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Compared with conventional plant oils, diacylglycerol (DAG)‐based fats exhibit a higher melting point and could serve as a solid base oil for preparing specialty fats. In this study, different chain length DAG‐based solid fats were prepared, and the influences of acyl groups on the physical property, crystal microstructure, and crystallization kinetics of the binary solid fat phase were explored. The slipping melting point (SMP) of obtained medium chain‐DAG (MCD‐fats), medium‐long chain‐DAG (MLCD‐fats), and long chain‐DAG (LCD‐fats) fats were 35.67, 40.70, and 52.30°C, and their original β′ crystal content were 46.3%, 56.1%, and 66.9%, respectively. The solid fat content (SFC) profiles and crystallization properties were significantly affected as the fatty acid chain length and acylglycerols compositions changes. The microstructure of crystal in DAG‐fats got denser slowly during storage. DAG can delay the translation of crystal form and stabilize β′ crystal form, which is related to their three‐dimensional crystalline network changes. The hardness of MCD‐fats and LCD‐fats were higher than that of MLCD‐fats because of the acylglycerol compositions as well as fat crystals in DAG‐fats. Applying high melting point DAG as a novel base stock has an immense potential value in the production of specialty fats with low saturated fat, high stability, and decent operability. [ABSTRACT FROM AUTHOR]

Palm kernel oil (PKO) is a vegetable oil containing active substances beneficial for medicine and health. The applications of PKO can be extended by synthesizing ozonated PKO (OPKO). In this study, the PKO was ozonated at different intervals (0, 1, 3, 7, and 24 h). The physicochemical properties of OPKO were studied, including iodine value (IV), peroxide value (PV), acid value (AV), anisidine value (p-AV), viscosity and fatty acid composition (FAC). Meanwhile, the spectroscopic characteristics, melting and crystallization properties of OPKO were also investigated. Besides, the present study also examined the antimicrobial properties of OPKO against Gram-positive and Gram-negative bacteria as well as fungi using agar disk-diffusion method. The results showed that PV, AV, and viscosity of the OPKO increased in parallel with increasing ozonation time, reaching 963.6 ± 25.0 meq O2/kg fat, 45.30 ± 1.45 mg KOH/g oil, and 196.3 ± 1.6 mPa.s, respectively, after 24 h of ozonation. On the other hand, prolonged ozonation time reduced oleic acid and led to lower IV of 1.6 ± 0.7 g I2/100 g oil. The p-AV exhibited an increasing-decreasing trend, reaching a peak at 3 h ozonation period. Spectroscopic analysis showed that the absorption band at 1712 cm−1, 1400 cm−1, and 1112 cm−1, attributed to C=O, O-H, and -C-O, respectively, were altered with the ozonation time, indicating the change in the chemical composition of PKO. Moreover, the change in the FAC also affected the crystallization and melting profiles of PKO. This work also demonstrated the excellent antimicrobial properties of OPKO with significant inhibition effects against several types of microorganisms tested. Therefore, OPKO can be an essential component with great potential for cosmetics and pharmaceutical products. [ABSTRACT FROM AUTHOR]

Various food formulations widely utilized solid fats to provide specific textural properties and sensory attributes. Partially hydrogenated oil was commonly used as solid fat before being banned by FDA recently because of the existence of trans fats. Oleogels, semi‐solid gel typically prepared from liquid vegetable oil and food‐grade oleogelators, is developed as an alternative for solid fats that is free of trans fat and low in saturated fats. Oleogels are prepared via indirect or direct oleogelation technology by which the liquid oil is entrapped in a three‐dimensional network with the aid of low molecular weight oleogelators (LMOGs) and high molecular weight oleogelators (HMOGs). Oleogels received tremendous attention from food scientists to be used in various food applications, particularly high‐fat products such as comminuted meat, chocolates, ice cream, shortening and margarine and even as a deep‐frying medium. They satisfy not only the current trends of consumers for healthy food products (free of trans fat and low in saturated fat) but also provide viscoelastic solid‐ and gel‐ like properties to structure high fat food products. More importantly, recent studies showed that oleogels tend to be metabolized differently from conventional fats and oils giving them an additional advantage in improving the nutritional value of high‐fat foods. Therefore, this review aims to provide an overview that captures the latest studies on oleogels from their production via direct dispersion and indirect dispersion methods, processing conditions that influence the physical properties, metabolism and health attributes as well as recent application in food products. [ABSTRACT FROM AUTHOR]

Highlights: [•] This is the first ever information related to fractionated diacylglycerol. [•] A process possible with palm-based diacylglycerol is presented. [•] Fractioned palm-diacyglycerol stearin (PDAGS) is utilised as bakery shortening. [•] PDAGS: PMF at 50%:50% and 60%:40% (w/w) were the optimum shortening blend. [•] The optimum blend has good miscibility in solid state and contain β′ crystal. [Copyright &y& Elsevier]

The present study investigated the health effect of two types of diacylglycerol (DG) produced from (i) palm kernel (PK) oil of medium-chain saturated fatty acids and (ii) soy-canola oil (SC) blend of long-chain unsaturated fatty acids in C57BL/6N mice. As compared to diet containing 30% PK triacylglycerol (TG), 16 wk feeding trial on C57BL/6N mice with a diet consisting of 30% PKDG and 30% SCDG significantly ( p<0.05) reduced the fat accumulation in epididymal and retroperitoneal regions. Serum glucose, cholesterol, leptin and insulin levels were significantly ( p<0.05) suppressed in PKDG- and SCDG-fed mice. In terms of gene expression, PKDG diet induced expression of acyl-CoA synthase long chain (ACSL) and acyl-CoA synthase medium chain mRNA in the small intestine of the mice while SCDG fed mice upregulated ACSL in liver and small intestine. This suggests that the difference in fatty acid composition of DG may potentially induce β-oxidation in different organs in mice. Besides, expression of apolipoprotein B mRNA were reduced in mice fed with PKDG and SCDG, indicating the ability of PKDG and SCDG to reduce LDL levels. In conclusion, structural differences between DG and TG markedly influenced the metabolism of lipids in the body while fatty acid composition has only showed a minor effect. Practical applications: Medium chain type of DG oil, if proven to have similar effects to long chain type DG in this study, can be incorporated into food for health purposes and can replace conventional cooking oil as healthy functional cooking oil. [ABSTRACT FROM AUTHOR]

Direct comparison of the frying performance of vegetable oils based on the data reported in literature is difficult because of the inconsistent experimental protocols used in different studies. This research aimed to develop a method, known as 'Rate of Parameter Change' (RPC) to evaluate the deep-frying results obtained from literature data. A literature search was conducted using PubMed, Web of Science and Scopus to identify the studies that reported the deep-frying results using different types of vegetable oils (palm olein, canola oil, soybean oil, sunflower oil). A total number of 32 studies were selected in this work based on the pre-defined selection criteria. The quality parameters examined were polyunsaturated fatty acid composition (PUFA), free fatty acid content (FFA), total polar compound content (TPC), anisidine value (AV) and di- and polymerized triacylglycerol content (DPTG). The data extracted from each study were normalized with the number of frying cycles reported in the study. The normalized values for a parameter examined were reported as RPC. The RPC computed from different studies were then compared and evaluated using a box plot. This method had revealed a distinct trend, where the PO was found to have a higher stability against thermo-oxidative alterations compared to the soft oils (CNL, SBO, SFO) during deep-frying application. However, some of the calculated RPC values have large standard deviations which are attributed to the inconsistent experimental protocols used in different studies. This observation calls for a standardized protocol in deep-frying experiments to facilitate the comparison of quality parameters between different studies and between different types of vegetable oils. • The rate of parameter change (RPC) during frying was computed from literature data. • This approach confirms PO has a higher frying stability compared to the soft oils. • RPC approach can be used to compare the results from different studies. • Deviation from the mean RPC values calls for the use of standard frying protocols. [ABSTRACT FROM AUTHOR]

Monochloropropanediol esters (MCPDE) and glycidyl esters (GE) are potential carcinogenic contaminants which are found in refined palm olein (PO). Although chemical refining has proven to effectively reduce the initial levels of MCPDE and GE in PO, there is a lack of information on the oxidative stability, formation and absorption of MCPDE and GE of chemically refined PO during deep-frying in comparison with physically refined PO. In this study, the chemically refined PO (CR-PO) and physically refined PO (PR-PO) were used to fry potato chips for up to 40 cycles. The CR-PO was found to be oxidatively more stable compared to PR-PO during deep-frying. As a result, the CR-PO was found to have a lower free fatty acid content, total oxidation value (TOTOX), specific extinction at 232 and 268 nm (K 232 and K 268), total polar compound (TPC) and polymerised triacylglycerol (PTG) contents compared to PR-PO during deep-frying. Furthermore, the CR-PO was found to have a lower darkening rate throughout the frying period compared to PR-PO owing to a lower initial total phenolic content. The initial 3-MCPDE and GE levels in CR-PO were low, at 0.35 ppm and 0.17 ppm, respectively, compared to 2.42 ppm and 3.23 ppm, respectively, in PR-PO. After 40 frying cycles, the 3-MCPDE and GE levels found in chips fried with CR-PO were 0.13 ppm and 0.08 ppm, respectively, which were approximately 2-times and 10-times lower than that of the chips fried with PR-PO. This finding shows that it is critical to keep the initial contents of MCPDE and GE in frying oil as low as possible to minimize their presence in both the oil and food. In conclusion, CR-PO is suitable for deep-frying application owing to its thermo-oxidative stability and the presence of very low MCPDE and GE contents in the oil before and after deep-frying. [Display omitted] • Chips were fried in physically (PR-PO) and chemically refined palm olein (CR-PO). • The initial 3-MCPDE and GE levels in CR-PO were 7- and 19-times lower than PR-PO. • CR-PO has higher thermo-oxidative stability and lower darkening rate than PR-PO. • Chips fried with CR-PO has 3-MCPDE level 2-times lower than those fried with PR-PO. • Chips fried with CR-PO has GE level 10-times lower than those fried with PR-PO. [ABSTRACT FROM AUTHOR]

• Ultrasound assisted extraction (UAE) used mild extraction strategies to extract oil. • UAE oil yield and recovery were comparable with Soxhlet extraction. • Mechanical pressing yielded < 50% of UAE. • Triacylglycerol profile and fatty acid composition were unaffected by UAE. • UAE helps in co-extracting antioxidants (carotene and tocopherol) from mahua oil. Ultrasound-assisted solvent extraction (UAE) was applied to extract underutilized Madhuca longifolia seed oil. The effect of extraction time, temperature, solvent type, solvent/sample ratio, and amplitude on the oil yield and recovery were investigated. Approximately 56.97% of oil yield and 99.54% of oil recovery were attained using mild conditions of 35 min, 35 °C, 40% amplitude, isopropanol to acetone (1:1), and solvent to sample (20 mL/g). UAE oil yield and recovery were comparable with Soxhlet extraction (SXE) whilst mechanical pressing (ME) yielded < 50% of UAE recovery. UAE does not affect the fatty acids composition (46% C18:1; 22% C16:0; 21% C18:0, 10% C18:2), and triacylglycerol profile (23% POO, 17% POS, 16% SOO, and 14% POP). Interestingly, UAE extracted oil conferred remarkably (P < 0.05) higher antioxidant capacity (IC 50 of DPPH 106.60 mg/mL and ABTS 39.80 mg/mL) than SXE (IC 50 of DPPH 810.40 mg/mL and ABTS 757.43 mg/mL) or ME (IC 50 of DPPH 622.38 mg/mL and ABTS 392.87 mg/mL). [ABSTRACT FROM AUTHOR]

Deep-frying is a popular method for food preparation because it improves the taste and sensory of food. Among the vegetable oils, palm oil is one of the commonly used oils for deep-frying application. During deep-frying, some of the oil would be absorbed by the food and subsequently be consumed together with the food. Hence, the quality and stability of the oil used for deep-frying are of critical food safety considerations. To address this issue, we produced refined palm oil from crude palm oil which has been treated with an aerobic liquor (AL) generated from a palm oil mill. The result shows that the refined palm oil produced from AL-treated CPO (aRPO) has improved quality, in particular the 3-monochloropropane-1,2 diol ester (3-MCPDE) and the glycidyl ester (GE) reduced by 58% and 46%, respectively. After 30 cycles of deep-frying, the used aRPO contained 68% lower FFA content, 13% lower polar content, and 43% lower 3-MCPDE content compared to the conventionally produced refined palm oil (RPO). Furthermore, the aRPO has a higher smoke-point and a higher resistance to darkening compared to the RPO. As a result, the fries prepared using aRPO have lower 3-MCPDE content and they have a better appearance and were less greasy when compared to the fries prepared using RPO. Overall, AL-treatment of CPO is a feasible method to improve the quality and deep-frying performance of refined palm oil and it could readily be adopted by the industry because it is simple and sustainable. [Display omitted] • Aerobic liquor (AL) washing improves palm oil quality. • AL washing reduces 3-monochloropropane-1,2 diol (3-MCPDE) and glycidyl esters (GE). • AL washing enhances deep-frying performance of refined oil. • Fries prepared had better sensory properties and lower 3-MCPDE. [ABSTRACT FROM AUTHOR]