As a food scientist, I often have to break traditional rules of flavor in order to fit our product into a can, box, plastic tray and pouch. The traditionalist chef inside of me, however, starts protesting loudly when I bend the rules too much, to the point where my newly developed food item only loosely resembles the original origin and flavor of the dish.

This is why it is important for us (the culinary scientists) to be well versed in both the science and culinary aspects of our food. While maintaining flavor is important, keeping our processed foods safe is crucial! The growth of dangerous pathogens like E. coli and C. botulinum must not only be prevented, but if they are present in the raw ingredients at low levels, must be killed off immediately!

In my early working days, I had the great pleasure of setting up regular challenge studies for shelf-stable salad dressings (translation: inoculating food with bacteria to see if the counts increase, decrease or stay the same). My boss, a hardcore food microbiologist, informed me that if the bacteria did not die off immediately, the product would fail and the R&D developers would have to jack up the preservative levels. Known as the bacteria police force, our agar-smelling department was not the most popular group in the house. It was our job to advise the developers on acid and preservative usage, to prevent the outgrowth of pathogens and spoilage organisms. The acidity kept the product below pH 4.6, preventing pathogenic outgrowth, while the second battalion of preservatives killed off all the spoilage organism like lactobacillus, yeast and mold. If a salad dressing company can sell their product at a higher cost, refrigeration is another viable and more-natural option for spoilage inhibition. Refrigerated products don’t need preservatives and will have a fresher final taste and cleaner label.

Most dressing-like products are cold-filled in order to maintain the integrity of the emulsion. Hot-fill methods (heating to 160º F for products under pH 4.6) can be used to kill spoilage organisms in durable, non-emulsion-style acidified products such as marinara, pizza and barbecue sauce. These products can maintain their identity even after being heated to 160º F and is shelf stable in its final form. The positives in this case are a lower-cost, shelf-stable product; the negatives are a product that has been heated to a higher temperature which could loose some of its valuable flavor.

But what about products that are only acceptable at pH levels above 4.6 like beef stews, tuna fish, Alfredo sauce and creamed corn? At this point, a flavor compromise must be made. Without the preventative measures of pH in place, there are only two other options. Heat the heck out of it, or spend the extra money to have a refrigerated or frozen product with a short (and expensive) shelf life. Thermal retorting, which involves heating the food to 250º F+ kills every living thing that ever lived in that food product. Processing specialists determine the minimum heat needed to kill everything up to the most difficult bacteria to kill in the can. End result is your typical jar or can of processed food. Heated to the point of total flavor loss, the food industry has done wonders to get those flavors back in there—however, we do have to adjust our standards to accept these products by names that they really might not be entitled to.

Bacteria are controlled by heat, acid, refrigeration and preservatives. The developer’s best tools are understanding bacterial growth and the means that can prevent it. The chef can help the scientist understand at what point the product will be so off the charts that it will be an insult to the original dish itself. The scientist can make sure that the company budget and manufacturing capabilities match their bacterial prevention system. Working together, the chef and the scientist can balance it out perfectly.



About rachel zemser