Whiteness and fluorescence of fabrics

A method was devised for measuring the whiteness of fabrics containing optical brighteners. It is simple in operation and gives excellent agreement with the visual appraisal by 27 observers of the whiteness for fabrics with different values for their fluorescence, lightness, yellowness or blueness, and redness or greenness. The fabrics contained different quantities of various blues and optical brighteners. Apart from duplicates it requires only four measurements for each surface, viz., lightness, tristimulus amber and blue reflectance, and the tristimulus blue part of the fluorescent light. Yellowness or blueness, redness or greenness, fluorescence effect on the whiteness, whiteness without fluorescence, and whiteness including fluorescence are calculated from the measurements. The method also indicates which fabrics cannot be called “near white” because they are too gray or too strongly colored. It can be adapted to different compositions of the incident light with regard to the relative intensity of the ultraviolet and visible portions.     

A review of soybean oil reversion flavor

Crude soybean oil has a characteristic “greenbeany” flavor, which during refining, bleaching and deodorization is eliminated to produce a bland tasting, light colored oil. However, flavor returns during storage and has been characteristically called the “reversion flavor” of soybean oil. This deleterious characteristics flavor has influenced the utilization of soybean oil and its fatty acids. Several theories for the cause of reversion flavor include: (a) oxidation of linolenic acid; (b) oxidation of isolinoleic acid of the 9,15-diene structure; (c) phosphatide reactions; (d) unsaponifiables; and (e) oxidative polymers. References are presented that support or contradict these theories. Recent publications concerning the isolation and characterization of the components of reversion flavor indicate slight oxidation of the fatty acids is the major cause. Techniques that are effective in increasing the flavor stability of soybean oil are presented.     

The fluorescence of chlorophyll in fats in relation to rancidity

Summary 1.) Difficulties in applying the “chlorophyll value” test to fat samples has led us to investigate the apparent “quenching” of chlorophyll fluorescence in mineral oil solution when cottonseed oil or lard is added to it. The disappearance of chlorophyll fluorescence in ultraviolet light caused by the addition of cottonseed oil appears to be due to the absorption of the light by the cottonseed oil and to the intense white fluorescence of the oil itself rather than to a chemical reaction of some constituent of the oil with the excited chlorophyll. 2.) There was no evidence of a stoichiometric quenching reaction between chlorophyll and acceptor substances in the fats used in this study and, in consequence, no “endpoint” was observed in any of the titrations. 3.) A lack of correlation between either the peroxide value or the stabilities measured in conventional ways and the amount of chlorophyll fluorescence of several fats makes the “chlorophyll value” test appear to have doubtful value as a generally applicable test for fat rancidity or stability. 4.) The crude absorption curves here presented suggest that the greater absorption of near ultraviolet light by oxidized fats may be related to their content of fat peroxides. This work was made possible by grants from the Rockefeller Foundation, the Hormel Foundation, and the Graduate School of the University of Minnesota. Assistance in the preparation of these materials was furnished by the personnel of Work Projects Administration, Official Project No. 165-1-71-440, Subproject No. 382.     

A new variety of low-linolenic rapeseed oil; Characteristics and room-odor tests

Two Canadian rapeseed oils, “Westar” and “low-linolenic”, supplied by the Canola Council were studied and compared with a French rapeseed. The linolenic acid content of the low-linolenic variety is about 3%. This drop in the C18∶3 is completely compensated for by an increase in the C18∶2. Seventy-two percent of the triglycerides with at least one linolenic chain disappeared. A strong increase in the OOL and OLL was observed. The room-odor tests showed that the “low-linolenic” had a significantly higher odor score than the French rapeseed and the “Westar”, both of these being very similar. A fruity odor dominated in the “low-linolenic”, and the fishy painty odors were particularly reduced.     

Interesterification of lard

The graininess, which develops at 27C (80F) in lard shortening which has not undergone interesterification, is due to large crystal aggregates of disaturated 2-palmitoyloleoylstearin (OPS) of intermediate melting level and existing in a β'-type form of triple-chain-length structure. This β'-3 phase exists in ordinary lard accompanied by the commonly reported β phase which is largely due to trisaturated glycerides. Random interesterification eliminates graininess, not by reducing the disaturated content which remains about the same, but by reducing OPS to its “random” proportion and producing a mixture of disaturated glycerides, which is substantially lower melting than the original OPS. The resulting product crystallizes typically in a β'-2 form, characteristic of hydrogenated vegetable oil shortenings. (Directed interesterification actually reduces disaturated content as well as graininess, while simultaneously creating trisaturated “hardstock.”)     

A quick dilatometric method for control and study of plastic fats

Summary A dilatometric method is presented which is of considerable convenience and reliability in application to commercial fats, notably shortening and margarine. The instrument is of volumetric type with mercury as confining fluid. The simplified calculations give results in terms of “Solid Content Index,” which is an approximation to the true % solid. The apparatus is applicable not only to basic study of composition and processing but is adaptable to hydrogenation control where it has been used with notable success for several years. With shortenings, for instance, the method cuts substantially the deviation from normal consistency encountered with the best thermal methods. Despite the high precision the determination can be completed in about two hours. Part of the reason for the combined precision and speed is a “tempering” step introduced to expedite approach to a steady state prior to final measurement.     

A study of the flavor stability and autoxidation of beef fats

Summary The odoriferous compounds isolated from a fresh edible tallow were found to be very complex in nature and could not be diminished by treatment with carbonyl reagents. When these compounds were removed by deodorization, the bland tallow which was obtained developed on autoxidation another type of odoriferous compounds. The latter contained various carbonyl compounds of the type which have been associated with flavor reversion in edible oils. The characteristic odor of oleo oil and edible tallow could be removed by slight hydrogenation of high selectivity under atmospheric pressure. This hydrogenation process raised the melting point by less than 2°C. but substantially decreased the linolenic and arachiidonic acid content. The hydrogenated products, after deodorization, were not only bland in odor and flavor but also had flavor stabilities better than those of some of the best commercial shortenings. Funds for this study were furnished by a grant-in-aid from Swift and Company, Chicago, Ill. Presented at the American Oil Chemists’ Society meeting, Minneapolis, Minn., October 11–14, 1954.     

The elimination of flavor reversion in linseed shortening by heat polymerization and solvent segregation of the oil

Summary The optimum conditions have been established for the high temperature polymerization and solvent segregation of linseed oil to produce a “non-reverting” edible shortening and an improved drying oil. The best oil is obtained by heating at 270–275° C. for 12–15 hours while carbon dioxide is continuously passed through the oil. Under these conditions the polymerized oil has a refractive index of 1.4858 to 1.4861 at 25° C. and yields 60–65% of acetone soluble oil with a refractive index of 1.4830 to 1.4834 at 25° C. and an acid value of less than 1%, calculated as oleic acid. Pie crusts containing shortenings made from the acetone soluble fraction of the oil have been judged to be of good quality. The best shortenings were obtained by hydrogenating to a refractive index of 1.4615-1.4605 (60° C.). Macodonald College Journal Series No. 209. Issued as paper No. 145 of the Canadian Committee on Food Preservation.     

The use of antioxidants in potato chipping

Summary Laboratory and commercial-scale fryings of potato chips have been made with various vegetable oils, vegetable shortenings, lard, and combinations of these. Fryings have been made with and without the addition of butylated hydroxyanisole as an antioxidant. The data from both types of experiments indicates that butylated hydroxyanisole possesses “carrythrough” antioxidant properties not only in animal fats but in vegetable oils and vegetable shortenings also. Data also indicates that the addition of propyl gallate and citric acid as synergists to the butylated hydroxyanisole increases the “carry-through” antioxidant properties. Presented at 23rd Fall Meeting, American Oil Chemists’ Society, Chicago, Ill., Oct. 31, Nov. 1 and 2, 1949. The Schaal Oven Tests were conducted at 145°F.     

Efficacy of tertiary butylhydroquinone on the storage and heat stability of liquid canola shortening

The sensory (odor and flavor) and physicochemical characteristics of tertiary butylhydroquinone (TBHQ) treated and butylated hydroxyanisole/toluene (BHA/BHT) treated liquid canola shortenings, subjected to accelerated storage (Schaal oven test at 65°C) and deep fat heating (at 185°C), were determined. Data for the Schaal oven test indicate that TBHQ was effective in retarding oxidative rancidity in liquid canola shortenings. However, addition of the commonly used mixture of BHA/BHT to canola shortenings resulted in only a slight decrease in oxidation during schaal oven storage. The results obtained from deep fat heating of canola liquid shortening show that neither TBHQ nor BHA/BHT was effective in enhancing oxidative and thermal stability of this product.     

Uses of defatted and partially defatted peanut flours

Defatted peanut flour produced by direct solvent extraction and partially defatted peanut flours produced by mechanical pressing have many potential uses in foods. The defatted peanut flour has a high protein solubility and is light colored, practically tasteless, and odor free. The defatted peanut flour has been evaluated as: an additive to increase the protein content of foods such as bread and other baked goods, macaroni, pancakes, and puddings; an extender in meats such as meat loaf and frankfurters; and an aid in preparing skim and full-fat (fat added) milk-like drinks and ice creams. The characteristics of this flour also make it useful in the preparation of protein concentrates (by air classification) and protein isolates. The partially defatted flour, with about 55% oil removed, is ideal for preparing full-fat, milk like drinks and can also be used in baked goods, ice cream, meats, and so forth. This flour can also be toasted to different degrees for use in foods such as baked goods, in which a nutty flavor may be desired. The “over roasted” flour has potential for use as a cocoa diluent.     

Room odor evaluation of oils and cooking fats

Panel evaluations have been made of room odors developed by edible oils and cooking fats heated to frying temperatures. Vegetable and mixed fat shortenings, as well as oils of different iodine value and from special processing, were investigated with and without added stabilizers. When silicones were added to frying fats, room odor scores improved markedly. Certain added autoxidative cleavage products had little effect on odor scores at levels where they were detected easily in taste tests. To be discernible in room odors, these additives had to be present at levels ca. 100-fold greater than their taste thresholds. Panel results show that the undesirable frying odors contributed by unhydrogenated soybean oil in mixtures with other oils could be detected readily at 25% levels. As the level of soybean oil was lowered further, the room odor scores of oil mixtures improved perceptibly. One of 13 papers presented in the symposium “Flavor Research in Fats and Fat Bearing Foods,” AOCS Meeting, Atlantic City, October 1971. N. Market. Nutr. Res. Div., ARS, USDA.     

3-cis-hexenal,the “Green” reversion flavor of soybean oil

By means of gas-liquid-chromatography the neutral volatile products obtained by stripping oxidized soybean oil were fractionated. The fraction with “green bean” odor (a well-known offflavor of soybean oil) was investigated. By the application of various methods it was possible to isolate the flavor carrier proper and, in spite of its small amount, to complete the analysis to a point at which the structure 3-cis-hexenal seemed highly probable. Synthesis and subsequent comparison with the natural product confirmed the correctness of the assumption. n-Hexanal and 3-trans-hexenal, also found in this fraction, play no significant role in the reversion flavor.     

Zero-<Emphasis Type="Italic">trans</Emphasis> shortening using palm stearin and rice bran oil

Several pilot-scale trials reported in this paper, using palm stearin-rice bran oil (PS-RBO) blends, obviously did not contain trans FA (TFA), whereas the commercial products were found to contain 18–27% TFA. The effects of processing conditions such as rate of agitation, crystallization temperature, and composition of the blends on the crystal structure of shortenings were studied. The products were evaluated for their physicochemical characteristics using DSC, X-ray diffraction (XRD), HPLC, and FTIR techniques. The formulation containing 50% PS and 50% RBO showed melting and cooling characteristics similar to those of hydrogenated commercial “vanaspati” samples. Analysis of the FA composition revealed that the formulated shortenings contained 15–19% C_18∶2 PUFA. Tocopherol and tocotrienol contents of the experimental shortenings were in the range of 850–1000 ppm with oryzanol content up to 0.6%. XRD studies demonstrated that the crystal form in the shortenings was predominantly the most stable β′ form, and there was less of the undesirable β form.     

The measurement of the hardness of margarine and fats with cone penetrometers

Summary In order to be able to compare the results of hardness measurements on margarine, fats, shortenings, etc., measured both with cone penetrometers and other rheological instruments, several measurements have been made with various cones and samples. The results obtained showed that the yield value can be calculated from the following formula: C=KW/p^1.6 in which C=yield value K=factor dependent on the angle of the cone p=the penetration depth in 0.1 mm. at a penetration during 5 seconds W=the weight of the cone (grams) This formula appeared to apply for cones with angles between 15 and 90° over a very wide hardness range (between 45 and 8300 g./cm²) for margarine, fat, shortening, and butter. The advantages of the proposed procedure for determining the yield value are that is is an objective measure instead of a “thumb test;” results obtained with various cones can be compared; and this method is highly suitable for standardizing.     

Techniques for flavor and odor evaluation of soy oil

Means of evaluating soybean oil for flavor on a “now” basis and on a “predictive” basis are presented. Emphasis is placed on more recent objective methodology for measuring oil volatiles and using their correlation with flavor. Applications of a modified volatile technique for use with soy isolates or soy proteins is shown. The importance of sensory analysis and a summary of methodology currently being used are discussed.     

The effect of “peaking” the ethylene oxide distribution on the performance of alcohol ethoxylates and ether sulfates

In comparison to conventional ethoxylates, a “peaked” ethoxylate has less unethoxylated alcohol, is more soluble, and has a higher concentration of the more desired homologs. A “peaked” ethoxylate therefore has a lower odor, is easier to formulate into liquids, and can perform better in terms of detergency and wetting performance. Since “peaked” ethoxylates have less unethoxylated alcohol, less alcohol sulfate is formed during sulfation. Decreasing the content of alcohol sulfate increases the capacity to salt-thicken and can potentially improve skin mildness.     

The energy consumption in a batch stripper and a batch rectifier

The energy consumption in a batch rectifier and a batch stripper was investigated with a shortcut mathematical model. The minimum energy consumption of a batch stripper was compared to that of a batch rectifier under “general constant reflux” and “general constant distillate composition” with the ratio of minimum energy consumption E_S/E_R. When the feed contains a large amount of light component, the product purity specification is low and the relative volatility is small, the minimum energy consumption of a batch stripper is less than that of a batch rectifier under “general constant reflux” and “general constant distillate composition”. When the feed contains a small amount of light component, the product purity specification is very high and the relative volatility is low, a batch stripper can also consume less energy only in the “general constant distillate composition” operation mode. In other cases, a batch rectifier can consume less energy.     

Unraveling the Nature of Individual Recognition by Odor in Hermit Crabs

Individual recognition is a key element in the social life of many invertebrates. However, most studies conducted so far document that several species are capable of a “binary” discrimination among conspecifics, but not of a “true individual recognition.” Our objective was to learn more about the mechanisms that underlie individual recognition by odor in hermit crabs by individuating some of its properties. Using Pagurus longicarpus Say 1817 as a model species, we conducted four series of experiments in which the response of every test crab (the “receiver”) to the different odor treatments (emitted by a “sender”) was evaluated from its investigative behavior toward an empty, high-quality shell. After having excluded the possibility that crabs chemically recognize familiar/unfamiliar shells and/or shells of high/low quality, we explored whether the receivers discriminate odors from two familiar senders and whether this discrimination also occurs with unfamiliar crabs. We also asked whether crabs form an association between the odor of a familiar sender and some of its relevant attributes, i.e., rank, size, and shell quality. Finally, the shells inhabited by familiar individuals were manipulated to modify the association between odor and shell quality. Results showed that: (1) there is no odor specific of a rank; (2) individual crabs discriminate their own odor from the odor of other individuals; (3) they can chemically discriminate between larger crabs inhabiting higher-quality shells and smaller crabs inhabiting lower-quality shells, provided that these crabs are familiar to them; (4) they associate the odor of an individual crab with the quality of the shell it inhabits; and (5) this association quickly changes when social partners switch to shells of different quality. These results indicate that the nature of chemical recognition in P. longicarpus is more refined than a simple binary system. The receiver appears able to associate a type of information from the sender with memories of past experiences, therefore suggesting the hermit crab's potential for relatively high-order knowledge about conspecifics.     

Factors affecting peanut butter preference

A sensory evaluation test with 320 subjects provided information pertinent to the preference of peanut butters. Results of paired preference test indicated that more than half the subjects (59%) preferred the “old fashioned” sample; flavor (aroma and taste) would have to be the primary reason since particle size was nearly the same in the prepared test samples. Chi-square tests of independence showed that the preference for the “old fashioned” sample was dependent on age (P<.05) and sensory attributes of flavor and textural perception (P<.05). Results of the survey showed that 47% of the total responding subjects listed “crunchy” peanut butter as their favorite type. Selection of one’s favorite brand of commercial peanut butter was found to be based primarily on its particle size.