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1.
Enzymatic interesterification of palm stearin with coconut oil was conducted by applying a dual lipase system in comparison with individual lipase-catalyzed reactions. The results indicated that a synergistic effect occurred for many lipase combinations, but largely depending on the lipase species mixed and their ratios. The combination of Lipozyme TL IM and RM IM was found to generate a positive synergistic action at all test mixing ratios. Only equivalent amount mixtures of Lipozyme TL IM with Novozym 435 or Lipozyme RM IM with Novozym 435 produced a significant synergistic effect as well as the enhanced degree of interesterification. The interesterification catalyzed by Lipozyme TL IM mixed with thermally inactivated immobilized lipase preparations indicated that the carrier property may play an important role in affecting the interaction of two mixed lipases and the subsequent reactions. A dual enzyme system, consisting of immobilized lipases and a non-immobilized one (Lipase AK), in most cases apparently endows the free lipase with a considerably enhanced activity. 70% Lipase AK mixed with 30% immobilized lipase (Lipozyme TL IM, RM IM and Novozym 435) can achieve an increase in activity greater than 100% over the theoretical value when the reaction proceeds for 2 h. The co-immobilization action of the carrier of the immobilized lipases towards the free lipase was proposed as being one of the reasons leading to the synergistic effect and this has been experimentally verified by a reaction catalyzed by a Lipase AK-inactivated preparation. No apparently synergistic effect of the combinations of Lipozyme TL IM and RM IM was observed when the dual enzyme systems applied to the continuous reaction performed in a packed bed reactor. In brief, this work demonstrated the possibility of increasing the reaction rate or enhancing the degree of conversion by employing a dual lipase system as a biocatalyst.  相似文献   

2.
The physicochemical properties of binary and ternary fat systems made of commercial samples of palm oil (PO) blended with anhydrous milk fat (AMF) and/or rapeseed oil (RO) were studied. Physical properties such as solid fat content by pulsed‐Nuclear Magnetic Resonance (p‐NMR), melting profile by differential scanning calorimetry (DSC), and polymorphism of the blends were investigated. Palm oil was then batch enzymatically interesterified for 27 h, using Lipozyme® TL IM as biocatalyst, and further blended with AMF and/or RO in the same way. The objective of the present work was to evaluate the effect of batch enzymatic interesterification (B‐EIE) of palm oil on physical characteristics of the investigated fat blends. For that purpose, iso‐solid diagrams have been constructed from p‐NMR data. It was shown that B‐EIE of palm oil modifies its melting behaviour, but also its polymorphic stability and miscibility with other fats. Under dynamic conditions, after B‐EIE, the non‐ideal behaviour (eutectic) detected at low temperatures in the ternary PO/AMF/RO system disappears in the corresponding EIE‐PO/AMF/RO. After static crystallization followed by a tempering, the hardness of palm oil is increased after B‐EIE, as well as the hardnesses of the blends containing this fat compared to the native one. Polymorphism stability of the binary and ternary fat systems is also modified after B‐EIE compared to the corresponding native systems.  相似文献   

3.
A blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch-wise (B-EIE) and in continuous (C-EIE). Better oil quality, mainly in terms of acidity, free tocopherol and partial acylglycerol content, was obtained after EIE. The clear melting point after any interesterification process was similar and about 9 °C lower as result of the modification in the TAG profile, which approaches the calculated random distribution. Interesterification changed the SFC profile significantly. For the fully refined interesterified blends, the SFC profile was similar and clearly different from the starting blend. Interesterification decreased the content of solids at temperatures >15 °C and increased the content of solids at temperatures <15 °C. This increase was less remarkable after C-EIE, suggesting that full randomization was not achieved in the used conditions, probably caused by a too short residence time of the oil in the enzymatic bed. During B-EIE, variations in SFC with time, principally at low temperatures, were still observed although the TAG composition was stable. At low temperatures, the reaction rate calculated from SFC was very low, confirming an important effect of the acyl migration on this parameter.  相似文献   

4.
Structured lipids (SL) were produced from enzymatic interesterification (EIE) of palm kernel stearin (PKS), coconut oil (CNO), and fully hydrogenated palm stearin (FHPS) blends in various mass ratios. The EIE reactions were performed at 60 °C for 6 hours using immobilized Lipozyme RM IM with a mixing speed of 300 rpm. The physicochemical properties, crystallization and melting behavior, solid fat content (SFC), crystal morphology and polymorphism of the physical blends (PB), and the SL were characterized and compared with commercial cocoa butter and cocoa butter alternatives (CBA). EIE significantly modified the triacylglycerol compositions of the fat blends, resulting in changes in the physical properties and the crystallization and melting behavior. SFC and slip melting point of all SL decreased from those of their counterpart PB. In particular, SL obtained from EIE of blends 60:10:30 and 70:10:20 (PKS:CNO:FHPS) exhibited a high potential to be used as trans-free CBA as they showed similar melting ranges, melting peak temperatures, and SFC curves to the commercial CBA with fine needle-like crystals and desirable β' polymorph.  相似文献   

5.
文章考察了Lipozyme TL IM脂肪酶在无溶剂条件下,催化棕榈油硬脂与棕榈油软脂的酯交换。混合油为棕榈油硬脂和棕榈油软脂的比例为75∶25,脂肪酶的添加量为油重量的4%,酶催化反应的操作温度为70℃,反应时间为20 h。酯交换产物的氧化稳定性更高,SFC35℃降低了24.79%,改善了酯交换油的打发性,提高了人造黄油的可操作性及口感。  相似文献   

6.
This study aims to synthesize a cocoa butter equivalent (CBE)‐structured lipid from a blend of illipe butter (IB) and palm midfraction (PMF) by means of enzymatic interesterification using Rhizomucor miehei sn‐1,3 specific lipase, Lipozyme® RM IM (Novozymes North America, Inc., Franklinton, NC, USA) as the biocatalyst. Physical and chemical attributes of the CBE and cocoa butter (CB) were analyzed. The synthesized CBE matched the triacylglycerol (TAG) profile range of a commercial CB and is therefore hypothesized to show similar physical and chemical characteristics to CB. The TAG profile, fatty‐acid constituents, melting and cooling behavior, polymorphism, and crystal morphology were determined using high‐performance liquid chromatography, gas chromatography, differential scanning calorimetry, X‐ray diffraction (XRD), and polarized light microscopy, respectively. Four enzymatically interesterified blends of IB:PMF at different weight ratios were analyzed for their TAG profiles, and a ratio of IB:PMF 10:3 (%, w/w) at 5% enzyme load and a reaction time of 30 min gave similar TAG results to CB. The TAG values of the IB:PMF 10:3 interesterified product (IP) were 1,3‐dipalmitoyl‐2‐oleoylglycerol at 19.1 ± 1.0%, 1‐palmitoyl‐2‐oleoyl‐3‐stearoylglycerol at 42.7 ± 1.0%, and 1,3‐distearoyl‐2‐oleoylglycerol at 29.9 ± 0.3%. The melting and the cooling profile of IP and CB showed no significant difference. XRD of IP and CB displayed similar dominant peaks at 4.6 Å, representing a β polymorph. Both CB and IP have similar granular spherulitic crystals.  相似文献   

7.
The objective of this study was to produce low saturated, zero‐trans, interesterified fats with 20 or 30 % saturated fatty acids (SFA) such as C16:0 or C18:0. Tripalmitin (TP) or tristearin (TS) was blended with high oleic sunflower oil (HOSO) at different ratios (0.1:1, 0.3:1, and 0.5:1 [w/w]). Total C16:0 and C18:0 compositions of the resulting TP/HOSO and TS/HOSO blends, respectively, were plotted against blending ratios. Linear interpolation was used to estimate blending ratios that would yield physical blends (PB) with 20 or 30 % SFA. Interesterified blends (IB) were then synthesized from the customized PB using Lipozyme TL IM as the biocatalyst. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability of PB and IB were compared. The total fatty acid compositions of PB and IB were similar but fatty acid positional distributions and TAG molecular species composition differed. IB contained 5–10 % more SFA at the sn‐2 position than corresponding PB. Furthermore, interesterification generated mono‐ and disaturated TAG species which resulted in broader melting profiles for IB. However, IB had lower oxidative stability than PB. The reformulation of food products with zero‐trans interesterified fats may be advantageous to the reduction of cardiovascular disease burden in the population.  相似文献   

8.
9.
In the present study attempt is made to substitute soft paraffin, a common commercial ointment base, with cheap fatty material like palm stearin. Palm stearin has been corandomised with coconut oil and tested as potential ointment base. The products show release of salicylic acid, a sparingly water soluble drug, much better than soft paraffin tested in vitro and in vivo and also sodium salicylate a water soluble drug, in the presence of surfactants as additives. They are also suitable ointment bases with respect to slip melting point, plasticity and consistency.  相似文献   

10.
Crude red palm oil of 11.4 % free fatty acid content was dry fractionated to obtain liquid crude red palm olein which was deacidified using enzyme (lipase from Rhizomucor miehei), solvent (ethanol), and chemical (aqueous sodium hydroxide), and its effect on physicochemical characteristics and phytonutrients retention was evaluated. Enzymatic deacidification showed 100 % product yield and no neutral lipid loss, whereas yields of 78 and 62 % and neutral lipid loss of 12 and 30 % were observed for solvent and chemical deacidification, respectively. Variation in viscosity (25.3–37.2 cSt at 40 °C), slip melting point (15–36 °C), monoacylglycerols (1.7–3.3 %), and diacylglycerols (5.8–27.9 %) were also observed. Carotenoid content was slightly reduced by enzymatic (535 mg/kg), solvent (556 mg/kg), and chemical (526 mg/kg) deacidification. Retention of phytonutrients such as phytosterols (1,235 mg/kg), total tocopherols (965 mg/kg), squalene (301 mg/kg), coenzyme Q10 (25.9 mg/kg), and total phenolics (3 mg/kg) was highest following enzymatic deacidification. The IC50 value of the enzymatic deacidified sample (21.8 mg/ml) indicates more radical scavenging activity than in samples obtained using solvent (42.0 mg/ml) and chemical (28.8 mg/ml) methods.  相似文献   

11.
12.
Glycerolysis of palm and palm kernel oils were carried out using commercial lipases from Candida antarctica (Novozym 435) and Mucor miehei (Novozym 388) as catalyst (500 units lipase/g oil) at 40°C and with an oil:glycerol molar ratio of 1:2 in a solvent-free system. Novozym 435 catalyzed the glycerolysis of palm and palm kernel oils giving reaction products in similar compositions. Partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils were 64% (wt) and 66% (wt), respectively. However, partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils conducted with Novozym 388 as catalyst at the same conditions were 44% (wt) and 56% (wt), respectively. On the other hand, free fatty acid contents of the glycerolysis products of palm and palm kernel oils obtained using Novozym 388 were higher, 25-30% (wt), than those obtained by Novozym 435, 4-5% (wt). The monoacylglycerols fraction with the highest content of oleic acid, 62.7% (wt), was obtained from the palm kernel oil glycerolysis reaction catalyzed by Novozym 435.  相似文献   

13.
Glycerolysis of palm and palm kernel oils were carried out using commercial lipases from Candida antarctica (Novozym 435) and Mucor miehei (Novozym 388) as catalyst (500 units lipase/g oil) at 40°C and with an oil:glycerol molar ratio of 1:2 in a solvent-free system. Novozym 435 catalyzed the glycerolysis of palm and palm kernel oils giving reaction products in similar compositions. Partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils were 64% (wt) and 66% (wt), respectively. However, partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils conducted with Novozym 388 as catalyst at the same conditions were 44% (wt) and 56% (wt), respectively. On the other hand, free fatty acid contents of the glycerolysis products of palm and palm kernel oils obtained using Novozym 388 were higher, 25–30% (wt), than those obtained by Novozym 435, 4–5% (wt). The monoacylglycerols fraction with the highest content of oleic acid, 62.7% (wt), was obtained from the palm kernel oil glycerolysis reaction catalyzed by Novozym 435.  相似文献   

14.
Semisolid fats obtained from oils and fats through enzymatic interesterification have interesting applications. The effect of certain reaction parameters (enzyme concentration, moisture content, reaction time, substrate ratio, temperature, and agitation level) over the enzymatic interesterification of fully hydrogenated soybean oil (FHSO) and refined soybean oil (SO) using two immobilized enzyme types (Lipozyme RM IM and Lipozyme TL IM), was studied with a fractional factorial design (FFD). The reaction products were analyzed with respect to melting point (mp), by-products content and triacylglycerols (TAG) composition. It was found that substrate ratio, reaction time, and their interaction presented the most significant contributions to mp, varying this from 43.4 to 61.5 °C. The highest contributions to by-product content were presented by time and its interaction with the amount of molecular sieves, mainly for Lipozyme TL IM. Through the models obtained, theoretical conditions to achieve minimal by-product generation and mp were found, being 5.0 % (w/wsubst.) of any of both lipases, 24 h, 70:30 (oil:fat,  % w/w), 65 °C, 230 rpm, and absence of molecular sieves. Regression models for TAG groups as a function of significant factors and interactions were constructed, offering useful information to establish the reaction conditions for obtaining a product with a target mp or chemical composition.  相似文献   

15.
Characteristics of crude palm oil are high FFA and DAG contents. High DAG content may affect throughput and yield during fractionation: high‐grade specialty fats such as hard palm mid fraction require premium crude palm oil to secure adequate crystallization properties. Moreover, DAGs are generally considered the main precursors for the formation of glycidyl esters during high‐temperature deodorization. The purpose of this study was to investigate the effect of enzymatic remediation on the reduction of FFA and DAG in crude palm oil. In practice, series of process parameters (vacuum and reaction time) were investigated, and the quality of enzymatically remediated crude palm oils was examined in terms of FFA and DAG reduction, TAG composition, and SFC and DSC melting profiles. Fully refined enzymatically remediated palm oils were then dry fractionated. The quality of the oleins derived from the enzymatically remediated palm oil was compared to that of regular RBD palm oleins.  相似文献   

16.
The lipase-catalyzed interesterification of extra virgin olive oil (EVOO) and fully hydrogenated palm oil (FHPO) was studied in a batch reactor operating at 75 °C. The compositions of the semi-solid fat products depend on the reaction conditions and the initial ratio of EVOO to FHPO. The dependence of the quasi-equilibrium product TAG profile on the reaction time was determined for initial weight ratios of EVOO to FHPO from 80:20 to 20:80. Lipozyme TL IM, Lipozyme RM IM and Novozym 435 were employed as biocatalysts. The interesterification reaction was optimized with respect to the type and loading of biocatalyst. Equilibrium was approached in the shortest time with Novozym 435 (80% conversion in 4 h). The chemical, physical, and functional properties of the products were characterized. Appropriate choices of the reaction conditions and the initial ratio of EVOO to FHPO lead to TAG with melting profiles and solid fat contents similar to those of commercial products. Differences were observed in the solid fat contents, melting profiles, and oxidative stabilities of the various interesterified products and also between the indicated properties of each category of product and the corresponding physical blend of the precursor reagents.  相似文献   

17.
Palm oil biodiesel (POB) is characterized by a very high cold soak filtration time (CSFT), which places the acceptability of this biofuel at risk. Therefore, the effect of four adsorbents, namely diatomaceous earth, natural silicate (NS), neutral bleaching earth (NBE), and acid activated bleaching earth (AABE), at two levels of addition (1 and 5 wt%) or two temperatures (25 and 110 °C) on the precipitate content and CSFT of POB was investigated. The impact on total glycerin content, moisture content, and oxidative stability was also examined. All treatments significantly decreased the precipitate content, total glycerin content, and moisture content, but only treatments with NS, NBE, and AABE at 5 wt% and 25 °C achieved acceptable filterability. The OSI value was also decreased; however, it remained above the ASTM limit. Operational conditions of treatment with AABE were further optimized in a two‐factor, five‐level center composite design. The combination of 0.65 wt% AABE and 10 min at 25 °C decreased CSFT to below the ASTM limit. Lower adsorbent concentrations could be effective down to 0.44 wt%, given a corresponding increase in the contact time up to 30 min.  相似文献   

18.
Oil palm empty fruit bunch fiber (OPEFB) is a lignocellulosic waste from palm oil mills. It is a potential source of glucose and xylose that can be used as raw materials for the production of valuable compounds such as succinic acid. The present study aims at producing biodegradable polyesters from OPEFB-derived monomer using enzymatic polymerization. Cellulose was extracted from OPEFB by using organosolv method. Enzymatic hydrolysis of cellulose was carried out using Celluclast and Novozyme 188 at 40?°C, with agitation rate of 145?rpm. Amount of enzyme and cellulose as well as reaction time were varied. The highest glucose concentration produced was 167.4?g/L. Succinic acid was produced when glucose was subjected to fermentation using Actinobacillus succinogenes with the highest concentration of 23.50?g/L. Biodegradable polyesters were produced when succinic acid together with 1,4-butanediol, glycerol and ethylene glycol, respectively, were subjected to Lipase (Candida Antartica CALB). Molecular weight obtained for poly(butylene succinate), poly(glycerol succinate), and poly(ethylene succinate) were 5.90?×?104, 6.20?×?104, and 4.53?×?104 g/mol, respectively. The greatest extent of biodegradability of polyester found was 78.65?±?0.65%.  相似文献   

19.
Dry fractionation of palm oil can be conducted as a multi-step process; this gives rise to new softer and harder fractions having multitudes of applications in fat foods. This work focuses on the liquid fractions obtained following a triple-step fractionation; the cloud point was measured on a set of 125 palm oil, olein, super olein and top olein samples, with the intention to correlate this value to the compositional properties. The Mettler cloud point, the diacylglycerol content, some selected single or groups of triacylglycerols and the iodine value (in total, 11 variables per sample) were measured and entered in a statistical model. A principal component analysis (PCA) was first carried out from which different sub-groups were highlighted. In each sub-group, various regressions (simple linear, simple non-linear and multiple linear) were applied and 28 significant equations were derived. Out of these, one multiple linear regression involving the iodine value, the UUU and PPP contents showed the best correlation with the Mettler cloud point. This equation was selected to predict the cloud point since it was further successfully validated by using a set of 25 other independent samples. A partial least square (PLS) regression was tested and also considered adequate to predict the cloud point.  相似文献   

20.
Random and directed interesterification characteristics of Mahua (Madhuca latifolia) oil in solution in n-hexane (60% w/w) were investigated. The results obtained were comparable with the corresponding conventional non-solvent reactions with respect to the physical and chemical properties induced by the interesterification reactions, although the time for reaching equilibrium was longer in the case of solvent interesterification. The results indicate the possibility of commercial utilization of the process for the production of plastic fats with greater ease and economy than the conventional non-solvent interesterification.  相似文献   

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