Policosanol distribution and accumulation in developing corn kernels

Policosanol is a mixture of long-chain primary aliphatic alcohols. The policosanol composition of whole corn kernel was determined in three varieties of corn (Astro, GH2547, Local). The total policosanol content of GH2547 (20.5 mg/kg of dry weight) was higher than those of Local (16.6 mg/kg) and Astro (15.2 mg/kg). The major policosanol components of whole corn kernel were dotriacontanol, triacontanol and tetracosanol. The distribution of policosanol in the germ, endosperm and pericarp of corn kernels was also determined. Corn pericarp had higher contents of policosanols (72.7–110.9 mg/kg) than the endosperm (4.0–16.2 mg/kg) and germ (19.3–37.1 mg/kg) fractions. Corn pericarp policosanol was mainly triacontanol (33.63–46.29 mg/kg), dotriacontanol (22.31–39.46 mg/kg) and octacosanol (8.13–14.0 mg/kg). In contrast, the corn germ fraction contained mostly dotriacontanol (more than 50%) and no triacontanol. The main components of corn endosperm policosanol were triacontanol and hexacosanol. The level of tetracosanol was highest in the germ fraction and lowest in the endosperm fraction. The greatest change in policosanol content (expressed as mg/100 g of oil) occurred during the early stages of corn kernel development. Although the structures of the alcohol constituents of policosanol are similar, their patterns of accumulation were different. The highest levels of octacosanol and dotriacontanol were detected at 20 days after pollination (DAP) followed by a rapid decrease between 20 and 30 DAP. Triacontanol levels decreased rapidly between 10 and 40 DAP, and then remained nearly constant.     

Phytostanols and phytosterols distributions in corn kernel

Recently, industry has focused attention on plant matrices rich in phytosterols and phytostanols for their ability to reduce serum cholesterol levels. Therefore, the objective of this study was to examine the phytosterols and phytostanols contents of different fractions (endosperm, pericarp, germ) of corn kernel. The germ fraction contained more oil (24.2–30.7%) than endosperm and pericarp fractions (0.4–1.2%). Endosperm oil had the highest levels of phytostanols and 4,4-dimethylsterols, while pericarp oil had the greatest amounts of 4-desmethylsterols and 4-monomethylsterols. In the oil extracted from three corn kernel fractions sitostanol was the predominant phytostanols (77–87%), followed by campestanol (13–23%). The high percentages of 24–methylencycloartanol and cycloartenol were detected in the endosperm and pericarp parts, respectively. Citrostadienol was detected in corn germ oil as the main component of the 4-monomethylsterols fraction. In different parts of corn kernel, β-sitosterol (62–69%) was the major 4-desmethylsterol, followed by campesterol (11–18%) and stigmasterol (5–13%).     

Investigation on fat-quality of embryo, endosperm and crush fractions of maize kernel (author's transl)]

Investigations were conducted on the composition of fatty acids in the fat of the embryo, the endosperm and several crush fractions of the maize kernel. The following results were obtained: 1. The embryo fat contained relatively lower contents of palmitin-, stearin- and linolenic acid, on the other hand higher contents of oleic- and linoleic acid in comparism to endosperm fat. 2. This result was identical to each one of the seven varieties examined. 3. The examined varieties presented clear differences both in the absolute contents of single fatty acids in the embryo and in the endosperm, as well as in the relationship between the components in the germ and in the endosperm. 4. The differences observed between the germ- and the endosperm fat in the crush fractions in some cases were clearly visible, while in other cases were not traceable.     

Distribution of insoluble bound phenolic acids in barley grain

Insoluble bound phenolic acids were analysed by g.l.c. and by h.p.l.c. in eight abraded fractions of barley grain. Vanillic, p-coumaric, ferulic and diferulic acids were identified in all the fractions. Ferulic and p-coumaric acids were quantitatively the most important. The outer layers, comprising husks, pericarp, testa and aleurone cells, contained the highest concentrations of total phenolic acids (0.6–0.9%) while their concentrations were considerably lower in the endosperm layers (0.1% or less). Calculated on the basis of the cell wall content in the fractions, the highest concentration of ferulic acid was found in fractions enriched with aleurone cells while the highest concentration of p-coumaric acid was found in fractions containing high levels of husks.     

普通玉米高油化对籽粒脂肪酸组分积累的影响

以3种高油玉米为授粉者,与2种普通玉米品种杂交,研究其籽粒形成过程中各脂肪酸组分含量的变化情况.结果表明,随着籽粒的成熟,饱和脂肪酸(棕榈酸、硬脂酸)和亚麻酸的含量不断下降,油酸和总不饱和脂肪酸的含量不断升高.与普通玉米自交相比,授高油玉米花粉的普通玉米籽粒成熟时含油量平均增加35.41％,油酸含量平均增加11.99％,硬脂酸、亚油酸和亚麻酸含量有所降低,杂交当代籽粒的总不饱和脂肪酸含量高于普通玉米自交的籽粒含量.说明高油玉米花粉的直感效应对普通玉米籽粒的脂肪酸组成有显著影响.     

Fatty acid and carotenoid composition of egg yolk as an effect of microalgae addition to feed formula for laying hens

Hens were fed five diets based on rapeseed/corn oils with or without addition of the marine microalgae, Nannochloropsis oculata. Colours of egg yolk, fatty acid profiles in phospholipid (PL) and triacylglycerol (TAG) fractions and carotenoid contents were analysed. The major effects on yolk fatty acid composition were observed in the PL fraction with changes in 18:2n − 6, 18:3n − 3, 20:4n − 6, 20:5n − 3 and 22:6n − 3. The highest amounts of eicosapentaenoic acid and docosahexaenoic acid were obtained from the diet containing 20% N. oculata, whereas the highest arachidonic acid content in yolk was from the corn oil diet. In addition, colour (a* value) and carotenoid content increased when N. oculata was included in the diet. Long chained fatty acids were almost exclusively present in the PL fraction of yolk. This study shows that fatty acid composition and carotenoid content of egg yolk are improved by addition of N. oculata in laying hen diet.     

玉米籽粒次生代谢物质分布及其抗氧化活性

基于玉米分层剥皮技术,结合靶向代谢组学检测方法,对玉米不同部位的类胡萝卜素等特征性成分及酚类物质等次生代谢物质进行分析,并探讨其抗氧化活性。结果表明：类胡萝卜素主要存在于玉米籽粒的糊粉层和外胚乳中;玉米酚类物质主要以结合态形式存在于果皮、种皮及糊粉层部位,各部位共检出单体特征酚17种,其中香草醛、对羟基苯甲酸、阿魏酸等含量较高;玉米籽粒各部位的抗氧化活性与其酚类物质含量极显著正?相关（P<0.01）,其中单体特征酚的贡献主要来自于香草醛、对羟基苯甲酸和丁香醛,玉米内皮层的抗氧化活性相对更高。     

SEASONAL VARIATIONS IN FATTY ACID COMPOSITION OF OIL IN DEVELOPING COCONUT

ABSTRACT

Studies on seasonal variation in oil and fatty acid profile of developing solid endosperm of two cultivars, West Coast Tall (WCT) and Chowghat Orange Dwarf (COD), and their hybrids indicated that oil percentage increased from 30% in 6‐month‐old nuts to 63% in matured nuts (12 months old). Nuts sampled during July from different levels of maturity had high oil percentage and followed by those sampled during April, October and January. During nut development to maturity, the percentages and contents of medium and long chain saturated fatty acids increased except that of palmitic and myristic acids. Concentration of long chain unsaturated fatty acids (LCUFAs) in developing coconut kernel were high at 5 and 6 months after fertilization and then decreased toward maturity. The LCUFAs were high in nuts developing during October; consequently, saturated to unsaturated fatty acid ratios were low during October. Results indicated that nuts matured during October had better nutritional quality for human consumption and those matured during January are more suitable for industrial purpose due to higher medium chain fatty acid concentrations.

PRACTICAL APPLICATIONS

Coconut is consumed either as the tender nut (5–6 months after fertilization) or as the kernel from mature nut (12 months after fertilization). Recent technologies of making snowball tender nut use the nuts aged 7–8 months old. Kernel also is consumed in this product. Apart from this, the coconut is being increasingly used for making different kernel‐based value‐added products. This information is useful, as the value‐added products are being developed using different maturities of coconut. Hence, it is of paramount importance that the fatty acid profile of coconut kernel is known in detail for assessing the safety of food consumption from the human health point of view. Apart from this, information on the seasonal variation in fatty acid profile of developing endosperm gives an integrated knowledge so as to optimize the usage of coconut kernel for both human consumption and industrial exploitation.

     

Mechanism of calcium uptake in corn kernels during the traditional nixtamalization process: Diffusion,accumulation and percolation

In the present work the results of the mechanism of calcium uptake in nixtamalized corn kernel were studied. The results showed that at a critical time, the calcium uptake in the pericarp suffers a drastic change; this fact cannot be associated only to the diffusive mechanism. The SEM analysis of processed corn kernels, taken at 1 h of steeping time illustrates a calcium cluster formation. It means that for short steeping times the calcium uptake in the total kernel is governed by an accumulation process in the most external layers of the pericarp and the diffusion process is not relevant. The apparition of micro-holes for critical time in dependence on the temperature indicates that another mechanism is contributing to the calcium uptake. These holes can pass thought the whole pericarp or form an interconnected lattice to develop a percolation path. The holes formations allow the entrance of water and calcium directly to the outermost layers of the endosperm and now the accumulation of calcium is not the predominant mechanism. It could be implied that, at this critical time the percolation of water and calcium thought these holes is the main mechanism to calcium uptake in the corn kernel and the diffusion process is not relevant.     

Hybrid mixture theory based moisture transport and stress development in corn kernels during drying: Validation and simulation results

The moisture transport and stress development mechanisms were elucidated for corn kernels using numerical solution of three-scale fluid transport equation. The 3D kernel structure was captured using micro-CT scanning and imported into finite elements package. The experimental drying profiles were predicted with reasonable accuracy (R² = 0.88-0.99 and CV = 3.5-9.5%). During simulations, the region with highest moisture content was observed to be away from the geometric center covering parts of soft-endosperm and germ. The high moisture flux was observed under the pericarp, in soft-endosperm toward top and in region connecting soft-endosperm and germ. The germ due to its lower moisture diffusivity in comparison to hard and soft endosperms, retained higher moisture and exhibited lower moisture flux. These observations agreed with previous magnetic resonance imaging based studies. Intermittent drying simulations indicated that fan on/off strategies with suitable time step-size would be a viable option for drying corn with lower stress-cracking and additional energy savings.     

Essential oil,fatty acid and sterol composition of Tunisian coriander fruit different parts

BACKGROUND: Seed and pericarp of coriander fruit were compared in terms of essential oil, fatty acids and sterols. RESULTS: Essential oil yield of coriander samples ranged from 0.30 to 0.68% (w/w) in fruit and seed, respectively. However, in pericarp, the essential oil yield was only of 0.04% (w/w). Linalool was the major compound in the whole fruit, seed and pericarp, with 86.1%, 91.1% and 24.6% of the oils, respectively. Fatty acid composition of pericarp and seed lipids were investigated by gas chromatography. Petroselinic acid was the main compound of fruit and seed, followed by linoleic and oleic acids. Palmitic and linoleic acids were estimated in higher amounts in pericarp lipids. Total sterol contents were 36.93 g kg^?1 oil in seed, 6.29 g kg^?1 oil in fruit and 4.30 g kg^?1 oil in pericarp. Fruit and pericarp oils were characterized by a high proportion of β‐sitosterol, with 36.7% and 49.4% of total sterols, respectively. However, stigmasterol (29.5%) was found to be the sterol marker in seed oils. CONCLUSION: Coriander oil is a rich source of many compounds such as essential oils, fatty acids and sterols. This compound distribution presented significant differences between whole fruit, seed and pericarp. Copyright © 2009 Society of Chemical Industry     

Successive Reduction Dry Milling of Normal and Waxy Corn: Grain,Grit, and Flour Properties

Dry milling of different corn types resulted in varied proportions of germ, pericarp, grit and flour. Grit and flour produced during different reduction stages varied in particle size and chemical constituents, hence applications in food industry. In this study, recovery of different fractions and variation in physicochemical and pasting properties of grit and flour fractions obtained during 3 successive reduction dry millings of 2 normal (African tall, HQPM1) and 1 waxy corn (IC 550353) were evaluated. Waxy corn grains had the highest L*, a*, b*, ash, fat, and protein content and the lowest weight. Waxy and African tall gave the highest recovery of germ and pericarp, respectively. Waxy corn showed lower grit and flour recovery as compared to normal corn. Flour fractions showed higher L* and lower a* and b* values than grit fractions. Particle size of grit and flour fractions ranged from 840 to 982 μm and 330 to 409 μm, respectively. Fractions with larger particle size showed lower L* value. The b* value showed positive correlation with yellow pigment content. Grit and flour from the 1st reduction stage showed higher ash and fat content. Protein content was correlated positively with ash content and negatively with L* value. Grit and flour fractions with higher protein content had lower pasting viscosities. Pasting viscosities were higher for flours than their corresponding grits. Protein profiling of grit and flour fractions from different stages showed quantitative and qualitative differences in medium (22, 28, and 35 kDa) and low molecular weight (16, 17, and 19 kDa) polypeptides and were related to grit and flour yield.     

11种品牌玉米油脂肪酸及异构体的主成分分析

对市售的11种品牌玉米油开展了脂肪酸(包括脂肪酸及其异构体)组成与含量的调查研究。采用气相色谱技术,结合主成分分析法,分析了不同品牌玉米油中脂肪酸的差异性和相关性。结果表明,11种品牌玉米油中共鉴定出19种脂肪酸,包括7种饱和脂肪酸,5种不饱和脂肪酸,6种反式脂肪酸(TFAs)和1种共轭亚油酸(t,t-CLAs),平均含量分别为14.18×10~(-2) g/g,80.32×10~(-2) g/g,1.47×10~(-2) g/g和0.23×10~(-2) g/g;其中,亚油酸(C18:2-9c12c)、油酸(C18:1-9c)和棕榈酸(C16:0)依次是玉米油中含量最多的3种脂肪酸;不同品牌玉米油中脂肪酸含量存在显著性差异(p0.05)。主成分分析揭示了不同品牌玉米油在脂肪酸含量上的相似性、差异性及脂肪酸之间相关程度,TFAs和CLAs正相关程度高。本研究为评价市售玉米油脂肪酸品质特征提供了较为全面的数据支撑。     

Nutritional composition of Canarium pimela L. kernels

The kernels of Canarium pimela L., obtained from Guangdong Province, PR China, were analysed for their proximate composition, fatty acid composition, amino acid profile and mineral contents. The kernels were abundant in fats (59.7%) and proteins (23.9%). The acid, iodine, and saponification values of the kernel oil were 0.33, 92.4 and 191, respectively. Oleic acid (43.0%) and linoleic acid (26.5%) constituted the main unsaturated fatty acids of the kernel oil, while palmitic acid (24.8%) was the major saturated fatty acid. The kernel proteins were rich in glutamic acid, arginine and aspartic acid (21.0%, 12.5%, and 6.80%, respectively), but not the limiting amino acid lysine (2.37%). The mineral elements were also involved in this study. The results indicated that C. pimela L. kernels may be a potential source of oil or protein for the human diet.     

Characterisation of fatty acids and bioactive compounds of kachnar (Bauhinia purpurea L.) seed oil

Information concerning the exact composition of kachnar (Bauhinia purpurea) seed oil is scare. In the present contribution, a combination of CC, GC, TLC and normal-phase HPLC were performed to analyse lipid classes, fatty acids and fat-soluble bioactives of kachnar seed oil. n-Hexane extract of kachnar oilseeds was found to be 17.5%. The amount of neutral lipids in the crude seed oil was the highest (ca. 99% of total lipids), followed by glycolipids and phospholipids, respectively. Linoleic, followed by palmitic, oleic and stearic, were the major fatty acids in the crude seed oil and its lipid classes. The ratio of unsaturated fatty acids to saturated fatty acid, was higher in neutral lipid classes than in the polar lipid fractions. The oil was characterised by a relatively high amount of phytosterols, wherein the sterol markers were β-sitosterol and stigmasterol. β-Tocopherol was the major tocopherol isomer with the rest being δ-tocopherol. In consideration of potential utilisation, detailed knowledge of the composition of kachnar (B. purpurea) seed oil is of major importance.     

Tocopherol,fatty acids and sterol distributions in wild Ecuadorian Theobroma subincanum (Sterculiaceae) seeds

Ecuadorian Theobroma subincanum (Sterculiaceae) seed parts were analyzed to determine quali-quantitative tocopherol distribution. Fatty acids and sterols in the embryos, teguments and endosperm were also evaluated with an aim to better-characterize the plant matrix for its potential use as a source of phytochemicals, for the cocoa butter processing industry and/or as a new source of low cost natural products in the cosmetic, drug and alimentary/nutraceutical industries. HPLC for tocopherols and gas-chromatography (GC), GC–mass spectrometry (MS) analyses for fatty acids profile (FAP) and phytosterols were performed. Tocopherols were particularly abundant in the embryo, with quali-quantitative data similar to wheat germ oil whereas, in the teguments and endosperm, the concentrations of tocopherols were lower. The fatty acid profile and phytosterol characterization of the seed parts showed qualitative homogeneous data. In the endosperm, 80% of the entire FAP consisted of oleic and stearic acid while, among sterols, cycloartenol was more abundant in endosperm than in embryos and teguments. Accordingly, T. subincanum seeds can be proposed as possible substitutes in the cocoa processing industry and as a potential source of vitamin E isomers.     

Fish oil in feeds for entire male and female pigs: Changes in muscle fatty acid composition and stability of sensory quality

A total of 72 crossbred [(Norwegian Landrace × Yorkshire) × Duroc] male and female growing-finishing pigs were restrictedly fed diets containing fish oil to study the fatty acid composition of Musculus longissimusdorsi and sensory quality of belly and neck. Six diets were used: two low-fat diets with or without 0.5% fish oil added, and four medium-fat diets with palm kernel oil to fish oil in ratios given as % inclusion: 4.1:0.0, 3.9:0.3, 3.6:0.5 and 3.4:0.7. Feeding fish oil gave a dose-dependent response between fatty acids in the diets and in the M.longissimusdorsi and increased the level of very long chain n−3 fatty acids, especially the C22:5n−3 (DPA). A more efficient n−3 fatty acids deposition was obtained when given as a medium-fat diet rather than the low-fat diet. Female pigs had a significant higher percentage of monounsaturated fatty acids and C18:1 than males suggesting a gender related difference in the delta-9-desaturase activity. No significant differences were found in sensory attributes for short-term stored neck and belly. For pigs fed the highest level of fish oil (0.7%) long-term stored (12 months at −80 °C, 6 months at −20 °C) belly showed a slight increase in fish oil flavour. After warmed-over treatment, fish oil odour and flavour as well as rancid flavour were increased in this group. The results suggest levels of dietary fish oil up to 0.5% produce a healthier meat fatty acid composition, without negative effects on sensory attributes, even in long-termed stored belly.     

Total lipid content, fatty acids and 4-desmethylsterols accumulation in developing fruit of Pistacia lentiscus L. growing wild in Tunisia

This research has determined oil, fatty acid and sterol contents of the Tunisian Pistacialentiscus (Lentisc) fruits during maturation. Low oil accumulation was observed during the first 35 days after the fruiting (DAF) date (from 1.83% to 2.57%). After that, two phases were distinguished (35th until the 60th and 105th to the 145th DAF), where the rate of oil accumulation increased significantly. At the last stage of maturation, the lentisc fruits had the highest percentage of lipid content, 42.54%. The changing profile of fatty acids during maturation had been marked mainly by an increase in oleic acid content (from 19.49% to 50.72%) paralleling a decrease in linoleic acid content (from 42.5% to 21.75%). At the 15th DAF, the alpha-linolenic acid was found with a maximum of 13.81%. At full maturity, the main fatty acids were oleic acid, followed by palmitic and linoleic acid. Other fatty acids were present in trace proportions, such as palmitoleic, stearic, linolenic, gadoleic and arachidic acid. In all stages of ripening only four sterols were identified and quantified. β-Sitosterol was the major 4-desmethylsterol in samples tested, followed by campesterol. Cholesterol and stigmasterol were detected in trace amounts. During the first stage of ripening, the amount of total sterols was about 5.19/100 g of oil. It decreased to 0.43/100 g in the last stage. Sitosterol and campesterol showed nearly the same profile during the ripening of P. lentiscus fruit which could be linked to the relation between these compounds during their biosynthesis.     

元宝枫果实成熟过程中出油率及脂肪酸成分变化

[目的]本文对元宝枫果实成熟过程中果实出仁率、种仁出油率、种仁中总脂肪酸含量及各脂肪酸含量等进行了研究,为元宝枫的品质育种及适时采收提供科学的理论依据;[方法]采用超临界CO2萃取法提取元宝枫油,使用气相色谱条件谱柱分析元宝枫果实成熟过程中油脂含量、脂肪酸变化规律。[结果]元宝枫果实出仁率、种仁出油率、总脂肪酸含量均在10月底达到最大值,出油率及总脂肪酸含量在11月份时有略微下降;[结论]元宝枫果实成熟过程中种仁中共检测出17种脂肪酸,总饱和脂肪酸含量在果实成熟过程中逐渐下降后保持稳定,而总不饱和脂肪酸含量为逐渐上升后保持稳定,各脂肪酸变化规律则不相同,在累积过程中彼此之间表现出一定的相关性。     

The effects of fish oil-enriched diets on growth,feed conversion and fatty acid content of red hybrid tilapia, Oreochromis sp.

Juvenile, red hybrid tilapia were fed diets containing cod liver oil (0%, 4%, 8%, 12% of total diet) substituted against corn oil. After 10 weeks, no significant differences between treatments were seen in weight gain, specific growth rate, feed conversion ratio, whole body or dorsal muscle (fillet) proximate composition. Gas chromatography revealed significant differences in the total n-3 content and fatty acid profiles of dorsal muscle. The total n-3 content of dorsal muscle increased from 7.6% to 18.6%, total n-6 content fell from 37.5% to 12.9% and docosahexanaenoic acid increased from 5.8–16.1% of total fatty acids, in fish fed 0% and 12% fish oil, respectively. The retention of eicosapentaenoic acid was low in all dietary groups, possibly indicating selective use as a substrate for β-oxidation. The results demonstrate the potential to enhance the total n-3 fatty acids and docosahexaenoic acid in tilapia fillets by increasing dietary fish oil.