Dr. Dennis D’Amico is an Assistant Professor of Dairy Foods at the University of Connecticut where his research, teaching, and outreach efforts focus on improving the safety and quality of milk and milk products with an emphasis on raw milk and artisan cheese. Prior to joining the faculty at UConn, Dennis earned his Ph.D. in Food Microbiology from the University of Vermont where he was a founding member of the Vermont Institute for Artisan Cheese. In his new position, Dennis continues to work closely with the artisan cheese industry through research and technical outreach programs addressing process controls, microbiological testing, risk assessment and reduction. In addition to countless presentations on the subject, Dr. D’Amico also developed the Artisan/Farmstead Cheesemaker Food Safety Workshop offered throughout the country. Among his service activities, Dennis is an active member of the American Cheese Society, delivering education sessions at Conference and serving on the Regulatory and Academic Committee.
Areas of Expertise (3)
University of Vermont: Ph.D., Food Microbiology
University of Vermont: M.S., Food Microbiology/Technology
University of Vermont: B.S., Nutrition and Food Sciences
University of Vermont College of Agriculture and Life Sciences New Achiever Alumni Award (professional)
The New Achiever Alumni Award recognizes and honors individuals who earned an undergraduate or graduate degree in the last 15 years (2003-2017) from a program currently or formerly affiliated with the College of Agriculture and Life Sciences.
Dennis J D'amico, Catherine W Donnelly
Staphylococcus aureus is an important agent of bacterial mastitis in milking animals and of foodborne intoxication in humans. The purpose of this study was to examine the genetic and phenotypic diversity, enterotoxigenicity, and antimicrobial resistance of S. aureus strains isolated from raw milk used for the production of artisan cheese in Vermont.
DJ D’amico, CW Donnelly
This study 1) evaluated the overall milk quality and prevalence of 4 target pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli O157: H7) in raw milk used for small-scale artisan cheesemaking and 2) examined specific farm characteristics and practices and their effect on bacterial and somatic cell counts (SCC).
Dennis J D'Amico, Marc J Druart, Catherine W Donnelly
This study was conducted to examine the fate of Escherichia coli O157: H7 during the manufacture and aging of Gouda and stirred-curd Cheddar cheeses made from raw milk. Cheeses were manufactured from unpasteurized milk experimentally contaminated with one of three strains of E. coli O157: H7 at an approximate population level of 20 CFU/ml. Samples of milk, whey, curd, and cheese were collected for enumeration of bacteria throughout the manufacturing and aging process.
Dennis J. D'amico, Marc J. Druart, Catherine W. Donnelly
Because of renewed interest in specialty cheeses, artisan and farmstead producers are manufacturing surface-mold-ripened soft cheeses from raw milk, using the 60-day holding standard (21 CFR 133.182) to achieve safety. This study compared the growth potential of Listeria monocytogenes on cheeses manufactured from raw or pasteurized milk and held for >60 days at 4°C. Final cheeses were within federal standards of identity for soft ripened cheese, with low moisture targets to facilitate the holding period. Wheels were surface inoculated with a five-strain cocktail of L. monocytogenes at approximately 0.2 CFU/cm2 (low level) or 2 CFU/cm2 (high level), ripened, wrapped, and held at 4°C. Listeria populations began to increase by day 28 for all treatments after initial population declines. From the low initial inoculation level, populations in raw and pasteurized milk cheese reached maximums of 2.96 ± 2.79 and 2.33 ± 2.10 log CFU/g, respectively, after 60 days of holding. Similar growth was observed in cheese inoculated at high levels, where populations reached 4.55 ± 4.33 and 5.29 ± 5.11 log CFU/g for raw and pasteurized milk cheeses, respectively. No significant differences (P < 0.05) were observed in pH development, growth rate, or population levels between cheeses made from the different milk types. Independent of the milk type, cheeses held for 60 days supported growth from very low initial levels of L. monocytogenes introduced as a postprocess contaminant. The safety of cheeses of this type must be achieved through control strategies other than aging, and thus revision of current federal regulations is warranted.
Dennis J. D'amico, Todd M. Silk, Junru Wu, Mingruo Guo
Nonthermal technologies are emerging as promising alternatives to heat treatment for food processing. Ultrasound, defined as sound waves with a frequency greater than 20 kHz, has proven bactericidal effects, especially when combined with other microbial-reduction strategies such as mild heating. In this study, ultrasound treatment (sonifier probe at 20 kHz, 100% power level, 150 W acoustic power, 118 W/cm2 acoustic intensity) with or without the effect of mild heat (57°C) was effective at reducing microbial levels in raw milk, Listeria monocytogenes levels inoculated in ultrahigh-temperature milk, and Escherichia coli O157:H7 in apple cider. Continuous flow ultrasound treatment combined with mild heat (57°C) for 18 min resulted in a 5-log reduction of L. monocytogenes in ultrahigh-temperature milk, a 5-log reduction in total aerobic bacteria in raw milk, and a 6-log reduction in E. coli O157:H7 in pasteurized apple cider. Inactivation regressions were second-order polynomials, showing an initial period of rapid inactivation, eventually tailing off. Results indicate that ultrasound technology is a promising processing alternative for the reduction of microorganisms in liquid foods.