Why a Comprehensive Study Is Key to Quality Frying

Editors’ note: This is the second in a series of three articles on frying. Part 1, “How To Ensure Quality in Fried Foods,” was published in the June/July issue of FQ&S, and Part 3, “An Overview of Oil Filtration for Frying Foods,” was published in the October/November issue.

In 1991, Blumenthal and Stier stated that optimum frying occurs when the frying process is economic and superior quality fried food is produced. The best means for evaluating a frying operation, whether an operator is a food processor or producing fried food in a restaurant environment, is to conduct a comprehensive frying study. It is simply not possible to optimize a system if the fryer operator does not understand the system or does not understand that a fryer operation is a system. Components of the system are the fryer, the food, and the people operating the system. In addition, frying is the most dynamic food preparation system around, given that the frying oil is constantly changing, thanks to the interactions of food, water, temperature, oxygen, and the condition of the fryer.

So, what are the reasons for conducting a frying study? The first is to establish a baseline for oil degradation under normal operating parameters. Frying studies should include the following elements:

1. Evolving oil chemistry;
2. Food quality over time;
3. Amount of food being fried; and
4. Frying operating parameters.

The greater the number of chemical tests that are done, the better one understands the system. When establishing a baseline, one of the operator’s main goals is to establish a relationship between the oil chemistry, or chemical markers of oil degradation, and the sensory parameters of the food being fried. So, the operators need to be involved, as they are the ones who best understand what would be deemed quality fried food.

Once an operator has established a baseline, they have the first tool necessary for optimizing their operation. There is now a yardstick against which they can compare changes to the system: a new oil, a filter system, the use of a new oil additive, a change in food mix, a change in a formulation, or any other change.

The reasons to conduct a frying study using a standard format include the following:

1. To ensure proper evaluation of the system;
2. To allow the gathering of technical data to demonstrate benefits/concerns to potential users;
3. To develop performance data to demonstrate benefits/concerns to potential users;
4. To ensure food safety/adequate processing or process lethality;
5. To understand the operations to maximize benefits or minimize concerns; and
6. To allow operators and users to make intelligent, well-informed decisions on direction.

Developing a Baseline for a Fryer

Prior to conducting any scientific study, it is imperative to establish a baseline. In deep-fat frying operations, this consists of determining the chemical, physical, and sensory parameters of oil and food in existing frying operations. Once this data has been gathered, any changes to the frying system can be evaluated against the baseline intelligently and without prejudice. The baseline for any fryer operator will be current practices. When conducting a baseline study, it is vital that nothing be changed before or during the study. Lastly, prior to initiating a baseline study or any other frying study, the researchers must determine what endpoint will be utilized—that is, a chemical measurement, sensory testing, or a quality parameter.

A frying study can be done in a restaurant, in a technical center, or in an industrial processing operation. When embarking on such a study, operators must be aware that these will be time consuming and can be quite expensive. If conducting the work in a restaurant or plant, one of the challenges is to minimize disruption of normal operations.