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De Graef V.,Ghent University | Vereecken J.,Ghent University | Smith K.W.,Fat Science Consulting Ltd. | Bhaggan K.,Loders Croklaan B.V. | Dewettinck K.,Ghent University
European Journal of Lipid Science and Technology | Year: 2012

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. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Garcia-Macias P.,University of Reading | Gordon M.H.,University of Reading | Frazier R.A.,University of Reading | Smith K.,Fat Science Consulting Ltd. | Gambelli L.,Loders Croklaan B.V.
European Journal of Lipid Science and Technology | Year: 2012

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. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smith K.,Fat Science Consulting Ltd. | Bhaggan K.,Product and Process Development Loders Croklaan BV
Lipid Technology | Year: 2012

Crystallization in fats is of fundamental importance in the production and consumption of fats per se and of food and home and personal care (HPC) products in which fats form a major part. While crystallization of fats as such has been extensively reviewed over the past decade there has been less emphasis on the role of minor components. A review by Smith et al. [1] redressed this; this article is based on that review. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Danthine S.,ULg | Delatte S.,ULg | Blecker C.,ULg | Smith K.W.,Fat Science Consulting Ltd. | Bhaggan K.,Loders Croklaan B.V.
European Journal of Lipid Science and Technology | Year: 2015

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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smith K.W.,Fat Science Consulting Ltd | Bhaggan K.,Loders Croklaan B.V | Talbot G.,Fat Consultant | Van Malssen K.F.,Unilever
JAOCS, Journal of the American Oil Chemists' Society | Year: 2011

Over the years, there has been a steady stream of publications on the influence that minor components and additives have on the physical properties of fat continuous systems. These have been reviewed here. Both indigenous and added components are taken into account. The various materials have been discussed, ranging from partial glycerides and phospholipids to esterified sugars and polyols. Within the publications in this area, the (sub-)micron effects that these minor components have on nucleation, crystal growth, morphology, heat capacity and polymorphic stability have been described and discussed and, sometimes, explained. Similarly, the effects on a macroscopic level, such as visual aspects, melting profiles, post-hardening and rheology have been the subject of research. Although limited compositional information, especially of additives, hinders appropriate discussions of the relevant mechanisms, some generic guidelines as to what type and strength of effect can be expected have been derived. As a general rule, a more significant influence is observed when the acyl group of the minor component (where present) is similar to those present in the fat itself. Additives may have different effects depending on the fat they are added to, their concentration and the temperature, especially with increasing undercooling (which typically reduces the effect of additives). © 2011 AOCS.

Vereecken J.,Ghent University | De Graef V.,Ghent University | Smith K.W.,Fat Science Consulting Ltd. | Wouters J.,University of Namur | Dewettinck K.,Ghent University
Food Research International | Year: 2010

In this study, the crystallization and polymorphic properties of eight fat blends with the same saturated fat content (50%) but with a varying TAG composition were investigated using DSC and X-ray diffraction. Blends were either palmitic (P) or stearic (S) based, and were all diluted with high oleic sunflower oil to obtain the same level of saturated fatty acids. Three different effects were investigated, namely the effect of chain length, the effect of trisaturated TAG and the effect of symmetry. The DSC results suggested that PPP, present in the palmitic based blends, seeded the crystallization process better than did SSS in the stearic based blends. Stop-and-return DSC revealed a two-step crystallization for almost all the blends at 15. °C, 20. °C and 25. °C. This behaviour was further elucidated by WAXD-analysis of the blends, showing an initial crystallization into an unstable polymorph followed by polymorphic transformation during crystallization. © 2010 Elsevier Ltd.

Garcia-Macias P.,University of Reading | Gordon M.H.,University of Reading | Frazier R.A.,University of Reading | Smith K.,Fat Science Consulting Ltd. | Gambelli L.,Loders Croklaan B.V.
European Journal of Lipid Science and Technology | Year: 2011

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. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ray J.,Loughborough University | Nagy Z.K.,Loughborough University | Nagy Z.K.,Purdue University | Smith K.W.,Fat Science Consulting Ltd. | And 2 more authors.
Biochemical Engineering Journal | Year: 2013

The acidolysis of high oleic sunflower oil (containing >70% triolein) with 11 different stearic-palmitic acid mixtures at an oil:acid ratio of 1:1.3 (w/w) has been performed using a 1,3 regiospecific lipase (Rhizopus oryzae), to produce specialised fats with a high disaturated triacylglycerol (TAG) content (~40%). The final conversions corresponded well to predictions from a probability model. The variation of TAG composition with time was also measured to study the reaction kinetics. Initially, a reaction scheme was formulated allowing all possible acidolysis reactions of TAGs with stearic, palmitic and oleic fatty acids at the 1 and 3 TAG positions. It was found that a first order scheme produced good fits to data and that reactions involving stearic and palmitic reactions in equivalent positions produced very similar fitted rate constants. When these rate constants were constrained to be equal, acceptable fits were also obtained. As the acidolysis reactions occur via the formation of diacylglycerols (DAGs) by hydrolysis (7.1-10.9%), a further scheme was tested whereby all possible reactions involving DAGs were included (with equal rate constants for equivalent reactions with palmitic and stearic acid to limit the number of fit parameters). This produced only a small increase in goodness of fit. Assuming a single value of rate constant for all reactions produced poor fits. © 2013 Elsevier B.V..

Ray J.,Loughborough University | Smith K.W.,Fat Science Consulting Ltd | Bhaggan K.,IOI Loders Croklaan Europe | Nagy Z.K.,Loughborough University | And 2 more authors.
European Journal of Lipid Science and Technology | Year: 2013

The crystallization of shea stearin was investigated both before and after pre-treatment with silica to remove a small amount (0.7wt%) 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 5min 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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smith K.W.,Fat Science Consulting Ltd. | Bhaggan K.,IOI Loders Croklaan B.V. | Talbot G.,The Fat Consultant
European Journal of Lipid Science and Technology | Year: 2013

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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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