Shelf life is a major problem in the marketing of pecans, particularly at the retail level. A procedure to extend the shelf life of pecans was described. The full-oil and supercritical carbon dioxide extracted (22% and 27% reduced-oil) native pecan kernels packaged in standard air mixture (21% O2, 79% N2), stored for up to 37 weeks at 25 °C and 55% RH, were subjected to hexanal analysis, sensory analysis, and determination of lipid class changes, that occur as the pecans age. Hexanal concentration of reduced-oil pecans was negligible throughout the storage, while full-oil pecans reached excessive levels by 22 weeks. Hexanal analysis was in agreement with the sensory scores. Free fatty acid lipid class was selectively extracted during the partial oil extraction process. Reduction in free fatty acids, and an overall reduction in lipid content on a per kernel basis, decreased the sites for oxidative deterioration and contributed to enhanced shelf-life of pecans. Work was supported by OCAST grant AR4-044 and the Oklahoma Agricultural Experiment Station.
Hydro-distilled essential oils from fresh and dry leaves and fresh and dry flowers of `Sweet Dani', a new ornamental lemon basil (Ocimum basilicum) cultivar with potential as a source of natural citral, were analyzed by GC and GC/MS. The essential oil contents were 0.18%, 0.19%, 0.30%, 0.28% w/w on a fresh weight basis of fresh and dry leaves, and fresh and dry flowers, respectively. Oils from leaves and flowers differed significantly in content and composition. The major constituents in dry leaf oil were neral 21.8% and geranial 33.5%. The major constituents in dry flower oil included: nerol 11.5%, neral 12.9%, geraniol 7.6%, and geranial 17.7%. Nerol (1.6%), and geraniol (0.4%) were very low in dry leaf oil. As citral is a combination of neral and geranial, the relative leaf and flower citral content is 55.3% and 30.6% of the total oil, respectively. Linalool and octanol were detected in flower oils only.
Six-year-old peach trees [Prunus persica (L.) Batsch] were sprayed with ethephon (100 mg·liter–1) in Oct. 1989, whitewashed in Jan. 1990, and sprayed with dormant oil on one or two dates in Mar. 1990 to study possible interactive effects on flower bud hardiness, pistil growth, time of bloom, and yield. Flower buds from ethephon-treated trees supercooled to a lower temperature [mean low temperature exotherm (MLTE) of –18.5C] than buds from nontreated trees (MLTE of –17.7C) in February; there was no main effect of whitewashing or any interaction with ethephon. No treatment effects on hardiness were detected in March. Ethephon-treated pistils were smaller than nontreated pistils, and pistils from buds on whitewashed trees were smaller than those on nonwhitewashed trees. No main effects or interactions of dormant oil on pistil size were detected. Ethephon and whitewashing delayed bud development during bloom, but prebloom oil application(s) had no effect. Buds from ethephon-treated and whitewashed trees were more tolerant of freezes during bloom than buds from oil-sprayed trees, and yield was enhanced by ethephon and whitewashing. Prebloom oil sprays reduced yield compared with controls. Chemical name used: 2-chloroethylphosphonic acid (ethephon).
Partial oil extraction is being investigated as a means to increase oxidative stability and provide reduced fat pecan halves. Supercritical extraction with carbon dioxide provided a means to extract twenty to thirty percent of resident oil, with little to no kernel damage and leaving no harmful residues in the kernel or the extracted oil. Variances in extraction time, temperature, pressure and total carbon dioxide volume used for extraction with a continuous flow extractor will be discussed. Fatty acid composition of oils extracted using supercritical carbon dioxide was essentially the same as oils obtained by solvent extraction and by cold press. Fatty acid yield in the oils was greater for supercritical extraction compared to the other two methods. Oxidative stability for extracted and unextracted pecans, determined using an accelerated aging technique, will be compared. Supported by USDA grant 92-34150-7190 and the Oklahoma Agricultural Experiment Station.
The essential oil constituent of Rosemary harvested in different times and grown in different introduction regions were analyzed with GC method and compared in this study. The composition of the essential oil in different harvest times were almost similar, the content of main constituents fluctuated regularly. Compared with main production countries of Rosemary, the composition of the essential oil in different introduction regions of our country have characteristics of their own, with high content of &-Pirene in Beijing, rich in Comphor and relatively high in Bonneol and Bonaryl acetate in Nanjing and with equally abundant &-Pirene and 1, 8-cineole in Kunming.
Roemarol, Cornosal and Rosmadial are separated from Residues of disfitled shoot and leaves of Rosemary, and are identified with MS and'H-NMR.
Ethephon was applied at 0, 625, 1250, 1875, and 2500 m·gliter-1 in 2 consecutive years to `Arbequina' olive trees to determine its effect on fruit removal with mechanical harvesting and on fruit oil composition. Ethephon increased the mechanical harvesting efficiency by 20%. Ethephon at 1250 and 1875 mg·liter-1 were the optimum treatments, resulting in 63% and 66% of the olives being mechanically harvested, respectively, with a preharvest olive drop of 10% and 11%. Leaf drop (4.6 and 4.8 kg/tree fresh weight, respectively) at these concentrations did not reduce flowering the following year. Oil acidity, peroxide value, and fatty acid composition were affected little by ethephon and the values observed were within the range of normal annual variation. These results suggest that ethephon did not modify oil quality and that its use on traditionally pruned `Arbequina' trees is not economically justifiable. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).
Several experiments showed that whole, unmilled olives (Olea europaea L.) could be dehydrated in 42 hours in a forced-air oven at 105 °C (221 °F), so that they could be used in determining their oil content in a nuclear magnetic resonance (NMR) analyzer. After confirming that the NMR and the official Soxhlet methods estimate the same oil percentages in milled olives, linear regression analysis also showed that NMR provides the same oil percentage results with milled and unmilled fruit. This new method avoids sample manipulation before dehydrating the fruit, making it possible to work with olive samples weighing as little as 70 g (2.47 oz). It allows for processing a large number of samples in a short period of time and may be also used with unmilled fruit flesh. The method is also very useful for screening genotypes, either from germplasm banks or progenies from olive breeding programs, and for evaluating cultivars in comparative trials.
Abstract
The comparative analysis of leaf-oil components separated by vapor phase chromatography was tested on stubborn infected and non-infected sweet orange leaves as a possible new technique for detection of stubborn disease of citrus. Three leaf-oil components: citronellol, nerol, and geraniol were found reduced in the stubborn infected leaves, but the reduction was shown to be related to the smaller leaf size and not due to the stubborn pathogen. However, one component, linalool, showed an increase in stubborn or stunt infected leaves relative to respective controls. This increase was not related to leaf size, but probably due to the presence of the pathogen.
Petroleum and vegetable oil hydraulic fluids were spread on `Tifgreen' bermudagrass at three volumes (125, 250, and 500 ml) and three temperatures (27, 49, and 94C) to simulate a turfgrass equipment leak. Initial damage, recovery, and effects for a 1-year period were compared among treatments. All hydraulic fluid treatments resulted in 100% leaf necrosis within 10 days of application. Turfgrass recovery was influenced primarily by the fluid volume. After recovery, only plots treated with petroleum hydraulic fluid were periodically chlorotic, resulting in lower turfgrass quality. Long-term negative effects of hydraulic leaks from golf course equipment may be reduced by using vegetable oil hydraulic fluid.
Abstract
Inhibition of flower bud development increased with the concn of naphthenic or paraffinic oil. In some cases, additions of 1 or 2% succinic acid 2,2-dimethylhydrazide (SADH) in oil sprays reduced bud injury and resulted in more flowering terminals and fruit set than oil sprays alone. A January 1969 spray of 50% naphthenic oil with 1% SADH appeared to delay bud activity and prevent freeze injury to the flower buds in early February. Trees that were sprayed with 50% naphthenic oil and 1% SADH on February 18, 1971, withstood a freeze on March 5 and produced a partial fruit crop.