Impact of infrared and dry air roasting on antioxidant potential, oxidative stability, chemical characteristics and fatty acid profile of black and white sesame (Sesamum indicum L.) oil

Authors: SUNDER, SHYAM - Guru Nanak Dev University; SINGH, BALWINDER - Khalsa College; KAUR, AMRITPAL - Guru Nanak Dev University; Yadav, Madhav

Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2022
Publication Date: 10/5/2022
Citation: Sunder, S., Singh, B., Kaur, A., Yadav, M.P. 2022. Impact of infrared and dry air roasting on antioxidant potential, oxidative stability, chemical characteristics and fatty acid profile of black and white sesame (Sesamum indicum L.) oil. Journal of Food Processing and Preservation. https://doi.org/10.1111/jfpp.17252.
DOI: https://doi.org/10.1111/jfpp.17252

Interpretive Summary: The sesame is the oldest known oilseed, which is widely used as an ingredient in fresh and processed foods due to its unique flavor and superior nutritional value. Sesame oil is highly nutritious and healthy due to its desirable composition of fatty acids, oxidative stability and antioxidative properties. It has enormous health promoting benefits like anti-inflammatory, anti-microbial and anti-aging properties. The roasting of oilseeds is a critical heat treatment process step for extracting their edible oils. The heat treatment or roasting of seeds before oil extraction facilitates the release of important oil constituents during the extraction process. It enhances oil extraction yield, inactivates enzymes, enhances flavor or aroma, increases oxidative stability, antioxidant activity and overall acceptability of the extracted oil. This prompted us to develop an optimized roasting condition to get a high yield of oil and increase its nutritional components. The present study has compared and evaluated the effect of dry air and infrared roasting (at 160, 180 and 200 degrees Celsius for 5, 10 and 15 min) on chemical characteristics, oxidative stability, and fatty acid composition of sesame seeds oil. Both the dry air and infrared roasting of sesame seeds at a higher temperature (180 degree Celsius for 15 min) significantly improved the quality of oil. Among the two roasting processes, the dry air roasting was more effective than infrared roasting in increasing the yield of oil and its oxidative stability, and the level of carotenoids, chlorophylls, and other high nutritional value components it contains. Thus, for getting healthy oil, the dry air roasting of sesame seeds at 180 degrees Celsius for 15 min can be suggested as its heat treatment process. This study can be of great value to sesame seed growers and food processing industries.

Technical Abstract: The present study reports the influence of infrared roasting (IRR) and dry air roasting (DAR) at 160, 180 and 200 degrees C for 5, 10, and 15 min on oil yield, chemical characteristics, oxidative stability index (OSI), colour, browning index (BI), pigments, total flavonoid content (TFC), total phenolic content (TPC), radical scavenging activity (RSA) and fatty acid composition (FAC) of white sesame oil (WSO) and black sesame oil (BSO). The oil yield, OSI, BI, pigments, TPC, TFC and RSA increased while acid, peroxide, L* and b* values of WSO and BSO declined by increasing DAR and IRR conditions. FTIR spectra exhibited a minor variation in peaks intensities which correlates with changes in FAC and p-AV of WSO and BSO. Both DAR and IRR techniques had improved the WSO and BSO quality. However, DAR at 180 degrees C for 15 min proved more promising in improving WSO and BSO yield and quality characteristics.