Summary and Conclusion An investigation has been made of the hygroscopic equilibrium of cottonseed over a range of 31% to 93% relative humidity. From 31% to 71% relative humidity the moisture content of cottonseed increased linearly from 6.03% to 10.27%. From 71% to 93% relative humidity the moisture content increased rapidly from 10.27% to 22.19%. When cottonseed was separated into meats and hulls, including linters, it was found that the hulls contained more moisture than the meats. On the basis of these results it is apparent that, when stored cottonseed is aerated, consideration should be given to the effect of local atmospheric conditions. The relative humidity of the air used for aeration can affect the moisture content of the stored seed either favorably or adversely. Although it may temporarily reduce heating by conduction of the heat of respiration, it may increase the moisture content and thus stimulate further respiration and heating.

Summary and Conclusions The hygroscopic equilibria and rates of attainment of hygroscopic equilibrium of freshly dug, naturally cured, and artificially cured peanuts have been determined over the range of 11–93% relative humidity at 25°C. The hygroscopic equilibrium does not appear to be dependent on the method of curing. At a constant relative humidity, the moisture content is distributed so that the moisture content of the skins is twice that of the meats and in general the moisture content is lowest in the meats, and is increasingly greater in hearts, shells, and skins, respectively. At 25° and 35°C, the relative humidity is of greater importance than the absolute humidity. Circulation of the air over the samples greatly increases the rate of attainment of hygroscopic equilibrium. At the higher temperature, the rate of attainment of hygroscopic equilibrium is further increased because of the increased rate of diffusion of moisture in the seed. Inasmuch as the hygroscopic equilibrium is the same at both 25° and 35°C., it is more advantageous when speed of drying is important to use the higher temperature because equilibrium is attained more rapidly.

IntroductionCottoniseed deteriorates upon1 storage, with the result that the contenit of free fattv acids in the seed oil is increased, the color of the oil in the seed is darkened, the seed protein is partially denatured, and viability is decreased. This increase in free fatty acid conitent is reflected in a higher refining loss during the processing of the crude oil and the darkened color of the oil reduces its desirability as ani edible product. AIALOWAN (7,8), FREYER (3), anid ROBERTSON anid CAMPBELL (14) have investi(gated the effects of methods of storage, moisture content, and temperature of the seed on the formationi of free fattv acids during the storaoe of cottonlseed. SIMPSON (16,17) has made a thorough study of the effect of storage coniditions on the viability-of cottonseed, and RUSCA and GERDES (15) have observed the effect of the drying of cotton prior to ginning uponi the subsequeint storage behavior of the seeds. All of these invest.igators have concluded that, with iniereasino moisture content of the seed and higrher temperature of storage, there is a greater tendency-for the formation of free fatty acids in the seeds and a corresponding loss in t.heir viability.It has become evidenit, however, both from studies of the behavior of individual lots of seed and from a statistical study of the cottoinseed in the Delta reoion (9), that moisture content an(d temperature are niot the only factors influencing the quality of stored seed. This meanis that two samples of cottonseed which have the same moisture contenit anid whieh are stored at the same temperature will not necessarily develop free fatty acids at the same rate.The presenit report covers the results of the first of a series of investi- PLANT PHYSIOLOGY meats was thoroughly homogenized in 10 ml. of distilled water by the use of a glass homogenizer (12). The pH was determined as sooni as the homlogenization was completed; otherwise inconsistent and generally lower results were obtained. A glass electrode wi-as used for all pH measurements.The determinations of free fatty acids were made on the oil which had been extracted with Skellysolve F (boiling range, 30°to 600 C.) from the iueats prepared as described above. Three ml. of oil, freed from solvent, were transferred by use of a calibrated pipette ilnto 50 ml. of hot. neutralized ethyl alcohol and were titrated with 0.05 N sodium hydroxide solutioln, usingy thymol blue as the indicator. Whenever an oil with a very high content of free fatty acids was titrated, a stronger alkali solution (0.5 N) was used. In order to provide for proper stirring and heating of the emulsion of alcohol and oil dcuring the titration, the assembly shown in figure 1 was used. The stirring, was accomplished by an air-driven stirrer operating in one arm of the cell, and heat was applied by means of a chromel resistance wvire wound around the bottom bend. A potential of 20 volts applied to three feet of no. 25 chromel wire provided sufficient heating.It is possible to estimate the content of free fatty acids in cotto...

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