In preceding papers it was shown that sorbic acid is an effective nontoxic and practical fungistatic agent for foods. Indeed it is unique among food additives, being a metabolizable food (3, 4 ) added for protective purposes t o another food. The published reports have dealt with the use of sorbic acid to inhibit mold spoilage in cheese. For a review of the earlier developments in four different laboratories, reference is made to the Smith and Rollin summary paper ( I d ) . EXPERIMENTAL PARTIn investigating the application of sorbic acid to other food products, a number of physio-chemical studies were carried out to obtain basic information of value in supplementing foods with this fungistatic agent. Earlier studies in this field have dealt with the spectrophotometric determination of sorbic acid in foods (5, 6) and on wrappers (6), the degrees of resistance to oxidative deterioration of sorbic acid as such, on wrappers, and in foods (8), and the importance of maintaining an adequately high ratio of sorbic acid to mold concentration (9). Additional basic information, accumulated since the earlier investigations, is now being reported. Purity of Commercially Available Sorbic AcidStudies were conducted on ten lots of commercially available sorbic acid" to determine the purity of the material available to investigators for use in both laboratory and plant studies, Most analyses were conducted on the materials as receivedb but with results expressed on a moisture-free basis.Melting point values were obtained on the sorbic acid samples after drying for 4 hours at 50°C. in a vacuum oven at 20 mm. (Hg) pressure.I n determining equivalent weight the sorbic acid was dissolved in neutral isopropanol and then titrated with 0.1 N sodium hydroxide solution to the first end-point with phenolphthalein as the indicator. Sorbic acid concentrations were calculated from the found equivalent weights using 112.12 as the theoretical for pure moisture-free sorbic acid. The ultra-violet * These samples were selected at random from aliquots of production lots retained by Carbide and Carbon Chemicals Company, New York. Sorbic acid loses moisture very rapidly during weighings at room temperature.For this reason, glass stoppered weighing bottles were employed in taking samples for analyses. 639

Tensimetric measurements of the system thorium bromide and ammonia, in mm. of mercury at 0°and at pressures up to 1190 mm. indicate that the equilibrium ThBr4-20NH3 ThBr4• 14NHg + 6NH3, exists and that the pres-sure of the higher ammine is 1180 mm. The decomposition pressure of ThBr4-14NH3 is 268 mm. and that of ThBr4T0NH3 is 22 mm. At 25°the decomposition pressure of ThBr4-10NH3 is 184 mm.Cambridge, Mass.

No abstract

No abstract

Studies with inter‐esterified fats prepared to maintain a high level of linoleic acid content have been undertaken in several series of experiments with rats. These fats are as digestible as the liquid nonhydrogenated oils and the biological value of the linoleic acid is not impaired by the inter‐esterification. Investigations involving growth, reproduction and lactation, longevity, tissue cholesterol levels and histological tissue examination have revealed that these inter‐esterified fats are utilized by the animal similarly to cottonseed oil. No tissue pathology or interferences with any of the nutritional indices are observed. When the inter‐esterified fats are included in atherogenic diets, the atheroselerotic lesions which develop in the coronary arteries and aorta of the animals are similar to, but less marked than, those found when animals are fed cholesterol‐containing diets with butter oil or conventional margarine oil of the all‐hydrogenated type. It is concluded that these inter‐esterified fats are at least nutritionally equal to other similar edible fats of equivalent essential fatty acid content.