Trans Fatty Acid Analysis of Frying Oil Using ATR-FTIR Spectroscopy: A Study on Indian Traditional Snack Foods

Abstract

Background: Trans Fatty Acid (TFA) content in oil is an important quality parameter due to its adverse health effect. This study was aimed to examine the TFA content in the frying oil used by street food vendors in India for two traditional snack foods.
 Methods: Totally, 143 oil samples were collected at different frying times (0, 2, and 4 h) from five different vendors for Samosa and Jalebi. TFA levels of the oil samples were analyzed by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATRFTIR). Statistical analyses were carried out using SPSS software version 23.0.
 Results: ATR-FTIR spectra exhibited an increase in peak intensity at 966 cm-1 with different frying time in both frying oil samples, indicating the formation of TFA. The TFA content in oils fried at 4 h was significantly higher than the ones at 0 and 2 intervals. It was found that 3 out of 74 (4%) Samosa fried oils and 12 out of 69 (17.4%) Jalebi fried oils were over the maximum allowed regulatory limit of TFA (5%). Jalebi fried oils had significantly higher TFA content than Samosa fried oils.
 Conclusion: The increase in frying time decreased the peroxide values and increased saturated fatty acids and TFA values of oils used for both food items. The local vendors and consumers should be educated by national authorities regarding health risk of TFA in street fried snacks.

Analysis of Total Polar Material in Selected Indian Snack’s Fried Oil

“…This may be due to the high moisture content in food that accelerates the hydrolysis reaction [19]. As mentioned in our earlier study [10], this increased TPM might be due to the use of hydrogenated fat by 40 % of the Jalebi vendors and the use of non-hydrogenated fat by the Samosa vendors. Furthermore, a recent study on the influence of fried food and oil type on a dielectric constant based rapid test analysis of TPM in restaurant fried oil concluded that the effect of oil type is more important than the food type to measure TPM using rapid test analysis [20].…”

“…The absorption spectra of all the collected samples were obtained by Fourier Transform Infrared (FTIR) Spectrometer (Bruker Optics, Model-Alpha, Germany). The detailed operation method of FTIR was followed as explained in previous articles [10,11]. An OPUS spectroscopy software version 7.2 was used for FTIR data collection and processing.…”

“…Therefore, a decrease in peak absorbance observed in the present study may also be due to the hydrolysis of oil. In a recent study, Trans Fatty Acid [10] was quantified in the frying oil of Samosa and Jalebi using FTIR Spectroscopy. An increased absorbance was observed at 966 cm -1 with an increase in frying time indicating the formation of TFA [10].…”

“…In a recent study, Trans Fatty Acid [10] was quantified in the frying oil of Samosa and Jalebi using FTIR Spectroscopy. An increased absorbance was observed at 966 cm -1 with an increase in frying time indicating the formation of TFA [10]. In this work, a simultaneous increase of TFA with TPM with time has also been identified.…”

“…It was evident from the study that, with a low prediction error and good accuracy level, TPM can be quantified using NIR and ATR-MIR combined with the PLS regression method [8]. Recent research examination regarding the oil quality and practices among small and medium-scale street vendors in West Delhi, India, revealed that 80% of the vendors were reusing the leftover oil/fat and the oils were found to have elevated saturated fats [9][10]. Though popular street snacks of Delhi, Samosa, and Jalebi were included in that study but TPM content was not measured.…”