Effect of the chemical refining process on perilla seed oil composition and oxidative stability

Abstract

The effect of chemical refining process on the physicochemical characteristics and oxidative stability of perilla seed oil was investigated. We analyzed five samples corresponding to each step of the refining process (degumming, neutralization, bleaching, deodorization, and refined oil). The results indicated that the acid value (2.20–0.24 mg KOH/g) and peroxide value (4.32–1.26 mEq/kg) decreased significantly, while the saponification value (178.81–196.24 mg KOH/g) and p‐anisidine value (3.45–9.55) increased dramatically. There was no significant difference in conjugated diene, except in the degummed oil. Additionally, the refractive index did not change throughout the process. Eleven fatty acids were identified in samples, and there was no significant difference observed among them. The refining process resulted in decreases in total tocopherol content (25.0%) and total phenolic content (51.7%). Degummed, neutralized, bleached, and deodorized oils have high primary oxidation stability, whereas refined oils exhibit low secondary oxidation rates. Practical applications The present study was designed to examine the physicochemical properties of perilla seed oil at various phases of refining, as well as its bioactive compounds and oxidative stability during the process. This study provides a good reference for the industrial parameters of the refining process to obtain high‐quality products for consumers.

Chemical Characterization of Chinese Perilla Seed Oil

“…It has been reported that the tocopherol content of polyunsaturated fatty acid (PUFA) rich oils was higher than that of the oleic acid-rich oils 22) . With good antioxidant, tocopherol in the perilla oil could reduce free radical, therefore protecting the unsaturated fatty acids of the oil 1) . However, the unsaponifiable matter of this oil was only 0.57 g/100 g, relatively lower than oliver oil (1.23 g/100 g) , peanut oil (0.94 g/100 g) and sunflower oil (0.81 g/100 g) 23) .…”

Establishment of an Effective Refining Process for Moringa oleifera Kernel Oil

“…Based on Table 2, both WD and AD were insignificantly different (p > 0.05) from each other in affecting the PV (3.33 ± 0.01 meq/kg), and these two methods significantly decreased the PV of the oil samples as compared to that of crude MO kernel oil (p < 0.05). A significant decrease in PV upon degumming was also reported in the case of MO kernel oil from seeds of South Sonora (Mexico) origin [9], kenaf seed oil [12], and perilla seed oil [21]. Decrease in the PV consequently resulted in degummed (WD and AD) oil samples with significantly lower total oxidation (TOTOX) values, with oil sample subjected to AD showing significantly lower value as compared to that which is subjected to WD.…”

“…In contrast, Sánchez-Machado et al [9] reported that neutralization did not significantly affect the PV of MO kernel oil, yet increased the oil's p-AV. Neutralization also significantly decreased the PV of perilla [21] and kenaf [12] seed oils, and increased the p-AV of these oils. On the other hand, both Yoon [25] and Lee et al [21] reported a significant increase (p < 0.05) in the PV of neutralized chufa oil and camellia seed oil, respectively.…”

“…Neutralization also significantly decreased the PV of perilla [21] and kenaf [12] seed oils, and increased the p-AV of these oils. On the other hand, both Yoon [25] and Lee et al [21] reported a significant increase (p < 0.05) in the PV of neutralized chufa oil and camellia seed oil, respectively. These varying results may be due to the different concentration of caustic agents and neutralization process employed, in addition to the differences in the quality of the crude oil samples used.…”

Multipurpose optimization of canola oil deodorization parameters and evaluation of linolenic acid isomerization kinetics during pilot-scale deodorization

“…In previous studies, optimization of refining conditions to reduce the formation of toxic contaminants such as 3-MCPD and GE in palm oil and olive oil has been studied (Özdikicierler et al, 2016;Zulkurnain et al, 2013). Since the elevated temperatures applied at deodorization cause a decrease in bioactive compounds such as tocopherols, sterols and phenolic compounds, optimization of the refining conditions to reduce the detrimental effect of refining has been discussed in several studies (Ceriani et al, 2008;Liu et al, 2019;Marangoni et al, 2019;Pan et al, 2019;Xie et al, 2019). Trans isomerization occurred during deodorization is another important issue investigated in many studies (Ceriani and Meirelles, 2007;Hénon et al, 1999;Kemény et al, 2001).…”