The Unique Healthy Soy Oil with Better Stability and Flavor
I was recently invited by the American Soybean Association – International Marketing (ASA-IM) to Amman, Jordan, to conduct seminars to promote the use of properly processed, good quality extruded full fat soybeans and Extruded-Expelled (ExPress®) soybean meal.
For those who are not familiar with the ExPress® System offered by Insta-Pro International, in simple terms, it is a mechanical cooking and oil expelling through the use of a high shear extruder and a horizontal press.
The emphasis of the conference was on Extruded and Extruded-Expelled Soybean Meal rather than the oil.
Although I shared some of the characteristics of this unique oil, I wish that I had the chance to acquaint the participants that came from 12 countries with more information about the ExPress® soy oil.
In the Middle East, Southeast Asia, Latin America and other parts of the world, people have developed tastes for fried food. Unfortunately, Middle Eastern countries import very expensive oil and fat sources from abroad that are less healthy than what they can produce themselves if they had the technology and know-how.
The results of many studies conducted by different universities here in the United States were going through my mind. I wished I could have shared them with the attendees, but there was no time for it. One of the studies is described below:
A few years ago, I listened to a presentation given by Kathy Warner of the USDA/ARS, National Center for Agricultural Utilization Research – Peoria, Illinois. She presented the findings of her research about the uniqueness and stability of physically refined, Extruded Expelled (ExPress®) soybean oil.
In one of their frying studies, they tested four oils including:
- ExPress® soybean oil
- Refined, bleached, deodorized soybean oil without the anti-oxidant additive tertiary butyl hydroquinone (TBHQ)
- Refined, bleached, deodorized soybean oil with TBHQ
- Hydrogenated soybean oil.
The oils were evaluated for frying stability by measuring total polar compounds and the flavor quality of french fried potatoes. The evaluation was done by a trained, experienced, analytical sensory panel. Below are the unique findings about the quality and stability of the extruded-expelled oil:
- The frying stability of the ExPress® soybean oil was significantly better than soybean oil with no additives, but similar to the stability of soybean oil with TBHQ, or hydrogenated soybean oil.
- Soybean oil used for 35 hr of potato frying had a total polar compound level of 17.7% whereas the Extruded-Expelled oil had 9.1%, soybean oil with TBHQ had 8.8% and hydrogenated soybean oil had 9.7%.
- In early frying stages, the potatoes fried in ExPress® oil had significantly lower intensities of fishy flavor than potatoes fried in soybean oils with or without TBHQ.
- Potatoes fried in hydrogenated oil were described as waxy, fruity and flowery which are flavors characteristic of hydrogenated oil.
Because of these differences in intensities and types of flavor attributes, the potatoes prepared with ExPress® oil had significantly higher flavor quality scores than the soybean oils with or without TBHQ and hydrogenated soybean oil during the first 15 hours of frying.
During later stages of frying at 25 and 35 hours, the french fried potatoes, fried in ExPress® soybean oil, still had significantly better overall flavor quality scores than the potatoes fried in hydrogenated soybean oil or soybean oil without TBHQ, but no significant differences were seen between the potatoes fried in ExPress® oil and soybean oil with TBHQ.
These results indicated that ExPress® oil increased the frying stability of oil compared to soybean oil with no additives and was comparable to soybean oil with TBHQ and hydrogenated soybean oil as evaluated by total polar compound levels. Flavor quality of the french fried potatoes prepared in the expeller oil was significantly better than soybean oil with TBHQ during the first 15 hours of frying. Therefore, food manufacturers may want to consider using ExPress® soy oil as an alternative to hydrogenation or added antioxidants.
Differences in frying stability of the oils and flavor quality of the french fried potatoes may be due to variations in minor oil constituents. For example, ExPress® soybean oil had slightly more total tocopherols and phytosterols than did the other soy oil samples. During frying, the presence of TBHQ in the soybean oil and unknown compounds in the ExPress® soybean oil inhibited the loss of tocopherols.
These results showed that ExPress® soybean oil produced similar or better effects on oil stability and fried food quality as did the addition of TBHQ to soybean oil and may be an alternative to added antioxidants or hydrogenation.