Tung Fruit Research Articles

Characterization of Polypropylene Composite Reinforced on Bio-waste from the Production of Tung Oil

The aim of the conducted study was to develop wood-polymer composites (WPCs) using secondary polymer waste and agricultural technology waste materials, which would have lower environmental impacts than WPCs made from virgin resources. The study focused on developing WPCs based on polypropylene filled with finely dispersed powders of waste products from tung oil production (PP+TOPW composites). Finely scattered powder (with an average grain size of 0.5–1.5 mm) was obtained from crushing and grinding the outer pericarp of tung fruit waste, which resulted from tung oil extraction. Tung oil is produced in Georgia from tung fruit that is grown in Tsalenjikha district, Georgia. In addition, to modify the properties of the WPCs, organic silicon oligomer tetraethoxysilane and powdered aluminum hydroxide were used as additives. The study found that the strength properties of the PP+TOPW composites can be optimized by modifying them with tung oil and other mineral additives. The optimal strength properties were observed at a filler content of 40 wt.%, where the compression and bending strength limits were 63.5 and 36.7 MPa, respectively. The water absorption of the PP+TOPW composites was reduced by modifying them with tung oil. The PP+TOPW composites with a filler content of 30 wt.% showed 0% water absorption, and the water absorption of composites with a filler content of 40 and 50 wt.% (modified with tung oil) was very low, ranging from 0.2–0.8%. The study also investigated the effect of modifying PP+TOPW composites with tetraethyl orthosilicate (TEOS), which increased all the strength parameters, including impact strength, and reduced water absorption, although not as much as when modified with tung oil. The introduction of a flame retardant, aluminum hydroxide, into the composite composition in the amount of 25–30 wt.% made the composites flame-retardant and low-combustible materials, expanding their potential applications, particularly in construction. Overall, the study successfully developed WPCs using waste materials with optimized properties, which have potential for various applications, including in construction, due to their flame retardant and low-combustible properties.

Flower biology and ontogeny of the tung tree (Vernicia fordii Hemsl.)

Low number of pistillate flowers in the tung tree is a major factor causing the low yield of tung fruits. The tung tree (Vernicia fordii Hemsl.), an economically important woody oil plant, produces excellent fast-drying oil from the seeds which has been used as a protective finish on projects and surfaces for centuries. Knowledge of sex determination and flower development of tung trees is helpful for high-yield cultivation and breeding of new elite cultivars. However, studies on tung flower biology and ontogeny are still lacking. Here, we reported a comprehensive study of the flower biology and ontogeny of the tung tree, focusing on flower cycle, flower morphology and flower development. The inflorescence phenophases of monoecious tung trees were divided into 12 pivotal stages and used as a unique timeline to reference the events registered throughout the flower cycle. Histological studies on sporogenesis and gametogenesis were also conducted. Meanwhile, all the unique events throughout flower cycle were linked together to show the correlation between inflorescence development phenophases, pistillate and staminate flower stages and its embryological development. Tung trees in our plantation were grouped into three major types, i.e., monoecious, gynoecious and androecious trees which produced different number of fruits in each inflorescence. We propose that low number of pistillate flowers in the tung tree is a major factor causing the low yield of tung fruits, and that any measures increasing the number of pistillate flowers would effectively improve the yield of tung fruits.

A catechol-type lignan and neolignans are specifically present in the seed coat of tung trees

The tung tree produces large seeds with approximately 40–50% of their composition consisting of non-edible oil. α-Eleostearic acid makes up about 80% of tung oil, while linoleic acid and oleic acid make up 7 and 6%, respectively. The oil is readily oxidized due to the three, conjugated double bonds in α-eleostearic acid; however, it is stable inside the tung seed, which is expected to contain strong antioxidative compounds that protect the oil from oxidation. Previously, we isolated and identified a catechol-type lignan (3,3′-bisdemethylpinoresinol) and neolignans (isoamericanol A and americanol A) from the seeds of tung tree fruits that exhibited strong antioxidative activity, similar to that of Trolox. In this study, we show that the catechol-type lignan and neolignans are specifically present in the seed coat of the tung tree fruit seeds. The lignans were not detected in any other tissue, such as the pericarp, bark, leaves, or wood of the tree. The lignan content was determined in each developmental stage of the fruit, and the amount of the three lignans in the tung seeds was the highest in the green mature stage. This was likely because the amount of tung oil was also at its highest during this stage, and the oil composition was stable. Our results indicate that the catechol-type lignan and neolignans are located within the seed coat of the tung tree fruit seeds, where they protect the oil in the endosperm from autoxidation and polymerization processes.

Effects of Low-Temperature Stress and Brassinolide Application on the Photosynthesis and Leaf Structure of Tung Tree Seedlings.

The tung tree is an important woody oil tree species. Tung oil extracted from the tung fruit seeds is used in the manufacture of environmentally friendly paint. This study investigated the effects of the application of brassinolide (BR) under different temperature conditions on the chlorophyll content, photosynthesis, chlorophyll fluorescence, leaf structure, and chloroplast ultrastructure in Vernicia fordii and Vernicia montana. The conditions used were 8°C-Control (low temperature and no BR), 8°C-BR (low temperature and BR application), 28°C-Control (normal temperature and no BR), and 28°C-BR (normal temperature and BR application), and effects were monitored from 5 to 15 days after the treatments (DAT). The results showed that the low temperature treatment (8°C-Control) significantly reduced the net photosynthetic rate (Pn), stomatal conductance (Gs), maximum fluorescence (Fm), maximum photochemical efficiency (F v/F m), and actual photochemical and quantum efficiency (Φ PSII) compared to the control condition (28°C-Control). However, the external application of BR alleviated the negative effects of low-temperature stress to some degree for all the above parameters for both species tested, except for P n and G s at 15 DAT. There were no significant differences in most of the parameters in either species between the 28°C-Control and 28°C-BR treatments. At 10 and 15 DAT of low-temperature stress, the 8°C-Control treatment significantly reduced leaf cell tense ratio (CTR) and increased spongy ratio (SR) compared to the 28°C-Control, whereas BR application alleviated the adverse effects. Moreover, the 8°C-Control treatment significantly destroyed the chloroplast structure, loosening the thylakoids until they disintegrated, while exogenous spraying of BR protected the chloroplast structure and enabled it to function properly in both species. Our results suggested that long-term low temperatures significantly reduced the photosynthetic efficiency of tung tree seedlings, affecting the formation of the internal structure of plant leaves and destroying the integrity and function of the chloroplast. To prevent this, external application of BR to tung tree seedlings could enhance the photosynthetic potential of tung trees by maintaining the stability of the leaf structure, morphology, and function, and alleviating the damage caused by cold injury. The results also showed that V. fordii seedlings are more resistant to low temperatures than V. montana seedlings.

Evaluation of a centrifugal impaction-type decorticator for shelling tung fruits

Tung, a potential tree-borne oilseed has many applications in paints, varnishes, foods and other non-food industries. De-shelling of tung fruit is an important process prior to its oil extraction. Manual de-shelling of tung fruits is a time consuming and tedious operation. Therefore, the effectiveness of a centrifugal impaction type decorticator for tung fruits was studied and evaluated for performance parameters. The performance test for maximum seed yield was evaluated on the basis of various performance indicators, which includes percentage of whole seed, broken seed, partially shelled fruit, unshelled fruit, machine efficiency and decortication efficiency. These performance indicators of the decorticator were evaluated at three different fruit moisture contents (8.65%, 12.13% and 15.61% d.b.) and at different speeds of rotating blades (1600, 1800 and 2000rpm). The clearance between rotating blade and striking plate was fixed at 100mm for optimum force. The best results of 52.24% recovery of whole seeds and machine efficiency of 74.63% were recorded at fruit moisture content of 8.65% (d.b.) with a blade speed of 1800rpm. These set of conditions were preferred, because of its rapid operation, low human-energy, low breakage factor for the seed as well as relatively little amount of dust being emitted during de-shelling. Its wider use is thus recommended for a healthier working atmosphere.

Identification of a Subtilisin-Like Protease in Seeds of Developing Tung Fruits

Summary A subtilisin-like protease was identified in the low-density microsomal fraction of developing tung seeds. The abundance of the protease changed significantly throughout seed development and showed a direct temporal correlation with accumulation of storage oil. Once storage oil synthesis was complete, the abundance of the protease decreased dramatically. Determination of the N-terminal amino acid sequence revealed that the protease sequence began just after a conserved pro-domain cleavage site, suggesting that the protease was fully active in developing tissue. Extraction of microsomal membranes with high salt or pH demonstrated that the protease was not a membrane-anchored protein.

The tung industry. II. Processing and utilization

Processing of tung fruit to produce high quality tung oil has been subjected to continuous modification, improvement, and mechanization. Domestic tung oil is high in eleostearate content and normally meets all recognized specifications. The basic chemistry of the major components of tung oil, the eleostearic acids, has been well established. Although the major industrial use of tung oil continues to be in the drying oil field, research is under way to take advantage of the unique chemical character of the eleostearic acids. Progress is being made in the utilization of the by-products, tung hulls and tung press cake.

Materials balance in a tung oil mill

SummaryWeights were determined and analyses made of tung fruit milled and of all products leaving the mill for two runs of about 90 tons each in a commercial mill under normal operating conditions. Dry matter, oil, and nitrogen in the fruit were satisfactorily accounted for in products leaving the mill, 101% of the oil being accounted for in each run. This showed that the methods of analysis and sampling were accurate.Losses occurred principally in particles of kernels occluded with the hulls and in the screw‐press cake. Seventy‐eight and 82% of the oil in the fruit was recovered as filtered oil.Repressing the filter‐press cake by adding it back to the stream of ground nuts just before they entered the screw‐presses was not proven to be economical as at the end of the run just as much cake was on hand, and it had as high an oil content as if no filter cake had been fed back through the screw presses. Only about half as much oil could be filtered per filtration cycle, resulting in an increase in cost of labor and a decrease in filtering capacity.The apparent oil content of the screw‐press cake decreases by about 2% after four to eight days as compared to its apparent oil content at the time of pressing because of polymerization. Thus, screw‐press cake samples should be analyzed for oil as soon as possible after extrusion.

Loss of oil in hulling tung fruit in the field and at the mill

SummaryMethods for analyzing commercial tung hulls for oil have been developed. Samples of tung hulls from mill and field hulling operations have been collected and analyzed. The loss of oil when the fruit are hulled was found to vary from 0.6% to 7.3% with an average loss of 2.7% based on the total amount of oil in the fruit. The difference in the loss of oil between grove and mill hulling was not significant. With a loss of 2.7% of the oil in hulling, a recovery of 87.9% oil on the hulled nuts would be equivalent to a recovery of 85.5% oil on the whole fruit.

The determination of moisture in tung fruit

Summary and ConclusionsSix methods for determining moisture in tung fruit and seeds were compared.The highest moisture values, and probably those most reliable, were obtained by drying the ground tung fruit in the vaccuum oven at 101°C. for 2.5 hours under 12‐mm. pressure, and by the Karl Fischer titration method. In using the Karl Fischer method on tung products, the sample must be digested in methanol at 60°C. Of these two methods the vacuum oven method is simpler and generally preferable.Somewhat lower moisture values were obtained by the forced draft oven and toluene‐distillation methods. The results obtained in the forced draft oven method were low because of oxidation of the oil in the samples. One hour at 101°C. in the forced draft oven seems to be the optimum time for moisture determination, and no appreciable error in the oil content results from using the percentages of moisture so determined to calculate the oil content to basis of sample as received.For routine analysis, heating the ground tung fruit sample in a hot air blower for 15 minutes at 126.7°C. (260°F.) and adding a correction of 1.35% to the percentage of moisture obtained gives sufficiently accurate values for factory control purposes.The radio frequency meter gave values close to those obtained in the vaccum oven method against which it was standardized. It was necessary to standardize the meter separately for fruit, seeds, and kernels. In practice many samples of wet fruit would be encountered which would exceed the range of the particular instrument used.

The determination of the oil content of ground tung fruit

SummaryThe Hamilton‐Gilbert method for oil determination has been adapted to the method of grinding and extracting whole tung fruit. A sample of 100 fruit is ground in a Wiley mill with sharp blades. A 10‐gm. portion is then extracted in a Waring Blendor and oil determined by the procedure previously described or a modification herein described. To approximate closely the values that would be obtained by the strictly accurate but more laborious method of separating kernels from hull and shell and extracting the kernels only (component method), a correction is required for non‐oil substances extracted from the hull and for factors such as adsorption of the kernel oil on particles of hull and decreased efficiency of extraction of the kernel oil in the presence of ground hull and shell. This correction factor is not constant throughout the whole range in oil content found in whole tung fruits, and the best estimate of true tung oil content is obtained by the formula:Estimated component value = 0.8958 (value by whole fruit method) + 1.37.The use of a regression equation such as that above in relating results of two empirical chemical methods is believed to be of very general application. The specific formula here arrived at was determined from 97 samples of air dry fruit ranging in oil content from 16.0 to 25.0%. It is not recommended for use with commercial samples of tung fruit, which vary widely in moisture content and usually range from 10.0 to 20.0% in oil content until adequate tests with such samples have been made.

The equilibrium moisture content of tung fruit and its components at different relative humidities

SummaryThe equilibrium moisture contents at 25°C. were determined for the whole tung fruit, the outer hull, the inner hull, shell, kernels, and seed of the fruit, and on the cake from continuous screw presses at nine different relative humidities. The relative humidities were maintained by enclosing saturated solutions of different salts in desiccators in a room maintained at constant temperature.

Comparison of the whole fruit and component methods of analysis of tung fruit

SummaryThe effect of moisture content and fineness of grinding on the percentages of oil extracted by the whole fruit method were investigated and the results compared with those obtained by the component method.The spacing of the plates on the Bauer laboratory mill used for grinding whole tung fruit for oil analysis was found not to be critical within certain narrow limits. No differences were found in the oil content when samples of fruit were ground with plate spacings from 0.004 inch to 0.012 inch, but the results were lower with plate spacings of 0.020 inch.No difference was found in the percentages of oil obtained by the component and the whole fruit methods when the results were calculated on the basis of the original moist sample and no correction had to be applied in the calculation of the results by the whole fruit method.The average percentage of moisture obtained by the two methods differ, consequently care must be used in comparing oil contents calculated to a moisture‐free basis since the differences in moisture content will be reflected in the values for the apparent oil content.Careful analyses of tung fruit by either the whole fruit or the component method yield reliable results over a wide range of moisture content although in the case of the component method unusually wet kernels (above 10% moisture) must be partially dried before regrinding in a mortar and pestle during the extraction operation.

A new procedure for the analysis of tung fruit

SummaryA new procedure for the analysis of tung fruit for oil and moisture content has been developed wherein it is possible to largely eliminate the sampling errors which occur in component procedure used in the past because of the relatively small samples used. Collaborative studies have indicated that to obtain results similar to those obtained in analysis by the component procedure a correction of 0.37% must be subtracted from the oil content obtained with the Wiley‐Bauer ground fruit, but no correction appears to be necessary in the case of the Wiley‐Raymond ground material.

Studies in the expression of oil from tung fruit

1. Tests indicated that best results in yield of crude and filtered oil by an expression procedure are obtained with a tung meal containing 4.2% moisture and 20% shell. 2. The drying of tung meal using an initial air temperature of 320° F. appeared to adversely affect the yield of filtered oil from the expeller process. 3. A filtration test was developed for determining the amount of foots in a crude tung oil. 4. It was found difficult to obtain efficient oil expression from tung meals containing filter cake; in one test with this material the resulting press cake was high in oil content, while in another test the crude tung oil contained about twice as much foots material as was present in crude tung oil from tung meal containing no filter cake. 5. The expression of tung oil from a tung meal consisting of ground old tung kernels and tung shell was found difficult if not impossible. This difficulty appeared to be due, at least partly, to the fact that the meal from old kernels will not plasticize when subjected to heat and pressure. When these kernels were mixed with new kernels no difficulty was experienced in expressing the tung oil from the meal. 6. Tests indicated that hulling the moist tung fruit in the grove does not interfere with the expression of the oil if the moist dehulled tung fruits are properly dried before pressing. 7. A process was developed for producing a clear tung oil by treating the crude oil with a chemical agent to precipitate certain non-oil constituents in the crude tung oil followed by either pressure filtration or centrifugation. 8. When tung oil filter cake was mixed with an equal amount of tung press cake, over 98 percent of the oil could be solvent-extracted by petroleum solvents.

Moisture determinations on tung fruit and its components for control purposes

Moisture determinations on tung fruit and its components for control purposes

The processing of tung fruit for oil

The processing of tung fruit for oil

Chick Feeding Experiments with Solvent-Extracted Tung Oil Meal

INTRODUCTIONTUNG oil meal is the residue remaining after the oil has been expressed from ground de-hulled tung fruit. The material used in this feeding experiment was solvent-extracted in a pilot plant at Picayune, Mississippi, and was obtained from the Tung Oil Laboratory of the Bureau of Agricultural Chemistry and Engineering, United States Department of Agriculture, Bogalusa, Louisiana.LITERATURE REVIEWLewkowitsch (1909) and Newell (1924) have reported the poisonous character of tung kernels and this is rather well known to the tung oil industry. Jamieson (1932) reported that tung press cake has strong purgative properties and is unsuitable for feeding stock. Little material has been published with reference to the feeding value of tung oil meal. Godden (1933), who fed tung oil meal to rats, poultry, cattle, and pigs, concluded that tung oil meal contains some substance which makes it unpalatable and some irritating material which has a harmful effect .

The moisture content of tung fruit from its electrical resistance

Oil and SoapVolume 18, Issue 9 p. 188-189 Article The moisture content of tung fruit from its electrical resistance R. S. McKinney, R. S. McKinney Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, United States Department of Agriculture, USASearch for more papers by this author R. S. McKinney, R. S. McKinney Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, United States Department of Agriculture, USASearch for more papers by this author First published: 01 September 1941 https://doi.org/10.1007/BF02543628 Agricultural Chemical Research Division Contribution No. 9. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue9September 1941Pages 188-189 RelatedInformation

A rapid method for the determination of oil in tung fruit

Oil and SoapVolume 18, Issue 2 p. 25-27 Article A rapid method for the determination of oil in tung fruit R. S. McKinney, R. S. McKinney Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, U. S. Department of Agriculture, USASearch for more papers by this authorW. G. Rose, W. G. Rose Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, U. S. Department of Agriculture, USASearch for more papers by this author R. S. McKinney, R. S. McKinney Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, U. S. Department of Agriculture, USASearch for more papers by this authorW. G. Rose, W. G. Rose Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, U. S. Department of Agriculture, USASearch for more papers by this author First published: 01 February 1941 https://doi.org/10.1007/BF02544233Citations: 2 Contribution No. 159 from the Carbohydrate Unit, Agricultural Chemical Research Division, Bureau of Agricultural Chemistry and Engineering, U. S. Department of Agriculture. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume18, Issue2February 1941Pages 25-27 RelatedInformation