Production, Properties and Application of Blends of Palm Stearin with Palm Kernel Olein, Sunflower Oil or Anhydrous Milkfat Transesterified by Lipases

Palm stearin, the cheaper and more solid fraction of palm oil, is a useful hard fat in the manufacture of edible fat such as margarine. However, with slip melting points ranging between 46 to 56°C, only 10% of palm stearin can be added to a standard table margarine. This study was conducted to investigate the performance of lipase-catalysed transesterified fat blends containing high levels of palm stearin (minimum 40%) when processed into table margarine. In the first part of the work, the effect of several reaction conditions on lipase-aided transesterification of palm stearin was studied. Results on the effect of lyophilisation of enzyme on transesterification indicated increases in % triglyceride (TG) when drying time was increased. The maximum yield was at 4 or 6 hours of drying. Studies on the effect of reaction time indicated that 8h of reaction produced the highest % TG remaining and Rhizomucor miehei and A lcaligenes lipases both showed maximum rates at 6h reaction time. The transesterification process also decreased the slip melting point (SMP) of palm stearin slightly after 24h reaction with R. miehei lipase registering the largest decrease (5.5°C) compared to the initial unreacted mixture. The catalytic stability of R. miehei and Pseudomonas lipases, after being subjected to ten runs of repeated usage indicated that the lipases can be reused to produce fairly constant products on a large scale. The rates of transesterification were found to vary with different lipase sources. Bacterial lipase of Pseudomonas was found to have the fastest rate of reaction (50.0h⁻¹) followed by R. miehei lipase (27.1h⁻¹). Generally, both the above lipases also produced the highest degree of transesterification and % FFA. Pseudomonas lipase-catalysed mixtures caused the biggest drop in SMP and solid fat content (SFC) in all the three mixtures studied

Diacylglycerols: healthy fats of the future?

Malaysia is the fattest nation in South East Asia. A recent survey by Social Security Organization (SOCSO) Malaysia on 308,039 Malaysian employees in 2013 showed that 36.94% were overweight, 17.63% were obese, 13.14% had hypertension, 61.76% had hypercholesterolemia and 8.45% had diabetes (The Star, 27 Feb 2015). Malaysians’ present lifestyle and culture were among the reasons cited for the rise in these figures. Excessive intake of fat in the diet has been linked to diseases such as heart disease, cancer, obesity and possibly, gallbladder disease. Increased saturated fat intake is associated with high blood cholesterol and increased risk of coronary heart disease. It is difficult for individuals to change their dietary habits to reduce or minimize fat intake, while enjoying their favourite foods. This problem and the interest shown by consumers in structured lipids led to the search, by the food industry and scientific community, for “Healthy Fats of the Future”. Just as micronutrients have been lauded to prevent disease, so too has the effect of structured lipids like diacylglycerols (DAG) on obesity and weight-related disorders. The physiological effect of DAG is believed to be attributable to its metabolic pathway, which is different from the normal triacylglycerol metabolism. With structured lipids, we can combine the different positive and nutritionally valuable fatty acids in palm oil to produce a potent structured lipid with maximum benefits and minimum adverse effects. The main aim of this talk is to provide a comprehensive review of palm-based DAG with emphasis on the production, process developments, applications and animal trials

Lipase-catalyzed acidolysis of palm olein and caprylic acid in a continuous bench-scale packed bed bioreactor

Enzymatic acidolysis of refined, bleached and deodorized (RBD) palm olein with caprylic acid was carried out in a continuous packed bed bioreactor to produce structured lipid (SL) that can confer metabolic benefits when consumed. Lipozyme® IM 60 from Rhizomucor miehei, a 1,3-specific lipase, was used as the biocatalyst in this study. After 24 h of reaction, 30.5% of the total fatty acid content of the modified oil was found to be caprylic acid, indicating its incorporation into the palm olein. The triacylglycerols (TAGs) of palm olein after acidolysis were separated and were characterized by seven clusters of TAG species with equivalent carbon number (ECN), C28, C30, C32, C34, C36, C38 and C40. Caprylic–oleic–caprylic TAGs were predicted in cluster C32, which recorded the highest amount, with 35.3% of the total TAG. Fatty acid composition at the sn-2 position was determined, by pancreatic lipolysis, as C8:0, 9.2%; C12:0, 2.3%; C14:0, 1.8%; C16:0, 21.3%; C18:0, 4.7%; C18:1, 60.7%. Iodine value (IV), slip melting point (SMP) and differential scanning calorimetric (DSC) analyses of SL were also performed. In IV analysis, SL recorded a drop of value from 60.4 to 48.2 while SMP was reduced from 13 to 4.2 °C, in comparison to RBD palm olein. DSC analysis of SL gave a melting profile with two low melting peaks of −15.97 and −11.78 °C and onset temperatures of −18.43 and −14.03 °C, respectively

Phase behavior of palm oil in blends with palm-based diacylglycerol

Phase behavior of palm oil (PO) in blends with different concentrations (10% intervals) of palm-based diacylglycerol oil (PO-DAG) was studied using the iso-solid diagram, solid fat content (SFC) with the hardness thermal protocol, DSC melting and crystallization curves, X-ray diffraction curves, and texture analysis (hardness). Minor eutectic effects were observed at around 20–50% PO-DAG in 20–50% SFC iso-lines. The phase behavior predicted by the iso-solid diagram as well as SFC with the hardness thermal protocol did not account for hardness variations observed between PO and PO blends with 10–40% PO-DAG. Nevertheless, the latter could be attributed to the corresponding DSC data as well as crystal polymorphism. However, as the concentration of PO-DAG increased from 40% to 100%, iso-line temperatures, SFC with the hardness thermal protocol, and also hardness were found to steadily increase. PO-DAG at 10% concentration was found to have a β′-stabilizing effect on the polymorphism of PO, while a β-tending effect was observed as the concentration of PO-DAG increased from 10% to 90%

In situ bioconversion of coconut oil via coconut solid state fermentation by Geotrichum candidum ATCC 34614

Coconut base solid state fermentation was carried out by Geotrichum candidum ATCC 34614 for in situ coconut oil bioconversion. Coconut oil, which contains highly saturated medium chain triglycerides, was partially bioconverted into a combination of medium chain diglycerides, medium chain monoglycerides and medium chain fatty acids by this fungus lipolytic activity. The product demonstrated improved aroma, flavor, thermal behavior and antibacterial activity. Maximum triglycerides conversion (76.5 %) occurred at 40 % moisture content and 50 % oil content after 25 days of incubation. Bioconverted coconut oil revealed as much as 95 % antibacterial activity as well as altered thermal characteristic towards lower melting and higher crystallization points. The fermented culture also revealed highly fruity and flora notes which contained five main short- and medium-chain esters known as aromatic compounds. The present study established the possibility of using G. candidum ATCC 34614 in coconut solid culture for bioconversion of coconut oil, which improves the fermented product characteristics

Comparison between conventional and alternative peeling methods on peeling efficiencies of Malaysian 'Chok Anan' mango (Mangifera indica L.) fruit

Fruit industries require convenient peeling method, especially during puree processing to prevent deterioration of fruit quality and product loss. Therefore, manual, chemical (sodium hydroxide/NaOH) and enzymatic (Pectinex Ultra SP-L) peeling methods were compared to determine the peeling efficiencies of ‘Chok Anan’ mangoes. The effect of different peeling parameters (concentrations [chemical peeling: 1.6-7.3% of 0.4M-1.83M; enzymatic peeling: 0.005-0.095%], temperatures [chemical peeling: 80-95°C; enzymatic peeling: 25-40°C], and duration of soaking [chemical peeling: 5-10 min; enzymatic peeling: 30-120 min]) were evaluated for peeling yield, peeling time, absorption of chemical and enzyme solution, the penetration depth of NaOH and enzyme activities (reducing sugar analysis). The enzymatic peeling had significantly (p0.05) in peeling yield (>86%), but there was significant (p<0.05) effect on absorption of both NaoH and pectinase solutions at 0.84g/100g (enzymatic) and 2.50g/100 g (chemical), 0.45 mm penetration depth of NaOH and significant decrease in enzyme activities from 20.04g/100 mL to 4.92g/100 mL using reducing sugar analysis. The optimal enzymatic peeling conditions (concentration: 0.009%, temperature: 25°C, duration of soaking: 120 min) had made it possible to recycle the pectinase solution twice thus may be beneficial for the mango processing industry compared to chemical peeling

Production of a Solvent, Detergent, and Thermotolerant Lipase by a Newly Isolated Acinetobacter sp. in Submerged and Solid-State Fermentations

The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6–11). The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications

Similar physical characteristics but distinguishable sn-2 palmitic acid content and reduced solid fat content of chemically interesterified palm olein compared with native palm olein by dry fractionation: a lab-scale study

The presence of solid fat content (SFC) of vegetable fats at human body temperature (37°C) has been linked to altered fat digestibility and metabolism. In this study, the possibility of reducing the SFC in chemically interesterified palm olein (CIEPO) while maintaining physical properties similar to native palm olein was explored by dry fractionation. Crystallization at 37°C for 155 min produced a CIEPO olein fraction with total fatty acid composition (FAC) broadly resembling that of native palm olein while the high proportion of sn-2 palmitic acid content was maintained at 39.1%. The CIEPO olein fraction has a reduced SFC at 37°C from 8.6 to 4.2%, overall decreased SFC, slip melting point (SMP) at 33°C, a reduced palmitoyl-palmitoyl-palmitoyl (PPP) from 6.0 to 3.7 mol% and lower heating peaks in thermal profile compared with the untreated CIEPO. Both CIEPO olein fraction and palm olein have broadly similar total FAC and SMP below 37°C but very distinguishable sn-2 palmitic acid content. CIEPO olein fraction and native palm olein can be used as effective comparison in human studies because the differences of both fats in PPP content and SFC at 37°C were narrowed

Interpretation of triacylglycerol profiles of palm oil, palm kernel oil and their binary blends

The effects of lipase-catalyzed interesterification (IE) on changes in the chemical composition of palm oil (PO), palm kernel oil (PKO) and their binary blends at 3:1, 1:1 and 1:3 (w/w) ratios, using both 1,3 specific Rhizomucor miehei, (Lipozyme™) and non-specific Pseudomonas sp. lipases were evaluated. IE of the native PO and PKO showed very distinct chemical composition changes. Catalysis of PO, using both lipases, caused synthesis of more medium and long chain triacylglycerols (TAG), with MMM/OLL, MMP, OOO and PPP (M, myristic acid; O, oleic acid; L, linoleic acid; P, palmitic acid) increasing in concentration. In contrast, IE of PKO resulted in the formation of more short and medium chain TAG, with LaLaO and LaMO (La, lauric acid; C, capric acid) experiencing noteworthy increments. Both Rhizomucor miehei and Pseudomonas sp. lipases showed high affinity in hydrolyzing PO fatty acids, resulting in high TAG losses and formation of high percentages of partial glycerides while these lipases were found to enhance the synthesis process in IE of PKO. Catalysis of the three binary blends caused similar TAG compositional changes where the synthesis process focussed on the medium chain TAG, while hydrolysis was observed in the short and long chain TAG that showed corresponding decreases. Catalysis of the three blends was influenced by the major fraction of these blends. Among these blends, PO: PKO at a 1:1 ratio exhibited the highest degree of IE. The diversity and quantity of available TAG are postulated to be the main causes of the different catalytic activities in these binary blends with Pseudomonas sp. lipase showing a higher degree and rate of IE than R. miehei

Physico-chemical properties of various palm-based diaclyglcyerol oils in comparison with their corresponding palm-based oils

Palm-based diacylglycerol (P-DAG) oils were produced through enzymatic glycerolysis of palm kernel oil (PKO), palm oil (PO), palm olein (POL), palm mid fraction (PMF) and palm stearin (PS). High purity DAG (83–90%, w/w) was obtained and compared to palm-based oils (P-oil) had significantly (P < 0.05) different fatty acid composition (FAC), iodine value (IV) and slip melting point (SMP). Solid fat content (SFC) profiles of P-DAG oils as compared to P-oils had less steep curves with lower SFC at low temperature range (5–10 °C) and the higher complete melting temperatures. Also, P-DAG oils in contrast with P-oils showed endothermic as well as exothermic peaks with higher transition temperatures and significantly (P < 0.05) higher crystallisation onsets, heats of fusion, and heats of crystallisation. Crystal forms for P-DAG oils were mostly in the β form