Oil and squalene in amaranthus grain and leaf

Amaranthus grain of 104 genotypes from 30 species was investigated for oil and squalene contents and fatty acid profiles. The overall average oil content in Amaranthus grain was 5.0%, ranging from 1.9 to 8.7%. Squalene concentration in extracted oils ranged from trace to 7.3%, with an average concentration of 4.2%. The average contents of three major fatty acids in Amaranthus grain were 22.2, 29.1, and 44.6% for palmitic, oleic, and linoleic, respectively. The average fat content in dried mature leaves of 45 Amaranthus genotypes was 1.63%, ranging from 1.08 to 2.18%. The squalene concentration in leaf lipid extracts averaged 0.26%, ranging from trace to 0.77%, which is much lower than that from seeds. The major fatty acids of leaf extracts were linolenic, linoleic, and palmitic. Linolenic ranged from 56.5 to 62.0% of total fatty acids; linoleic, from 15.5 to 24.7%; and palmitic acid, from 13.5 to 15.5%. As for the fatty acid compositions at different growth stages, fatty acid content in leaf lipid was lower in mature leaves than in young leaves. The saturated/unsaturated ratio decreased when the leaf grew to maturity. Principal component analysis (PCA) was carried out on compositional characteristics of grain. The first two components accounted for 70% of the total variance (38.3 and 21.7%, respectively). There was a positive correlation between oil content and squalene yield, and a negative correlations were found between linoleic and either of the other two major fatty acids, palmitic and oleic. The taxonomic relationship among the species was also elucidated by PCA.     

Supercritical carbon dioxide extraction of oil and squalene from amaranthus grain

Supercritical carbon dioxide (SC CO(2)) was used for the extraction of oil and squalene from Amaranthus grain. Very small amounts of oil could be extracted by SC CO(2) from undisrupted grains, although SC CO(2) possesses higher diffusivity. Grinding increased the extraction rate and oil yield, and smaller particle size gave higher extraction rate. The oil yield and initial extraction rate increased linearly with the increasing SC CO(2) flow rate from 1 to 2 L/min. Increasing the flow rate of SC CO(2) above 2 L/min resulted in only a slight increase of oil yield and extraction rate. In the pressure range of 150-250 bar, extraction decreased with increasing temperature at a constant pressure, whereas at a pressure of 300 bar, the extraction yield increased with increasing temperature. Possible reasons for this are discussed. Effects of temperature and pressure on squalene yield were different from those on oil yield. A good oil yield (4.77 g of oil/100 g of grain) was obtained at 40 degrees C and 250 bar. The highest squalene yield (0.31 g of squalene/100 g of grain) and concentration (15.3% in extract) were obtained at 50 degrees C and 200 bar, although the oil yield under this condition was low (2.07 g of oil/100 g of grain). The moisture content within 0-10% had little influence on yields of oil and squalene at 40 degrees C and 250 bar. Finally, the oil yield and the squalene concentration in the extracts by SC CO(2) were compared to those by solvent extraction.     

富钾植物籽粒苋根系分泌物及其矿物释钾作用的研究

应用１４ Ｃ 同位素示踪技术研究了籽粒苋品种根系分泌物的动态、构成以及对含钾矿物钾素释放的作用。结果表明,具有高效富钾特性的籽粒苋品种, Ｃ Ｏ２ 同化能力强,光合产物向根外分泌的比例大。籽粒苋根系分泌物中的有机酸主要是草酸,占有机酸总量的９５ ％ 以上。不同种属的籽粒苋分泌有机酸的能力不同,一般是 Ａ Ｄｕｂｉｓ＞ Ａ Ｒｅｔｒｏｆｌｅｘｕｓ ＞ Ａ Ｃｒｕｅｎｔｕｓ 。同一种内,则钾素利用高效型品种一般型品种。钾亏缺处理显著提高光合产物向根外的分泌量。钾利用高效型籽粒苋品种的草酸分泌量明显增加。根系分泌物对含钾矿物有明显的解钾作用。草酸含量与根系分泌物解钾量显著相关,籽粒苋的草酸分泌能力是籽粒苋高效吸收利用土壤钾及富钾特性的重要机理之一。     

First report of the characterization of the threatened plant species Amaranthus pumilus (Seabeach amaranth)

This paper reports the first ever investigation of the chemical components/composition of the seeds of Amaranthus pumilus (a threatened amaranth species) and compares the results to those of the more commonly cultivated Amaranthus hypochondriacus (Plainsman). This study clearly revealed that much genetic diversity exists between these species, indicating that potential breeding possibilities for the improvement of more commonly cultivated amaranth lines do exist. A. pumilus offers a much larger and more desirable seed size and weight (2-3-fold higher), permitting greater biomass production, in addition to lower levels (half) of free carbohydrate for improved value/performance in diabetic-type diets. In addition to the higher edible oil content found in A. pumilus, its lower saturated/unsaturated ratio (one of the lowest thus far measured) makes it potentially a better source of nutritional oil. In addition to the 2-fold-higher quantity of vitamin E found in A. pumilus, the higher levels of squalene also found may one day serve as a renewable crop source of this compound and may diminish the world's dependence upon marine animals. Considering the imminent danger posed to the survival of the seabeach amaranth in its native environment, it is hoped this study will raise public awareness of the importance of this species and thereby protect it from reaching extinction.     

富钾植物籽粒苋(Amaranthus spp.)对土壤矿物钾的吸收利用研究

运用土培、石英砂培、有机酸释钾实验及矿物X衍射分析研究了不同基因型籽粒苋(Amaranthusspp.)对土壤矿物钾的吸收利用及其机制。结果表明,籽粒苋能有效地利用土壤和云母(黑云母和金云母)中的钾;籽粒苋品种R104、CX4对钾的吸收量高于一般型品种(CX77);籽粒苋根系能引起云母矿物向蛭石转化;籽粒苋根系分泌物中的草酸比一般有机酸具有更高的释放矿物中钾素的能力。     

Determination of esters of fatty acids with low molecular weight alcohols in olive oils

A simple and precise analytical method was developed for the simultaneous determination of squalene and methyl, ethyl, propyl, and butyl esters of fatty acids present in olive and olive pomace oils. A fraction containing squalene and fatty acid alkyl esters was isolated from the oil by solid phase extraction on silica gel cartridges and quantitatively analyzed by gas chromatography. A modification of the procedure allowed the isolation of squalene and esters separately. Repeatability and recovery of the method were good. The method was applied to extra and lampant virgin olive oil categories and also to oils obtained from olive pomace by second centrifugation and solvent extraction. Extra virgin olive oils contained low amounts of fatty acid methyl and ethyl esters, while oils obtained from altered olive or olive pomace showed high concentrations of fatty acid alkyl esters, mainly ethyl esters. Correlation between oil acidity and ethyl esters concentration was poor.     

Unsaponifiable lipid constituents of some underutilized tropical seed oils

Sterols, triterpene alcohols, and hydrocarbons present in the unsaponifiable fraction of some underutilized tropical seed oils have been examined.The seeds include Telfairia occidentalis (TLO), Andenopus breviflorus (ADB), Cucumeropsis edulis (CME), Antiaris africana (ATF), and Monodora tenuifolia (MNT). The oil content of the seeds was high (34.7-68.8%), whereas triacylglycerols comprised the dominant lipid group in the oils (65.4-73.9%). The percentage of unsaponifiables ranged from 1.1 to 7.9%. Ten sterols were identified in the fractions. In the Cucurbitaceae oils (TLO, CME, and ADB), Delta(7)-sterols constituted the dominant sterols. These include 24-ethylcholesta-7,22E,25-trienol (7), 24-ethylcholesta-7,25-dienol (9), 24Z-ethylidenecholes-7-enol (10), and 24-ethylcholesta-7, 24-dienol (11). However Delta(5)-sterols (1-5) occurred at the highest concentration in the other two samples (ATF and MNT). Fifteeen triterpene alcohols were detected in the fractions. Olean-12-enol (16), isomultiflorenol (8), and lupeol (23) were the dominant alcohols in the Cucurbitaceae family, whereas alpha-amyrin (urs-12-enol) (20) was the dominant triterpene alcohol in ATF and MNT. A mixture of C(18)-C(34) n-alkanes, squalene, and some monoterpenes was detected in the hydrocarbon fraction.     

Wild Amaranthus caudatus seed oil, a nutraceutical resource from Ecuadorian flora.

Seed oil of wild Amaranthus caudatus from Ecuador was analyzed for determining the tocopherol, fatty acid, and sterol contents. The data obtained were compared with the analogous chemical profile of seed oil of Italian A. caudatus with the objective of evaluating the nutraceutical and alimentary potential of the Ecuadorian matrix. Supercritical fluid and ultrasound-enhanced extractions were performed on both matrices. Qualitative and quantitative determinations of tocopherols were performed by HPLC, whereas GC and GC-MS were used to determine the fatty acid composition and sterols, respectively. Supercritical fluid extraction at 400 atm was the most efficient extraction method in terms of both total yield extract and tocopherol yield. Seeds of Ecuadorian of A. caudatus contained higher levels of tocopherols than Italian samples, whereas the fatty acid composition and sterol content were similar. From the obtained results it can be suggested that seed oil of wild Ecuadorian A. caudatus can prove to be an effective nutraceutical and alimentary resource and a valid alternative to the European varieties.     

Crop–weed hybrids are more frequent for the grain amaranth ‘Plainsman’ than for ‘D136-1’

White-seeded cultivated amaranth [Amaranthus caudatus L., A. cruentus L., and A. hypochondriacus L.] grain is less valuable if contaminated with brown off-type seeds from the hybrid weedy progeny of spontaneous crop–weed crossing. Crop–weed crossing frequency was estimated by using two grain amaranth cultivars. Both cultivars were planted at the same nine locations in the Midwest United States and exposed to pollen from local weedy Amaranthus species. Harvested seeds were grown in a greenhouse, and the frequency of crop–weed hybrids was determined by observing dominant weed traits in the progeny. The cultivar ‘Plainsman’ was approximately tenfold more likely to hybridize with weedy amaranths than was ‘D136-1’. These are the first amaranth cultivars to be evaluated in this way. The reduced hybridization potential of ‘D136-1’ or similar material can be exploited to reduce the occurrence of off-type seed contamination in grain amaranths.     

Processing stability of squalene in amaranth and antioxidant potential of amaranth extract

The processing stability of squalene in amaranth and the antioxidant capacity of the oil-rich fraction of amaranth were studied. The processes investigated were continuous puffing and roasting. Puffing was carried out using a single screw extruder, while roasting was carried out in a convection oven. High-performance liquid chromatography was used to quantify squalene content before and after processing. The L-ORAC method was used to study the antioxidant activity of pure squalene and lipophilic amaranth extract containing squalene. It was found that squalene was stable during all of the processing operations with a maximum loss of 12% during roasting (150 degrees C, 20 min) and no loss during puffing. The L-ORAC test showed pure squalene to be a weak antioxidant, whereas the lipophilic extract of amaranth showed higher antioxidant activity as compared to pure squalene at the same concentration, suggesting that tocotrienols and other minor ingredients also played a role as antioxidants.     

Oil goldenberry (Physalis peruviana L.)

Whole berries, seeds, and pulp/peel of goldenberry (Physalis peruviana L.) were compared in terms of fatty acids, lipid classes, triacylglyerols, phytosterols, fat-soluble vitamins, and beta-carotene. The total lipid contents in the whole berries, seeds, and seedless parts were 2.0, 1.8, and 0.2% (on a fresh weight basis), respectively. Linoleic acid was the dominating fatty acid followed by oleic acid as the second major fatty acid. Palmitic and stearic acids were the major saturates. In pulp/peel oil, the fatty acid profile was characterized by higher amounts of saturates, monoenes, and trienes than in whole berry and seed oils. Neutral lipids comprised >95% of total lipids in whole berry oil and seed oil, while neutral lipids separated in lower level in pulp/peel oil. Triacylglycerols were the predominant neutral lipid subclass and constituted ca. 81.6, 86.6, and 65.1% of total neutral lipids in whole berry, seed, and pulp/peel oils, respectively. Nine triacylglycerol molecular species were detected, wherein three species, C54:3, C52:2, and C54:6, were presented to the extent of approximately 91% or above. The highest level of phytosterols was estimated in pulp/peel oil that contained the highest level of unsaponifiables. In both whole berry and seed oils, campesterol and beta-sitosterol were the sterol markers, whereas Delta5-avenasterol and campesterol were the main 4-desmethylsterols in pulp/peel oil. The tocopherols level was much higher in pulp/peel oil than in whole berry and seed oils. beta- and gamma-tocopherols were the major components in whole berry and seed oils, whereas gamma- and alpha-tocopherols were the main constituents in pulp/peel oil. beta-Carotene and vitamin K(1) were also measured in markedly high levels in pulp/peel oil followed by whole berry oil and seed oil, respectively. Information provided by the present work is of importance for further chemical investigation of goldenberry oil and industrial utilization of the berries as a raw material of oils and functional foods.     

Variation of polyphenols and betaines in aerial parts of young, field-grown Amaranthus genotypes

Amaranthus hybridus and Amaranthus mantegazzianus are commonly cultivated and the entire young fresh plants consumed as vegetables in regions of Africa and Asia. A. hybridus and A. mantegazzianus were cultivated at four sites in three climate regions of the world: Santa Rosa, Argentina; Lleida, Spain; and Prague and Olomouc, both in the Czech Republic. The contents of flavonoids (isoquercitrin, rutin, nicotiflorin), hydroxybenzoic acids (protocatechuic acid, 4-hydroxybenzoic acid, vanillic acid), hydroxycinnamic acids (caffeic acid, p-coumaric acid, ferulic acid), hydroxycinnamyl amides (N-trans-feruloyltyramine, N-trans-feruloyl-4-O-methyldopamine), and betaines (glycinebetaine, trigonelline) were determined. The variation in phytochemical content due to species and cultivation site was analyzed utilizing the multivariate statistical methods of principal component analysis (PCA) and graphical model (GM). The Argentinean samples differed from the three other locations due to higher contents of most compounds. The samples from Spain and the Czech Republic differed from each other in the content of the negatively correlated metabolites trigonelline and the flavonoids. The two amaranth species were separated primarily by a higher content of trigonelline and the two hydroxycinnamyl amides in A. mantegazzianus. The GM showed that the quantities of the different analytes within each compound group were intercorrelated except in the case of the betaines. The betaines carried no information on each other that was not given through correlations with other compounds. The hydroxycinnamic acids were a key group of compounds in this analysis as they separated the other groups from each other (i.e., carried information on all of the other groups). This study showed the contents of polyphenols and betaines in the aerial parts of vegetable amaranth to be very dependent on growth conditions, but also revealed that some of the compounds (trigonelline and the two hydroxycinnamyl amides) may be useful as features of a taxonomic classification.     

Characteristics of structured lipid prepared by lipase-catalyzed acidolysis of roasted sesame oil and caprylic acid in a bench-scale continuous packed bed reactor

Structured lipid (SL) was prepared from roasted sesame oil and caprylic acid (CA) by Rhizomucor miehei lipase-catalyzed acidolysis in a bench-scale continuous packed bed reactor. Total incorporation and acyl migration of CA in the SL were 42.5 and 3.1 mol %, respectively, and the half-life of the lipase was 19.2 days. The SL displayed different physical and chemical properties, less saturated dark brown color, lower viscosity, lower melting and crystallization temperature ranges, higher melting and crystallization enthalpies, higher smoke point, higher saponification value, and lower iodine value, in comparison to those of unmodified sesame oil. The oxidative stability of purified SL was lower than that of sesame oil. There were no differences in the contents of unsaponifiables including tocopherols and phytosterols. However, total sesame lignans content was decreased in SL due to the loss of sesamol when compared to sesame oil. Most of the 70 volatiles present in roasted sesame oil were removed from SL during short-path distillation of SL. These results indicate that the characteristics of SL are different from those of original sesame oil in several aspects except for the contents of tocopherols and phytosterols.     

Stability of virgin olive oil. 1. Autoxidation studies

Virgin olive oil samples with similar oxidative stabilities and fatty acid compositions were stored for 24 months. Changes in the lipid substrate were followed by peroxide value and K(232) measurements. HPLC was used to evaluate changes in the alpha-tocopherol, pigment, and squalene contents. Total polar phenol content was measured colorimetrically. The loss of alpha-tocopherol and carotenoids was comparable with that of polar phenol content, suggesting an active participation in autoxidation. The limited role of squalene in autoxidation was further confirmed using an olive oil model and in the presence of alpha-tocopherol. Pheophytin a degradation was high, although spectrometric estimation of chlorophyll content did not indicate so. Evaluation of pheophytin a activity at three different levels of addition on the oil model indicated a concentration-dependent antioxidant role more pronounced at elevated temperatures, which could be partially due to the activity of certain degradation products.     

Oxalate in grain amaranth

Grain amaranth (Amaranthus spp.) is a widely adaptable C4 pseudo-cereal crop that has interesting nutritional characteristics including high protein and calcium concentrations and a lack of gluten. To date, no antinutrient has been found at problematic levels in grain amaranth; however, oxalate has not been thoroughly studied. Dietary oxalate is a potential risk factor for kidney stone development, and its presence in food lowers calcium and magnesium availability. Oxalate concentration and forms and calcium and magnesium concentrations were determined in 30 field-grown grain amaranth genotypes from the species A. cruentus, A. hybrid, and A. hypochondriacus. The effects of seeding date and fertilization with calcium ammonium nitrate were evaluated in field experiments conducted in multiple environments; the effects of cooking were also evaluated. Mean total oxalate concentration in the 30 genotypes analyzed was 229 mg/100 g, with values ranging between 178 and 278 mg/100 g, the greatest proportion being insoluble (average of 80%). Calcium concentration averaged 186 mg/100 g and ranged between 134 and 370 mg/100 g, whereas magnesium averaged 280 mg/100 g and ranged between 230 and 387 mg/100 g. Fertilization only marginally increased total oxalate concentration and had no effects on other variables. Seeding date had no effects on any of the variables studied. Boiling increased the proportion of soluble oxalate but did not affect total oxalate concentration. Grain amaranth can be considered a high oxalate source, however, as most is in insoluble form, and due to its high calcium and magnesium concentrations, oxalate absorbability could be low. This should be confirmed by bioavailability studies.     

苋菜对钾素吸收和利用上的基因型差异

The kinetics of K^ absorption and the utilization of both applied K and K in a calcareous alluvisol with low available K by different genotypes of grain amaranth(Amaranthus spp.),an ancient pseudo-cereal that produces a large biomass and a rich source of health nutrients and mineral elements,were studied by means of ion depletion technique and pot experiments.Grain amaranth had a high affinity for K^ absorption comparison with corn and cotton.However,there were differences among Amaranthus spp.in Kabsorption and utilization.Some cultivars such as R104,CX-4,Du001,Hy015 and Hr029 which had a higher rate of K absorption and stronger affinity for K^ were typical varieties with high K-use efficiency(KUE).The results showed that high KUE cultivars grew quickly,possessed stronger ability to take up soil slowly available K and Mineral K,and did not respond to K fertilization in the soil with low available K.Correspondingly,grain amaranth cultivars CX-77,Cr024,Vd001,Re003 and Sn003 were relatively low in KUE,Compared with high KUE cultivars,they took up more soil available K and both of their dry matter accumulation and K uptake responded to K applied significalty.     

Relationship between fatty acid profile and vitamin E content in maize hybrids (Zea mays L.)

The balance between the vitamin E (tocochromanols) and polyunsaturated fatty acid (PUFA) contents mainly determines the susceptibility to lipid peroxidation and the storage stability of corn oil. In 1997, field experiments were conducted at two different locations to evaluate a collection of 30 corn hybrids for fatty acid profiles and tocochromanol contents. Hybrids differed significantly (p < 0.01) for major fatty acids, as well as for tocochromanol contents and composition. The major fatty acids were palmitic, oleic, and linoleic acids, whose contents were in the ranges 9.2-12.1%, 19.5-30.5%, and 53.0-65.3%, respectively. The tocopherol contents ranged as follows: alpha-tocopherol, 67-276 mg (kg of oil)(-1); beta-tocopherol, 0-20 mg (kg of oil)(-1); gamma-tocopherol, 583-1048 mg (kg of oil)(-1); delta-tocopherol, 12-71 mg (kg of oil)(-1); total tocopherol, 767-1344 mg (kg of oil)(-1). gamma-Tocopherol was the predominant derivative among all tocopherols. The tocotrienol contents were in the ranges 46-89, 53-164, and 99-230 mg (kg of oil)(-1) for alpha-, gamma-, and total tocotrienol contents, respectively. The tocotrienol profile was not characterized by the predominance of any tocotrienol homologue. alpha-Tocopherol was positively correlated with PUFA (r = 0.41) and with the vitamin E equivalent (vit E equiv) (r = 0.84), and it was not correlated with gamma-tocopherol. gamma-Tocopherol was highly correlated with total tocopherol and tocochromanol contents (r = 0.93 and r = 0.90, respectively), indicating that the contribution of this vitamer to the total tocochromanol content is the most important among all tocochromanols. The high positive correlation found between the vit E/PUFA ratio and the vit E equiv, as well as the absence of correlation between this ratio and PUFA indicates that a higher vit E/PUFA ratio can be easier achieved be increasing the vitamin E content than by modifying fatty acid profile in corn oil.     

籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用

通过大田和模拟试验等方法 ,研究了籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用 ,研究结果表明 :(1)籽粒苋根际土壤的速效钾含量较非根际土增加了 1.7倍 ,缓效钾 (K)的含量也提高了 5 5 .9% ;(2 )用籽粒苋根际土壤处理后的花岗岩粉末 ,其速效钾和缓效钾含量均较对照有所增加 ,增幅分别为 2 .8%～ 2 4.7%和 15 .7%～ 44 .7% ;用籽粒苋根际土壤处理后的紫色土 ,其速效钾和缓效钾含量较对照分别增加了 18.5 %和 11.1% ;(3 )通过对y值的综合贡献率计算可知 ,不同籽粒苋模拟根系分泌物对花岗岩粉末中矿物态钾的活化能力大小依次为 :草酸 >蔗糖 >核酸 >乳酸 >柠檬酸。     

Determination and toxicity of saponins from Amaranthus cruentus seeds.

The concentrations of four triterpene saponins present in amaranth seeds were determined with high-performance liquid chromatography. It was shown that the total concentration of saponins in seeds was 0. 09-0.1% of dry matter. In germinating seeds an increase in concentration to 0.18% was observed after 4 days of germination, which remained stable for the next 3 days and later dropped to 0.09%. Highly purified extracts from the seeds were tested for their toxicity against hamsters. The hydrophobic fraction obtained by the extraction of seeds with methylene chloride showed no toxicity; the behavior of tested animals was similar to that of the group given an equivalent dose of rapeseed oil. A crude saponin fraction, containing approximately 70% of pure saponins in the matrix, showed some toxicity; the approximate lethal dose was calculated as 1100 mg/kg of body weight. It is concluded that low contents of saponins in amaranth seeds and their relatively low toxicity guarantee that amaranth-derived products create no significant hazard for the consumer.     

Characterization of soluble amaranth and soybean proteins based on fluorescence, hydrophobicity, electrophoresis, amino Acid analysis, circular dichroism, and differential scanning calorimetry measurements.

Intrinsic fluorescence (IF), surface hydrophobicity (S(o)), electrophoresis, amino acid analysis, circular dichroism (CD), and differential scanning calorimetry (DSC) were used to study folded and unfolded soluble proteins from Amaranthus hypochondriacus (A. h.) and soybean (S). Globulin (Glo) and albumin subfractions (Alb-1 and Alb-2) were extracted from A. h. and S and denatured with urea. Electrophoretic and functional properties indicated a significant correlation between soluble protein fractions from soybean and amaranth. The protein fractions shared some common electrophoretic bands as well as a similar amino acid composition. The larger percent of denaturation in protein fractions, which is associated with enthalpy and the number of ruptured hydrogen bonds, corresponds to disappearance of alpha-helix. The obtained results provided evidence of differences in their secondary and tertiary structures. The most stable was Glo followed by the Alb-2 fraction. Predicted functional changes in model protein systems such as pseudocereals and legumes in response to processing conditions may be encountered in pharmaceutical and food industries. These plants can be a substitute for some cereals.