The pigments of cottonseed

Summary A method for the purification of gossypol has been developed which yields material differing in optical properties from those previously reported for gossypol preparations. A colorimetric test for extractable gossypol has been described. It has been shown that cottonseed contains at least three pigments in addition to gossypol. Some of the properties of the three pigments have been reported. One of these newly detected pigments, gossypurpurin, has been shown to be the substance which, mixed with gossypol, constitutes the so-called “red gossypol” of Podol’skaja. The frequently reported water-dispersable blue pigment of cottonseed has been shown to be either a complex of gossypol, gossypurpurin and protein or a mixture of two protein-pigment complexes. Its dissociation into the two pigments and protein has been accomplished. Presented before the 34th Annual Meeting of the American Oil Chemists’ Society, New Orleans, Louisiana, May 12–14, 1943.     

Dependent light scattering in white paint films: clarification and application of the theoretical concepts

Among the numerous publications analyzing the causes and consequences of titanium dioxide crowding on the optical properties of white paint films, one notes some inconsistencies. First, a significant number of studies are inclined to describe “dependent” and “multiple” scattering of light as distinct phenomena. Second, the transition from independent to dependent light-scattering is often associated with an ill-defined “threshold” concentration. The aim of this study is to clarify the intricate connections between these two scattering regimes and in particular to show that for white paint films loaded with rutile titanium dioxide pigments, “dependent” light scattering is merely a particular manifestation of multiple scattering processes. We also clarify that the transition from independent to dependent scattering is a continuous process that cannot be formally related to a specific threshold in the pigment volume concentration. Finally, we propose a simple method based on the dependent scattering amplitude to assist paint formulators facing the task of improving the hiding power of a white paint either by increasing the quantity of pigments or by improving their spatial state of dispersion.     

Reaction of thiobarbituric acid with saturated aldehydes

The reaction of thiobarbituric acid (TBA) with saturated aldehydes, i.e., 1-butanal, 1-hexanal and 1-heptanal, produced a 455-nm yellow and a 532-nm red pigment. Formation of the pigments depended on the reaction conditions. The yellow pigment was unstable in the presence of excess amounts of the saturated aldehydes. The red pigment was formed only when the reaction was performed at a TBA/aldehyde ratio of 1∶1 in aqueous acetic acid. Formation of the yellow and red pigments required molecular oxygen. The colorless adducts, intermediates for the yellow and the red pigments, were isolated from the reaction mixtures. Aldol condensation and dehydration of 2 mol of the saturated aldehydes initially gave the α,β-unsaturated aldehydes, which in turn reacted with TBA to form the colorless adducts, pyranopyrimidine derivatives. The adducts were then converted into the yellow and red pigments under aerobic conditions.     

Binding of gossypol under conditions of complete rupture of the pigment glands

Summary The “free” gossypol of cooked cottonseed meats is composed of gossypol and of “gossypol-like pigments,” which are soluble in 70% aqueous acetone. The “gossypol-like pigments” may account for 30 to 100% of the “free” gossypol as determined by the A.O.C.S. method. Thorough comminution, followed by prolonged cooking, results in reduction of all the pigments in cotton-seed meats. “Free” gossypol is not completely eliminated, but the gossypol level, as determined by the benzene transfer method, may be reduced to zero. “Gossypol-like pigments” are converted into gossypol by the action of hot aqueous hydrochloric acid. Good agreement is observed between the data for “total” gossypol, as determined through the use of the A.O.C.S. oxalic acid method and through the use of hot aniline. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Fractionation of animal fat glycerides by crystallization from acetone. Am improved lard oil

Summary Various edible and inedible grades of animal fats, such as lard, grease, tallow, and selectively hydrogenated lard, grease and tallow were separated into “oils” and “stearins” by crystallization from acetone. The chemical and physical properties as well as the yields of oils and stearins obtained by this method are described. Antioxidants and metal deactivators are much more effective in stabilizing lard and grease oils produced from partially hydrogenated fats than in stabilizing corresponding products from unhydrogenated fats. Report of a study certain phases of which were made under the Research and Marketing Act of 1946. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Characterization of chlorophyll pigments in ripening canola seed (Brassica napus)

This study characterizes the chlorophyll pigments in ripeningBrassica napus seed. Seed samples, collected weekly as the crop ripened, were analyzed by high-performance liquid chromatography to characterize chlorophyll pigment composition. Chlorophyll A, chlorophyll B, pheophytin A and pheophytin B were the predominant pigments, while pheophorbide A, methylpheophorbide A and pyropheophytin A were minor components. No differences in pigment composition were observed between the three cultivars tested or between early and late seeding dates. There were differences in pigment composition between the two years of the study, which may result either from seed aging during storage or from environmental influences. Pigment composition was dependent on seed maturity, with physiologically mature green seeds containing both chlorophylls and pheophytins, but fully mature seeds containing only chlorophylls. Pheophytins and the minor components appeared transiently, presumably formed from the chlorophylls and subsequently degraded. The ratio of chlorophyll A/B increased during seed ripening, with fully mature canola seed having a chlorophyll A/B ratio twice that of physiologically mature green seed. The “B” derivatives degraded faster than the “A” derivatives, suggesting enzymatic reactions. The initial steps in the chlorophyll breakdown pathway in canola seed appear to be:      

Design of polymeric dispersants for waterborne coatings

Block and random copolymers of ammonium methacrylate and dimeth-ylaminoethyl methacrylate have been synthesized and tested as dispersants of various organic and inorganic pigments in formulations for waterborne paints. Blockiness of the co-monomer distribution is a prerequisite for good color characteristics in the final paint. It is however noteworthy that a tapered diblock (one-step anionic synthesis), a diblock copolymer with a regular change in composition from one block to the other one, has an interfacial activity quite comparable to the parent “pure” diblock copolymer (two-step anionic synthesis). The most interesting observation is that the poly(dimethylaminoethyl methacrylate) anchoring block can impart stability to dispersions of pigments as different as iron oxide, a blue Cu-phthalocyanine pigment, and a red organic pigment based on pyrrole in representative aqueous paint formulations. This type of diblock copolymer is promising for the design of universal dispersants. Center for Education and Research on Macromolecules (CERM), Sart-Tilman, B6, 4000 Liège, Belgium. Rijksstraatweg 31, P.O.Box 3, 2170 BA Sassenheim, The Netherlands.     

Buckwheat leaf meal fat. II. Composition of the fatty acids

Summary The composition of fatty acids of the saponified fat of buckwheat leaf meal was investigated. The mixed fatty acids amounted to 49.6% of the composition of the fat. The chief organic acids found were: linolenic, 15.1%; oleic, 13.1%; linoleic, 8.5%; and palmitic, 8.0%. Less than 1% each of such acids as formic, lactic, stearic, arachidic, hexacosanoic, and octacosanoic, and only traces of acetic, lignoceric, and tricontanoic (or higher) acids were found. The so-called “insoluble acids” of the saponified fat, less the unsaponifiable matter, contained 28.5% (18.5% based on the original fat) of material identified as red pigment and probably a mixture of chlorophyll degradation compounds, chiefly phylloerythrin. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Relationship between surface chemistry and surface energy of different shape pigment blend coatings

The influence of pigment shapes and pigment blends on the surface energy was investigated and compared with the surface chemistry of pigmented latex coatings. The coatings were made of different volume ratios of two pigments: plate-like kaolin clay pigment and prismatic precipitated calcium carbonate (PCC) pigment. These were mixed together with carboxylated styrene–butadiene–acrylonitrile latex (SBA), and applied over nonabsorbent substrates as well as absorbent substrates. The composition of the surface of the coatings was investigated by X-ray photoelectron spectroscopy (XPS). Two approaches were used to estimate the total surface energy and the components of the coatings: a conventional approach—“the Kaelble approach”—and a more modern approach—“the van Oss approach.” Pigment blends with different shapes and increments caused a change in the surface chemistry and the surface energy of the latex coatings. As the prismatic PCC pigment particles increased in the kaolin/SBA coating system, the SBA latex content at the coating surface increased and the total surface energy of the coating decreased. This is valid for both nonabsorbent as well as absorbent substrates. It was found that there was a strong correlation between the surface energy and the surface composition. The surface energy of the coatings estimated by the Van Oss approach was always lower than that estimated by the Kaelble approach. Colloidal interactions between pigment–pigment and/or pigment–binder were thought to play an essential role in determining the final coating surface energy and its components. Changes in the surface latex content and the surface energy due to the different pigment blends investigated were found to fit straight-line equations.     

Oxidations involving the heme complex in raw meat

In raw meat systems one is concerned with both lipid and pigment oxidations. Heme pigments catalyze oxidation of tissue lipids causing a stale or rancid odor and flavor. Free radicals from lipid oxidation can oxidize and decompose the red ferrous hemes. This results in the brown colored meat commonly rejected by the consumer. This paper reports three approaches taken to study means of reducing these nonmicrobial oxidative changes: (1) enzymatic reduction of metmyoglobin to maintain ferrous pigments; (2) inhibition of lipid and pigment oxidation and decomposition by means of an antioxidant and reducing agent; (3) the use of model systems to study the kinetics of lipid and heme oxidations. While a biological metmyoglobin reducing system has been found to exist in post mortem suscles, its practical significance in relation to retention of meat color and odor is not fully understood. Anaerobic conditions are usually necessary to achieve complete reduction. The common phenolic antioxidants, butylated hydroxyanisole (BHA) and propyl gallate, along with ascorbic acid will protect meat color and odor for up to eight days according to both chemical analyses and sensory evaluations. Such meat can be packaged aerobically. Surface pigments will remain as the bright red oxymyoglobin familiar to the consumer rather than the purple reduced myoglobin of anaerobically packaged meat. The peroxide-heme ratio may be an important factor in determining rate of oxidation of both pigment and lipid. Maintenance of a high proportion of heme to lipid appears to prevent catalysis of lipid oxidation. The importance of this in relation to actual storage life of meat has not been explored. One of 28 papers presented at the Symposium, “Metal-Catalyzed Lipid Oxidation,” ISF-AOCS World Congress, Chicago, September 1970.     

Note on acetone-soluble material in cottonseed meals

Summary In connection with a study of methods of eliminating traces of “free” gossypol from cottonseed meals a procedure for isolation of gossypol from the 70% acetone extracts of the meals by transfer to benzene solution has ben developed. A procedure is also given for quantitative determination of the isolated gossypol. Analysis of four samples of cooked cottonseed meats and meal by the method showed that in each instance substances other than gossypol are measured by the A.O.C.S. method for “free” gossypol in meals containing low concentrations of residual “free” gossypol. This procedure promises to provide another analytical tool for the study of residual material in processed cottonseed meal that causes egg discoloration when fed to laying hens. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

Lysine,gossypol, and nitrogen solubility in chemically treated cottonseed meals

The effects of treatment of commercial prepress-solvent extracted and direct-solvent extracted cottonseed mares with several chemical agents and solvents were studied. The analytical results for “free” and “total” gossypol of the finished meals show that treatment with aliphatic amines, followed by extraction with a suitable solvent, removed large proportions of the “free” as well as “bound” gossypol. This reduction of “free” and “bound” gossypol was accompanied, in some experiments, by an increase in the nitrogen solubility and available lysine, as compared with the results obtained with the untreated air-dried marcs. The available lysine contents of the treated mares was significnatly correlated with the nitrogen solubility in 0.02N aqueous NaOH. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Heat Treatment Improves Olive Oil Extraction

To determine the effect of hot water pre-treatment on olive oil extraction, six cultivars of olive fruit (Olea europaea L. cvs. “Arbequina”, “Hojiblanca”, “Lechín”, “Manzanilla”, “Picual”, and “Verdial”) were heated at 50, 55, and 60 °C prior to laboratory scale oil extraction. Heat treatment resulted in higher oil extraction than unheated control samples. Quality parameters of the oils were not significantly (P < 0.05) affected by these treatments; however, oil stability and bitterness intensity were reduced and pigment content was increased through pre-heat treatment. This process may be incorporated economically into olive oil processing.     

Pigments of cottonseed. IV. Gossypurpurin,a purple pigment related to gossypol

Summary Gossypurpurin was prepared from gossypol via diaminogossypol, and its properties compared with gossypurpurin isolated from cottonseed pigment glands. A tentative molecular formula for synthetic gossypurpurin, C₃₀H₃₂O₇N, has been proposed on the basis of its elementary composition. The native pigment could not be obtained in the same degree of purity as the synthetic product and the analytical data could therefore not be brought into exact agreement for the two products. However solutions of both pigments in chloroform exhibit almost identical absorption spectra and identical antimony trichloride tests. Qualitative reactions seem to indicate that the functional groups of both native and synthetic gossypurpurin are identical, and the ready conversion of both products to gossypol upon contact with acid seems to indicate that their basic structures are similar. Presented before the 4th Southwest Regional Meeting of the American Chemical Society, Shreveport, La., December 9–10, 1948. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Effect of crop season on the composition of virgin olive oil with protected designation of origin “Les garrigues”

In recent years a growing demand for agricultural produce with an identifiable geographical origin has developed. The aim of this work was to study differences in quality and composition of virgin olive oils produced over four consecutive crop seasons in the region of the protected designation of origin “Les Garrigues” (Catalonia, Spain), taking the harvesting period and the climatic conditions of the year into consideration. The results obtained in this study indicate that virgin olive oil composition is greatly influenced by climatic conditions, mainly the cumulative rainfall in the case of FA composition and phenolic compounds, and the minimum temperatures during harvest period in the case of chlorophyll, carotenoid pigments, and α-tocopherol content. The harvest period influenced most of the parameters analyzed, apart from the PV and FFA content. Prediction models for carotenoid pigment content, oxidative stability, and bitter index were found.     

Various interactions in chocolate flavor

More than 300 volatile compounds have been identified in roasted cocoa beans and its products, making chocolate one of the most complicated natural flavors. Most beans, after harvesting, are subjected to a fermentation that is an important step in the formation of flavor precursors. Roasting is essential to the development of chocolate flavor both with respect to the loss of undesirable volatiles and the generating of key aroma compounds. Flavor is modified to meet demand using blends of beans and through variation in roasting conditions and the mechanical treatments employed to process beans into chocolate liquor and coating. The effect of fermentation and roasting on certain chemical properties related to flavor in chocolate is reviewed. Particular attention is given to monocarbonyls, headspace volatiles, pyrrole aldehydes and alkylpyrazines. One of 13 papers presented in the symposium “Flavor Research in Fats and Fat Bearing Foods,” AOCS Meeting, Atlantic City, October 1971. Presented in part in the symposium “Thermally Produced Flavor Components,” American Chemical Society Meeting, Washington, D.C., September 1971. Paper No. 4135 in the Journal Series of the Pennsylvania Agricultural Experiment Station.     

Surface characteristics of coating layers formed by coating pigments with different particle sizes and size distribution

The effects of coating color raw material variables were tested on absorbing and non-absorbing base materials. The particle size of the coating pigments was the main variable affecting the gloss of the non-absorbing base materials. Adding binders and increasing the drying temperature has a negative effect on the gloss development of both calendered and uncalendered coating layers. On calendered layers, coating layer films showed more gloss development than for coated papers, especially with coarse particles. Uncalendered calcium carbonate-coated papers have a higher PPS roughness than calendered clay-coated papers. The effectiveness of calendering, as described by “calenderability,” showed an increase in gloss with increasing number of nips, irrespective of size, and size distribution of pigment particles.     

A survey of some plant waxes of southern arizona

Summary The yield and characteristics of the waxes from 42 species of plants native to southern Arizona were determined. Although a few have high yields of wax when expressed on the basis of amount of wax per unit area of plant surface, the majority of species contains only a small amount of wax. It was concluded that the often quoted statement, “plants indigenous to arid and hot regions have waxy cuticles,” is untenable and should be modified to read “... waxlike cuticles.” Some taxonomic relationships and some effects of sex on plant waxes were discussed. This survey was supported by a grant from S. C. Johnson and Son Inc., Racine, Wis. Arizona Agricultural Experiment Station Technical Paper No. 453.     

Bifurcation structures in gas detonation

The possibility of existence of two-scale (bifurcation) structures of detonation in ammonia-oxygen, ammonia-air, and ammonia-nitrous oxide mixtures with wide-range variations of the initial parameters is analyzed. It is established that ammonia-oxygen mixtures are characterized by a classical irregular structure. Bifurcation properties are manifested if nitrous oxide or hydrogen peroxide is added. This shows that systems with bifurcation properties have certain flammability limits in terms of fuel, which are responsible for the multiscale character of the structure. The critical diffraction diameter of the detonation wave with bifurcation properties in mixtures close to a stoichiometric composition depends on the greater cell size; the presence of small-scale cells and additional “hot spots” at the points of collisions of transverse waves does not lead to any noticeable improvement of initiation. This fact contradicts the “hot spot” hypothesis, which implies that detonation initiation is facilitated if a greater number of “hot spots” are available.     

Theoretical study of the scattering efficiency of rutile titanium dioxide pigments as a function of their spatial dispersion

We propose an original theoretical framework to model the scattering efficiency of white paint films as a function of the volume fraction and spatial state of dispersion of rutile titanium dioxide pigments, taking into account electromagnetic couplings. Numerical calculations are performed using a multiple T matrix formalism on an “elemental” volume extracted from the bulk of the paint and which we model as pigments and fillers in a polymer matrix. Qualitative studies show that, due to the dependent scattering phenomenon, the size of fillers can modulate the magnitude of loss in scattering efficiency by modifying the spatial state of dispersion of the pigments in the polymer matrix. In particular, fillers whose size is comparable to the dimension of the pigments improve the scattering efficiency by impeding crowding. It is also shown that the optical properties of the bulk material at arbitrary concentration can be approximated by extrapolating the optical properties calculated on a limited number of scatterers.