Stearin Fractions Research Articles

Inter-esterified blends of Palm kernel oil, Palm oil, Palm oil Fractions and their derivatives as low Trans and low-cost fats as potential cocoa butter substitutes

Cocoa Butter Substitutes (CBS) were produced from Chemical Inter-esterification (CIE) of Fully Hydrogenated Palm Oil (FHPO), Fully hydrogenated Palm Kernel Oil (FHPKO), Palm Kernel Oil (PKO), Stearin fraction of Palm Oil (PPO), Olein fraction of Palm Oil (PO) blends in various quantitative proportions and Inter-esterified to form Inter-esterified Fats (IEF). The CIE reactions were carried outat 110○C for 1 hour using Sodium methoxide at 0.2% as a catalystwith a mixing speed of 200 rpm. The physical and chemical properties, melting profile, Solid Fat Content (SFC) were analyzed andcompared with commercially marketed cocoa butter. CIE substantially altered the fatty acid distribution in the triglyceride profileof the fat blends, culminating in a significant change in the melting profile of Inter-esterified Fats (IEF) as compared to their Physical Blends (PB). CBS obtained from CIE of blends of pure Lauric Oils and their fully hydrogenated products are found to be the closest to Cocoa butter in terms of melting profile followed by HPKO: PKO (50:50) and HPKO: PKO (60:40) showing N35 (Solid fat content at 35C of almost 0%) making them most suitable alternative for Cocoa Butter. While Lauric and Non Lauric oil blends such as FHPKO: FHPO (20:80), FHPO: FHPKO (30:70), and 40:60 (PPO: FHPKO) indicated a high potential option as Low trans-CBS in Confectionery Industry and Frozen Dessert Fat as they exhibited similar SFC curves and melting profile to the commercial Cocoa Butter (CB).

Compostos bioativos de frações de óleo de palma com maior teor de ácido oleico

Abstract BRS Manicoré cultivar is an interspecific hybrid between Elaeis oleifera and Elaeis guineensis(ISH OxG). It has shown high yield potential and genetic resistance to phytosanitary problems in cultivation in Brazil. Studies have indicated differences in the composition of ISH OxG and palm oils, as well as the influence of genotype and environment on palm oil characteristics. The aim of this study was to assess the distribution of fatty acids, carotenoids, and tocochromanols in the olein and stearin fractions of the oil produced by the ISH OxG cultivated in municipality of Una, state of Bahia, Brazil by liquid and gas chromatography. There were significant differences for fatty acids, carotenoids and total tocochromanols between olein and stearin (p<0.05). The olein was richer in oleic acid (59% vs 57%), while stearin was higher in saturated fatty acids (31% vs 29%), alpha and beta-carotene (232 vs 213 mg/Kg, and 347 vs 299 mg/Kg, respectively), alpha-tocotrienol (136 vs 90 mg/Kg), and alpha-tocopherol (52 vs 32 mg/Kg). No difference was observed for gamma-tocotrienol (598 – 450 mg/kg) and delta-tocotrienol; nonetheless, the high content of the former in both fractions was notable. The ISH OxG oil fractions showed distinct patterns, indicating different applications.

Crystallization and Polymorphism of Cocoa Butter Equivalents from Blends of Palm Mid Fraction and Hard Stearins Produced by Enzymatic Acidolysis of High Oleic Sunflower Oil

AbstractCocoa 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.

Evaluation on the quality of Malaysian refined palm stearin

The quality of Malaysian palm stearin was monitored through a twelve-month survey in 2018, by participation of palm oil refineries and oleochemical plants from Peninsular Malaysia and Sarawak. Quality parameters requirement as listed in the Palm Oil Refinery Association of Malaysia (PORAM) specification such as moisture, impurities, free fatty acids, slip melting point, peroxide value and iodine value were determined. Other identity characteristics analyses as detailed in the palm stearin specification namely Malaysian Standard MS 815:2007 and Codex Alimentarius CXS 210-1999 documents were also analyzed, which were apparent density, refractive index, fatty acids composition, triacylglycerols, etc. Results obtained from this survey indicated that the quality of Malaysian palm stearin complied with the requirements specified in MS 815:2007 and Codex CXS 210-1999 documents. The iodine value determined was ranged from 28 g I2/100 g oil to 48 g I2/100 g oil, with 60.9% of the palm stearin tested were in the range of 30 g I2/100 g oil to 35 g I2/100 g oil. Meanwhile, some deviations are found in the average of parameter such as refractive index, apparent density, slip melting point, oleic and palmitic acids of the palm stearin produced. These deviations could be due to the improvement in current fractionation technologies causing less olein entrainment in stearin products, which resulted of harder stearin fraction in the sample itself, giving a more representative reading of the parameters.

A Review on the Fundamentals of Palm Oil Fractionation: Processing Conditions and Seeding Agents

AbstractFractionation is a well‐established process adopted in the fats and oils industries. It involves the separation of low and high melting triacylglycerol under controlled cooling conditions into olein and stearin fractions with distinct chemical and physical properties. Amongst the other vegetable oils, palm oil is one of the most fractionated oils in the past few decades mainly attributed to its semisolid properties. The various fraction of palm oil allows it to be used in different types of food products such as margarine, frying oil, and cocoa butter substitute. In fractionation, proper control of the fractionation conditions is important to produce the fractions with desirable stearin and olein quality. The purpose of this paper is to critically review the fractionation conditions (crystallization temperature, agitation, cooling rate and crystallization time) that affect the yield and quality of the oil produced. Additionally, it also provides the latest updates on the influence of seeding agents (diacylglycerol, monoacylglycerol, hard fat, phytosterol, phospholipid, lecithin, essential oil, sugar, polyglycerol ester, and talc) used in fractionation. This article is useful to provide a fundamental understanding of fractionation to scientists from the industries or academia working in the fats and oils industries.Practical Applications: This paper provides an in‐depth understanding of fractionation particularly on the parameters of fractionation in influencing the quality and yield of the stearin and olein produced. It also for the first time presents the effect of addition of various seeding agents on palm oil fractionation which can help the industry to select the appropriate seeding agents to improve the currently employed fractionation process. Thus, it can act as a guideline for the industry to understand and select the appropriate fractionation conditions when developing a new product using this approach. The fractionation conditions discussed here can also be used as a reference when fractionating other types of fats and oils as most of them share a common background.

Use of confocal Raman imaging to understand the microstructure of anhydrous milk fat-based oleogels

This work explores confocal Raman microscopy as a novel approach to study the microstructure of oleogels, using milk fat-based oleogels as a case study. Anhydrous milk fat (AMF) was sequentially fractionated to obtain two olein and two stearin fractions with different thermal properties. These and the unfractionated AMF were structured into oleogels using ethyl cellulose as gelling agent. Although the fatty acid profile of the different fractions showed only minor changes (in most cases < 10% change), the microstructure of the various oleogels was markedly different, especially the unfractionated AMF based oleogels, which exhibited distinct pseudo-spherical features suggesting segregation of components. Different univariate and multivariate data analysis approaches, were compared to map the distribution of components in the oleogels using confocal Raman microscopy. The univariate approach only provided accurate microstructural information for oleogels prepared with olein (liquid at the temperature of analysis). The multivariate approaches, although more complex, provided reliable results for all oleogels. Mapping lipids with different degrees of mobility (liquid vs solid) within the oleogels was possible with this technique. Solid lipids were located preferentially in close proximity to ethyl cellulose, and were confirmed to be the main component of the microspheres found in the unfractionated AMF oleogels.

Physicochemical properties of bambangan kernel fat and its stearin mixtures with cocoa butter

The fractionated cocoa butter improver from the bambangan kernel fat (BKF) was blended with commercial cocoa butter (CB), and the physicochemical properties of the blends were determined. The characteristics, such as solid fat content (SFC), fatty acids composition and physicochemical properties of pure BKF, its first (S-1) and second stearin (S-2) fractions integrated with CB at varying ratios (g/100 g) were determined. B4, F4, and M4 blends containing 20% BKF or S-1 and S-2 with 80% CB showed good compatibility with the presence of 22.42–22.57% palmitic, 37.23–37.63% stearic, and 33.67–33.91% oleic acids. These blends also showed similar pattern of SFC curves as CB, at which the SFCs of the three blends dropped to 0% after 35 °C. Moreover, the blends also exhibited comparable iodine value (36.17–36.58 g iodine/g) and slip melting point (SMP) (28.83–29.17 °C) with the commercial CB. In comparison with the hard fat (S-1 and S-2), which had high SMP and stearic acid (44.71–48.51%), the fatty acids composition of fat blends significantly (p < 0.05) decreased and resulted in low SFC values. The results obtained in this study proposed that the best blends to converge with CB were B4, F4 and M4.

Effect of sucrose esters on polymorphic behavior and crystallization kinetics of cupuassu fat and its fractions

AbstractPolymorphism of natural fats is very important in the food industry since it is related to macroscopic properties of final products, including texture, color and appearance. The effect of addition of sucrose esters on crystallization kinetics and polymorphic behavior of cupuassu fat (CF) and its stearin fractions obtained by dry fractionation at 29°C (S‐29), 26 (S‐26), and 24 (S‐24) was studied by polarized light microscopy, differential scanning calorimetry, and small and wide angle X‐ray scattering. In situ experiments were performed in real‐time using synchrotron radiation as the light source. Sucrose esters S‐170 and P‐170 shortened induction times of crystallization, acting as a seed even at low supercooling. In addition to the kinetic effects, S‐170 modified polymorphic behavior. Depending on processing conditions used (under thermal cycles or isothermal storage), it promoted crystallization in a specific polymorphic form: β′2 (CF and its stearins) or β2 (S‐29). Crystallization in a stable and unique β′‐form makes CF and its stearins a good alternative to trans‐fats. With the addition of sucrose ester S‐170, S‐29's increased tendency to crystallize in β2‐form extends its applications in chocolate and coatings.

Thermal and Physical Properties of Crude Palm Oil with Higher Oleic Content

Interspecific hybridization of oil palms (E. guineensis × E. oleifera) was initially exploited to provide disease resistance and, consequently, increased oleic acid content. Besides the growing importance of this cultivar to the market, there is little information about this oil’s properties. In this context, this study aimed to determine a comprehensive physicochemical and thermal characterization of hybrid palm oil (HOPO) compared with the better-known African palm oil (APO). Differences in the distribution of fatty acids, carotenoids, and tocols were observed. Minor differences in density and viscosity were found between the oils, with no relevance for the materials’ processing design. Nevertheless, HOPO showed unique crystallization behavior, which potentially can affect industrial operations, such as fractionation. HOPO did not present the two thermal characteristic regions of APO, attributed to olein and stearin fractions. The HOPO demonstrated a decrease in the melting point of more than 3 °C in relation to APO, and a reduction in the crystallization point of more than 6 °C. Furthermore, besides the higher content of unsaturated fatty acids, HOPO was more stable than APO due to a higher antioxidant content. These results could be useful to establish operation conditions for processes using palm oil from hybrid oil palm.

Dry Fractionation Approach in Concentrating Tocopherols and Tocotrienols from Palm Fatty Acid Distillate: A Green Pretreatment Process for Vitamin E Extraction

AbstractPalm fatty acid distillate (PFAD) is a rich source of vitamin E. As compared to other vegetable oil, PFAD has higher tocotrienol (70–80%) over tocopherol content, which makes it a valuable source for vitamin E extraction. Current vitamin E extraction methods are not sustainable due to the intensive usage of chemical and high operational cost. Hence, the present study investigated for the first time using dry fractionation process as a green and economical pretreatment method for separating solid fraction (stearin) and liquid fraction (olein) in order to concentrate vitamin E from PFAD in olein fraction. We examined the dry fractionation conditions: crystallization ending temperature (36–44 °C), cooling rate (0.3 and 1.5°C min−1), stirring speed (20–125 rpm), and holding time (0–60 min) on the composition of unsaturated and saturated fatty acids as well as vitamin E content in liquid fraction (olein) and solid fraction (stearin) using gas chromatography and high performance liquid chromatography, respectively. In most of these conditions, vitamin E was ultimately higher in olein fraction as compared to stearin fraction, which is correlated with the high degree of unsaturation. Under a cooling rate of 0.3°C min−1, 90 rpm stirring speed, and ending crystallization of 38 °C, the highest vitamin E rich olein fraction was attained with 1479 ± 10.51 ppm in 50 g olein fraction as compared to 1366 ± 7.94 ppm in 500 g of unfractionated PFAD.

Impact of fractionation on fatty acids composition, phenolic compounds, antioxidant characteristics of olein and super olein fractions of flaxseed oil

Flaxseed oil was fractionated at −40°C, filtrate was designated as olein fraction (31% yield), which was further fractionated at −60°C, and filtrate was named as super olein fraction (17% yield). Flaxseed oil, olein, and super olein fractions were stored at 25°C–30°C for the duration of 90 days. Alpha linolenic acid in flaxseed oil, olein, and stearin fraction was 55.26%, 63.47%, and 71.61%. High-performance liquid chromatography (HPLC) characterization showed that phenolic compound was concentrated in olein and super olein fractions. In super olein fraction of flaxseed oil, concentration of gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, syringic acid, p-coumaric acid, and ferulic acid was 8.14, 40.59, 75.38, 7.95, and 9.27 mg/100 g. Total phenolic contents of flaxseed oil, olein, and super olein were 145, 185, and 247 mg GAE/100 g. Peroxide value of 90 days stored flaxseed oil, olein, and super olein was 0.59, 0.75, and 0.96 (MeqO2/kg) with no difference in color and flavor scores. Practical applications Several fractions of palm oil and milk fat are commercially produced for large number of industrial applications. However, fractionation of flaxseed oil is not previously performed, and chemical characteristics of olein and super olein fractions of flaxseed oil are not reported in literature. In this study, olein and super olein fractions of flaxseed oil were produced by dry fractionation. Super olein fraction revealed more than 70% alpha linolenic, higher magnitude of phenolic compounds than parent flaxseed oil, with reasonable oxidative stability and acceptable sensory attributes. Olein and super olein fraction of flaxseed oil may be conveniently used for the supplementation of large number of food products.

Contrastive analysis of lipid composition and thermal and crystallization behavior of olein/stearin fractionated by novel layer melt crystallization from palm oil.

Melt crystallization is typically recognized as a highly efficient and green method for oil fractionation. This work concentrated on novel layer melt crystallization for preparing desirable olein and stearin products from palm oil and the evaluation of fraction quality. Layer melt crystallization was performed at various temperatures and the effects on fractions were evaluated using iodine value (IV), solid fat content (SFC) and melting point. The lipid composition, thermal and crystallization properties, and phase behaviors of the final optimized fractions were determined using gas chromatography, high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry and differential scanning calorimetry. Increasing crystallization tube temperatures under the same jacket temperature increased the melting point and SFC, while decreasing the IV of the olein product. Opposite results were observed for the stearin product. Major fatty acids in fractions were determined as palmitic acid and oleic acid. 1,2-Dioleoyl-3-palmitoylglycerol and 1,3-dipalmitoyl-2-oleoylglycerol were identified as the main triacylglycerols in olein and stearin fractions, respectively. A critical effect of crystallization temperature on co-crystallization of oleins and stearins was revealed. A transition from plate-like crystal growth to spherulitic growth with spontaneous nucleation was indicated in palm oil and stearin fractions with increasing crystallization temperature. As for olein fractions, a temperature increase resulted in heterogeneous nucleation from instantaneous nucleation. Novel layer melt crystallization was successfully applied and optimized for fractionating palm oil. The composition and property changes of obtained fractions were analyzed and explained at both macroscopic and microscopic levels. © 2021 Society of Chemical Industry.

Characterization of sheep tail fat dry fractionation at the pilot scale

Abstract Two-step dry fractionation was employed to prepare the liquefied sheep tail oil at the pilot scale. Sheep tail oil was separated into fat residuals, crude oil, stearin A, stearin B, olein A, and olein B. The extracted rates for crude oil, olein A, and olein B were 66.7, 45.9, and 35.0%, respectively. The ratios of saturated/unsaturated fats in the crude oil, olein A fractions, and olein B fractions were 0.62, 0.63, and 0.60, respectively. The olein B was liquid at ambient temperature and its melting point was 5.32 °C. The iodine values of stearin samples were significantly decreased compared to the crude oil samples (P &lt; 0.05). For the stearin fractions, the polymorphic form was mainly β’ form, and the solid fat content was significantly higher than the olein fractions (P &lt; 0.05), which can be used to make the shortening product.

Dry Fractionation of Cupuassu (Theobroma grandiflorum) Fat: Physical–Chemical Properties and Polymorphic Behavior

AbstractPhysical chemical properties of cupuassu fat were modified by dry fractionation. Stearin and olein fractions were obtained at 29, 26, and 24 °C. Polymorphic behavior of unfractionated cupuassu fat (UCF) and its fractions were studied in situ by small‐angle (SAXS) and wide‐angle (WAXS) X‐ray scattering using synchrotron light. Polymorphic transitions were followed in real time tempering samples with a thermal cycle. For UCF, the main polymorphic form crystallized under selected conditions was the β’2. α and β’1‐forms appeared in trace amounts. β2‐form was obtained after storage at 25 °C for 3 months. Stearins obtained at 26 (S‐26) and 24 °C (S‐24) showed a similar polymorphic behavior. However, S‐26 with improved physical properties might be more suitable for chocolate production or as a trans‐fat alternative than UCF. Stearin fraction obtained at 29 °C (S‐29) had a complex polymorphic behavior. The α‐form was the first polymorphic form detected followed by β’2‐form. There was a polymorphic transition from α to β’1‐form but no transition between β’‐forms. They were independent to each other showing fractionation in two different solid solutions. Increased contents of the triacylglycerols (TAG) SOA and SOB together with lower contents of SOO compared to UCF led to co‐crystallization because there was no complete compatibility among all TAG present in S‐29. β1‐form crystallized after storage forming crystals with a double‐layer arrangement and a characteristic morphology. This form could be useful for accelerating crystallization process in melted liquid systems.

Physicochemical Properties of Palm Oil Fraction (Elaeis guineensis Jacq)

Study about physicochemical properties of olein and stearin fraction of palm oil has been conducted. Research aim was to determine the chemical physical properties of the olein and stearin fractions of palm oil (Elaeis guineensi Jacq) that was originated from North Mamuju, West Sulawesi. Palm oil was fractionated by dry fractionation method to collect the olein and stearin fractions. The physical chemical characteristics of fractions were determined by acid value, saponification value, peroxide value, and iodine value parameters that measured by titrimetry method. The result of analysis showed that the acid values for the olein and stearin fractions acid were 7.04 and 5.83 mg NaOH/g, saponification values were 198.53 and 194.71 mg KOH/g, peroxide values were 0.77 mek O 2 /kg and 0.79 mek O 2 /kg, and iodine values were 34.12 and 32.87 g iod/100 g.

Effects of fractionation technique on triacylglycerols, melting and crystallisation and the polymorphic behavior of bambangan kernel fat as cocoa butter improver

Cocoa butter improver (CBI) is typically composed of high melting symmetrical triacylglycerols (TAGs) that aid in the hardness of chocolate products in tropical/subtropical regions. High-melting symmetrical TAG (1,3-di-stearoyl-2-oleoyl-glycerol, SOS) rich fats were produced by two-stage acetone fractionation. Different chromatographic and thermal techniques were used to determine TAGs, thermal properties, and polymorphic behavior of each bambangan kernel fat (BKF) fraction. The first (S-1) and second (S-2) stearins composed of 55.83% and 64.70% symmetrical SOS were the valuable CBIs produced from the fractionated BKF. The stearin fractions also melted and crystallised rapidly at high temperatures with one maximum peak starting at 20.30–21.74 °C and ending at 38.72–42.45 °C (melting), and another starting at 17.05–18.46 °C and ended at 5.63–8.20 °C (crystallisation). In comparison with pure BKF and commercial cocoa butter (CB), the stearins showed sharper melting curves and higher melting properties. The stearins also exhibited β-polymorphic form which was similar to that of CB. Results suggested that the stearins were suitable to be applied as CBI to improve the melting properties and the availability of confectionery products in tropical/subtropical countries.

Preliminary Large Scale Mitigation of 3-Monochloropropane-1, 2-diol (3-MCPD) Esters and Glycidyl Esters in Palm Oil.

Approximately 900 tonne of crude palm oil (CPO) underwent washing using 5 to 10% hot water (90 to 95°C) at a palm oil mill. The aim of the CPO washing was to eliminate and/or reduce total chlorine content present in the conventional CPO, as it is known as the main precursor for the formation of 3-monochloropropane-1, 2-diol esters (3-MCPDE). By a simple hot water washing, more than 85% of the total chlorine was removed. However, washing did not have significant (p > 0.05) effect on other oil quality parameters such as the deterioration of bleachability index (DOBI), free fatty acid (FFA) content and diacylglycerol (DAG) content of the oil. The latter has been established as the main precursor for glycidyl esters (GE) formation. The treated CPO was then transported using tankers and further refined at a commercial refinery. Refining of washed CPO resulted in significantly (p < 0.05) lower formation of 3-MCPDE, but GE content remained slightly high. Post-treatment of refined oil significantly reduced the GE content (p < 0.05) to an acceptable level whilst almost maintaining the low 3-MCPDE level. The study has proven that water washing of CPO prior to refining and subsequent post-refining is so far the most effective way to produce good quality refined oil with considerably low 3-MCPDE and GE contents. Dry fractionation of refined palm oil showed these contaminants partitioned more into the liquid olein fraction compared to the stearin fraction.

Isolation and Evaluation of Stearin and Olein Fractions from Rice Bran Oil Fatty Acid Distillate by Detergent Fractionation and Conversion into Neutral Glycerides by Autocatalytic Esterification Reaction

AbstractDetergent fractionation (Lanza process) offers a valuable separation process for edible oils that contain varying amounts of saturated and unsaturated fatty acids. The rice bran oil fatty acid distillate (RBOFAD), obtained as a major byproduct of rice bran oil deacidification refining process, was fractionated by detergent solution into a fatty acid mixture as follows: low‐melting (19.00 °C) fraction of fatty acids as olein fraction (44.50 g/100 g) and high‐melting (49.00 °C) fatty acids as stearin fraction (37.15 g/100 g). A high amount of palmitic acid (42.75 wt%) is present in stearin fraction, while oleic acid is higher (48.21 wt%) in the olein fraction. The stearin and olein fractions of RBOFAD with very high content of free fatty acids are converted into neutral glycerides by autocatalytic esterification reaction with a theoretical amount of glycerol at high temperatures (130–230 °C) and at a reduced pressure (30 mmHg). Acid value, peroxide value, saponification value, and unsaponifiable matters are important analytical parameters to identity for quality assurance. These neutral glyceride‐rich stearin and olein fractions, along with unsaponifiable matters, can be used as nutritionally and functionally superior quality food ingredients in margarine and in baked goods as shortenings.

Tailoring cream by modifying the composition of the fat and interfacial proteins to modulate stirred milk gel texture

The formulation-structure-texture relationship in stirred emulsion-filled food gels has rarely been analysed, let alone in realistic conditions. By studying thermal (calorimetry), structural (laser diffraction, confocal microscopy and mathematical morphology analysis) and textural (rheology and tribology) properties, this work advanced the understanding of this relationship in stirred gels made entirely from milk ingredients. Indeed, tailoring the fat composition (AMF, olein or stearin fractions) and interfacial proteins (native or heat-aggregated WPI) in cream resulted in different properties. Crystallisation of the fat droplets and probably their interactions (aggregation or partial coalescence), pore size, microgel size and the coarseness of the protein network in stirred milk gels were all modified by the cream formulation. The changes in properties led to different textures and lubrication behaviours of the stirred milk gels. The highlighted relationships between formulation, structure and texture are recapitulated in a concluding diagram.

Effect of Chemical Interesterification on the Physicochemical Characteristics and Fatty Acid Profile of Bakery Shortening Produced from Shea Butter and Fluted Pumpkin Seed Oil Blend

The objective of this work was to evaluate the effect of chemical interesterification, as a modification process on the physicochemical properties and fatty acid profile of bakery shortening produced from a blend of Shea stearin and fluted pumpkin seed oil. The Shea nut oil was fractionated, and the solid stearin fraction blended with fluted pumpkin seed oil in the following ratios: 30:70, 40:60, 50:50,and 60:40 (Shea stearin: fluted pump seed oil), The blends were stabilized with recommended additives such as; distilled monoglyceride (E471) and preservatives such as; citric acid (E330), BHT (E321), homogenized by continuous stirring and crystalized by cooling at 17°C, then tempered at 23 – 25°C for 48h, to attain a stable polymorphic form, used as non-interesterified blends (NIEBs). Another set of 30:70; 40:60; 50:50; and 60:40 (Shea stearin: fluted pumpkin seed oil), were chemically interesterified with sodium methoxide (CH3ONa) as catalyst, crystalized, stabilized, and used as chemically interesterified blends (CIEBs).The chemical properties, physical characteristics (including solid fat content), and the fatty acid profile of all the chemically interesterified (CIEB) and the non-interesterified (NIEB) samples were determined. There was no significant (p>0.05) change in the peroxide value, iodine value, and the refractive index of NIEBs and there corresponding CIEBs. The acid value, free fatty acids, slip melting point, density, and solid fat content were significantly (p<0.05) reduced after interesterification. Interesterification caused rearrangement of triacylglycerol species, resulting in increased unsaturated fraction and reduction in the saturated fraction. Interesterification gave fats with wide plastic range suitable for bakery fats, icing-shortening, filler fats, and all-purpose shortenings.