Dr. V.M. “Bala” Balasubramaniam is a Professor of Food Engineering with Departments Food Science and Technology and Department of Food Ag Biological Engineering at The Ohio State University. His interest in retaining food freshness through minimal processing approaches led him to study the effect of high pressure processing on almond milk. He and his colleagues published the study, “Effect of high pressure processing on the immunoreactivity of almond milk,” in Food Research International. The article can be purchased here.
Q: Briefly, what led you to towards the research study “Effect of high pressure processing on dispersive and aggregative properties of almond milk”?
A: Our lab has been studying various aspects of high pressure processing since 1995 (http://u.osu.edu/foodsafetyeng/). About six years ago, a number of food processors approached us about HPP for plant-based beverages, such as cashew or almond milk. There wasn’t a lot of literature available on pressure effects on nut proteins, which led us to this study.
Q: What visible effects (color, texture, pH, particle size) did you notice in your almond milk samples when they were subjected to varying pressures?
A: Our study looked at factors like pressure, temperature and holding time in order to document side effects of HPP on almond beverages. Immediately after pressure treatment, we did not notice any difference in color or texture of the sample. However, if you allow the sample to store over time, we could see a clear separation between sediments versus the liquid on top.
Q: What effect did HPP have when it came to inactivating various spoilage organisms? Did you evaluate the samples for shelf-life extension?
A: This particular study didn’t focus on bacteria after HPP treatment. Over the years, we have looked at pressure effects on various vegetative forms of bacteria as well as spore forms of bacteria. You need to consider the product acidity. If it’s a low acid type of food matrix, then the process needs to be much more severe. If it’s high acid, treatment intensity can be less severe. With more research we could identify pressure temperature conditions that lead to a safe beverage.
Q: Do you think more experimentation of HPP on various plant-based drinks could ultimately result in less food being wasted? If yes, please explain.
A: Looking at this from the context of U.S. consumers versus developing countries, the source of food waste is different in each case. Developing countries lose more food loss occurs at the farm-level, whereas in the U.S., food makes it past the harvest stage, but is wasted more retail and consumer settings. HPP has potential to help reduce food waste at the retail level. However, we still need more consumer education to kick in to reduce waste at that level.
Q: What do you think is/are the most important next step(s) to facilitate more adoption of HPP as a food processing method?
A: Coming from my perspective in a U.S. academic institution, HPP is one of the revolutionary methods available to food processors to protect foods. In addition, health-conscious consumers want minimally processed foods, so there is a growing interest in the cleaner-label products and reduced additives that HPP can potentially bring forth.
The basic and applied science behind high pressure pasteurization was primarily developed from the mid-70s to 90s. Looking ahead, we have an opportunity for more research around how high pressure processing can help the food processors to formulate extended shelf-life, healthier, cleaner-label products, and facilitate industrial adoption. In the last six years, there has been a decline in funding of academic research around HPP with federal and state budget cuts. Because of a lack of academic funding today, it’s up to the food processors to facilitate stable research funding for academia. Unfortunately, processors don’t have funds for research, so it creates a bad recurring cycle. As the community of food producers, food processors and university researchers, we need to address this challenge by educating policy makers on importance of supporting this line of academic research. By bridging the gap between industry and academia, ultimately consumers benefit by having more availability of healthier and more minimally processed foods.