Blends Of Palm Olein Research Articles

Production of healthier palm‐based edible oil blends and enzymatic interesterified structured lipids for cooking and trans‐free fat formulation applications

AbstractPresent study aimed to prepare palm‐based blends with edible oils to obtain healthier smart blends with a desired fatty acid profile of SAFA:MUFA:PUFA ratios as established by international health authorities for potential use in cooking and trans‐free fat formulation applications. Several blends of palm olein (POo), super olein (SOo) and palm stearin (PS) with sunflower (SFO), soybean (SBO), rice bran (RBO), mustard (MO), olive (OO) and sesame (SMO) oils were prepared in different mass (wt/wt) ratios. Among the prepared blends, the 6:4 POo:SFO, 1:1/6:4 POo:SBO, 6:4 SOo:SBO and 4:6 PS:RBO/SMO blends; 2:8 POo:RBO, 6:4 SOo:SFO blends and 1:1/6:4 POo:SMO, 1:1/6:4 POo:RBO, 6:4 SOo:SMO blends were found to have the balanced fatty acid profiles closer to AHA/JMHW/WHO recommended SFA:MUFA:PUFA ratios of 1:1:1/1:1.5:1/1:1.5:0.7, respectively. In addition, the 1:1/6:4 POo:SBO and 6:4 SOo:SBO blends also fulfilled the required ω‐6/ω‐3 ratios of 9.5 and 10.5 along with balanced fatty acid profile of 1:1:1 as per the nutritional guidelines. The 6:4 POo/SOo with SFO/SBO, 1:1 SOo:SMO and 4:6 PS:RBO/SMO smart blends were further processed for enzymatic interesterification (EIE) employing Lipozyme TLIM packed in a specially designed basket type stirrer (BTS) equipped in a bioreactor at 70°C with agitation speed of 390 rpm for 9 h to obtain trans‐free interesterified (IE) structured lipids (SLs) with desired physicochemical properties. This BTS technology helped to sustain the structure and morphology of the enzyme intact, and enable to process about 9 kg of the edible oil blends for IE with excellent recyclability and stability for 81 active hours.

Improved physical properties and structural stability of value-added mayonnaises based on red palm olein by using high-shear homogeniser

The present work formulated value-added mayonnaises based on red palm olein (RPOL) with improved physical properties and structural stability using a high-shear homogeniser (H-mayonnaise) as compared to the use of a lab-scale mixer (M-mayonnaise). The fat portions of the mayonnaises were blends of palm olein and RPOL at different ratios of 100:0, 75:25, and 50:50. The H-mayonnaises exhibited significantly smaller (p < 0.05) droplet size (448.95 - 515.61 vs 532.44 - 672.37 μm) and amount of separated oil (0.00 - 1.83 vs 16.83 - 42.68%) with more intact structure than M-mayonnaises. As the RPOL was increased from 0 to 50% (w/w), significant decrease (p < 0.05) was observed in the L* value (M-, 74.80 to 64.76; H-, 77.73 to 70.64), while both the a* (M-, -1.61 to 15.22; H-, -1.49 to 11.49) and b* (M-, 28.37 to 59.64; H-, 25.34 to 55.13) values increased in palm-based M- and H-mayonnaises. However, the fat portions had no significant effect on water activity, droplet size, and the amount of separated oil. All H-mayonnaises had higher storage modulus (G’ values), which highlighted greater mechanical rigidity and solid-like texture than M-mayonnaises. Different RPOL contents had no significant effect on the sensory acceptability of H-mayonnaises, except for the colour properties and overall acceptability. Overall, the physical properties and structural stability of RPOL-based mayonnaises were significantly improved by high-shear homogenisation relative to the use of a lab-scale mixer, while their sensory acceptance was comparable with mayonnaise prepared using soybean oil. Findings reported herein highlighted the potential development of mayonnaise based on RPOL for commercialisation purposes. There is also a potential for continuous demand of RPOL which could help to sustain its production, thus benefiting both the food and agricultural sectors.

Enhancement of Oxidative Stability of Perilla Seed Oil by Blending It with Other Vegetable Oils.

Perilla seed oil is mainly composed of omega-3 fatty acid (α-linolenic acid, ALA). Despite being nutritionally favorable and rich in unsaturated fatty acids, its low oxidative stability limits its application in food. Thus, the present study aimed to formulate a stable oil blend using perilla seed oil with selected vegetable oil of higher stability characteristics and balance the ratio of the fatty acids. Hence, improving the nutritional and functional value of the blended oil. Perilla seed oil was blended with different edible oil (palm olein, coconut oil, and groundnut oil) in ratios of 20:80 and 30:70. All the blended oils were studied for their fatty acid composition, physicochemical properties, oxidative stability, and nutritional quality index. It was found that perilla seed oil blended with saturated oil like palm olein had improved physicochemical properties and oxidative stability (0.5 h to 6.5 h). The fatty acids ratio of perilla and palm olein blends was close to the recommended value given by the World health organization (WHO). The nutritional quality indices (atherogenic index, the thrombogenic index, and hypocholesterolemic: hypercholesterolemic ratio) of blended oil were also improved compared to the individual oils.

Chemical and deep-frying oxidative stability of sunflower–red palm olein blends

PurposeThe effect of the addition of red palm olein (RPO) as a natural antioxidant to sunflower (SF) on chemical properties and deep-frying oxidative stability of resultant oil during storage.Design/methodology/approachRPO was added to SF at different levels 0, 5, 10, 15, 20, 25, 50, 75 and 100 (w/w), and potato chips were fried in oil blends repeatedly at 180 °C for 2.5 min for five days to evaluate the effect on chemical properties and oxidative stability.FindingsThe results revealed that linoleic acid and total polar compound (TPC) contents decreased in all RPO and SF resultant oil after five days of storage. Colour significantly (p = 0.05) decreased, while peroxide and iodine values were significantly lowered during storage. The oxidative stability increased significantly in the resultant oil. However, an increase in free fatty acid (FFA) before frying significantly reduced with repeated frying of resultant oil during storage. RPO (5–75%) therefore retards oxidative rancidity in the resultant oil after repeated deep frying and storage.Originality/valueSF oil is high in polyunsaturated fatty acids but prone to oxidation upon heating and storage. RPO is an important ingredient used in industrial frying rich in phytonutrients and a better replacement to synthetic antioxidants. This study indicated that supplementing SF oil with RPO may be recommended to improve the oxidative stability of oils during frying.

Flaxseed oil and palm olein blend to improve omega-6: omega-3 ratio.

The objective of the study was to develop the oil blend with improved omega-6 to omega-3 fatty acid ratio (ω-6:ω-3) with good oxidative and thermal stability. Flaxseed oil and palm olein were selected for the blending. Flaxseed oil is rich in anti-inflammatory omega-3 fatty acid (ω-3 FA)but isoxidatively very unstable. Palm olein has low omega-6 fatty acid content and high thermal and oxidative stability. Blends containing various percent (v/v) of flaxseed oil and palm olein were prepared. Oxidative and thermal stability was determined by analyzing peroxide value, acid value, smoke point, % free fatty acids, para-Anisidine and TOTOX values. Nutritive quality was confirmed by determining fatty acid composition. Nine month storage stability of the blend containing highest flaxseed oil percentage was assessed in terms of peroxide and acid value and fatty acid composition. The biological effects were studied in THP-1 cell line as the effect on cell survival, FA uptake and inflammatory markers. The data indicates that, blending improved ω-6:ω-3 ratio. Oxidative and thermal stability study, and nine month storage stability study suggested that palm olein imparted stability to the blend. Fatty acid profiles of the cells treated with these blends showed uptake of Alpha Linolenic Acid (ω-3 FA). These blends lowered inflammatory TNFα level without affecting cell survival. Thus, blending of flaxseed oil with palm olein may result in better health benefits owing to their improved nutritional and stability properties.

Enzymatic Interesterification of Palm Stearin and Palm Olein Blend Catalyzed by sn-1,3-Specific Lipase: Interesterification Degree, Acyl Migration, and Physical Properties

Acyl migration of fatty acid at sn-2 is often observed alongside enzymatic interesterification (EIE), causing the loss of lipase selectivity toward the acyl group at sn-1,3. In this study, an oil blend consisting of palm stearin (PST) and palm olein (POL) was interesterified via a chemical interesterification (CIE) and enzymatic method using a packed bed reactor. Characterization in terms of the triacylglycerol (TAG) compositions, sn-2 fatty acid distributions, and solid fat content profiles was performed. In comparison to that of CIE fats, EIE fats showed different modification effects on the solid fat content. Under similar reaction conditions, different interesterification degrees (IDs) were obtained according to the various blend ratios. Using the same mass ratio of substrates (POL/PST of 9:1), the EIE reaction time and temperature affected the ID and the change in the fatty acyl group at the sn-2 position. Under the reaction time of 46 min, an ID of 94.41% was acquired, while at 80 °C, the degree of acyl migration at sn-2 was 92.87%. EIE with high acyl migration exhibited a lower crystallization rate than that of EIE with low acyl migration. However, the effect of acyl migration on crystal polymorphism and oxidative stability was insignificant. Outcomes from this study are meaningful for the establishment of a theoretical basis for a controlled positional-specific EIE that is catalyzed by sn-1,3-specific lipase.

Quality Parameters of Palm Olein, Palm Kernel Oil and its Blends Subjected to Thermal Stress using Photometric Technology

There is no much information regarding the partial replacement of palm olein with palm kernel oil. Palm olein mixed with palm kernel oil is commonly sold in Nigeria market today without proper blending and without determination of their suitability to consumer also ignorant of what ratio to be blended. Therefore, blends of palm olein (POL) and palm kernel oil (PKO) were formulated to assess their stability under elevated temperature using a fast, simple and reliable CDR palm oil tester photometric technology. The results were then compared with those obtained in POL. The blends studied were to investigate the effects of palm kernel oil partial replacement on the chemical stability of palm olein. the blends as partial replacement were missed in the ratio of PKO:POL(100:0), PKO:POL(80:20), PKO:POL(60:40) and POL:PKO(100:0), POL:PKO(80:20), POL:PKO(60:40). The POL, PKO and its blends were heated at 100, 150 and 200ᵒC. The time of heating were 20, 40 and 60mins respectively, making a total of 1 hour for heating without any frying operations. The physicochemical properties of the oil samples were fatty acid composition, free fatty acid, peroxide value, iodine value, anisidine value, cloud point, colour, melting point, viscosity and totox value were evaluated over heating time. Blending palm olein (POL) unsaturated oils with saturated (PKO) generally improved the parameters comparable to those demonstrated in palm olein (POL) and palm kernel oil alone. The result showed that as PKO was increased the concentration of saturated fatty acid also increased while unsaturated fatty acid decreased. Saturated oils were generally more stable to oxidation and less sensitive to thermal stress. Increase in the amount of PKO lead to reduction in FFA.

Synthesis of Medium and Long-Chain Structured Lipids from Oil Blend of Palm Olein and Palm Kernel Olein by Geobacillus sp. Strain ARM Lipase

Synthesis of Medium and Long-Chain Structured Lipids from Oil Blend of Palm Olein and Palm Kernel Olein by <i>Geobacillus sp.</i> Strain ARM Lipase

Study on the Release of Quinine Sulfate from Polylactic Acid/Chitosan/Quinine Sulfate Composite Materials

Recently, the polylactic acid /chitosan composite has been used as a drug carrier to regulate the drug release aim to increase effective and decrease drug dosage. Polylactic acid/chitosan composite materials carry 10-50% quinine sulfate was prepared by the water/oil water method to study the release of quinine sulfate. Effects of quinine sulfate content, pH and kinetics of quinine sulphate release were investigated. The results showed that polyacid/chitosan composite materials with high quinine sulfate content for slow speed of release quinine sulfate. The polylactic acid/chitosan composite materials carry 50% quinine sulfate is smallest speed of release quinine sulfate. In pH = 7.4 the release rate of quinine sulfate is greater than the pH = 2.0. The process of releasing quinine sulfate from polylactic acid/chitosan/quinine sulfate composites materials follows the Korsmeyer-Peppas kinetics model and diffuses following the Fick law.&#x0D; Keyword&#x0D; Release, composite materials, polyaxit lactic, chitosan, quinin sulfat&#x0D; References&#x0D; [1] Nguyễn Thúy Chinh, Nghiên cứu sự giải phóng thuốc nifedipin được mang bởi vật liệu tổ hợp poly axit lactic/chitosan, Luận án tiến sĩ hóa học, Hà Nội, (2016).[2] Silverajah V.S., Nor A.I., Norhazlin Z., Wan M., Wan Y. and Hazimah A.H., Mechanical, thermal and morphological properties of poly (lactic acid)/ epoxidized palm olein blend, Molecules, 17, 11729, (2012). [3] Gavhane Yogeshkumar N., Gurav Atul S. and Yadav Adhikrao V., Chitosan and its applications: A review of literature, International Journal of Research in Pharmaceutical and Biomedical Sciences, 4(1), pp. 312-331, (2013). [4] Harvie B.F., Poly-L-lactic acid (PLA) in surgery, Philosophy Doctor Thesis, Smith Nephew, First choice in Endoscopy, (2000).[5] Prabaharan M., Rodriguez - Perez M.A., de Saja J.A., Mano J.F., Preparation and characterization of poly (D,L-lactic acid)/ chitosan hybrid scaffold with drug release capability, J. Biomed Mater Res B Appl Biomater, 81(2), pp. 427-434, (2007).[6] Dev A., Binulal N.S., Anitha A., Nair S.V., Fruike T., Tamura H., Jayakumar R., Preparation of poly(lactic acide) nanopaticles for anti-HIV drug delivery applications, Carbohydrate Polymers, 80, pp. 833-838 (2010). [7] Nanda R., Sasmal A., Nayak P.L., Preparation and character-rization of chitosan-polylactide composites blended with Cloisite 30B for control release of the anticancer drug Paclitaxel, CarbohydratePolymers, 83, pp. 988-994, (2011).[8] Portero A., Remunan Lopez C., Vila-Jato J.L., Effect of chitosan and chitosan glutamate enhancing the dissolution properties of the 144 poorly water soluble drug nifedipine, International Journal of Pharmaceutics, 175, pp. 75–84, (1998).

TRIBOLOGICAL PERFORMANCE OF REFINED, BLEACHED AND DEODORISED PALM OLEIN BLENDS BIO-LUBRICANTS

Vegetable oils have been investigated to replace petroleum lubricants due to their environmental-friendly characteristics and have become a vital source of bio-lubricants. In the investigation of the tribological characteristics of palm oil as the vegetable oil, using in its neat form or as partial bio-lubricants, a reciprocating machine was employed. Initially, refined, bleached and deodorised (RBD) palm olein with mineral oil blends were optimised using the design of experiments procedure from the outcomes of the four ball tribotester. The optimised blend was found to have characteristics that were better or at par with mineral oil. Then, a reciprocating machine was used for verifying the blend. In the investigation of the optimised blend, the sample was tested for a total of 60 hr in intermittent operation. Other than having similar viscosity for the ISO requirements, the optimised blend demonstrates decreased in the values of material weight loss and cylinder temperatures as compared with mineral oil. Finally, it is concluded that the RBD palm olein blend (E53.11/RB46.89) could be a potential partial bio-lubricant due to having no negative impact on wear and decent performance as a bio-lubricator.

Use of pilot plant scale continuous fryer to simulate industrial production of potato chips: thermal properties of palm olein blends under continuous frying conditions.

Binary blends of palm olein (PO) with sunflower oil (SFO), canola oil (CNO), and cottonseed oil (CSO) were formulated to assess their stability under continuous frying conditions. The results were then compared with those obtained in PO. The oil blends studied were: (1) 60:40 for PO + SFO; (2) 70:30 for PO + CNO; and (3) 50:50 for PO + CSO. The PO and its blends were used to fry potato chips at 180°C for a total of 56 h of operation. The evolution of analytical parameters such as tocols, induction period, color, p-anisidine value, free fatty acid, smoke point, polar compounds, and polymer compounds were evaluated over the frying time. Blending PO with unsaturated oils was generally proved to keep most qualitative parameters comparable to those demonstrated in PO. Indeed, none of the oils surpassed the legislative limits for used frying. Overall, it was noted that oil containing PO and SFO showed higher resistance toward oxidative and hydrolytic behaviors as compared to the other oil blends.

Enzymatic transesterification of palm stearin and olein blends to produce zero-trans margarine fat

BackgroundFood industries aim to replace trans fat in their products by formulations having equivalent functionality and economic viability. Enzymatic transesterification can be a technological option to produce trans free fats targeting commercial applications.ResultsPalm stearin and palm olein blends in different ratios were enzymatically transesterified in a solvent free system using a Rhizopus oryzae lipase immobilised onto CaCO3 to produce a suitable fat for margarine formulation. Slip melting points and triacylglycerols profiles were evaluated upon transesterification. Results indicated that all transesterified blends had lower slip melting points than their non transesterified counterparts. Furthermore, the triacylglycerols profile showed a decrease in the concentration of the high melting point triacylglycerols. The rheological analysis showed that margarine prepared with the transesterified blend showed a better spreadability than that of a control margarine prepared with non transesterified fat. Adding powder of dry bark orange to margarine preparation improved its colour and fairly affected its spreadability and rheological behaviour. The margarine prepared with transesterified fat displayed a rheological behaviour that was comparable to that of commercial sample.ConclusionsThis study is an ecofriendly approach to the utilization of relatively low value bioresources like palm stearin and palm olein for making margarine free of trans fatty acids that are now implicated as risk factor for heart diseases.

Frying of potato chips in a blend of canola oil and palm olein: changes in levels of individual fatty acids and tocols

SummaryThe changes occurring in the levels of nutritionally relevant oil components were assessed during repeated frying of potato chips in a blend of palm olein and canola oil (1:1 w/w). The blend suffered minimal reductions in omega‐3 and omega‐6 polyunsaturated fatty acids. There was no significant difference between the fatty acid composition of the oil extracted from the product and that of the frying medium, in all three cases. The blend also contained a significant amount of tocols which add a nutritional value to the oil. The concentration of the tocols was satisfactorily retained over the period of oil usage, in contrast to the significant loses observed in the case of the individual oils. The blend also performed well when assessed by changes in total polar compounds, free fatty acids, p‐anisidine value. When fried in used oil, the product oil content increased progressively with oil usage time. This study shows that blended frying oils can combine good stability and nutritional quality.

Characteristics of Eutectic Compositions of Restructured Palm Oil Olein, Palm Kernel Oil and Their Mixtures

AbstractThe physico‐chemical characteristics of blends of palm olein and palm kernel oil which were further modified by chemical interesterification were studied. The slip melting points of non‐interesterified blends were 19.7, 16.2, 14.5, 14.5 and 14.4 °C while those of the chemically interesterified blends were 17.7, 16.2, 19.8, 18.7 and 18.7 °C at 40, 30, 20, 10 and 0% palm kernel oil, respectively. Chemical interesterification lowered the solid fat content of the pure samples and blends across different temperatures except 90% palm olein at 15 °C where the solid fat content was higher than for non‐interesterified samples. Palm kernel oil, palm olein and their blends before and after chemical interesterification, crystallized mainly in the β′ form. However, chemical interesterification modified the microstructure from a combination of fat particles with void regions of crystalline materials to fat particles without regions of void crystalline materials. Palm olein and palm kernel oil blends are mainly used for food preparation in Nigeria. This study has shown that there are no significant differences in the physical and chemical properties of non‐chemically interesterified and chemically interesterified blends of palm olein and palm kernel oil. This implies that blending of palm olein and palm kernel oil without chemical interesterification can provide the fluidity desirable at ambient temperatures for food applications in the tropics.

A Freedom of Choice-Sensory Profiling and Consumer Acceptability of Oil Blends

Taking into consideration the regional preferences of the local population to sesame oil, the study was planned to exploit its antioxidant properties and to reduce the high priced demand of the oil. Sesame oil was blended with soyabean oil, ricebran oil, cottonseed oil, palmolein, mustard oil and corn oil in the ratios of 80: 20 and 20:80 and muruku (deep fried Indian traditional snack) and bobbatlu (shallow fried traditional regional snack) were prepared with those blends. Consumers who were conversant with the factors governing quality of the products and raw oil blends were chosen as sensory panel. The present consumer acceptance trials indicated no strong rejection of an oil blend in comparison with control. In raw oils and in the products made with the blends sesame-rice bran blends of 80:20 and 20:80 and sesame-cottonseed blend of 80:20 and sesame- palmolein blend of 20:80 were significantly better than control.

Characterization of palm kernel oil, palm stearin, and palm olein blends in isosolid diagrams

AbstractThe binary and ternary phase behaviors of mixtures of palm kernel oil (PKO), palm stearin (POs), and palm olein (POo) were studied using isosolid diagrams. Both PKO/POs and PKO/POo binaries displayed eutectic behavior at high temperature, while binary POs/POo mixture showed good compatibility and only slight monotectic effect was observed at low temperature in the 10–50% POs addition range. Ternary phase diagrams showed that eutectic effects were observed in all ternary blends at 10–20°C and the degree of interaction depended on the content of PKO, POs, and POo in the blends. The depression of the contours in the isosolid diagrams demonstrated the dominant role of PKO and POo in the ternary system. When the amounts of POs and POo were both 45%, the derivation (ΔSFC) reached a minimum at 10–20°C, which means the weakest eutectic interaction. X‐ray diffraction results showed that addition of PKO into the blends could stabilize the β′ crystal whereas the increase of the content of POs would make the blends undergo a β′ to β polymorph state transformation.

Physico-chemical properties of blends of palm olein with other vegetable oils

Palm oil (olein) was blended with other edible oils for the enhancement of its market acceptability in terms of melting point depression and shelf life. The physico-chemical properties like viscosity, density, melting behavior, peroxide value (PV), saponification value (SV) and iodine value (IV) of four different binary blends with four vegetable oils were evaluated. Palm olein was found to be more stable against rancidity than the other oils. For the stability against oxidation and melting point depression the palm olein-canola (PO/CO) blend was found to be better than the others. The Differential Scanning Calorimeter (DSC) thermogram of the melting behavior of the blends traces some new polymorphs of the triglyceride. This study will help the oil producing industry to find out the most economically viable oil blends for cooking purposes, with maximum nutrition as well as desirable physico-chemical properties.

Evaluation of commercially available rapid test kits for the determination of oil quality in deep-frying operations

It is a challenging task to rapidly determine the quality of frying oils at various stages of frying. This study aims to evaluate the performance of eight different rapid test kits on three different types of oils, viz palm olein, cooking oil (a blend of palm olein, sesame oil and peanut oil) and sunflower oil. Two commonly consumed foods, French fries and chicken nuggets were selected as the frying food materials. Out of the eight test kits, five of them, namely FASafe™, 3M™ Low Range Shortening Monitor, Fritest®, Oxifrit-Test® and TPM Veri-Fry® were based on colorimetric reactions; whereas the other three test kits, namely Food Oil Monitor 310, Testo 265 and CapSens 5000 were based on dielectric constant. It was found that the test kits based on physical parameter provided more objective and valuable results as compared to those based on colorimetric reactions.

Production of zero trans Iranian vanaspati using chemical transesterification and blending techniques from palm olein, rapeseed and sunflower oils

SummaryChemical transesterification and blending techniques were used for producing zero trans fats suitable for use as Iranian vanaspati. Triple blends of palm olein (POo), rapeseed (RSO) and sunflower oil (SFO) were subjected to two different treatments: (i) blending and then transesterification (BT) and (ii) transesterification of pure POo before blending with RSO and SFO (TB). The changes in slip melting point (SMP), solid fat content (SFC), carbon number (CN) triacylglycerol (TAG) composition, induction period (IP) of oxidation at 120 °C and IP of crystallisation at 20 °C of blends before and after treatments were investigated. Both BT and TB methods resulted in an increase in the CN48 TAG molecules, SMP and SFC, and a decrease in the IP of oxidation and crystallisation of initial blends. Samples made by TB method had higher CN48 TAG content, SMP, SFC and IP of oxidation, and lower IP of crystallisation than those made by BT method. Correlation between SFC at 20 °C and saturated fatty acid (SFA) content of the treated blends indicated that the SFA must be higher than 33.1% and 26.8% for BT and TB methods, respectively, to obtain fats suitable for use as vanaspati.

Melting and Solidification Properties of Palm Kernel Oil, Tallow, and Palm Olein Blends in the Preparation of Shortening

AbstractTernary systems composed of palm kernel oil (PKO), tallow, and palm olein (POo) were studied in terms of their physical properties such as solid fat content (SFC), melting characteristics by DSC and polymorphism by X‐ray diffraction. Ternary phase behavior was analyzed with isosolid diagrams. The results showed that as the POo content of the blends was increased the SFC value decreased, while the increase of tallow content increased the SFC value. Eutectic effects within the ternary system were confirmed from the deviation of the measured SFC from the calculated SFC for corresponding thermodynamically ideal blends. The deviation reached a maximum when the amounts of PKO and POo are both about 45%. X‐ray diffraction results showed that addition of PKO into the blends promoted stabilization in the β′ crystalline form.