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Six methods for estimating starch were applied to three samples of lucerne leaflet tissue. Three of the methods, each incorporating the specific glucose-oxidase procedure to estimate the starch hydrolysis products, gave values in close agreement with each other. These values were lower than those obtained using three other methods which employed only a non-specific hydrolysate measurement. Further investigation indicated that the elevated values probably were caused by inclusion of non-starch polysaccharide in the estimation. It is suggested that the specific oxidase procedure could be easily incorporated into one of the methods which gave elevated values.

Solids content and amylose/amylopectin ratios were determined in different parts of tubers of White Rose, Red La Soda, Kennebec, Russet Burbank, Norchip and Lenape at harvest, after storage at 7 C for 2 and 4 mo, and after reconditioning at 20 C for 3 wk following each storage period. In all cultivars, solids content was greatest in stem-end, lower in bud-end and lowest in core tissue. The relationships for distribution of solids among the different parts of the tubers was not changed by storage treatments in any of the cultivars. Amylose/amylopectin ratios were similar in all parts of the tuber. Both the solids content and amylose/amylopectin ratio were changed by storage, but not uniformly in all cultivars.

Sugar-containing potato extracts were analyzed for sugars before and after invertase hydrolysis using Sumner and Sisler’s dinitrosalicylate method, modified and automated. Amylose and total starch were determined on sugar-free potato flour by automated methods, amylose was analyzed by the iodine color reaction, and starch as glucose was determined after hydrolysis with trifluoroacetic acid and reaction with dinitrosalicylate. Results were sufficiently reliable and satisfactory for surveying white potato samples for carbohydrates.

A simple procedure is described for determining sodium in sodium hydroxide-treated rice straw and rye grass, lye-peeled potato wastes, and brine-frozen vegetables. Samples containing ≤4% sodium were extracted with 0.05M ammonium carbonate and the extracts were analyzed directly by using a sodium ion selective electrode over the range 10−4 to 10−2M sodium ion. Comparable analyses of the same extracts by atomic absorption spectrometry agreed to within 10%. Recovery of sodium added to control rice straw was 102%.

In no-choice tests but not in choice tests, alligatorweed flea beetles,Agasicles hygrophilaSelman & Vogt (Col.: Chrysomelidae) exposed to alligatorweed plants grown with two levels of mineral nutrition fed significantly more on those grown in full mineral nutrient than those grown with deficient phosphate. Chemical analysis showed that the full nutrient plants had more ethanol-soluble nitrogen compounds but less total carbohydrate than the phosphate-deficient plants. The response of beetles to phosphate-deficient alligatorweed may thus result from a change in the carbohydrate-nitrogen composition of host plants, though further investigation is needed for confirmation. Flea beetle response was identical to terminal and mature leaf tissue of full nutrient plants.

R(~ceived for /Juhiiration A /l.g;ust 10, 1967 Molasses formation from beet sugar liquors has had the attention of technologists for more than 100 years. Its formation in the factory is dependent on many factors but probably the most important variables are the effect of some non-sug-ars In decreasing the rate of crystallization and others in increasing the solubility of sucrose in the molasses solution. Since equilib­ rium between crystallized sugar and sugar in solution is not reached in industrial molasses because of the time necessary to reach this equilibrium, factory molasses contains more sug-ar than a completely exhausted molasses. Molasses in this paper refers to factory discard molasses. In an attempt to determine what chemical factors were re­ lated to variations in molasses purity a composition study was made of molasses produced in the different beet sugar areas of the United States. Samples were selected from straight house and Steffen factories and analyzed for a large number of com­ pounds and groups of compounds. The analytical methods used and the data obtained are presented in Part I of the paper while the statistical evaluation of the data is presented in Part II. Experimental Molasses sample'S were obtained during the' 1956 campaign from a cross sectIOn of the beet sugar producing areas of the Fnited States. Straight house samples were obtained from Bet­ teravia, Clarksburg and ;-vlanteca, California; Brighton, Eaton and Swink, Colorado; Rupert, Idaho; Carrollton, Michigan; Crookston and Moorhead, Minnesota; Sidney, :Montana; Fre­ mont, Ohio; Belle Fourche, South Dakota; v\'est Jordan, Ctah; Toppenish, Washington, and Green Bay, \Visconsin. Spring and fall campaign samples were obtained from Betteravia. Swink ordinarily operates as a Steff en house', but the sample included in this study was produced from Kansas beets while the factory was operating as a straight house. Steffen house samples were 1 Western R egional R esearch Labora to ry. Agricnltural R esearch Service. U. S. Depart­

The action of tomato and avocado enzyme preparations on polygalacturonic acids was compared with that of fungal polygalacturonase (PG). Fungal, tomato, and avocado preparations hydrolyzed polygalacturonic acid and also tri-and digalacturonic acid to galacturonic acids. The preparations also hydrolyzed methyl digalacturonic acid to galacturonic and methyl galacturonic acid. Their specificities seem to be qualitatively the same and their apparent differences lie mainly in their relative rates of hydrolysis of oligouronic acids, such as digalacturonic as compared with polygalacturonic acid. The rate of hydrolysis of digalacturonic acid is much lower with the fruit enzymes than with a preparation of fungal origin.

The annual processing of citrus fruit wastes in the United States has reached two million tons. Forty thousand tons of pectin could be produced, compared with current production of three thousand tons. The physical and chemical properties of pectic substances are important botanically and industrially. Pectic substances aid in maintaining texture of fruits and vegetables and serve as jellying agents in preserves. The availability of increasing amounts of citrus wastes, combined with improvements in manufacturing techniques and new uses, promises expansion of industries concerned with pectin production and utilization.

Nelson and Auchincloss (10) working with potato tissue showed that sucrose is synthesized from glucose or fructose rather than from starch as has been supposed by some investigators. That such a conversion occurs in plant metabolism has also been shown by Virtanen and Nordlund (14) in red clover and wheat plants, and more recently by Hartt (3) in detached sugar cane leaves. Since sucrose, consisting of a glucose and fructose molecule, can readily be synthesized from either of these monosaccharides, it may be assumed that such synthesis involves a preliminary conversion of each of these hexose sugars into the other. The fructose component of the sucrose molecule exists in the furanose form (unstable ? form with the five-membered ring) and is different from the six-membered fructose (pyranose configuration) from which it can be synthesized. The plant apparently also possesses a mechanism to render this transformation possible. The fact that sucrose is synthesized when plants are artificially supplied with glucose or fructose can serve indirectly in the study of transformation of other hexoses in the plant into these monosaccharides. If, for example, synthesis of sucrose is observed after supplying the plant with mannose, it could be assumed that a preliminary conversion of the latter into glucose and fructose must take place before the synthesis of sucrose occurs. The hexoses that are known to occur naturally in plants are: d-glucose, d-fructose, d-mannose, and dgalactose ; of these the last two have not been detected in the free state and are found in plants only as units in polysaccharides. If, as it is generally assumed, some form of glucose is the first product of photosynthesis, the plant should possess a mechanism whereby this molecule is transformed into mannose or galactose before the synthesis of the corresponding polysaccharide can be possible. In this investigation, using the infiltration method (8), the following compounds were artificially supplied to barley plants : d-glucose, d-fructose, d-mannose, d-galactose, sucrose, lactose, maltose, 1-arabinose, d-xylose, mannitol, sorbitol, gluconic acid, pyruvic acid, and glyceric aldehyde. The increase of sucrose was observed after certain periods of time to determine the ability of the plant to transform these compounds into glucose or fructose and, if possible, to ascertain the mechanism of this transformation.

A drop-scale modification of the common volumetric lactic acid method is described. Samples containing from 1,22 to 28,85γ of lactic acid were analysed in simple solutions and in various blood samples. The accuracy of the method was usually about the same as in the macro procedure.

An atomic absorption spectrophotometer was used for the quantitative analysis of reducing sugars by determining unreduced copper. Copper reduced in alkaline solution by sugar forms insoluble Cu2O. The Cu20 was centrifuged from the solution, and the unreduced copper in solution was measured with an atomic absorption spectrophotometer. The concentration of sugar present in test solutions was determined from a working curve prepared from known amounts of sugar.

Two common environmental pollutants are agricultural residues (skins, pits, husks, tannin bark, grape pomace) and waste streams of water containing only traces of heavy metals (such as mercury at 10 or more ppb) from mining or manufacturing operations. Agricultural residues contain tannins, polyphenolic substances, pectin, and other polymers-all with chemically reactive groups that can chelate, reduce, oxidize, demonstrate ion exchange properties, and aid in removing traces of heavy metals from dilute waste water streams at low cost. Finely ground and water-washed agricultural residues were slurried in water and packed into columns for absorption tests with heavy metals. Solutions of known concentrations of heavy metals were passed through the packed columns which were then eluted with water or with alkaline or acidic solutions. The fractions and the column absorbents were then analyzed by standard atomic absorption methods. The nature of the physical and chemical forces that are effective in metal absorption from agricultural residues is not clear.