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Cocoa butter equivalents (CBEs) are formulated by mixing palm mid fraction (PMF) with silica‐treated hard stearin fractions produced via enzymatic acidolysis of high oleic sunflower oil with various mixtures of stearic and palmitic acids. The CBE blends always contain ≈30% 1,3‐distearoyl‐2‐oleoyl‐sn‐glycerol, but vary in 1,3‐dipalmitoyl‐2‐oleoyl‐sn‐glycerol (POP; 40–45%) and rac‐1‐palmitoyl‐2‐oleoyl‐3‐stearoyl glycerol (POSt; 10‐16%) content. Overall symmetric disaturated monounsaturated (Sat‐O‐Sat) levels range from 81–86%. The effects of varying POP/POSt content on the non‐isothermal and isothermal crystallization (at 20 °C) of the CBEs are then studied using differential scanning calorimetry (DSC), stop and return DSC, and X‐ray diffraction (XRD), and compared with CB. Four polymorphs (I/sub‐α, II/α, IV/β′, and V/β) are identified which appear at different stages. The addition of PMF (raising POP levels) slows crystallization rates compared to the original stearins, but higher levels of POP also produce a small amount of V/β in under 4 h at 20 °C via apparent transformation from II/α. This does not occur with (high POSt) CB samples. However, after storage at 20 °C for 7 days, CB demonstrates greater transformation to V/β (from IV/β′) as confirmed via XRD. Solid fat contents of CBE blends are higher than CB due to higher Sat‐O‐Sat levels. Practical applications: The paper demonstrates a new route for formulating CBEs. The relative proportions of StOSt, POSt and POP in the formulation can be controlled by changing the proportions of palmitic and stearic acid used in the enzymatic acidolysis and the blend ratio with the PMF. This can then be used to fine‐tune the crystallization behavior. [ABSTRACT FROM AUTHOR]

The kinetic phase behavior and phase transformation paths of pure tripalmitoylglycerol (PPP), 1‐palmitoyl‐2,3‐distearoyl‐sn‐glycerol (PSS), and 1,3‐dipalmitoyl‐2‐stearoyl‐sn‐glycerol (PSP) and binary mixtures thereof, are investigated at 10.0 °C min−1 (fast cooling) and 1.0 °C min−1 (slow cooling) cooling rates, and further re‐heating at 5.0 and 1.0 °C min−1. Mixtures are studied in terms of polymorphism, crystallization, and melting behavior. Kinetic phase diagrams are determined from DSC heating thermograms and XRD data. Independent of the cooling rate, most samples crystallized in the α‐polymorph and transformed into the more stable β′‐form via melt‐mediated crystallization or direct recrystallization from the α‐phase. Samples containing a high amount of PSP crystallized in the β′‐form at slow cooling rate and samples containing high PPP concentration ultimately transform to the most stable β‐form. The kinetic phase diagram of PPP‐PSS mixtures present an apparently typical eutectic behavior with a eutectic point at XPSS = 0.3, when the samples are melted at the higher heating rate, which shifts to higher concentration, XPSS = 0.5, when the lower heating rate is applied. The eutectic temperature (58.4 ± 0.3 °C) is independent of the cooling and heating rates used. The kinetic phase diagram of PSS‐PSP mixtures display two types of behaviors, a probable monotectic behavior in the most stable phase and a eutectic behavior in the meta‐stable phase when the samples are melted at higher heating rate. This study shows that PSS has a strong effect on the physical properties of PPP‐PSS blends and affects a large part of the phase behavior of this binary system. At lower PSS concentrations, the mixtures transform to the most stable β form, but at increasing PSS concentration, the samples stabilize in the β′‐phase. In the PSS‐PSP binary systems, all the mixtures stabilize in the β′‐phase, which is preferred in many food applications since it is associated with a smooth texture. Practical Applications: This research extends a previous study on the phase behavior of the most common trisaturated triacylglycerols and the results are useful for the food industry as they can help in understanding the functionality of hard fat based structuring agents in end applications, and in developing new triacylglycerol based crystallization and structuring agent for specific food applications. The kinetic phase behavior of trisaturated triacylglycerol containing stearic and palmitic acid were studied under three sets of conditions. The binary systems showed different behaviors at the conditions studied. An apparent eutectic phase behavior was obtained for mixtures containing mono‐acid and symmetric triacylglycerols. However, the samples containing asymmetric triacylglycerols showed a probable monotectic phase behavior in the most stable β′1‐phase. [ABSTRACT FROM AUTHOR]

The kinetic phase behavior and phase transformation paths of tripalmitoylglycerol (PPP) and 1,3‐dipalmitoyl‐2‐stearoyl‐sn‐glycerol (PSP) mixtures are investigated at 10.0 °C min−1 (fast cooling) and 1.0 °C min−1 (slow cooling) cooling rates, and re‐heating at 5.0 and 1.0 °C min−1. Mixtures with 0.1 XPSP increments are studied in terms of polymorphism, crystallization, and melting. At the higher cooling rate, all samples crystallized in the α polymorph, while at the lower cooling rate, samples containing XPSP ≤ 0.3 crystallized in the α polymorph and samples containing XPSP > 0.3 crystallized in the β′ polymorph. During heating, all samples transformed to a more stable β′ form and melted finally in the β form (XPSP ≤ 0.3) or in the β′ form (XPSP > 0.3). Kinetic phase diagrams are determined from the DSC heating thermograms and XRD patterns obtained during cooling and heating and displayed an eutectic behavior with an eutectic point at XPSP = 0.3 irrespective of the rate at which the samples are cooled and re‐heated. The eutectic temperature is independent of the cooling and heating rates used. This study shows that PSP has a strong effect on the physical properties of PPP–PSP mixtures and dominates a large part of the phase behavior of the PPP–PSP binary system. At lower PSP concentration, the mixtures transform to the most stable β form, but at increasing PSP concentration the mixtures stabilize in the β′‐phase which is preferred in many food application because this results in a smooth texture. Practical Application: The results of this study are useful for the food industry as they can help in understanding the functionality of hard fat‐based structuring agents in end applications and in developing new triacylglycerol‐based crystallization and structuring agent for specific food applications PPP–PSP mixtures, either cooled or heated at lower or higher rate, all samples display different type of phase behavior: α‐ to β′‐phase development via recrystallization from the melt for mixtures having low PSP concentration, an α‐ to β′‐phase development via solid–solid transformation, a β′2‐ to β′1‐phase development via solid–solid transformation, and a β′‐ to β‐phase development via solid–solid transformation with an apparently typical eutectic behavior, with an eutectic concentration (XE) of about XPSP = 0.3. The eutectic temperature is not affected by the processing conditions applied. In the XPSP ≤ XE side of the phase diagram, the transition is different, being more β stable and is strongly affected by increasing PSP content (XPSP > XE side), which are more β′ stable. [ABSTRACT FROM AUTHOR]

Filling fats are used in bakery and confectionery applications. These fats are made up of complex mixtures of triacylglycerols (TAG). The crystallization, melting behaviour and polymorphic stability of fat blends are determined by the behaviour of the TAGs that they contain. Filling functionalities are influenced by their fat composition but also by the processing conditions used for crystallization. In this study, the crystallization behaviour of fat blends, all based on shea stearin as hard fat (which is high in 1,3-distearoyl-2-oleoyl glycerol (SOS)) combined with either sunflower oil, shea olein or rapeseed oil, were investigated by means of pulsed nuclear magnetic resonance (pNMR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Blends containing either 30 or 40% shea stearin combined with one of the soft fats were selected as they met the criteria required for filling fats. Under static isothermal conditions (at 10°C, 15°C or 20°C), a two-step crystallization was observed for those blends, which can be explained by polymorphic transitions from α-form into more stable forms. All the selected blends exhibited different crystallization mechanisms according to the TAG composition of the liquid phase and their complementarity with TAG from the solid phase. Practical applications: Results of this research are useful for the fat industry as they could help to develop new filling fats, based on shea stearin, with a reduced content of saturated fats, while maintaining the desired physical properties of such specific products. pNMR isothermal crystallization curves obtained at 10°C (A), 15°C (B) and 20°C (C) for binary blend made of 30% shea stearin and 70% sunflower oil (plain lines) and binary blend made of 30% shea stearin and 70% shea olein (dashed lines) and corresponding XRD pattern collected at the end of the isothermal period (4 h). A1, B1, C1: 30% shea stearin/70%sunflower oil; A2, B2, C2: 30% shea stearin/70%shea olein. [ABSTRACT FROM AUTHOR]

Nine different stearin fractions with 1,3-distearoyl-2-oleoyl-sn-glycerol (StOSt) contents ranging from 69-84% were obtained via fractionation from fats produced by acidolysis of high oleic sunflower oil (HOSO) with various mixtures of stearic (either 95 or 98% pure) and palmitic acids (98% pure). Samples were further treated with silica to reduce the oxidised glyceride and DAG content. Isothermal crystallisation at 20°C showed a single main peak, but evidence of crystallisation during the initial DSC transient was also apparent for high StOSt content samples. This was confirmed as the α form by stop-and-return DSC and XRD. The main crystallisation event was generally faster (including a shorter induction time) for samples with higher StOSt levels (lower POSt levels). Silica treatment generally accelerated transformations to higher polymorphs (γ, β′ and β). Raman microscopy experiments showed that crystallisation of the β-form was achieved after 7 days storage at 20°C but only in the silica treated stearin samples. This is consistent with higher solid fat content (SFC) values that were obtained with silica treated samples, which also increased with higher levels of StOSt. The results suggest that such stearins could potentially replace shea stearin in cocoa butter equivalents (CBE) formulations. Practical applications: This paper has two main practical applications: (i) Provides knowledge and understanding of the crystallisation and polymorphic behaviour of isolated hard stearins, obtained from enzymatic acidolysis of high oleic sunflower oil, which can be further used in CBE formulations. (ii) The presence of minor components significantly delays the crystallisation of the stearins, confirming the desirability of higher quality (less oxidised/hydrolysed) fat ingredients. [ABSTRACT FROM AUTHOR]

The crystallization of shea stearin was investigated both before and after pre-treatment with silica to remove a small amount (0.7 wt%) of diacylglycerols (DAGs) and oxidized material. NMR (for solid fat content), X-ray diffraction (XRD), polarized light microscopy, confocal Raman microscopy, and non-isothermal, isothermal and 'stop-and-return' differential scanning calorimetry (DSC) techniques were used. Four major polymorphs previously found with 1,3-distearoyl-2-oleoyl-sn-glycerol (StOSt) were detected: α, γ, β′, and β; whilst evidence for a further (δ) polymorph was found by DSC and possibly XRD but not Raman spectroscopy. Isothermal crystallization of shea stearins by DSC at 20°C produced α and δ forms within 5 min which then transformed to γ. Microscope images showed that after 1 day these had transformed into β′ with a few crystals of β, with further conversion to β after one week. Silica treated samples showed a faster initial crystallization, with faster transformation or direct crystallization into δ and then γ and β′ forms. Non-isothermal DSC also showed a faster transformation into γ from α on the subsequent remelt. However, further transformation into β appeared to occur at reasonably similar rates for both types, suggesting that DAGs have less influence on this transformation and may be excluded from higher forms. Practical applications: This paper has two main practical applications: (i) Provides knowledge and understanding of the crystallization and polymorphic behavior of commercial shea stearin, which is a widely used fat in the confectionery, cosmetic, and pharmaceutical industries. (ii) The presence of small amounts of DAGs significantly delays the crystallization process of shea stearin, particularly of the lower polymorphs. [ABSTRACT FROM AUTHOR]

The unique properties of cocoa butter (CB) are due to the fact that it is composed, for the most part, of just three TAGs, 1,3-dipalmitoyl-2-oleoylglycerol (POP), 1,3-distearoyl-2-oleoylglycerol (StOSt), and rac-1-palmitoyl-2-oleoyl-3-stearoylglycerol (POSt). In this study we have examined blends, at 10% intervals, across the ternary of these three TAG by stabilizing them during a lengthy temperature regime designed to induce the most stable polymorph at the point of melting. The liquidus observed is in good agreement with that predicted using the Hildebrand model. A eutectic is seen in each binary system, with a possible ternary eutectic present at about POP:POSt 1:1 and <10% StOSt. CB stabilized following the same regime exhibits solid fat contents much greater than those obtained following the standard IUPAC 2.150(b) stabilization, likely to be due to the presence of the βVI polymorph rather than the βV form. Practical applications: The processing characteristics and final properties of fat based products depend greatly on the composition, crystallization, and melting properties of the fat or fats involved. In the case of chocolate and confectionery, this fat is CB. The present study confirms many of the relevant published phase diagrams and emphasizes the compositional areas having similar melting behavior to that of CB and, hence, suitable for cocoa butter equivalents. [ABSTRACT FROM AUTHOR]

Four blends formulated with low saturated fatty acid content, with the saturated component rich in stearic acid, were prepared from shea stearin, interesterified shea stearin, fully hardened soybean oil and high oleic sunflower oil in order to study their performance as shortenings in puff pastry products. The blends had a low saturated fatty acid content (30.1 ± 1.1%) compared to butter (65.9%). Saturates in the four blends examined came mainly from SSS, SOS, SSO and SOO. Puff pastry prepared from the blend that contained SOS as the main source of saturates had better properties than the other blends. It was similar to butter in compressibility of the baked product. The β-polymorphic form was present in all blends, although blends containing the highest levels of SSS also showed some β′ crystals. [ABSTRACT FROM AUTHOR]

TAGs play an important role in determining the functional properties of fat-based food products such as margarines, chocolate, and spreads. Nowadays, special attention is given to the role of the TAG structure and how it affects functional properties such as mouth feel, texture, and plasticity. Key to this research is the need to develop more healthy fats with a reduced level of trans and saturated fatty acids (SFAs), while maintaining the desired properties. In this study, fat blends with identical levels of SFA (50%) but differing in the ratio asymmetric/symmetric blends were evaluated by pulsed NMR and texturometry as a function of storage time and storage temperature. A higher trisaturated TAG content gave rise to a higher solid fat content (SFC) at higher temperature and a lower SFC at lower temperature for both palmitic and stearic based blends. On the other hand, the effect of symmetry on the SFC-profile of the blends was only clear for the stearic based blends. At lower temperatures, the SFC of symmetric TAG based blend (blend SM) was markedly lower than that of asymmetric TAG based blend (blend iS). However, from 30°C onwards, the SFC of blend SM was clearly higher than that of blend iS. The microscopic analyses revealed a denser crystal network for a higher degree of trisaturated TAG and for symmetric stearic based blends. Moreover, some blends showed a clear evolution of the microstructure during storage with smaller crystals transforming into larger ones. Finally, texture analyses demonstrated the importance of the crystallization and storage temperature on the hardness of the blends. [ABSTRACT FROM AUTHOR]

Four fat blends based on palm fractions in combination with high oleic sunflower oil (HOSF) with a relatively low saturated fatty acid content (29.2 ± 0.85%, i.e. less than 50% of that of butter) were prepared. The saturated fat was located in different TAG structures in each blend. Principal saturated TAG were derived from palm stearin (POs, containing tripalmitoyl glycerol-PPP), palm mid-fraction (PMF, containing 1,3-dipalmitoyl-2-oleoyl glycerol-POP) and interesterified PMF (inPMF, containing PPP, POP and rac-1,2-dipalmitoyl-3-oleoyl glycerol-PPO). Thus, in blend 1, composed of POs and HOSF, the saturates resided principally in PPP. In blend 2, composed of POs, PMF and HOSF, the principal saturate-containing TAG were PPP and POP. Blend 3, composed of inPMF and HOSF, was similar to blend 2 except that the disaturated TAG comprised a 2:1 mixture of PPO:POP. Finally, blend 4, a mixture of PMF and HOSF, had saturates present mainly as POP. The physical properties and the functionality of blends, as shortenings for puff pastry laminated in a warm bakery environment (20-24°C), were compared with each other, and with butter. Puff pastry prepared with blend 1 (POs:HOSF 29:71) and blend 4 (PMF:HOSF 41:59), was very hard; blend 2 (POs:PMF:HOSF 13:19:68) was most similar to butter in the compressibility of the baked product and it performed well in an independent baking trial; blend 3 (inPMF:HOSF 40:60) gave a product that required a higher force for compression than butter. [ABSTRACT FROM AUTHOR]

Crystallisation from acetone of 1,3-dipalmitoyl-2-oleoylglycerol (POP), tripalmitoylglycerol (PPP) and their mixtures has been studied at a range of cooling rates, determining the metastable zone width using turbidimetry. A log-log plot of the cooling rate against the maximum undercooling for POP indicated a relative insensitivity of the metastable zone width to the cooling rate. The PPP metastable zone width demonstrated a slight dependence on concentration. POP crystals were spherulitic, having a more open structure at slower cooling rates. PPP crystals were more plate-like, producing powdery, more amorphous crystals at high cooling rates. In pure POP systems, onset of crystallisation was quickly followed by rapid crystal growth. The presence of PPP markedly increased the temperature of the onset of crystallisation (by 17 °C at 8% PPP), but the temperature at which crystal growth occurred, although raised, did not increase to the same extent. The clear point of the pure systems was independent of the previous cooling rate, but this was not true in the mixed system, where it decreased with increasing cooling rate. This suggests that a greater proportion of the PPP-rich phase separates during slower cooling. The morphology of the crystals from the mixed system differed from that in the pure POP system, with just 2% PPP being sufficient to shift the structure to a more lamellar appearance. Keywords: POP, PPP, solubility, supersaturation, undercooling, metastable zone. [ABSTRACT FROM AUTHOR]