Monitoring of heat-induced carcinogenic compounds (3-monochloropropane-1,2-diol esters and glycidyl esters) in fries

Effects of Heat-Cooking with Edible Fats and Oils on the Levels of 3-Chloro-1, 2-Propanediol Fatty Acid Esters (3-MCPDEs), 2-Chloro-1, 3-Propanediol Fatty Acid Esters (2-MCPDEs) and Glycidyl Fatty Acid Esters (GEs) in Processed Foods

This study investigated the effect of cooking on the levels of 3-chloro-1, 2-propanediol esters (3-MCPDEs), 2-chloro-1, 3-propanediol esters (2-MCPDEs) and glycidyl esters (GEs) in deep-fried rice cracker, fried potato, croquette, fish fillet, chicken fillet and cooking oils (rice bran oil and palm oil). The levels of 2-/3-MCPDE in rice cracker fried with rice bran oil and the used oil remained about the same, while the levels of GEs in them fell with frying time. The levels of 2-/3-MCPDEs in fried potato, croquette, fried fish and chicken cutlet fried with rice bran oil and palm oil respectively fell with frying time, while the level of GEs in them remained about the same. The levels of 2-/3-MCPDEs and GEs in fried rice cooked with rice bran oil were under the method limit of quantification. These results provide insights the cooking has no influence with the levels of 2-/3-MCPDEs and GEs in cooked foods.

Optimization of water washing for mitigation of 3-monochloropropane 1,2 diol ester in palm oil physical refining process

The presence of 3-monochloropropane-1,2 diol ester (3-MCPDE) and glycidyl ester (GE) in processed palm oils is of concern, as these oils are widely used for edible purposes. The mitigation method studied here optimizes the removal of chloride through water washing of crude palm oil (CPO), to limit the formation of 3-MCPDE. The contaminant removal obtained via washing CPO supports the quantitative findings. By utilizing 5% water in the washing step, water-soluble chlorides in CPO are removed by up to 76%, resulting in a 71% reduction of 3-MCPDE to within statutory limits. In this study, a linear correlation was developed between the chloride and the corresponding 3-MCPDE with a correlation coefficient (R2) of 0.99. Using the correlations, 1.0 mg/kg of 3-MCPDE in refined, bleached and deodorized palm oil (RBDPO) will be obtained from CPO with 1.2 mg/kg chloride with 7% wash water usage. The study also showed minor GE reduction between 7 and 11% was attained after water washing.

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.

Occurrence and risk assessment of 3-monochloropropanediols esters (3-MCPDE), 2-monochloropropanediol esters (2-MCPDE), and glycidyl esters (GE) in commercial infant formula samples from Malaysia

The presence of 3-monochloropropanediol esters (3-MCPDE), 2-monochloropropanediol esters (2-MCPDE) and glycidyl esters (GE) in infant formula products has raised serious concerns. They incorporate vegetable oils, particularly palm-based oils, which are well-known to contain large amounts of these process contaminants. An analysis was conducted on infant formula samples (n = 16) obtained from the Malaysian market to determine the levels of 3-MCPDE, 2-MCPDE and GE using gas chromatography-mass spectrometry (GC-MS). The method was validated, with a limit of quantification (LOQ) on instrument of 0.10 µg/g for all analytes. The median concentrations of 3-MCPDE, 2-MCPDE and GE in infant formula in this study were 0.008 µg/g, 0.003 µg/g and 0.002 µg/g respectively. The estimated dietary intakes calculated from consumption of infant formula show higher exposures to infants within the age group of 0 to 5 months, highest for GE (1.61 µg/kg bw/day), followed by 3-MCPDE (0.68 µg/kg bw/day) and 2-MCPDE (0.41 µg/kg bw/day) compared to the age group of 6 to 12 months. Only one sample, relating to GE exposure is a potential risk for both age groups with MOE value below 25,000.

The Formation of 3-Monochloropropanediol Esters and Glycidyl Esters during Heat-Induced Processing Using an Olive-Based Edible Oil

With the prevalence of edible diacylglycerol (DAG) oil, which is beneficial to human, the generation of 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) as well as the stability of physical properties during heat-induced processing still need to be explored. In this study, the experiment used olive-based edible oil with different contents of DAG (40, 60, and 80%) to make crackers and fry chicken. They were heated at 160 and 180 °C to determine the changes in 3-MCPDE and GE, the crackers’ hardness and gumminess, and the physical properties of the oil. During baking and frying, 3-MCPDE decreased, while the content of GE slightly increased with the prolonged heating duration. Finally, 3-MCPDE and GE were lower than 1.25 mg/kg and 1.00 mg/kg, respectively. The AV increased proportionally as duration increased and POV was below 0.30 g/100 g. In general, the changes in 3-MCPDE and GE were related to the heating temperature and duration, and not significantly (p > 0.05) related to the content of DAG.

Methods, principles, challenges, and perspectives of determining chloropropanols and their esters

Chloropropanols and their esters are a group of food contaminants that have various toxicities to the human body. Research and control to chloropropanols and their esters is important to food safety. Therefore, the sensitive, accurate, precise, and effective determination of chloropropanols and their esters is highly essential to study their concentration, formation, and mitigation. The indirect method, commonly applied in the determination of chloropropanols and their esters, is based on the cleavage of ester bond, extraction, and derivatization. The conventional indirect method will still be the mostly used method in the near future due to its good sensitivity and feasibility, although its parameters need to be chosen and optimized according to sample stuffs and chloropropanol concentrations. Meanwhile, direct method and other quantitative methods should also be developed for special applications, such as studying the profile of chloropropanol esters and rapid screening protocol. The challenges and future perspectives of these methods are discussed in this review. This review can provide a reference on the selection, designation, and modification of methods for determining chloropropanols and their esters.

Effects of Deodorization on the Formation of Processing Contaminants and Chemical Quality of Sunflower Oil

Tocopherols and phytosterols are generally considered to be nutritionally beneficial, and 3-Monochloropropane-1,2-diol esters (3-MCPD esters), glycidyl esters (GEs) and trans fatty acids (TFAs) are generally considered to be harmful. The high temperature deodorization step is when these harmful 3-MCPD esters, GEs and TFAs are generated. Knowing how deodorization conditions affect levels of these substances is essential for designing refining processes that will produce nutritious, high quality edible oils. This study analyzed the changes of these components of sunflower oil at different temperatures (210, 230, 250 and 270°C) and times (60, 80, 100 and 120 min) during deodorization. Our research found that during the whole deodorization process (including undeodorized sunflower oil), the contents of 3-MCPD esters, GEs and TFAs all progressively increased, from 0.47 to 11.18 mg/kg, 0.24 to 18.42 mg/kg and 0.062% to 0.698%, respectively. However, the deodorization process significantly decreased the levels of tocopherols (from 535.94 to 240.26 mg/kg) and phytosterols (from 2803.58 to 1864.34 mg/kg). Meanwhile, the retention ratios of total tocopherols and total phytosterols also decreased from 96.29% to 44.83% and 92.29% to 66.50%, respectively.

Effect of Frying Process on Nutritional Property, Physicochemical Quality, and in vitro Digestibility of Commercial Instant Noodles

The effects of frying process on the nutritional property, physicochemical quality, and in vitro digestibility of instant noodle products are investigated in this study. Scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR) were also used to explore the changes in the microstructure and protein transformation. Noodles, after the frying process, showed a lower proportion of carbohydrate, protein, fiber, and also total starch and digestible starch, but higher content of fat and resistant starch in the proximate analysis. The frying process was also considered to improve the texture, surface color, and sensory properties of instant noodle products, accompanied by better cooking quality, including shorter cooking time and lower cooking loss during the rehydration. The honeycomb-like, porous, and less uniformed structure, and also the higher levels of β-sheets and β-turns, and the lower proportion of α-helixes of protein structure from fried instant noodle was also observed. The in vitro digestibility of starch and protein were downregulated in the fried group (81.96% and 81.31, respectively, on average) compared with the non-fried group (97.58% and 88.78, respectively, on average). Thus, the frying process lowered the glycemic index and regulated protein secondary structure by inhibiting continuous digesting enzyme activity, generating starch-lipid complexes, and changing the levels of protein transformation. In conclusion, our findings will provide an innovative evaluation of the frying process on instant noodles and even other various starch-based prepared food products.

Glycidol Fatty Acid Ester and 3-Monochloropropane-1,2-Diol Fatty Acid Ester in Commercially Prepared Foods

Glycidyl fatty acid esters (GEs), which are the main pollutant in processed oils, are potential mutagens or carcinogens. 3-Monochloropropane-1,2-diol fatty acid esters (3-MCPDEs) are also well-known food processing contaminants. 3-MCPDEs are believed to be a precursor to GEs in foodstuffs. In vivo, lipase breaks down the phosphate ester of GEs and 3-MCPDEs to produce glycidol and 3-MCPD, respectively, which are genotoxic carcinogens. Thus, it is important to determine human exposure to GEs and 3-MCPDEs through foodstuffs. There are only reports on the amount of GE and 3-MCPDE in cooking oils and cooked foods. The content in multiple types of foods that are actually on the market was not clarified. In this study, 48 commercially prepared foods were analyzed to identify other sources of exposure to GE and 3-MCPDE. All of them contained relatively high amounts of GEs and 3-MCPDEs. The correlation between GEs and 3-MCPDEs in individual foods was examined. There was a correlation between the amounts of GEs and 3-MCPDEs in the food products (r = 0.422, p < 0.005). This is the first report on the content in multiple types of commercially prepared foods that are actually on the market was clarified.