structure-function properties of milk proteins

The casein proteins account for 80% of the total protein content in bovine milk and 40% of the total protein content in human milk.  The casein proteins aggregate into so called “casein micelles” of spherical shape and ca. 150 nm diameter. Bovine milk is white because of the 1015 casein micelles) dispersed in every mL of milk. The agreed biological function of the casein micelles is to transport amino acids and calcium from mother to young. This is widely accepted based on the fact that milk is supersaturated with calcium (bovine milk contains ca. 1.2 mg calcium per mL of milk whereas water can only dissolve up to 0.02 mg of calcium – as calcium phosphate – per mL) and because the phospho-serine amino acids responsible of holding calcium-rich clusters are conserved throughout virtually all mammal species. The casein micelles have also a tremendous technological relevance as they constitute the building blocks of traditional dairy foods, including cheese and yogurt. We are elucidating casein micelle structure-function relationships that are relevant to the fundamental understanding of the biological relevance of this nano-delivery system and the engineering of novel application within the food and health industries.

Nonthermal technologies for fluid foods: valve homogenization

Homogenization is a term used by food scientists and engineers to describe a wide variety of processes including ultrasonic, rotary, membrane, colloidal mill, and valve homogenization … among others. The ambiguity in the use of the word "homogenization" rises from the fact that any process that reduces the relative heterogeneity of a system can be called homogenization. We focus on what is typically referred to as "high pressure valve homogenization" or "dynamic high pressure homogenization" where several physical phenomena (including hydrostatic pressure, cavitation, shear stress, temperature) promote changes ranging from microbial and virus inactivation to protein structural modification and atypical molecular interactions. This process is applied to liquid foods by devices consisting of a positive displacement pump (usually a plunger type pump) and one or more restrictions to flow (stages) created by valves or nozzles. We arbitrarily define "high pressure homogenization" as homogenization processes where pumps are able to deliver at least 100 MPa hydrostatic pressure to a liquid food. We are currently working at maximum pressures that are six times that at bottom of the Marianas trench. As homogenization technologies keep “evolving” and higher pressures are achieved, the agreement on how to define “high pressure” vs. “low pressure” will most certainly change too.

Recent Publications

Tran, M., Roberts, R. F., Felix, M., and Harte, F*. 2018. Effect of high-pressure-jet processing on the viscosity and foaming properties of pasteurized whole milk. Journal of Dairy Science. https://doi.org/10.3168/jds.2017-14103.

Qu, Y., Harte, F., Elias, R. J. and Coupland, J. N. 2018. Effect of ethanol on the solubilization of hydrophobic molecules by sodium caseinate. Food Hydrocolloids, 77:454-459.

Zhang, H., Dudley, E. G., and Harte, F*. 2017. Critical Synergistic Concentration of Lecithin Phospholipids Improves the Antimicrobial Activity of Eugenol against Escherichia coli.  Applied and Environmental Microbiology, 83(21): e01583-17. 

Cheema, M., Hristov, A. N. and Harte, F*. 2017. The binding of orally dosed hydrophobic active pharmaceutical ingredients to casein micelles in milk. Journal of Dairy Science, 100(11):8670-8679.

Culler, M. D., Saricay, Y., and Harte, F*. 2017. The effect of emulsifying salts on the turbidity of a diluted milk system with varying pH and protein concentration, Journal of Dairy Science, 100(6): 4241-4252.

Zhang, H., Dudley, E. G., Davidson, P. M., and Harte, F*. 2017. Critical concentration of lecithin enhances the antimicrobial activity of eugenol against Escherichia coli. Applied and Environmental Microbiology, 83(8): e03467-16.

Harte, F. 2016. Food Processing by High-Pressure Homogenization. In High Pressure Processing of Food (pp. 123-141). Springer New York.

Ye, R., Hayes, D. G., Burton, R., Liu, A., Harte, F., and Wang, Y. 2016. Solvent-free lipase-catalyzed synthesis of technical-grade sugar esters and evaluation of their physicochemical and bioactive properties. Catalysts, 6(6):78.

De Veth, M. J., Artegoitia, V. M., Campagna, S. R., Lapierre, H., Harte, F., and Girard, C. L. 2016. Choline absorption and evaluation of bioavailability markers when supplementing choline to lactating dairy cows. Journal of Dairy Science, 99(12), 9732-9744.

Mohan, M. S., Ye, R. and Harte, F*. 2016. Initial study on high pressure jet processing using a modified waterjet on physicochemical and rennet coagulation properties of pasteurized skim milk. International Dairy Journal 55: 52-58.

Castel, V., Zivanovic, S., Jurat‐Fuentes, J. L., Santiago, L. G., Rubiolo, A. C., Carrara, C. R., and Harte, F. 2016. Chromatographic fractionation and molecular mass characterization of Cercidium praecox (Brea) gum. Journal of the Science of Food and Agriculture 96(13):4345-50.

Patents

Harte F., Martinez M., Mohan M.S. 2016. Foaming and emulsifying properties of high pressure jet processing pasteurized milk. The Penn State Research Foundation, assignee. United States patent application US 15/185,296.

Harte F., Mannam V., Worley S., Wilkerson J., Smith D. 2016. Soak chamber and system to measure the seed density hydration profile of seeds. Bush Brothers & Co., assignee. United States patent US 9,285,350.