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1.
Although cocoa butter (CB) is an ideal fat for use in chocolate, it softens with heat and is not suitable for use in warm climates. CB extenders or improvers, preferably from stearic acid‐rich fats, are good candidates to increase the heat‐resistance property of CB and chocolate. In the present investigation, one such fat, kokum, is used as an improver to increase the hardness of chocolate. Kokum fat is added in various proportions replacing CB in dark and milk chocolate formulations and its effects on rheology, hardness and triglyceride composition were studied. The results revealed that up to 5% kokum fat addition by weight of the product did not significantly affect the plastic viscosity or yield stress of milk or dark chocolate. Hardness of both dark and milk chocolate increased with increase in addition of kokum fat. The solids fat content at and above 30 °C increased with increase in level of kokum fat with CB, especially at and above 15%. These physical properties are due to increase in 2‐oleodistearin triglycerides with addition of kokum fat with CB. The results revealed that kokum fat could be used up to 5% by wt of the product to increase the heat‐resistance property of chocolate so that it can be used in warm climates. Copyright © 2004 Society of Chemical Industry  相似文献   

2.
The effect of major chocolate ingredients (sugar, cocoa particles and lecithin), in combination with the two pre-crystallization techniques, seeding and non-seeding, was investigated with respect to the kinetics of cocoa butter crystallisation and the resulting microstructure. Confocal laser scanning microscopy (CLSM) was used to monitor microstructural evolution under dynamic thermal conditions. DSC measurements and image analysis were also applied in order to quantify the impacts of processing and formulation on microstructure. All ingredients and pre-crystallisation techniques considered proved to have a large impact on fat crystallisation kinetics and the resulting microstructure. Seeded samples tended to form multiple nucleation sites, inducing rapid growth of a crystal network. The non-seeded samples showed an altering structure, with some domains developing large spherical crystals while in other domains a more heterogeneous microstructure resulted. Lecithin showed a remarkable impact on crystallisation kinetics in both the seeded and non-seeded samples. For the seeded samples, the effect was most noteworthy in samples containing cocoa butter and sugar, where lecithin significantly reduced the induction time. In the absence of seeds, lecithin itself acted as the nucleation site for fat crystallisation.  相似文献   

3.
This paper describes the preparation of samples and the evaluation techniques applied to determine the Solid Fat Content (SFC) by means of pulsed nuclear magnetic resonance (NMR) in confectionery fats characterized by distinct polymorphism (cocoa butter, cocoa butter equivalents and their mixtures). Due to the deviation of SFC values in certain softer cocoa butter equivalents at the temperature of 20 °C, an internal method devised at Karlshamns Oils & Fats AB is applied as well. When compared to the official IUPAC 2.150 (b) method, Karlshamns' method involves a lower temperature and a prolonged period of time at the stage of the final SFC stabilization in the pre-treatment of fat samples. The calculation of SFC in the analysed samples for the purposes of this paper was carried out by employing both methods (the indirect method and a serial procedure). The results are presented graphically. Differences were reflected in the SFC of the fats and their mixtures that were under observation depending on the method and temperatures applied. The obtained results indicated a considerable advantage of employing the Karlshamns method since the results yielded by this method are more lucid. Moreover, the behaviour of fats in the production process can be more easily predicted on the basis of these results.  相似文献   

4.
Bambangan (Mangifera pajang) is one of the underutilised tropical fruits found in the Borneo islands (Malaysia, Indonesia and Brunei). The physicochemical and thermal properties of bambangan kernel fat (BKF) were investigated in an effort to identify an innovative fat that could be exploited in confectionery applications. The fatty acids and triglyceride (TG) contents, melting behaviour and solid fat content (SFC) of the BKF were determined by various chromatographic and thermal techniques. BKF had three main TGs, namely 1‐palmitoyl‐2‐oleoyl‐3‐stearoyl‐glycerol (POS) (11.6%), 1,3‐distearoyl‐2‐oleoyl‐glycerol (SOS) (28.7%) and 1‐stearoyl‐2,3‐dioleoyl‐glycerol (SOO) (11.2%), with SOS being the major component. Stearic, oleic and palmitic acids were the dominant fatty acids with the area percentage of 36.4%, 44.5% and 8.4%, respectively. The melting behaviour indicated a single curve with only one maximum shoulder. With respect to the physicochemical and thermal properties, BKF is ideal for use in formulations (blending components) as an alternative to CB in food products, especially confectionary products.  相似文献   

5.
The partial replacement of cocoa butter (CB) with milk fat (MF) strongly influences micro-scale topographic evolution and fat phase crystallisation in milk chocolate. Adding MF reduces the incidence of large surface crystals and the number and diameter of amorphous, welled CB deposits (‘cones’), with a concurrent decrease in initial surface roughness (p < 0.05) and rate of surface coarsening. Presence of MF also slows the solidification of the cones into disorganised crystalline masses. Finally, MF reduces the initial solid fat content, and slows the rate of change in whiteness index, as well as the form V to VI polymorphic transition. Fat crystal growth is accelerated by repeated temperature-cycling (26–29 °C) compared to isothermal conditioning (26 °C). However, cone hardening occurs more rapidly when isothermally-stored. Irrespective of fat composition and storage conditions, fat crystal growth, welling and ultimately fat bloom begin only at specific locations on the chocolate surface, suggesting that chocolate’s microstructural heterogeneity is responsible for distinct surface fat crystallisation pathways.  相似文献   

6.
可可脂在非等温条件下结晶及融化特性的研究   总被引:1,自引:0,他引:1  
采用差式扫描量热仪(DSC)研究了升降温速率和乳化剂对可可脂非等温结晶和融化过程中晶体衍变过程的影响。结果显示:可可脂结晶和融化过程都对温度变化速率(λ)敏感,随λ的提高,放热峰和吸热峰强度均增大,峰值(Tp)则分别降低和升高;单甘酯促进可可脂组分分离,降低结晶温度,改变晶体的融化特性;卵磷脂则提高可可脂结晶温度,对融化特性不产生影响,添加单甘酯和卵磷脂都使可可脂结晶量增加。   相似文献   

7.
Standard methods of fractionating milk fat from the melt produce solid fractions that exhibit melting at temperatures considerably lower than that used for the fractionation. The use of high concentrations of aqueous detergent, in the presence of ammonia as an aid to centrifugation, has resulted in this solid material being sub-fractionated into a semi-solid, plastic material and a crystalline solid. The technique may be applied directly to milk fat to produce three fractions at a given fractionation temperature. Fatty acid compositions and separations according to triglyceride number are recorded for the parent fats and their fractions. Melting fingerprints, obtained by differential scanning calorimetry, are shown for the various samples, and the heats of melting are discussed.  相似文献   

8.
Blends of anhydrous milk fat (AMF) and canola oil (CO) were cooled from 35 to 5°C at 0.1°C/min, held for 24 h, and centrifuged to separate the liquid and crystalline fractions. The blends’ crystallization behaviors and microstructures depended on the level of CO present. Onset and half times of crystallization reflected a slower crystallization mechanism at higher levels of CO dilution. These differences were accompanied by a change in microstructure from large spherulites to smaller particles. The biggest change occurred between the 1:4 and 1:5 blends. Canola oil dilution also influenced the polymorphism of milk fat. Whereas only the β′ polymorph was observed in the crystallized 1:2 blend, the β polymorph predominated in the 1:8 blend. Some solubilization of AMF solids into CO was observed. This increased gradually with increasing CO concentration. Compositional analysis revealed the exchange of AMF and CO species between the liquid and crystalline fractions. The crystalline fractions were slightly enriched in AMF triacylglycerols, particularly with the more dilute blends (1:7 and 1:8). Large amounts of oil were trapped in the crystalline fractions, particularly for the concentrated AMF:CO blends where the β′ crystals and spherulitic microstructures were observed. Although the solid fat content profiles of the fractionated blends were marginally higher than those of the starting blends, the samples were very soft and oily. This strategy of using CO to fractionate milk fat was limited by the poor separation of solids and liquid during centrifugation.  相似文献   

9.
Searching new protein sources is essential due to an increase in protein demand. In this study, rambutan seed albumin concentrate (RSAC) with the protein content of 80.8% was isolated from defatted rambutan seed meal. The effects of pH and sodium chloride concentration on solubility and functional properties of RSAC were investigated. RSAC had minimum solubility at pH 4. Water absorption capacity at pH 7 and oil absorption capacity of RSAC were 0.79 and 6.13 mL g?1, respectively. Both foaming and emulsifying capacities achieved maximal levels at pH 12. In sodium chloride solution, foaming capacity and stability achieved maximal levels at the concentration of 0.6 mol L?1, while the highest emulsifying capacity and stability were noted at the concentration of 0.2 mol L?1. The least gelation concentration of RSAC was 100 g L?1 and this value decreased by five times as salt concentration in the protein solution was 0.6 mol L?1. RSAC was a potential functional ingredient in food processing.  相似文献   

10.
An exhaustive analysis of the crystallisation behaviour of palm oil was performed using low-resolution magnetic pulsed nuclear resonance, differential scanning calorimetry, polarised light microscopy and X-ray diffraction. The aim of this study was to characterise the changes induced in the crystallisation of palm oil by the addition of two different levels of tripalmitin and two different types of monoacylglycerols. The addition of monoacylglycerols led to the formation of a large number of crystallisation nuclei without changing the final solids content, accelerating the process of crystal formation, leading to the formation of smaller crystals than those found in the refined palm oil. Higher levels of tripalmitin produced crystals with larger dimensions, reducing the induction period and resulted in a higher level of solids at the end of the crystallisation period. The addition of monoacylglycerols and tripalmitin induced the formation of a polymorphic β-form.  相似文献   

11.
Physical characteristics of precrystallised binary mixtures of cocoa butter (CB) and 5, 10, 15, 20, 25 and 30% (w/w) cocoa butter replacer (CBR) or cocoa butter substitute (CBS) were determined. The lipid composition was obtained by chromatography and the solid fat content (SFC) by nuclear magnetic resonance. Tempering was carried out using a lab‐scale agitated jacket vessel reactor. Bars made with tempered samples were submitted to X‐ray diffraction and rupture tests. Snap values of crystallised mixtures decrease with an increase in the amount of alternative fat. X‐ray diffraction patterns confirmed the predominant formation of the beta polymorph habit for CB and beta prime form for CBR and CBS. Mixtures of CB and CBR exhibit chemical compatibility. The knowledge of the snap values and of the variation of SFC with temperature proved to suffice to adequately anticipate the influence of the addition of alternative fats on chocolates physical attributes.  相似文献   

12.
Low-fat cheeses dehydrate too quickly when baked in a forced air convection oven, preventing proper melting on a pizza. To overcome this problem, low-fat Mozzarella cheese was developed in which fat is released onto the cheese surface during baking to prevent excessive dehydration. Low-fat Mozzarella cheese curd was made with target fat contents of 15, 30, 45, and 60 g/kg using direct acidification of the milk to pH 5.9 before renneting. The 4 portions of cheese curd were comminuted and then mixed with sufficient glucono-δ-lactone and melted butter (45, 30, 15, or 0 g/kg, respectively), then pressed into blocks to produce low-fat Mozzarella cheese with about 6% fat and pH 5.2. The cheeses were analyzed after 15, 30, 60, and 120 d of storage at 5°C for melting characteristics, texture, free oil content, dehydration performance, and stretch when baked on a pizza at 250°C for 6 min in a convection oven. Cheeses made with added butter had higher stretchability compared with the control cheese. Melting characteristics also improved in contrast to the control cheese, which remained in the form of shreds during baking and lacked proper melting. The cheeses made with added butter had higher free oil content, which correlated (R2 ≥ 0.92) to the amount of butterfat added, and less hardness and gumminess compared with the control low fat cheese.  相似文献   

13.
研究了无水奶油和BL-41两种油脂之间不同的比例对淡奶油粒径分布、界面蛋白含量、脂肪部分聚结率及表观粘度的影响,并在此基础上探讨了其作用机理。研究结果表明,随着BL-41比例的不断增大,淡奶油的上层粒径d3,2、脂肪部分聚结率和表观粘度呈先增大后减小的趋势,在无水奶油∶BL-41为17.5∶17.5时达到最大值,而界面蛋白含量则先降低后升高,在无水奶油∶BL-41为17.5∶17.5时达到最小值。此外,随着储存时间的延长,上层粒径d3,2、脂肪部分聚结率和表观粘度均逐渐增大,而界面蛋白含量则逐渐降低。   相似文献   

14.
Fat/oil blends, formulated by mixing fully hydrogenated palm oil stearin or palm oil stearin with vegetable oils (canola oil and cottonseed oil) in different ratios from 30:70 to 70:30 (w/w %), were subjected to chemical interesterification reactions on a laboratory scale. Fatty acid (FA) composition, iodine value, slip melting point (SMP) and solid fat content (SFC) of the starting blends were analysed and compared with those of the interesterified blends. SMPs of interesterified blends were decreased compared to starting blends because of extensive rearrangement of FAs among triacylglycerols. These changes in SMP were reflected in the SFCs of the blends after the interesterification. SFCs of the interesterified blends also decreased with respect to the starting blends, and the interesterified products were softer than starting blends. These interesterified blends can be used as an alternative to partial hydrogenation to produce a plastic fat phase that is suitable for the manufacture of margarines, shortenings and confectionary fats.  相似文献   

15.
Rambutan seed is discarded during fruit processing. However, the seed contains a considerable amount of crude fat. Hence, the objective of this study was to determine two anti-nutritional constituents, namely saponin and tannin, and to characterize the fat of the seeds of 11 varieties of rambutan fruit. Results showed that the range of crude fat content is fairly narrow (36.13–39.13 g/100 g dried seeds). The iodine value and free fatty acid content of the fat were 38.50–50.61 g I2/100 g fat and 0.99–2.18% as oleic acid, respectively. Oleic (33.35–46.64%) and arachidic (26.03–33.27%) acids were the main fatty acids in the fat. HPLC analysis showed that the fat comprised mainly five unknown triacylglycerols (83.94–95.33%). The melting and crystallization curves showed that the fat exhibited four to nine non-distinct peaks. The complete melting and crystallization onset temperatures of the fat were 24.8–50.6°C and 24.1–39.4°C, respectively, while the melting and crystallization enthalpies of the fat ranged from 71.2 to 141.7 J/g and from 60.4 to 88.9 J/g, respectively. At 0°C, the solid fat index of the fat ranged between 87.4% and 91.6% and the fats of some varieties melted completely at human body temperature. The saponin and tannin contents of the seed were 14.27–18.96 mg soya saponin/100 g and 4.40–26.68 mg catechin equivalent/100 g, respectively. Findings showed that rambutan seed fat has potential to be used in various sectors of food industry.  相似文献   

16.
This research describes the interesterification of Malaysian mango seed oil (MSO) and palm oil mid‐faction (POMF) to develop a cocoa butter equivalent. Fat blends, formulated by binary blends of palm oil mid‐fraction and mango seed oil at different ratios ({100:0}, {60:40}, {50:50}, {40:60}, {0:100}), were subjected to enzymatic interesterification. The solid fat content revealed that all interesterified blends except 100% POMF {0:100} melted completely at body temperature. The interesterified {50:50} blend exhibited a slip melting point (30.35 °C) and saponification value (186.89) close to cocoa butter (P < 0.05). Thermal behaviour analysis by differential scanning calorimetry showed fusion and crystallisation behaviour similar to cocoa butter. Moreover, both the blend and cocoa butter scavenging abilities were based on the 2,2‐diphenyl‐1‐picrylhydrazyl assay, with the concentration required to reduce radical absorbance by 50% (IC50) of 43.08% and 41.1%, respectively. Therefore, the MSO: POMF blend may have use as a health‐promoting food in human diets.  相似文献   

17.
Avocado fat is a semi-solid substance with potential functional lipid characteristics. A study was carried out to evaluate the effect of addition of palm stearin and cocoa butter on the solidification behavior of avocado fat to formulate a mixture to become similar to lard. A total of three mixtures were prepared: avocado fat:palm stearin:cocoa butter (88:7:5), avocado fat:palm stearin:cocoa butter (86:7:7), avocado fat:palm stearin:cocoa butter (84:7:9; w/w), and identified by the mass ratio of avocado fat to palm stearin and cocoa butter. The fat mixtures were compared with lard in terms of the fatty acid and triacylglycerol compositions using gas chromatography and high-performance liquid chromatography, thermal properties using differential scanning calorimetry and solid fat content using p-nuclear magnetic resonance. Although there were considerable differences between lard and the fat mixtures with regard to fatty acid and triacylglycerol compositions, some similarities were seen with regard to thermal properties and solid fat content profile. Of all the fat mixtures, avocado fat:palm stearin:cocoa butter (84:7:9) displayed closer similarity to lard with respect to thermal transitions at –3.59°C and its solid fat content profile showed the least difference to that of lard throughout the temperature range measured.  相似文献   

18.
Irvingia gabonensis kernels are a promising oleiferous source. Their total lipid content was 72.3%. C14:0 and C12:0 represented the most abundant fatty acids. Triacylglycerols with ECN 32 and 46–48 were identified for the first time by HPLC-DAD-ESI-MSn. Comprehensive GC-FID and GC-MS analyses revealed novel insights into minor lipids like phytosterols and tocochromanols. Among the latter, γ-tocopherol was found to be the major vitamer. β-Sitosterol and stigmasterol were the prevailing phytosterols in the kernel fat. The high saturation level of the fat resulted in a sharp differential scanning calorimetry melting curve with a high melting temperature of 42.1 °C. The fat remained solid over a wide temperature range and still contained 66.6% solid fats at 35 °C. Consequently, kernels of the African mango provide a viable source for the recovery of solid fats applicable in the food industry as sustainable alternatives to replace palm-based fats or hardened vegetable oils.  相似文献   

19.
This research was performed to evaluate the rheological properties of myofibrillar protein gels (MPs) with basil seed gum (BSG) alone or in combination with gelatin (0.25%, 0.5%), and to determine the physicochemical properties of low‐fat sausages (LFSs) manufactured with BSG alone (0.5%) or combined with gelatin (0.25%). Viscosity and cooking yields (%) of MPs with BSG alone or in combination with gelatin were higher than those of the control. However, gel strength of MPs with the combination of BSG and gelatin (0.25%) was higher than that with BSG alone. The combination of BSG and gelatin produced a more stable and denser structure than control or BSG alone. In the LFSs, the addition of BSG reduced the percentages of expressible moisture and cooking loss, and the combination of the BSG and gelatin improved gumminess and cohesiveness compared to BSG alone. The use of BSG as a water binding agent and gelatin to improve gel formation will be considered as fat replacer for the manufacture of low‐fat comminuted sausages.  相似文献   

20.
Three structured fats were prepared by the total catalytic hydrogenation and random chemical transesterification using medium (coconut oil) and long (palmstearine, low and high erucic rapeseed oil) chain saturated fatty acids triglycerides. All three structured fats crystallized in β′ modification and had the same solid fat content profile. Hardness was dependent on the type of long chain fatty acid (palmitic, stearic and behenic) in structured fat. Molar ratio of medium:long chain fatty acids was 2:1. Model fat blends prepared on the base of these structured fats had the same solid fat content profile (at constant content of structured fat). Yield stress of the fat blends was dependent on the content and mainly on the composition of structured fat. None of the model fat blends crystallized in β modification. The substitution of the stearic–palmitic by stearic or by stearic–behenic acids in the structured fats appears possible.  相似文献   

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