S. Yella Reddy

Cocoa butter extenders from Kokum (Garcinia indica) and Phulwara (Madhuca butyracea) butter

Cocoa butter extenders, suitable for use in chocolate and confectionery, were prepared from Kokum fat and a Phulwara butter fraction. The latter fraction was prepared from Phulwara butter by two-stage dry fractionation and blended with Kokum fat in selected proportions to obtain a series of hard butters with different melting profiles. The blends with higher proportions of Kokum fat were harder and hence may find application in warm climates. The blends with higher proportions of Kokum fat were harder and hence may find application in warm climates. The blends had solidification properties, fatty acid and triacylglycerol compositions similar to those of cocoa butter. In addition, they had narrow melting ranges like cocoa butter, and they were compatible with cocoa butter and have tolerance toward milk fat.

Chemical and thermal characteristics of milk-fat fractions isolated by a melt crystallization

Anhydrous milk fat (AMF) was fractionated by a two-stage dry fractionation process to produce three fractions: high melting (HMF), middle melting (MMF), and low melting (LMF). The HMF (m.p. 42°C) exhibited a broad melting range similar to a plastic fat. The MMF (m.p. 33°C) resembled the original AMF (m.p. 31°C), but with slightly higher solid fat content. The LMF (m.p. 16°C) was liquid at ambient temperature. Differences in the thermal properties of these fractions were attributed to the triacylglycerols (TAG) and their fatty acid composition. Saturated TAG with carbon numbers of 36–54 were concentrated in the HMF; whereas unsaturated TAG of carbon number 36–54 predominated in the LMF. Likewise, the long-chain saturated fatty acids were significantly higher and the long-chain unsaturated fatty acids were significantly lower in the HMF fraction. Binary blends of milk-fat fractions with a range of melting profiles were produced by mixing HMF with AMF, MMF, or LMF. Laboratory-prepared fractions were similar to commercially available fractions.

Effect of triglycerides containing 9,10-dihydroxystearic acid on the solidification properties of sal (Shorea robusta) fat

Components affecting solidification properties of sal (Shorea robusta) fat have been studied. Triglycerides containing 9,10-dihydroxystearic acid (DHS-TGs) present to about 3% have been found to affect the supercooling property of sal fat at as low a level as 2%. The DHS-TGs were composed of 57.5% stearic, 5.8% arachidic, 6% palmitic and 30.5% 9,10-dihydroxystearic acids. As DHS-TGs are soluble in acetone, solvent fractionation using acetone improved the supercooling capacity of stearin while that of the olein fraction was not affected. When the fat was subjected to dry fractionation at 35 C, DHS-TGs, due to their high melting nature, were removed to a greater extent in the form of stearin, thereby improving the supercooling capacity of the olein.

Tempering method for chocolate containing milk-fat fractions

Anhydrous milk fat (AMF) was fractionated by a two-stage dry fractionation process to produce three fractions—high-(HMF), middle-(MMF), and low-melting (LMF). The effect of replacing 12.2–40% by weight of cocoa butter with these fractions on the tempering profile of milk chocolate was studied. Degree of temper was evaluated by differential scanning calorimetry, and expressed as the ratio of enthalpies of melting for higher-stability polymorphs to those of lesser stability. The degree of temper was dependent on the crystallization time and temperature, and the type and quantity of milk-fat fraction in the formulation. Chocolates containing AMF or its fractions in concentrations of up to 20 wt% (total fat basis) were tempered after a conventional thermocycling tempering process (50°C/30 min, 27.7°C/4 min, 31°C/2 min) to obtain products with good contraction and mold release properties. For those milk chocolate formulations that did not temper by the conventional method and resulted in poor contraction and mold release, a new tempering protocol was developed. Lower crystallization temperatures and/or longer holding times were required at concentrations of AMF, MMF, or LMF above 20%. Chocolate containing HMF required slightly higher crystallization temperatures because of high viscosity. Chocolates containing up to 35% HMF and up to 40% of the total weight of fat in the chocolate of AMF, MMF, and LMF were successfully tempered by adjusting crystallization time and temperature.

Study on the polymorphism of normal triglycerides of sal(Shorea robusta) fat by DSC. I. Effect of diglycerides

The effect of diglycerides (DG) on the phase transition of various polymorphic forms of normal triglycerides (TG) of sal fat was investigated by differential scanning calorimetry. Three levels of DG, 5, 10 and 15%, were used. DG delayed the phase transition of lower melting crystal forms to higher forms of TG when the samples were brought to a congealed state by rapid cooling (20 C/min) and heated at rates ranging from 1.25 to 10 C/min; the extent depended on the level of DG and the rate of heating. As the level of DG and the rate of heating increased, the delay in phase transition of crystal forms I → II → III was more pronounced. The phase transition of crystal forms I, II and III to form IV was delayed at 5 and 10% levels of DG, while at the 15% level the phase transition of form I to higher forms was completely stopped when the samples were tempered at 0 C for 18 hr and heated at 10 C/min. DG at 10 and 15% levels retarded the phase transition of form IV to the most stable (V) form of TG when the samples were tempered at 0 C for 1 hr followed by 3 hr at 26 C.

Isolation of 9,10-Dihydroxystearic acid from sal (Shorea robusta) fat

Abstract9,10-Dihydroxystearic acid and its triglycerides (DHS-TGs) were isolated from sal fat by silica gel adsorption and solvent and dry fractionation processes, followed by crystallization. Silica gel adsorption gave a higher yield of DHS-TGs than the other two fractionation processes. However, the dry fractionation process was found to be comparatively easy to carry out. 9,10-Dihydroxystearic acid was isolated and identified by TLC, GLC, M.P. and IR-spectrometry. The DHS-TGs were found to contain 30.5% 9,10-dyhydroxystearic, 57.5% stearic, 6.0% palmitic and 5.8% arachidic acids. These processes were found to be useful for recovery of DHS-TGs and also to improve the solidification properties of sal fat required for confectionery.

Effect of triglycerides containing 9,10-dihydroxystearic acid on polymorphism of sal (Shorea robusta) fat

The effect of the triglycerides containing 9,10-dihydroxystearic acid (DHS-TG) on the phase transition of polymorphic forms of normal triglycerides (TG) of sal fat was investigated by differential scanning calorimetry (DSC) under different cooling and heating modes. Four levels of DHS-TG, 2, 5, 8 and 10%, were used. DHS-TG accelerated the phase transition of lower melting crystal forms I → II → III of TG obtained under rapid (20°C/min) or slow (2°C/min) rates of cooling. They delayed the phase transition of crystal form III to IV of TG at 0°C. Also, DHS-TG reduced the heat of fusion (ΔH) of the stable form (V) of TG obtained after tempering at 0°C and at 26°C.

Confectionery fats from sal (Shorea robusta) fat and phulwara (Madhuca butyracea) butter

Abstract Stearins from sal fat and phulwara butter were blended in selected proportions to obtain confectionery fats or cocoa butter extenders. The sal fat stearin was obtained by removing about 20% olein from sal fat by acetone fractionation at 15°C, and the phulwara butter stearin was obtained by two-stage acetone fractionation. In the first stage of phulwara butter fractionation, a small amount of stearin (equal to 10% by weight of butter) was removed from the phulwara butter. The resulting olein was further fractionated at 15°C to obtain stearin (yield 65% by weight of olein). The blends containing 75–85% of sal fat stearin and 15–25% of phulwara butter stearin had solidification properties and solid fat indices close to those of cocoa butter. These blends could be used as cocoa butter extenders. Cocoa butter extenders which impart a greater cooling sensation in the mouth were prepared by decreasing the proportion of sal fat stearin to 50–67% in the blend. The blends containing 50:50, 67:33, 75:25 and 85:15% of sal fat: phulwara butter stearins were compatible with cocoa butter when admixed even at equal proportions. The tolerances of the blends towards milk fat were similar to that of cocoa butter. Thus, a series of cocoa butter extenders or confectionery fats, having a narrow melting range and melting profiles similar to those of cocoa butter could be prepared by altering the proportion of sal fat and phulwara butter stearins in the blends.

Influence of hydrothermal processing on functional properties and grain morphology of finger millet

Finger millet was hydrothermally processed followed by decortication. Changes in color, diameter, density, sphericity, thermal and textural characteristics and also some of the functional properties of the millet along with the grain morphology of the kernels after hydrothermal processing and decortication were studied. It was observed that, the millet turned dark after hydrothermal processing and color improved over native millet after decortication. A slight decrease in grain diameter was observed but sphericity of the grains increased on decortication. The soft and fragile endosperm turned into a hard texture and grain hardness increased by about 6 fold. Hydrothermal processing increased solubility and swelling power of the millet at ambient temperature. Pasting profile indicated that, peak viscosity decreased significantly on hydrothermal processing and both hydrothermally processed and decorticated millet exhibited zero breakdown viscosity. Enthalpy was negative for hydrothermally processed millet and positive for decorticated grains. Microscopic studies revealed that the orderly structure of endosperm changed to a coherent mass after hydrothermal processing and the different layers of seed coat get fused with the endosperm.

Preparation and Properties of Encapsulated Fat Powders Containing Speciality Fat and ω/Pufa-Rich Oils

Fat powders with high fat content using three types of fats/oils, namely semi-solid fats like vanaspati, trans free speciality fat, and liquid oils like safflower or flax seed, were prepared by spray drying. The effect of type and quantity of wall materials and additives on total fat and quality of powders were studied and found that casein was effective as wall material to encapsulate maximum fat of up to 75%. Sugar and tricalcium phosphate were found to improve flowability of the powders. The quantity of fat encapsulated depends on type of fat or oil and found that semi-solid fats could be encapsulated at a higher percentage compared to liquid oils. The moisture of powders was 1–2 g/100 g, bulk density 0.3–0.4 g/cc, surface fat 15–19% and angle of repose 50–55°. The powders with bakery fat or speciality fat were lighter (creamish) in appearance compared to those with safflower or flax seed oils, which were light yellow due to the colour of the parent oil. Scanning electron microscopy of fat powders revealed that those prepared with bakery fat or speciality fat and with casein and sugar showed distinct spheres indicating effective encapsulation. Scanning electron microscopy of powders with skim milk powder and also those without added sugar showed aggregation of particles. The powders with PUFA-rich oils had a high proportion of ω-3 and PUFA. Equilibrium relative humidity and storage stability of powders were determined.