Alex P Mathers

Bio: Alex P Mathers is an academic researcher from Internal Revenue Service. The author has contributed to research in topics: Wine & Lithium. The author has an hindex of 2, co-authored 8 publications receiving 13 citations.

Regioselective Homo- and Codimerization of 1-Alkynes Leading to 2,4-Disubstituted 1-Buten-3-ynes by Catalysis of a (η5-C5Me5)2TiCl2/RMgX System

Abstract: A series of 1-alkynes (RC≡CH where R=Et, n-Pr, n-Bu, n-C6H13, cyclohexyl, Ph, Me3Si, Me3SiCH2, and Me3SiOCH2) was found to dimerize regioselectively (>99%) to 2,4-disubstituted 1-buten-3-ynes in 92–99% yields by catalysis of (η5-C5Me5)2TiCl2/i-PrMgBr at 30 °C in 1–3 h. The catalyst system is also effective for the regioselective codimerization of various 1-alkynes with 1-ethynylcyclohexene or ethynylbenzene.

The chemistry and technology of the pretreatment and preservation of fruit and vegetable products with sulfur dioxide and sulfites.

Abstract: Publisher Summary This chapter summarizes present status of knowledge in the chemistry and technology of the pretreatment and preservation with sulfur dioxide and sulfites, which is restricted to foods of plant origin. The theoretically available sulfur dioxide content and the usual range of SO 2 content for various preparations have been shown. The chapter summarizes that sulfur dioxide added to fruit and vegetable products as liquid sulfur dioxide, as gaseous sulfur dioxide, as solution of sulfurous acid in water, or as dry or dissolved sulfites will exist as the undissociated sulfurous acid, as the free bisulfate ion, as the free sulfite ion, and as combined sulfur dioxide in the form of the hydroxysulfonates. The chapter discusses the preservative value of sulfur dioxide in fruit and vegetable products and other foods and beverages. The possibility of removing the sulfite added as a preservative by heating to decompose the combined sulfur dioxide and remove the free sulfur dioxide by volatilization has been investigated. In addition to desulfiting by physical methods, chemical methods ranging from treatment with oxidizing agents like hydrogen peroxide to addition of substances to combine with free sulfur dioxide such as acetaldehyde have been proposed for the treatment of juices and dried fruits. The chapter discusses sulfur dioxide as an inhibitor of enzymic and nonenzymic browning and the source and application off sulfur dioxide are mentioned. It discusses the uses of sulfur dioxide in fruit juices, syrups, concentrates and purees, wine and vinegar making, dehydrated and dried fruits and vegetables product, and in transportation and storage of grapes and other products.

Composition of wines. I. Organic constituents.

Abstract: Publisher Summary This chapter is limited to the organic components of wines and to publications in the period 1930 to 1953. Both phases of enology have been reviewed, but it is obvious that the more significant studies have been those of a physical-chemical nature. The organic components of wines have been discussed in broad general groups-acids, carbohydrates, alcohols, etc. For each component, information on the methods of determination has been given first, followed by a review of work on the occurrence or significance of the compound. Wines are classified, taxed, and bought and sold according to alcohol content. Therefore, great attention has been given to its accurate and rapid determination. Some errors of the method and of the instruments in the ebulliometric determination of alcohol have been pointed out. Further difficulties in determining the alcohol content of sweet wines using the ebullioscope were found. Another physical method is based on the principle of extracting the alcohol with an immiscible solvent and reading the per cent alcohol from the position of the meniscus. The disagreement on the exact relation between the sugar content of the must and the resulting alcohol content of the wine was reviewed. The difficulty of determining methyl alcohol in the presence of ethyl alcohol was stressed. The mechanism of the formation of higher alcohols has been studied, which reported that higher alcohol formation coincided with the beginning of the main fermentation

Some essential nutrient elements in forest plants as related to species, plant part, season and location

Abstract: Natural vegetation common to the forested areas of Nova Scotia was sampled and analyzed for the nutrient elements calcium, phosphorus, cobalt, molybdenum, manganese, zinc and copper. Results showed considerable variation within and between species. Variations due to plant part, season and location of sampling also occurred but to a lesser degree. With the possible exception of molybdenum and copper, the elements are present in adequate quantities for normal nutrition. The average range of nutrient content for cobalt was found to be 0.09 to 0.44; molybdenum 0.01 to 0.32; zinc 13.0 to 91.0; manganese 44 to 594; copper 4.9 to 31.7 in terms of parts per million while calcium ranged from 0.36 to 1.11 per cent and phosphorus from 0.06 to 0.21 per cent. re]19750210

The mechanism of cloud loss phenomena in orange juice

Abstract: The importance of many factors for the cloud stability of orange juice was investigated. By the determination of methanol, cloud loss of orange juice could be ascribed directly to the action of pectin esterase. However, clarification only occurs if calcium ions are available to precipitate the low methoxy pectin formed by pectin esterase. This mechanism was confirmed when the addition of pectic acid clarified the orange juice artificially. Clarification did not occur if the formation of high polymer calcium pectate was prevented either by degrading the juice pectin by a purified pectin lyase before substantial action of pectin esterase, or by enzymic hydrolysis by a yeast polygalacturonase of the low methoxy pectin formed. Methanol determinations showed that cloud stabilization had been achieved in spite of normal action of pectin esterase. Methods to determine cloud stability have been discussed. Literature on the research of cloud stability of fruit juices, on pectic substances and pectic enzymes, and on methods to determine pectin esterase have been reviewed.