Search Results

You are looking at 121 - 130 of 1,223 items for :

  • Refine by Access: All x
Clear All
Open access

L. F. Flora and R. C. Wiley

Abstract

Oil content as extracted with chloroform - methanol ranged from 5.2 to 18.4% among the 12 mutant genotypes examined. GLC analysis of the methyl esters of the corn oil fatty acids showed widely significant differences in composition among the genotypes. Action of the opaque-2 gene on the inbred caused the greatest decrease in oil content and greatest increase in the proportion of polyunsaturates. The brittle-2 gene caused the greatest increase in oil content and greatest decrease in the proportion of polyunsaturates. A positive relationship was evident between saturated and oleic acids and oil content. An inverse relationship was evident between polyunsaturated acids and oil content.

Open access

R. J. Clark and R. C. Menary

Abstract

Oil yield of peppermint (Mentha piperita L.) per unit area obtained from plant density treatments 30 and 40 plants/m2, reached a maximum early in the growing season, whereas oil yield from the lower density treatment, 10 plants/m2, continued to increase even at a menthol content of 50%. The latter density treatment yielded less oil per unit area. At the 2 highest densities, herb harvested at a stage when oil contained 45% free menthol resulted in maximum oil yield and optimum oil quality. Delaying harvest once the above stage had been reached resulted in increased levels of menthol but at the expense of increased levels of menthofuran and decreased oil yields. As the growing season progressed, menthol and menthyl acetate contents of oil increased while menthone decreased. This effect was accelerated at the high plant densities.

Free access

Yousheng Duan, Zhiqiang Ju, and Zhiguo Ju

Effects of different plant oils (soybean, corn, peanut, cottonseed, conola, sunflower, safflower, rape seed, and linseed) on mealiness, leatheriness, and flesh browning (FB) in `Elegant Lady' peaches (Prunus persica Batsch) were studied. Fruit were harvested at three dates (10 days apart) with the second harvest concomitant to commercial harvest, dipped in a 5% or 10% oil emulsion for 3 min, and stored at 0 or 5 °C, respectively. After 6 weeks at 0 °C, fruit developed more leatheriness and FB but less mealiness in early harvested compared to late-harvested fruit. When stored at 5 °C, fruit did not develop any leatheriness regardless of harvest dates, but fruit from the last harvest developed high levels of mealiness and FB compare with fruit from the other two harvests. FB was found only, but not in all, leathery or mealy fruit. None of the oils affected leatheriness, but all reduced mealiness to the same extent at the same concentration. Oil treatments controlled FB completely in both leathery and mealy fruit. Oil at 10 % was more effective in controlling mealiness and FB than at 5%. Oil-treated fruit had higher flesh firmness and titratable acidity and developed less decay than the controls at removal from storage.

Free access

Ashraf Abdallah, Miguel H. Ahumada, and Thomas M. Gradziel

Seed of California almond [Prunus dulcis (Mill.) D.A. Webb, syn. P. amygdalus Batsch, and P. communis (L.) Arcangeli, non-Huds.] genotypes contained very low saturated fatty acids, high monounsaturated fatty acids, and low polyunsaturated fatty acids. Kernel oil consisted primarily of five fatty acids: palmetic, palmetoleic, stearic, oleic, and linoleic. Linolenic acid was only present in amounts of <0.02% and only in a few samples. Small but significant differences among genotypes and sampling sites were found in the proportions of palmetic, palmetoleic, and stearic fatty acids. The major differences in fatty acid composition among genotypes was found in the proportions of oleic, a monounsaturated fatty acid, and linoleic, a polyunsaturated fatty acid. The proportion of oleic acid was highest, ranging from ≈62% to 76%, and was highly and negatively correlated with linoleic acid levels. Usable genetic variation and a significant genotype × environment interaction were identified for oil content and composition. The introgression of new germplasm from peach and related species does not appear to reduce oil quantity or quality, and may offer opportunities for further genetic improvement of kernel oil composition.

Open access

Paul R. Adler, James E. Simon, and Gerald E. Wilcox

Abstract

Sweet basil (Ocimum basilicum L.) plants were grown, until flower buds became visible, in a peat-lite mix and watered daily with a complete nutrient solution with 10 mm N as either NO 3 or NH 4 + . Ammonium decreased plant height and stem plus petiole dry weight. Leaf blade dry weight was not affected by N form. However, the essential oil content was decreased by 28% with NH 4 + , thereby decreasing the essential oil yield per plant. Although NH 4 + decreased the content (nl·g-1 leaf blade dry weight) of linalool and eugenol, their percentage was not altered. Therefore, the changes in total yield of these individual constituents was simply a reflection of less total extractable essential oil. The total amount of the other major constituents in sweet basil, 1,8-cineole, methyl chavicol, and total sesquiterpenes was not affected significantly. While N form did not alter the percentage of monoterpenes and aromatic polypropa-noides, NH 4 + -N increased the total sesquiterpene percentage. Nitrogen form altered the essential oil content and composition of sweet basil and, therefore, should be considered in nutritional studies with aromatic plants.

Open access

J. W. Kesterson, R. J. Braddock, R. C. J. Koo, and R. L. Reese

Abstract

Arsenic (As) and lead (Pb) sprays applied to grapefruit (Citrus paradisi Macfad.) accelerate fruit maturity but do not contribute to the As and Pb content of the peel oil. The physicochemical properties of the expressed oils are influenced by this induced maturity but would occur naturally in the course of normal fruit maturation.

Open access

Arthur O. Tucker, Michael Maciarello, and John T. Howell

Abstract

The yield of inflorescences and essential oil of ‘Dutch’ lavandin (Lavandula x intermedia Emeric ex Loisel.) was increased significantly with the addition of a 2.5-cm topdressing of white sand. Fertilization did not increase yields on a near-optimally fertile soil.

Free access

Shahrokh Khanizadeh and Andre Bédanger

Leaves of three strawberry cultivars (Bounty', `Honeoye', and `Kent') were collected at random from plants growing in an experimental trial at the Agriculture Canada, Research Station farm at Lavaltrie, Quebec. Steam-distillation was carried out on 300g of leaves in 3L of distilled water in a 5L flask. The essential oils were analyscd with a Varian 6000 gas chromatogmph. Thirty-seven compounds were detected of which sixteen were identified. The major components were linalool and nonanal. Many of the other constituents were aliphatic in nature. Differences in oil composition among the three cultivars were observed. Essential oil composition might therefore be used as a selection criteria for insect or disease resistance. Their effect upon mites will be assayed in future studies by testing them as sex, food, or oviposition lures.

Free access

David A. Dierig, Anson E. Thompson, Earl R. Johnson, and Gail H. Dahlquist

Vernonia galamensis is a potential new crop for production of epoxidized oil with many industrial applications. This plant is native to equatorial Africa, and not adapted for culture in temperate zones since it requires a short daylength to initiate flowering and subsequent seed development. One collection of V. galamensis ssp. galamensis var. petitiana, flowered freely and produced seeds during long-day conditions throughout the United States. This variety lacks important plant characters for successful commercialization. The favorable genetic recombination of day-neutral response with more desirable plant growth characteristics, desirable seed oil and fatty acid content from other accessions of V. galamensis has been accomplished in hybrids and segregating populations, and selections are being widely evaluated throughout the U.S..

Free access

C.L. Murphy, N.W. Hopper, C.B. McKenney, and D.L. Auld

The oil extracted from seed of selected accessions of Oenothera, also known as the wildflower evening primrose, has documented medical applications. Evening primrose oil contains from 0.0 to 12.0% gamma-linolenic acid (GLA) (C 18:3, delta 6, 9, 12). This unique fatty acid, which occurs in only a few plant species, can correct deficiencies in the delta 6 desaturase enzyme. Low levels of this enzyme prevent formation of the long chain fatty acids responsible for the production of prostaglandins and thromboxanes. Supplementation of the diet with evening primrose oil rich in GLA ensures adequate levels of these essential products. Inconsistent seed germination, poor emergence, and small seed size of accessions containing higher levels of GLA have limited commercial production of this crop. Currently, most producers establish their field through transplants. In this project, methods of improving seed germination have been explored. Seed coatings using diatomaceous earth were shown to facilitate handling and improve germination in the laboratory. Osmotic priming and red light exposure were also evaluated as means of improving germination.