Development of Heat Resistant Chocolate

Development of commove Resistant ChocolatePRALINEThe term drinking drinking umber comes from the word cacao that is taken directly from Mayan andAztec languages. Chocolate has been derived from cocoa beans, present in the centre to the proceeds of cocoa tree, Theobroma cacao, which originated from the South Ameri stinkpot region.(Afoakwa 2010)Chocolate is unmatched of the most popular products throughout the world. The detail that it is solid at get on temperature but melts in the mouth, giving a smooth delicate taste, makes it iodin of the most yearned product. From a more technical point of view, cocoa is a complex food do of solid particles of cocoa powder, sugar and milk powder in a continuous dilate phase. The achievement of chocolate consists of multiple steps among which tempering argon one of the most important step. During this the temperature of the chocolate depart be varied to get the right crystalline stimulate of the fatten.Chocolate pralines are a br oadcast more complex product since they also contain a softfilling which will interact with the chocolate shell. Migration can happen from the filling to the shell which can result in geomorphologic alter kindred cracking.A nonher effect can be fat vertex which is a grayish fogginess on the praline surface.This occurs due to the migration of the liquid fat through the shell to the surface and crystallizing.Cracking and fat bloom are both major issues that lead to reduced shelf life in chocolatepralines. The of import suggestions for crack governance are that cracks form due to moisture orethanol migration through the chocolate shell, or due to an unbalanced distribution ofmoisture in the filling that ca utilisations some parts to slenderize and early(a)(a) to expand. (SLETTENGREN 2010)Most of the fat inside chocolate must be cocoa cover. Cocoa butter consists of antithetic triacylglycerols (triglycerides), each of which will solidify at a distinct temperature and at a d ifferent speed in correlation with time. To make it more complicated there are six different counsellings the crystals can pack together.If the fat is present is not right or if the chocolate has not been crystallized properly, thusly fat bloom occurs. All fats are made of mixtures of triglycerides i.e. they make up third bufflehead cuttings attached to a glycerol backbone. In cocoa butter there are three chief(prenominal) acids which account for over 95% of those present. Almost 35% is oleic acid (C180) and almost 26% is palmitic acid (C160). Since the cocoa butter has few chief(prenominal) components that it melts rapidly over such a small barf of temperature be adrift i.e. between room and mouth temperatures.POSt molecules are palmitic acid (P) in position 1, oleic acid (O) in position 2 and stearic acid in position 3. If the stearic and oleic acids are inverted then this would become PStO, which is quite atypical even though the constituents are similar.The stearic and palmitic acids are restrict acids i.e. the hydrocarbon bowed stringed instrument which makes up the fat does not have any double bonds.In unsatu countd fats this chain has one or more double bonds, as is the case for oleic acid. About 80% of the cocoa butter has oleic acid as the middle acid. 1% to 2% of cocoa butter has saturated massive chain trisaturatedtriglycerides (SSS) where the saturated fat is mainly palmitic or stearic and the melting point is mellowed.From 5% to 20% on the other hand consists of two oleic acids and is mostly fluid at room temperature.When the above two have been have then fat of the cocoa butter will be partially fluid at room temperature. If the temperature is raised fat will melt according to the proportions of the different types of fat present.The property of to crystallize every(prenominal) time differently is known as polymorphism. As the anatomical structure becomes denser and gets lowered in energy, it becomes more stalls and harder to me lt. Polymorphic forms are solid phases of the same chemical part that differ among themselves in crystalline structure but permit identical liquid phases.Beca map of their shape the fat molecules fit together with other molecules the likes of stacking chairs which can be done in two offices i.e. via double chain packing and soprano chain packing. There are staple fiberally 3 polymorphs (,,) each with their own specific properties. The melting range and stability of the polymorphs are in the following range . The least stable polymorph will crystallize offset printing and transform to a stable polymorph as a function of time.Cocoa butter has six polymorphs. heretofore the chocolate industry numbered them as I to VI. Forms V and VI are the most stable and are triple chain packing whereas the other forms are double. Form V is good for confectionary products as it is answerable for the hardness with a good snap, glossy appearance and the justification to bloom. (SLETTENGREN 201 0)Mixing different fats (Fat eutectics)It is important that after(prenominal) mixing two or more fats the final product should sets at a suitable rate and has the correct texture and melting properties in the mouth. An unstable structure can form when other fats have been interracial with cocoa butter. fifty-fifty though the fats are triglycerides it will be like fitting another(prenominal) size of chairs within the stacks. Disruption would be less(prenominal) if only a less amount of other fat is present. The actual hardness can be near to the expected one. When cocoa butter is mixed with veg or other fat in equal proportions then the softening effect is largest.The certain vegetable fat made by Unilever and many other that are now in the food market are known as cocoa butter equivalents. These are like cocoa butters and can be personate in any proportion without ca exploitation any major softening or circle effect. Other fats can be employ only if almost all the cocoa but ter is re primed(p) and these are known as cocoa butter replacers.The vegetable fat should crystallise in the same way as cocoa butter (i.e. using the chair analogy, have the same size and shape chair) so that it can be added to the cocoa butter without causing eutectic effect. Cocoa butter contains palmitic (P), stearic (S) and oleic (O) on a glycerol backbone, with the majority of the molecules being POP, POSt, and StOSt.From nuts or seeds of fruits generally two types of subdivisionation are engrossd to obtain the easy melting and the hardest melting fraction. In dry fractionation the fat is kept at a more predefined temperature and then by pressing and filtering the liquid part is separated from solid. In resolve fractionation the fat is fade out in acetone or hexane. After this the higher melting triglycerides are crystallized and filtered out. The StOSt and the add-ond amounts of POSt are hard to obtain.By altering the proportions of StOSt it is possible to make the chocol ate so that it will not melt until the temperature is several degrees higher than the normal cocoa butter, but cannot put behind the feeling of stickiness in the mouth. (SLETTENGREN 2010)LegislationIn June 2000, the European parliament agreed to permit the use of vegetable fat other than cocoa butter in chocolate. This directive came into force on imperious 2003 and for the first time, harmonised chocolate legislation across all the member states of Europe. A number of restrictions were placed on use of vegetable fat by the EU in terms of where oils should be sourced from, and what affect methods have to apply. To maintain miscibility and compatibility with cocoa butter (as is required by the EU Directive) it is necessary to use vegetable fats which contain a similarly high levels of these triglycerides. This means that a) these triglycerides would often need to be concentrated by fractionating the permitted base oils and b) the resulting fats would be needed to blend together to get an optimum mix of the three triglycerides. Even though the CBEs turn up equivalence with the cocoa butter at all compositions but they have been curtail to a maximum level of 5% of the total composition in EU chocolate.(Geoff Talbot 2008)Development of Heat Resistant Chocolate using high melting fatChocolate generally melts at 33.8C when solid cocoa butter transitions to liquid and the crystals of cocoa butter are in stable form V. The development of heat resistant chocolate would allow it to be enjoyed in tropical and humid climates. threesome main methods have been developed to make heat resistant chocolates enhancement of the microstructure of the materials, addition of a polymer and increase the melting point of the fat phase. The approach that is used for the development of heat resistant chocolates for this thesis is to desegregate fats with higher melting points. (Stortz and Marangoni 2011) (Stortz and Marangoni 2011)One specific example of this was done by Jeyarani and Reddy (1999) and focused on using mahua (Mahua Latifolia) and kokum (Garcinia indica) fats to increase the melting point of cocoa butter blend. The kernels found in the fruits of mahua trees consist of semi-solid fat. Conversely, kokum kernels contain a hard, brittle fat with a melting point 39-43 C. The oils are fractionated and then blended. After that these fats were evaluated for their ability to increase the melting temperature of and replace the fat phase in chocolate products. Fractionation were used to separate the stearin fraction from kokum and mahua fats because it was reported that addition of fats rich in 2-oleodistearins to cocoa butter can increase the solid fat content (SFC) , increase the melting point and decrease the tempering time of chocolate.The meted successfully produced a fat phase that achieved higher SFCs at elevated temperature than conventional chocolate. However, once the temperature reached 37.5 C the SFC of most of the blended fats was less than 2 0% indicating that the heat resistance of the chocolate would be lost at temperatures higher than this. Another fire was done to improve the heat resistance via replacement of some cocoa butter with kokum fat. Kokum fat was thin but not fractionated. It was blended with cocoa butter at different levels. The chocolate had good sensational properties. However, the heat resistance of the chocolate was not as desired considering the melting temperature is only 34.8C with 5% inclusion body of kokum fat. Finally , the chocolate formulas exceeded some countries legal limits for inclusion of NCVF.(Stortz and Marangoni 2011)Gel FillingHydrocolloidsHydrocolloids are a intricate group of long chain polymers (polysaccharides and proteins) which are characterised by their property of forming viscous dispersions and/or jellyatins when dispersed in water. Presence of large number of hydroxyl (-OH) groups increases their affinity for binding water molecules which results in hydrophilic compo unds. Further, a dispersion is produced which is intermediate between a true solution and a suspension, and the properties exhibited are that of a colloid. Considering these two properties, they are aptly termed as hydrophilic colloids or hydrocolloids.The important creator behind the ample use of hydrocolloids in foods is their ability to modify the rheology of food system. This includes the two basic properties of food system namely, flow doings (viscosity) and mechanical solid property (texture). The modification of texture and/or viscosity of food system modify its afferent properties, and thus, hydrocolloids are used as important food additives to perform specific purposes.Hydrocolloids have a wide range of function. These include thickening, gelling, emulsifying, stabilisation, and controlling the crystal growth of ice and sugar through the basic properties for which hydrocolloids find extensive use as thickening and gelling. Hydrocolloids disperse in water to give a thicke ning or viscosity producing effect. This water thickening property is general for all hydrocolloids and is the primary reason for their overall use.Gel ecesis is the phenomenon that involves the association or cross linking of the polymer chains to form a three dimensional network that traps or immobilises the water within to form a rigid structure that is resistant to flow. In other words, it becomes visco-elastic showing both the characteristics of a liquid and a solid. The textural properties (e.g. elastic or brittle, long or spreadable, chewy or creamy) of a gel vary widely with the type of hydrocolloid used. The other sensory properties such as opacity, mouth feel and taste also depend on the hydrocolloid employed. (Saha and Bhattacharya 2010)GelsGels may be defined as a form of matter intermediate between solid and liquid and show mechanical rigidity. They consist of polymer molecules cross linked to form tangled and interconnected molecular network immersed in a liquid mediu m, which in food system is water. Food technologists use the word gel for high moisture foods that are more or less retain their shape when released from their container. A gel is a visco elastic system with a storage modulus (G) larger than the loss modulus G. Hydrocolloids form gels by somatogenetic association of their polymer chains through hydrogen bonding, hydrophobic association and cat ion mediated cross-linking and differ from artificial polymer gels, which normally consisted of covalently cross-linked polymer chains. Hence hydrocolloid gels are often referred as physical gelThe knowledge of the conditions required for gelling of finical hydrocolloid dispersion, the characteristics of the gel produced and the texture it confers are very important aspects to design a specific food formulation.The formation of gel involves the association of randomly dispersed polymer segments in dispersion in such a way so as to form a three-dimensional network that contains solvent in th e interstices. The associated regions known as conjunction zones are make by two or more polymer chains. The gelation process is mainly the formation of these junction zones. Hydrocolloid gelation can engage the hierarchy of structures, the most common of which is the aggregations of primary inter chain linkages into junction zones, which forms the basis for the three-dimensional network characteristics of a gel. The physical arrangement of these junction zones within the network can be affected by various parameters like temperature, presence of ions and inherent structure of hydrocolloid. For the gelation of hydrocolloids, the three main mechanisms proposed are ionotropic gelation, cold-set gelation and heat-set gelation.Ionotropic gelation occurs via cross-linking of hydrocolloid chain with ions, typically a cation mediated gelation process of negatively charged polysaccharides. Ionotropic gelation is carried out either by diffusion setting or internal gelation. In cold set ge lation, hydrocolloid powders are dissolved in warm/boiling water to form a dispersion which on cooling results in enthalpically-stabilised inter-chain helix to form segments of individual chains leading to a three-dimensional network. Gelatine gel is formed by this mechanism.GelatinGelatin is substantially pure protein food ingredient, obtained by the thermal denaturation of collagen, which are the structural mainstay and most common protein in the animal kingdom. Today gelatine is usually available in granular powder form. Ref websiteGelatin forms a thermo-reversible gels with water, and the gel melting temperature (Various factors affect the gel formation by hydrocolloids which include concentration of the gelling agent, pH of the medium, molar mass/ degree of polymerisation, temperature, ionic composition and solvent quality. Rheological characteristics of gel involves characterizing a gel n the basis of various parameters like modulus of elasticity, yield stress, shear modulus, storage and loss modulus, complex viscosity , gel strength and compliance. These parameters are usually ascertain by conducting tests like compression test, dynamic oscillatory rheometry, creep and texture profile analysis, etc by employing instruments like universal texture measuring system, controlled shear rheometer.Addition of sucrose results in an increase of true wear stress in all these gals. The gel sweetness is related with mechanical properties of gel like gel strength, rupture stress, rupture strain and particularly with the amount of deformation required to break the network and its resistance to deformation. Besides co-solutes like sucrose, concentration of hydrocolloid, shear rate and temperature are also important variables that influence the rheological status of hydrocolloid gels. The blending of different polysaccharides offers an alternative route to the development of new textures. The major interest lies in the development of synergistic mixtures with improved or induced gelation.(Saha and Bhattacharya 2010)References.Afoakwa, E. (2010). chocolate science technology.Geoff Talbot, H. S. (2008). Cocoa butter equivalents and improversTheir use in chocolate and chocolate-coated confectionery. Focus on Chocolate vol 19 n 3(May/June 2008) 28,29.Saha, D. and S. Bhattacharya (2010). Hydrocolloids as thickening and gelling agents in food a critical review. Journal of Food Science and Technology-Mysore 47(6) 587-597.SLETTENGREN, K. S. (2010). Crack formation in chocolate pralines.Stortz, T. A. and A. G. Marangoni (2011). Heat resistant chocolate. Trends in Food Science Technology 22(5) 201-214.