High-voltage Atmospheric Cold Plasma (HVACP) hydrogenation of soybean oil without trans-fatty acids

• Published in: Innovative food science & emerging technologies Vol. 38; pp. 169 - 174
• Main Authors: Yepez, Ximena V., Keener, Kevin M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2016
• Subjects: Atmospheric cold plasma; Hydrogenation; Oil chemistry; Processing technology; Soybean oil; Processing technology; Atmospheric cold plasma; Soybean oil; Hydrogenation; Oil chemistry
• ISSN: 1466-8564; 1878-5522
• DOI: 10.1016/j.ifset.2016.09.001

Fats and oils are essential ingredients in the food industry. Partially hydrogenated oils (PHOs) have a high content of trans-fatty acids, which have been linked to cardiovascular diseases. High-voltage Atmospheric Cold Plasma (HVACP) is investigated to produce partially hydrogenated soybean oil without the formation of trans-fatty acids. In this study, soybean oil was exposed to highly energized species from hydrogen and nitrogen. HVACP treatment of soybean oil reduced iodine value from 133 to 92 over a 12-h treatment. Such iodine value reductions are similar to the traditional soybean oil hydrogenation process. Saturated fatty acids increased 12%, monounsaturated increased 4.6%, and unsaturated fatty acids decreased 16.2%. No measurable trans-fatty acids were detected. Atomic hydrogen species are likely responsible for the HVACP hydrogenation, and were identified with optical emission spectroscopy. Through this innovative technology, chemical synthesis of PHO's can be achieved in a non-traditional manner without trans-fatty acids. Industrial relevance: HVACP has been extensively studied to achieve food decontamination using nitrogen, oxygen, and carbon dioxide gas blends. The use of this technology with hydrogen gas demonstrates further possibilities in room temperature chemical synthesis. In this study, the application of HVACP was aimed to affix hydrogen atoms at the double bonds of unsaturated fatty acids. The advantages of the HVACP technology over the current hydrogenation processes are that the former can be performed with the following conditions: (1) at room temperature, (2) under atmospheric pressure, and (3) catalyst-free. Bakery products, frozen meals, desserts, and several snacks are the most challenging products for reformulations replacing PHOs. This technology is relevant because it may lead to an increase of the use of local vegetable oils, whose unsaturated fatty acid contents can be chemically modified without the formation of trans-fatty acids. Furthermore, this technology could be broadly used to selectively hydrogenate for various industrial purposes, producing new chemical structures without the requirements of heat, pressure, or catalyst. This study is the first study demonstrating an alternative processing technology to traditional catalytic hydrogenation. Additional research is needed to optimize the treatment process, and evaluate the performance of the HVACP partially hydrogenated oil.
•A novel processing technology is proposed to partially hydrogenate soybean oil.•Changes in the fatty acid composition and iodine value were achieved.•Atomic hydrogen species were identified with optical emission spectroscopy.•Treated samples showed an iodine value similar to a commercial hydrogenated oil.