Lipid composition of rice (Oryza sativa L.) bran

The composition of lipids of bran from three varieties of rice is reported. Lipids extracted amounted to 21.9–23.0% of the bran dry weight and consisted of 88.1–89.2% neutral lipids, 6.3–7.0% glycolipids and 4.5–4.9% phospholipids. Neutral lipids consisted mostly of triacylglycerols (83.0–85.5%), monoacylglycerols (5.9–6.8%) and small amounts of diacylglycerols, sterols and free fatty acids. Three glycolipids and eight phospholipids were separated and characterized. Acylated steryl glucoside and digalactosyldiacylglycerol were the main glycolipids, while monogalactosylmonoacylglycerol was present in small amounts. The major phospholipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidic acid. Phosphatidylglycerol, lysophosphatidylcholine, lysophosphatidylethanolamine and acyl-phosphatidylethanolamine were present in small quantities.     

Measurement of lipase activity in single grains of oat (Avena sativa L.)

Seed oil ofSterculia colorata is found to contain the following acids (wt %): sterculic (4.9%), malvalic (3.2%), myristic (0.3%), palmitic (29.4%), stearic (1.7%), oleic (56.6%), and linoleic (3.9%). The co-occurrence of malvalic and sterculic acids was established by gas liquid chromatography of the silver nitrate methanol-treated esters usingS. foetida esters as reference standard.     

Measurement of lipase activity in single grains of oat (Avena sativa L.)

Lipase activity (LA) in individual oat grains was measured as the increase in free fatty acid (FFA) content by lipolysis of the endogenous lipid in a crushed sample of seed incubated at 38 C for 30 min. FFA content was determined by a modified copper soap method. The dough stage, about 2 weeks before normal harvest, showed the highest LA. Stored samples of mature grains showed about 45–50% loss of LA in 2 years. Contribution no. 395 from the Food Research Institute Agriculture Canada, Ottawa.     

Volatile food attractants forOryzaephilus surinamensis (L.) from oats

The sawtoothed grain beetle,Oryzaephilus surinamensis (L.) (Coleoptera: Cucujidae), is attracted to certain volatile components that occur in whole and rolled oats as determined by a laboratory pitfall chamber bioassay. More than 100 components were detected in the attractive carbonyl-containing fractions; 14 of these, making up 60% of the total, were identified and bioassayed. Although hexanal, heptanal, octanal, (E)-2-heptenal, and 2-furaldehyde, at doses ranging variously from 1 to 100 g, were all significantly attractive, only 1 /10 to 1 /100 as much (E)-2-nonenal or (E,E)-2,4-nonadienal was necessary to produce comparable insect response. In addition, propanal and formaldehyde (previously reported in oats but not detected by us) were bioassayed and found to be attractive.Presented at the North Central Branch meeting of the Entomological Society of America in St. Louis, Missouri, March 15–17, 1983.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Lipid composition and oxidative stability of oils in hazelnuts (Corylus avellana L.) grown in New Zealand

Hazelnut (Corylus avellana L.) samples were collected from six different cultivars of trees grown in an experimental orchard at Lincoln University. Three U.S. commercial cultivars (Butler, Ennis, and Barcelona), two European commerical cultivars (Tonda di Giffoni and Campanica), and one New Zealand selection (Whiteheart) were evaluated. The total oil, stability to oxidation of the oil, and fatty acid, tocopherol, and sterol composition were determined on samples of freshly extracted hazelnut oil. The total oil content of the seeds ranged from 54.6 to 63.2% while the stability of the oil, as measured by the Rancimat test ranged from 15.6 to 25.3 h. The content of the monounsaturated oleic acid in the oils ranged from 73.8 to 80.1% of the total fatty acids, while the tocopherol content ranged from 225.8 to 552.0 mg/g freshly extracted oil. The major desmethylsterols were sitosterol, ranging from 1416 to 1693 μg/g, campesterol, ranging from 78 to 114 μg/g, and Δ5-avenasterol, ranging from 110 to 170 μg/g. The oil extracted from the cultivar Whiteheart was more stable (measured by Rancimat) than the oil from all other cultivars grown at the same location and under the same conditions. Whiteheart contained higher levels of total and γ-tocopherol when compared to the other cultivars. The higher levels of tocopherol in Whiteheart help to explain the greater stability of the oil during the oxidative stress test. These results suggest that nuts from the cultivar Whiteheart could be stored longer than the other nuts tested. Presented as a poster at the 87th AOCS Annual Meeting, Indianapolis, Indiana, April 28–May 1, 1996.     

Lipid classes,fatty acid composition and triacylglycerol molecular species of kidney beans (Phaseolus vulgaris L.)

Seed oils from five legume cultivars of Phaseolus vulgaris, grown in Japan, were extracted and classified by thin‐layer chromatography (TLC) into seven fractions: hydrocarbons (HC; 0.7–1.4 wt‐%), steryl esters (SE; 1.7–3.3 wt‐%), triacylglycerols (TAG; 33.8–45.9 wt‐%), free fatty acids (FFA; 0.6–1.5 wt‐%), sn‐1,3‐diacylglycerols (1,3‐DAG; 0.3–1.0 wt‐%), sn‐1,2‐diacylglycerols (1,2‐DAG; 0.4–1.2 wt‐%) and phospholipids (PL; 49.4–58.8 wt‐%). Fatty acids derivatized as methyl esters were analyzed by gas chromatography (GC) and a flame ionization detector. Molecular species and the fatty acid distribution of TAG isolated from the total lipids in the beans were analyzed by a combination of argentation‐TLC and GC. A modified argentation‐TLC procedure, developed to optimize the separation of the complex mixture of total TAG, provided 18 different groups of TAG, based on both the degree of unsaturation and the total length of the three acyl chains of fatty acid groups. SDT (3.2–4.2 wt‐%), M₂T (3.8–5.0 wt‐%), D₃ (4.8–5.9 wt‐%), MDT (8.0–13.9 wt‐%), D₂T (12.5–15.8 wt‐%), MT₂ (19.4–22.7 wt‐%), DT₂ (17.8–23.5 wt‐%) and T₃ (9.2–13.0 wt‐%) were the main TAG components. The dominant fatty acids of TAG were α‐linolenic (48.5–57.8 wt‐%) and linoleic (16.7–25.8 wt‐%) acids, with appreciable amounts of palmitic (8.3–13.2 wt‐%) and oleic (7.8–13.8 wt‐%) acids. The high content of α‐linolenic acid in the cultivars of P. vulgaris could very likely play a beneficial role in reducing the risk of coronary heart disease among the large populations consuming them in Japan.     

Lipid class composition during embryonic and early larval development in Atlantic herring (Clupea harengus,L.)

The lipid class compositions of Atlantic herring eggs and larvae were determined immediately before fertilization, after fertilization and at various times during subsequent embryonic and early larval development. Total lipid constituted 15% of the dry wt of ripe eggs, 70% of the total lipid being polar lipid with phosphatidylcholine (PC) accounting for almost 90% of the polar lipid. In general, the total lipid content decreased gradually during embryogenesis and in particular during larval development. Within 3 hr after fertilization the relative percentage of neutral lipid decreased slightly. This was followed by a general decrease in polar lipid which, by the stage of yolk sac absorption, was reduced to 52% of the total lipid. The decreased percentage of polar lipid was due entirely to a decrease in PC, which was reduced to 66% of the polar lipids at the stage of yolk sac absorption. The accompanying increase in the percentage of neutral lipids was mainly due to increased percentages of triacylglycerols (TAG) up to yolk sac absorption and cholesterol esters in the larval stages. During the first 4 days after hatching, phospholipids and to a lesser extent cholesterol were preferentially depleted in the yolk sacs, which also had higher levels of free fatty acids. The results are discussed in relation to possible roles of different lipids during embryonic and early larval development.     

Chemical composition of tobacco seeds (Nicotiana tabacum L.)

Chemical characterization of tobacco seeds is supposed to be an interesting tool in order to extend the knowledge on alternative products of this crop which is of great economic interest. This paper describes chemical composition of meals, fat, ash, protein, fiber and nitrogen-free-extract; furthermore, particular emphasis is given to the composition of lipid fraction, with a complete characterization of triglycerides, fatty acids, and unsaponifiable matter. Trilinolein and palmitodilinolein are the main triglycerides, while linoleic is the main fatty acid. Cholesterol, as in otherSolanaceae, is present in the sterol fraction. Cycloartenol is the main component of the triterpenic alcohols fraction. Amino acids and glucides composition is also reported.     

Effects of different nitrogen doses on thymoquinone and fatty acid composition in seed oil of black cumin (Nigella sativa L.)

Black cumin, Nigella sativa L. belonging to Ranunculaceae, is a valuable medicinal plant because of the curative effects of seed and oil. Despite studies on black cumin, there are few studies on the effects of nitrogen on fatty acid composition, no records on thymoquinone yield, and the thymoquinone content of the seed oil. In this study, the effects of different nitrogen doses on the seed oil yield, thymoquinone ratio/yield, and fatty acid compositions were investigated. Field studies with nitrogen doses (0, 40, 60, 80, and 100 kg/ha) were studied using the randomized plot design. As a result of the research, nitrogen doses significantly affected the oil and thymoquinone yields while insignificant on the thymoquinone ratio. The highest oil yield with 501.6 kg/ha was obtained from 80 kg/ha of the nitrogen doses, while the highest thymoquinone yield with 10.24 kg/ha was obtained from the control plots. Thymoquinone yields were in the same statistical group with other nitrogen doses, except for means of 100 kg/ha nitrogen doses. Linoleic, oleic, and palmitic acids were major fatty acids of black cumin, and their variations were insignificant in nitrogen applications. The values of butyric, capric, and linolenic acids varied significantly in different nitrogen doses. As a result of the study, it was determined that the highest oil yield was obtained from 80 kg/ha nitrogen application. It has been determined that nitrogen doses above 60–80 kg/ha should be avoided for the seed oil and thymoquinone yields in black cumin.     

Oat (Avena sativa) caryopses as a natural lipase bioreactor

The caryopses of oats, when moistened and immersed in oils, constitute a natural lipase bioreactor. Hydrolysis was monitored by titration of the free fatty acids in the oil phase and by thin-layer chromatography. The optimum amount of additional water was about 20% of the weight of the caryopses, and the optimum temperature was about 40°C. The reaction was accelerated by gentle agitation, by reducing the viscosity of the oil phase by the addition of nonpolar solvents, and by increasing the amount of lipase on the caryopses. The reaction was inhibited by the accumulation of glycerol in the interior of the caryopses and free fatty acids in the oil phase. The lipase hydrolzyed all three positions of glycerol and there was little accumulation of mono- or diglyceride in the lipid phase. The time necessary to obtain 90% hydrolysis varied for a few days to several weeks. Greater degrees of hydrolysis could be obtained by replacing the caryopses when they became inhibited or by diluting the oil phase with hexane. The glycerol that was released could be recovered by extracting the caryopses with water. The moist oat bioreactor also was capable of catalyzing transesterification and interesterification reactions. Journal Paper No. 13447 of the Iowa Agriculture and Home Economics Experiment Station, Ames. Project No. 2799.     

Factors affecting refining losses in rice (Oryza sativa L.) bran oil

Components of rice bran oil have been assessed for their effect on refining losses. Rice bran oil used in the study had the following (percent) analysis: free fatty acids, 6.8; phosphatides, 1.25; wax, 2.85; monoglycerides, 1.67; diglycerides, 4.84, and oryzanol, 1.85; the rest (80.74) was mostly triglycerides. The phosphatides and mono- and diglycerides had no noticeable effect on refining losses at levels of up to 2% in the oil. Waxes and oryzanol increased the refining losses substantially. In model experiments where these were incorporated into peanut oil individually and in combination, the wax at as low a level as 1% increased the refining losses by about 80% more than control and the refining losses increased with concentration of wax. Oryzanol had a similar effect. When wax and oryzanol were present together in the oil, the effect was synergistic—the refining losses were higher than the sum of their individual effects. Phosphatides, mono- and diglycerides tended to reduce the adverse effect of wax and oryzanol. The main components responsible for higher than normal refining losses in rice bran oil have been identified as wax and oryzanol.     

Inhibition of protein synthesis in lettuce (Latuca sativa L.) by allelopathic compounds

The effects of ferulic, cinnamic, and ellagic acids on the development of roots and protein synthesis in lettuce seedlings (Latuca sativa L., variety of Black Seeded Simpson) are reported here. Both ferulic and cinnamic acids were found to inhibit protein synthesis of the seedlings either when added from the beginning of the germination period, or when added for a short period of time to seedlings which had already germinated under control conditions. Ellagic acid, at the same pH and osmotic concentrations as the effective inhibitors, was completely ineffective in inhibiting either growth of roots or protein synthesis. It is shown that utilization of [¹⁴C] amino acid incorporation into seedlings appears to be a sensitive, reliable, and appropriate indicator of allelopathic inhibition of plant growth. Utilizing this method, it should be possible to determine if the effect on protein synthesis by putative allelopathic compounds is a general phenomenon and may, in turn, help to elucidate the role of these compounds.     

Phloem sap collection from lettuce (Lactuca sativa L.): Methodology and yield

Three methods to collect phloem sap on different lettuce lines were optimized and are described in detail. The success ratio for stylectomy of aphids was over 80% through the combination of a specially designed setup and electrical penetration graphs to monitor phloem sap ingestion. For unknown reasons on some lettuce lines stylets never showed sustained exudation. There were clear differences in stylet exudation between two aphid species on the same lettuce line. Honeydew collection in hexadecane made accurate quantitative analysis possible; samples were large and clean, but biotransformed. The EDTA chelation method produced large samples, but dilution, oxidation, and impurities from the wound surface reduced the reliability.     

Foam fractionation for effective recovery of leaf protein from alfalfa (Medicago sativa L.)

ABSTRACT

Foam fractionation for recovering leaf protein from alfalfa (Medicago sativa L.) has been investigated. The extraction yield of alfalfa leaf protein (ALP) from the dried alfalfa leaves reached 71.90% under the extraction conditions of pH 8.0, temperature 70°C, and extracting time 40 min. For strengthening foam drainage at room temperature, a novel foam fractionation column with a cross-internal component covered superhydrophobic coating was developed. By using the extraction liquor as the feeding solution, a two-stage foam fractionation had been performed. Under the suitable operation conditions, the enrichment ratio and the recovery percentage of ALP were 4.33 and 89.0%, respectively.     

Oil composition of pistachio nuts (Pistacia vera L.) from Turkey

The oil content, fatty acid and sterol compositions and other parameters of pistachio nut (Pistacia vera L.) samples corresponding to five different varieties, all cultivated in Turkey were determined. Mean values were 59.69 ± 1.80% for fat content, 0.9143 ± 0.006 for specific gravity of the oil, 1.4693 ± 0.004 for refractive index, 94.23 ± 1.510 for iodine value, and 188.2 ± 3.80 for saponification value. Fatty acids identified in the oil samples were palmitic, palmitoleic, stearic, oleic, and linoleic acids with oleic acid as the dominant fatty acid (68.78 ± 2.05%). Halebi variety had the highest level of oleic acid among the varieties studied. The sterols isolated from the unsaponifiable fraction were campesterol, stigmasterol, β-sitosterol, and Δ⁵-avenasterol with β-sitosterol as the major constituent (84.95 ± 2.80%). Higher levels of β-sitosterol were found in Kιrmιzι variety. The high level of oil, oleic acid and β-sitosterol content was found in all the varieties studied. Fat content, iodine value, palmitic acid and oleic acid content significantly differed between varieties.     

Oxidative stability of black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) crude seed oils upon stripping

Information on stability of edible oils is important for predicting the quality deterioration of the oil during storage and marketing. Stripping of crude oils removes most of non‐triacylglycerol components, including polar lipids and phenolics. Oxidative stability of black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) crude and stripped seed oils was investigated and compared. The factors influencing the oxidative stability of different seed oils were also discussed. Oil samples were stored under accelerated oxidation conditions for 21 d. The progress of oxidation at 60 °C was followed by recording the ultraviolet absorptivity and measuring the formation of oxidative products (peroxide and p‐anisidine values). Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by p‐anisidine value and stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. In general, oxidative stabilities of crude oils were stronger than their stripped counterparts and the order of oxidative stability was as follows: coriander > black cumin > niger seed. Levels of polar lipids in crude oils correlated with oxidative stability. Thus, the major factor that may contribute to the better oxidative stability of crude oils was the carry‐over of their polar lipids.     

Characterization of High-Value Bioactives in Some Selected Varieties of Pakistani Rice (Oryza sativa L.)

The present study reports the composition and variation of fatty acids, sterols, tocopherols and γ-oryzanol among selected varieties namely Basmati Super, Basmati 515, Basmati 198, Basmati 385, Basmati 2000, Basmati 370, Basmati Pak, KSK-139, KS-282 and Irri-6 of Pakistani rice (Oryza sativa L). Oil content extracted with n-hexane from different varieties of brown rice seed (unpolished rice) ranged from 1.92% to 2.72%. Total fatty acid contents among rice varieties tested varied between 18240 and 25840 mg/kg brown rice seed. The rice tested mainly contained oleic (6841-10952 mg/kg) linoleic (5453-7874 mg/kg) and palmitic acid (3613-5489 mg/kg). The amounts of total phytosterols (GC and GC-MS analysis), with main contribution from β-sitosterol (445-656 mg/kg), campesterol (116-242 mg/kg), Δ(5)-avenasterol (89-178 mg/kg) and stigmasterol (75-180 mg/kg) were established to be 739.4 to 1330.4 mg/kg rice seed. The content of α-, γ- and δ-tocopherols as analyzed by HPLC varied from 39.0-76.1, 21.6-28.1 and 6.5-16.5 mg/kg rice seed, respectively. The amounts of different γ-oryzanol components (HPLC data), identified as cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate and β-sitosteryl ferulate, were in the range of 65.5-103.6, 140.2-183.1, 29.8-45.5 and 8.6-10.4 mg/kg rice seed, respectively. Overall, the concentration of these bioactives was higher in the Basmati rice cultivars showing their functional food superiority. In conclusion, the tested varieties of Pakistani rice, especially the Basmati cultivars, can provide best ingredients for functional foods.     

The Influences of Drying Process on Crude Protein Content of Naked Oat Cut Herbage (Avena nuda L.)

The effects of thin-layer drying naked oat cut herbage process (hot air temperature, air velocity, and drying time) on crude protein content were investigated. It was observed that an increase in drying temperature could lead to a significant drop in the crude protein content of naked oat cut herbage. The crude protein content also decreased with an increase in drying time and air velocity, and air velocity had a minimal impact during processing. A thin-layer drying mathematical model of crude protein content for naked oat cut herbage was established. The optimal drying parameters were determined as hot air temperature of 88.6–94.2 ^° C, air velocity of 0.28–0.32 m/s, and drying time of 16.4–20.6 min.     

Characteristics and composition of guava (Psidium guajava L.) seed and oil

The proximate composition of guava seed and the physicochemical characteristics of the solvent-extracted oil are reported. The fatty acid profile of the oil indicates the presence of linoleic acid (C_18∶2) to the extent of 76.4% and resembles that of safflower oil in composition. The oil is easily refined and bleached on laboratory scale.     

Lipid components of borage (Borago officinalis L.) seeds and their changes during germination

The changes in composition of total and neutral lipids (NL) as well as glycolipids (GL) and phospholipids (PL) of borage (Borago officinalis L.) seeds, germinated in the dark at 25^°C for 10 d, were studied. Total lipids constituted 34.0% of the dry matter of borage seeds. During germination, the content of total lipids was decreased by 95%. NL accounted for 95.7% of total lipids prior to germination and were composed of triacylglycerols (TAG; 99.1%), diacylglycerols (DAG; 0.06%), monoacylglycerols (MAG;0.02%), free fatty acids (FFA;0.91%), and sterols (0.02%). The content of TAG was significantly (P≤0.05) decreased, while that of other components, such as MAG and FFA, significantly (P≤0.05) increased during germination. However, the content of DAG did not change. GL and PL accounted for 2.0 and 2.3% of total lipids, respectively, and their contents significantly (P≤0.05) increased as germination proceeded. The thin layer chromatography-flame-ionization detection studies showed that phosphatidylcholine (PC; 69.7%) was the major PL present. The total content of phosphatidylserine (PS) and phosphatidylethanolamine (PE), which were coeluted, was 18.2%; phosphatidic acid (PA) was present at 11.2% of the total PL fraction. Lysophosphatidylcholine was detected at 0.9%. The proportion of PC, PS, and PE significantly (P≤0.05) decreased during germination, but that of PA increased (P≤0.05) markedly. The fatty acid composition of lipid fractions changed as germination proceeded. The predominant fatty acids of total lipids, NL, and GL were linoleic and linolenic acids, while those of PL were linoleic and palmitic acids. The present study demonstrated that the overall changes of lipids seen in borage seeds during germination agree well with results for other oilseeds. Changes in lipid compositions during germination result from the formation of tissues and metabolic interconversion of lipid classes. Rapid changes in lipid composition during seed germination may enhance the nutritional value of the sprouts.