Bambangan (Mangifera pajang) kernel fat: a potential new source of cocoa butter alternative

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.     

分提棕榈油性质及其等温结晶过程研究

对比分析熔点为44℃(A)、24℃(B)两种分提棕榈油甘三酯组成、固脂含量、等温结晶特性及等温结晶动力学规律。结果表明：甘三酯的组成对于两者的结晶性能具有很大影响。在等温结晶过程中,样品A能够较快速达到结晶终点。在各等温条件下,A的Avrami指数n与B相差不大,说明两者基于过冷状态下的结晶机理相同。     

类可可脂原料油中低熔点甘油三酯的组成、含量调控与综合利用

为了实现类可可脂在巧克力中更为高效的应用,降低其对产品品质的影响,综述了类可可脂原料油中低熔点甘油三酯的组成与熔化性质,概括了不同种类甘油三酯对巧克力霜变行为的作用特征;进一步讨论了控制低熔点甘油三酯含量的技术方法,包括基因工程和分提;最后,总结了经分提获得的低熔点成分的再利用。类可可脂原料油中低熔点甘油三酯可能对巧克力的制造(尤其是调温)和质量控制(如软化、起霜等)产生不利影响。通过分提选择性降低低熔点甘油三酯含量是制备高品质类可可脂的优选路径。     

巧克力样品中反式脂肪酸含量的测定

采用气相色谱内标法,对20个巧克力样品中的反式脂肪酸含量进行测定分析。试验结果表明,以代可可脂为主要原料的巧克力样品中,反式脂肪酸含量范围在未检出至4．96％之间。以可可脂为主要原料的巧克力样品中,反式脂肪酸含量范围在未检出至0．844％之间。所测定的巧克力样品中反式脂肪酸以反十八碳一烯酸为主。     

Effect of Diglycerides on the Crystallisation of Palm Oleins

The crystallisation time of palm olein was found to be rapidly reduced with the addition of palm diglycerides. Of the palm diglycerides, the dipalmitoylglycerol in particular the 1,3-isomer was more effective in causing rapid crystallisation of palm olein. On the other hand, the palmitoyloleoylglycerol appeared to have a retardation effect on the crystallisation time, while the effect from dioleoylglycerol was not very significant. The effects of diglycerides were also discussed in relation to the unsaturation of the olein.     

气相色谱-质谱法分析棕榈果脂肪酸组成

采用索氏抽提法分别提取棕榈果肉和棕榈果仁中的油脂,以氢氧化钾—甲醇溶液对油脂进行甲酯化处理,用气相色谱-质谱(GC-MS)法分析。从棕榈果肉和棕榈仁的油脂中均分离并鉴定了9种脂肪酸,其中棕榈果肉中饱和脂肪酸质量分数为49.5%,主要有棕榈酸和硬脂酸,不饱和脂肪酸主要有油酸、亚油酸以及少量的亚麻酸和13,16-二十二碳二烯酸。棕榈仁中饱和脂肪酸80%以上,其中月桂酸质量分数达到41.5%,肉豆蔻酸和棕榈酸含量也较高,此外还含有少量的己酸、辛酸、癸酸和硬脂酸,不饱和脂肪酸有油酸和亚油酸。     

Dietary Fat Reduces Odd-Numbered and Branched-Chain Fatty Acids in Depot Lipids of Rabbits

Forty eight Californian×New Zealand White rabbits were randomly distributed in three groups of 16 animals each. A control (with no added fat) and two diets enriched at a rate of 30 g fat kg^-1 were used. Olive oil and sunflower oil were used as sources of fat for the fat-supplemented diets. Branched chain (BCFA) and n-odd-numbered carbon fatty acids (ONFA) in the perirenal fat depots of control animals were respectively 5 and 22 mg g^-1 of total fatty acids, while in fat-enriched diets they were around 3 and 16 mg g^-1, respectively. The ratio of unsaturated: saturated fatty acid in perirenal fat was 1·25:1 when the control diet was administered and around 1·80–1·95:1 in fat-enriched diet groups, which represents approximately a 50% increase (P<0·01). However the melting points of the fats showed little difference (NS) between the control group and the group with olive oil addition whilst the sunflower oil-supplemented group showed only a 5·7% lower value (P<0·01). In a second experiment in which diets with equal digestible energy and protein were used, reductions in total amounts of ONFA (P<0·01) and BCFA (P<0·05) were observed in the perirenal fat of animals receiving the fat-enriched diets. The addition of fat depressed the concentrations of ONFA and BCFA, which may act to maintain the consistency of fat in a narrow range, avoiding to some extent the production of undesirable soft and floppy carcasses. © 1997 SCI.     

结构脂酶法合成的研究进展

对酶在中碳链结构甘三酯、含有多不饱和脂肪酸的甘油三酯、代可可脂、婴儿配方脂肪等领域的应用研究进行了综述。并对酶在脂质的合成与生产中具有广阔的应用前景进行了展望。     

Lipophilic compounds and thermal behaviour of African mango (Irvingia gabonensis (Aubry-Lecomte ex. O'Rorke) Baill.) kernel fat

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.     

Lipid Modification Strategies in the Production of Nutritionally Functional Fats and Oils

Rapid improvements in the understanding of the nutritional requirements of both infants and adults has led to new developments in the modification of fats and oils. Specific targets include the improvement in growth and development of infants, treatment of disease in adults, and disease prevention. Efforts have been focussed on the production of structured lipids using medium-chain acids and long-chain polyunsaturated fatty acids (PUFAs), as well as the concentration of long-chain PUFAs from new and existing sources. Short- and medium-chain fatty acids are metabolized differently than long-chain fatty acids and have been used as a source of rapid energy for preterm infants and patients with fat malabsorption-related diseases. Long-chain PUFAs, specifically docosahexaenoic acid and arachidonic acid, are important both in the growth and development of infants, while n-3 PUFAs have been associated with reduced risk of cardiovascular disease in adults. Based on the requirements for individual fat components by different segments of the population, including infants, adults, and patients, ideal fats can be formulated to meet their needs. By using specific novel fat sources and lipid modification techniques, the concentrations of medium-chain, long-chain saturated, and long-chain polyunsaturated fatty acids as well as cholesterol can be varied to meet the individual needs of each of these groups. While genetic modification of oilseeds and other novel sources of specific lipid components are still being developed, chemical and lipase-catalyzed interesterification reactions have moved to the forefront of lipid modification technology. Fractionation of fats and oils to provide fractions with different nutritional properties has potential, but little work has been performed on the nutritional applications of this method. The choice of suitable lipid modification technologies will depend on the target lipid structure, production costs, and consumer demand. A combination of some or all of the present lipid modification techniques may be required for this purpose.     

基于棕榈仁油的特医脂肪乳液制备及其对小鼠血脂的影响（网络首发、推荐阅读）

中链甘油三酯是特医脂肪组件的重要组成成分,棕榈仁油是其天然食物来源。为开发基于棕榈仁油的特医脂肪乳液产品,依据《特殊医学用途配方食品通则》《中国居民膳食营养素参考摄入量》等进行脂肪酸均衡型乳液油相配方设计,并分析其脂肪酸组成;以Zeta电位、粒径为指标优化脂肪乳液制备工艺,并对研发产品进行稳定性评价,通过小鼠试验研究其对血清血脂的影响。结果表明,油相不饱和脂肪酸中n–6与n–3比值为5.16±0.05;采用分步乳化法,最佳乳化工艺为乳化速度10 000 r/min,乳化时间20 min, 乳化温度50 ℃;初乳液经高压均质机50 MPa均质三次,121 ℃高压灭菌10 min,在上述条件下制备的脂肪乳液产品质量稳定。动物试验结果表明,该脂肪酸均衡型脂肪乳液具有显著降低小鼠血清甘油三酯（Triglycerides,TG）含量（P<0.01）、降低血清总胆固醇（Total cholesterol,TC）含量（P<0.01）,以及降低低密度脂蛋白胆固醇（Low-density lipoprotein cholesterol,LDL-C）含量（P<0.05）和升高高密度脂蛋白胆固醇（High-density lipoprotein cholesterol,HDL-C）含量（P<0.01）的作用,对于调节血脂水平具有一定意义。     

植物油脂多不饱和脂肪酸的分离与富集研究

利用低温冷冻结晶和尿素包合法在同一工艺条件下考察了五种植物油脂中多不饱和脂肪酸的分离和富集效果。低温冷冻结晶初步分离得到的脂肪酸Ⅰ中,仅含少量饱和脂肪酸,总不饱和脂肪酸含量达到95%以上,达到PUFAs的预浓缩目的。尿素包合法富集PUFAs实验中,光皮油、棕榈油脂中PUFAs的分离效果最好,亚油酸纯度达到96.67%和97.18%;小桐子油和大豆油脂中亚油酸含量分别为81.74%和91.75%;桐油中PUFAs的富集效果不明显,总PUFAs纯度仅由原来的85.36%提高到91.62%。      

Infrared spectroscopy in the study of edible oils and fats

The use of infrared spectroscopy in the study of fats and oils is reviewed. The importance of the mid-infrared region in the study of lipids is shown. Differences between dispersive and Fourier-transform infrared techniques are commented on and the experimental methods used in the handling of oil and fat samples are reported. The assignment of oil and fat bands of mid-infrared spectra is made, and the usefulness of this technique to characterise oils and fats and to detect adulterations is reviewed. The application of spectroscopic data to determine the degree of unsaturation or iodine value, trans- double bonds content, free fatty acid content, average chain length or saponification number, solid fat content, as well as peroxide and anisidine values, is commented on. Also, the importance of this technique for monitoring oxidation processes is shown. © 1997 SCI.