George Cavender PhD, CFS, EIT, Assistant Professor, University of Georgia

Dr. Harshavardhan Thippareddi, Professor of Poultry Science, University of Georgia

▪ Brief overview of HPP ▪ Common uses▪ Exciting developments

▪ Brief overview of HPP ▪ Common uses▪ Exciting developments

▪ Processing foods using extreme pressures ▪ No official range, though 100-800 Mpa has

been suggested by FDA▪ Most commercial processed are performed in

the 300-600 MPa range▪ Also sometimes called “pascalization” or

“High Hydrostatic Pressure” (HHP)

▪ Much older than you might think▪ Used primarily as a safety measure

▪ Water as a working fluid▪ Most foods processed in package▪ Can disrupt non-covalent bonds, allowing

it to:▪ Denature proteins▪ Inactivate enzymes▪ Disrupt membranes

▪ Minimal thermal effect

▪ Control of Vibrio in seafood▪ Also significantly aids in shelf-life and further

processing

▪ Control of post-cook contamination in RTE meats

▪ “Cold Pasteurization” of juices and smoothies

▪ Limited use in dairy ▪ Smoothies▪ “Raw Milk” (Made by Cow, AUS)▪ Cow colostrum (Col+, NZ)▪ Some research has shown possible benfits in fermented

dairy products (milk, cheese, etc)

▪ Most work to date has dealt with pathogen control▪ Even the processing benefits of HPP on

seafood was something of a happy accident

▪ HPP can do so much more.

▪ “Fully cooked” or “safe to eat?”

▪ Many people from many cultures around the world prefer foods that are not cooked to a level experts consider safe.

N=106

We can use HPP to render undercooked foods safe. ▪ Recent example: Beef Steak

▪ HPP can reduce O157:H7 in rare steak by six logs

▪ https://doi.org/10.1016/j.lwt.2017.07.037

▪ Resulting steak retains red color, similar texture

▪ Further cooking via immersion circulator (sous vide) showed little difference in behavior

▪ This tends to work better than processing Raw foods▪ HPP effects changes in the myoglobin and other

proteins, resulting in a “cooked appearance”

▪ This tends to work better than processing Raw foods▪ HPP effects changes in the myoglobin and other

proteins, resulting in a “cooked appearance”

▪ Altering Myoglobin state may help alleviate some color changes, but so far is not a silver bullet.

Control 600MPa/ 6min 600MPa/ 3min 450MPa/ 3min

A: Deoxymyoglobin

B: Oxymyoglobin

C: Metmyoglobin

D: Carboxymyoglobin

A: Control (No HPP)

B: 600 MPa / 3 min.

C: 600 MPa / 6 min.

D: 450 MPa / 3 min.

SN SN+E CJ CJ+CP SN-O SN+E-0

▪ We can use HPP for improving quality as well as safety

▪ HPP is not a magic bullet, it has limitations

▪ Understanding the nature of the limitations can help to create ways to mitigate the limitations

▪ We can also think outside the box and create new and exciting products for which the limitations are strengths