Effect of Anti-Clouding Agent on the Fate of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Palm Olein during Repeated Frying

Simultaneous mitigation of 3-monochloropropane 1,2 diol ester and glycidyl ester in edible oils: a review

The rising concern about the presence of 3-monochloropropane 1,2 diol ester (3-MCPDE) and glycidyl ester (GE) in food has prompted much research to be conducted. Some process modifications and the use of specific chemicals have been employed to mitigate both 3-MCPDE and GE. Alkalisation using NaOH, KOH, alkali metals or alkaline earth metals and post sparging with steam or ethanol and short path distillation have shown simultaneous mitigation of 51-91% in 3-MCPDE and of 13-99% in GE, both contaminants achieved below 1000 µg/kg. Some of the mitigation methods have resulted in undesirable deterioration in other parameters of the refined oil. When the processed oil is used in food processing, it results in changes to 3-MCPDE and GE. Repeated deep frying above 170 °C in the presence of NaCl and baking at 200 °C with flavouring (dried garlic and onion), resulted in increased 3-MCPDE. Repeated frying in the presence of antioxidants (TBHQ, rosemary and phenolics) decreased 3-MCPDE in processed food. The GE content in foods tends to decline with time, indicating instability of GE's epoxide ring.

Monitoring the oxidation process of soybean oil during deep-frying of fish cakes with 1H nuclear magnetic resonance

The oxidation process of soybean oil (SBO) during frying fish cakes was investigated. The TOTOX value of before frying (BF) and after frying (AF) was significantly higher than control (CK). However, the total polar compound (TPC) content of AF reached 27.67% in frying oil continuously frying at 180℃ for 18 h, and 26.17% for CK. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) loss in isooctane and methanol significantly decreased with the extension of frying time and then tended to be stable. The decrease of DPPH loss was related to the increase of TPC content. Antioxidant and prooxidant balance (APB) value below 0.5 was obtained after 12 h for heated oil. (E)-2-alkenals, (E, E)-2,4-alkadienals, and n-alkanals were dominant ingredients among the secondary oxidation products. Traces of monoglycerides (MAG) and diglycerides (DAG) were also detected. These results may improve our understanding of the oxidation deterioration in SBO during frying.

An Efficient Deacidification Process for Safflower Seed Oil with High Nutritional Property through Optimized Ultrasonic-Assisted Technology

Safflower seed oil (SSO) is considered to be an excellent edible oil since it contains abundant essential unsaturated fatty acids and lipid concomitants. However, the traditional alkali-refined deacidification process of SSO results in a serious loss of bioactive components of the oil and also yields massive amounts of wastewater. In this study, SSO was first extracted by ultrasonic-assisted ethanol extraction (UAEE), and the extraction process was optimized using random centroid optimization. By exploring the effects of ethanol concentration, solid−liquid ratio, ultrasonic time, and the number of deacidification times, the optimum conditions for the deacidification of safflower seed oil were obtained as follows: ethanol concentration 100%, solid−liquid ratio 1:4, ultrasonic time 29 min, and number of deacidification cycles (×2). The deacidification rate was 97.13% ± 0.70%, better than alkali-refining (72.16% ± 0.13%). The values of acid, peroxide, anisidine and total oxidation of UAEE-deacidified SSO were significantly lower than those of alkali-deacidified SSO (p < 0.05). The contents of the main lipid concomitants such as tocopherols, polyphenols, and phytosterols in UAEE-decidified SSO were significantly higher than those of the latter (p < 0.05). For instance, the DPPH radical scavenging capacity of UAEE-processed SSO was significantly higher than that of alkali refining (p < 0.05). The Pearson bivariate correlation analysis before and after the deacidification process demonstrated that the three main lipid concomitants in SSO were negatively correlated with the index of peroxide, anisidine, and total oxidation values. The purpose of this study was to provide an alternative method for the deacidification of SSO that can effectively remove free fatty acids while maintaining the nutritional characteristics, physicochemical properties, and antioxidant capacity of SSO.

Selection of Vegetable Oils and Frying Cycles Influencing Acrylamide Formation in the Intermittently Fried Beef Nuggets

This study aims to investigate the effect of different vegetable oils and frying cycles on acrylamide formation during the intermittent frying of beef nuggets. Different vegetable oils, palm olein (PO), red palm olein (RPO), sunflower oil (SFO), and soybean oil (SBO), were used for a total of 80 frying cycles. Oil was collected at every 16th frying cycle and analyzed for peroxide value (PV), p-anisidine value (p-AV), free fatty acid (FFA), total polar compound (TPC), polar compound fractions, and fatty acid composition (FAC). Total oxidation (TOTOX) value was calculated, and acrylamide content was quantified in the nuggets. Regardless of the oil type, PV, p-AV, and TOTOX initially increased but gradually decreased. However, FFA and TPC continued to develop across the 80 frying cycles. The C18:2/C16:0 remained almost unchanged in PO and RPO but dropped progressively in SFO and SBO. The lowest acrylamide content in fried products was observed in the PO, while the highest content was observed in RPO. Bivariate correlation analysis showed no significant (p ≤ 0.05) correlation between oil quality attributes and acrylamide concentration. The oil type but not the frying cycle significantly affected the acrylamide concentration in beef nuggets.

The occurrence of 3-monochloropropane-1,2-diol esters and glycidyl esters in vegetable oils during frying

3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) are processed-developed contaminants presence in vegetable oils after undergo refining process under excessive heat. Refined oils are extensively used in various frying applications, nevertheless, the reservation against their quality and safety aspects are of major concern to consumers and food industry. Realizing the importance to address these issues, this article deliberates an overview of published studies on the manifestation of 3-MCPDE and GE when vegetable oils undergo for frying process. With the modest number of published frying research associated to 3-MCPDE and GE, we confined our review from the perspectives of frying conditions, product properties, antioxidants and additives, pre-frying treatments and frying oil management. Simplicity of the frying process is often denied by the complexity of reactions occurred between oil and food which led to the development of unwanted contaminants. The behavior of 3-MCPDE and GE is closely related to physico-chemical characteristics of oils during frying. As such, relationships between 3-MCPDE and/or GE with frying quality indices - i.e. acidity in term of free fatty acid or acid value); secondary oxidation in term of p-anisidine value, total polar compounds and its fractions, and refractive index - were also discussed when oils were subjected under intermittent and continuous frying conditions.

A Revisit to the Formation and Mitigation of 3-Chloropropane-1,2-Diol in Palm Oil Production

Process-based contaminants in food—particularly in vegetable oils—have been a topic of interest due to their potential health risk on humans. Oral consumption above the tolerable daily intake might result in health risks. Therefore, it is critical to correctly address the food contaminant issues with a proper mitigation plan, in order to reduce and subsequently remove the occurrence of the contaminant. 3-monochloropropane-1,3-diol (3-MCPD), an organic chemical compound, is one of the heat- and process-induced food contaminants, belonging to a group called chloropropanols. This review paper discusses the occurrence of the 3-MCPD food contaminant in different types of vegetable oils, possible 3-MCPD formation routes, and also methods of reduction or removal of 3-MCPD in its free and bound esterified forms in vegetable oils, mostly in palm oil due to its highest 3-MCPD content.