Many necessities such as food products and drugs, as well as clothes, can be considered as organic compounds including examples of biological origin. Not surprisingly, obtaining sufficient amounts of these necessities in a safe manner will continue to be the greatest supreme interest for human beings. As for clothes, responding to an increase in demand for naturally-derived cotton, wool, and silk, various textile products, including nylon, Orlon, and polyesters, began to be massively produced world-wide in the middle of the 20th century, in part answer to solving major issues on clothing as an absolute necessity.
Here, I would like to focus on methods for efficient and safe synthesis of food ingredients and pharmaceutical products from organic chemicals, with especial attention to metalorganic compounds. The “metalorganic compound” features use of organometallic complexes as reagents and/or intermediates, but only rarely as final products. Why are such metal-containing reagents or intermediates employed? This is because they facilitate efficient production of safe and pure ingredients for intended foodstuffs and pharmaceutical products. Regarding obtaining pure ingredients, one difficult issue which was not been sufficiently resolved until recently is highly stereoselective organic synthesis, in which optically active compounds have either enantiomer dominant (99 % or more). This issue was raised in the middle of the 19th century when L. Pasteur in France found that 2 samples of different tartaric acid showed optical rotation of reversed forms with an identical angle of rotation. About a half century later, E. Fischer in Germany succeeded in the synthesis of various saccharides with stereochemical purity using an elaborate method that was nothing short of an absolute masterpiece. Already with his method, target substances were obtained diastereoselectively based on the difference in energy between molecules, in which stereochemically-pure compounds were used as starting materials. Another half century later, K. Ziegler in Germany succeeded in initiating the polymerization reaction of alkene with simultaneous control of each stereochemical property and developed a process of ordinary pressure polymerization of isotactic polyethylene. Moreover, G. Natta in Italy succeeded in developing high-performing polypropylene, which h a d been earlier appeared impossible, and this development has subsequently given rise to a gigantic world-wide industry.
What should be taken into consideration is the fact that a Ziegler-Natta polyolefin synthetic reaction is diastereoselective, meaning relative stereochemical associations between vicinal monomers are extremely important, while an absolute stereochemical property, that is a configuration around an asymmetric carbon with an absolute configuration of R or S, is less important. However, with the above important exception, the absolute stereochemical property (absolute configuration) is typically very important and should be controlled at the intended level as necessary. Epoxidation of olefin performed by K. B. Sharpless in the US and asymmetric reduction of olefin achieved by R. Noyori in Japan have been evaluated as pioneering work in this field. Oxidation-reduction reactions for olefin are increasingly used and are well known as a subject for a Nobel Prize in 2001. What should be focused on is that allyl alcohols are used as starting materials in most cases of the above reactions, and that the intended stereoisomers are obtained in a diastereoselective manner based on the stereochemical property of the starting compound. An enantio-selective alkene carbometalation independent from the stereochemical property of the starting material was achieved by our study group after about 20-years of study.
(View PDF for the rest of the abstract)

View full abstract

Acetaldehyde is a major volatile organic chemical compound which serves as an essential intermediate product in several intracellular metabolic pathways, increasing with ethanol detoxification and acetic acid fermentation. Of particular importance, acetaldehyde is very toxic to all living cells, because it readily forms adducts with proteins and DNA, blocking cell growth and interfering with a wide range of cellular metabolic activities. The budding yeast Saccharomyces cerevisiae has an especially well-developed and strong acetaldehyde tolerance system, due to yeast its exposed to acetaldehyde stress during alcohol fermentation. Indeed, with acetaldehyde exposure, yeast cells up-regulate the pentose-phosphate pathway to produce large amounts of NADPH, which is utilized in several acetaldehyde tolerance systems, like oleate synthesis and glutathione reduction. These findings promise great potential for application in drug development against disease related to acetaldehyde, and for molecular breeding of industrial microorganisms, e.g., budding yeasts and acetic acid bacteria.

View full abstract

White leaf tea is a generic term for tea the color of the new shoots that remain white or yellowish color when grown. Targeting the white leaf tea cultivars ‘Koganemidori, Kiraka, Yamabuki and Hoshinomidori’, and shading the plants with a cheesecloth to cultivate ′shaded white leaf tea′, and green tea cultivar ‘Yabukita’, we compared the chemical composition (amino acid or catechin contents, etc.) and morphological characteristics of new shoots harvested at different times. Although the contents of total free amino acids (TFAs) of white leaf teas were around two fold higher than the green tea cultivar ‘Yabukita’ in the 1st crop season, the rate of arginine was markedly higher. Caffeine content was also higher in white leaf teas than the green tea cultivar. On the other hand, catechin contents were lower than green tea cultivars. The leaf color and photosynthetic rate in the white leaf teas were also lower than that of ‘Yabukita’.

View full abstract

Acrylamide is found in a wide range of high-temperature processed and/or cooked foods. Formed mainly from asparagine in Maillard reactions in the presence of a reducing sugar such as fructose and glucose, the compound can be metabolized to glutathione conjugates and is also oxidized to glycidamide, a genotoxic agent which forms DNA adducts. Acrylamide is known to exert genotoxicity, neurotoxicity, and reproductive and developmental toxicity and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) concluded a health risk from acrylamide in foodstuffs. The major foods contributing to total intake of acrylamide were found to be French fries, potato chips, coffee, pastry and sweet biscuits, and bread and rolls/toasts. The committee concluded based on national estimates that an intake of 1 μg/kg bw per day of acrylamide could be taken to represent the average for the general population. The Committee selected 0.18 mg/kg body weight per day as the most sensitive carcinogenicity estimate from animal study data. The margin of exposure (MOE) for the general population was thus calculated to be ca. 200 times, which is low for a carcinogen and indicates a potential human health concern. The Code of Practice for the Reduction of Acrylamide in Foods was adopted by Codex Alimentarius Commission in 2009 based on scientific analytical data obtained worldwide. Food Drink Europe published “Acrylamide Toolbox” to provide national and local authorities, as well as manufacturers, including small and medium size enterprises, with brief descriptions of intervention steps which may prevent or reduce formation of acrylamide in specific manufacturing processes and products. In Japan, the Ministry of Agriculture, Forestry and Fisheries has published acrylamide mitigation guidelines for manufacturers and consumers. Acrylamide levels in foods are decreasing owing to such mitigation measures, but the MOE is still considered to be less than 1000.

View full abstract

For this article, a comparative analysis of EU/Germany and Japan was conducted regarding official control of food laws, which ensures implementation of legal measures and verifies the compliance of food business operators. The following four problems regarding the official control system in Japan were identified: (1) While in the EU there is a regulation which lays down the framework of official control for food and feed laws along with the food chain, no such framework exists in Japan; (2) In Japan, the competent authorities for implementation of laws are not unified but rather divided along the food chain and among various aspects; (3) Decisions of frequency of control of food establishments depends on the local government in Japan and depends on the business type so it does not directly reflect the situation of each individual establishment. In Germany, in contrast, a framework for risk based control of food establishments was developed according to which each establishment is assessed for an appropriate frequency of inspection; and (4) Competent authorities for control in the European member states must carry out internal audits. In addition, the European commission carries out audits in member states regarding the functioning of official controls. However, there is no such system for ensuring the effectiveness and reliability of control activities in Japan.

View full abstract

I recognized that a food manufacturer focused on the PCR method for detection of allergens, according to its press releases and the annual security reports. Therefore, I collected papers concerning this technology from scientific and technical literature databases, and displayed them in chronological order, including extracted cited literature about them. As a result, the relationship between social issues, regulations by the government, and research and development projects which are collaborative efforts among industry, academia and government with leadership by the national institute, were visualized. Furthermore, I recognized that the research spread into private enterprise and brought economic and social value through public research organizations such as health, hygiene, and environment facilities in each province. This information was not noticed by the persons concerned with the issue.

View full abstract

Japan has a wealth of fermented food products and beverages. In 2013, Japanese food was registered on UNESCO's World Culture Heritage List. The fermenting agent used in many of these foods is koji, a fungus of the genus Aspergillus. Koji is steamed rice that has been inoculated with koji spores (Aspergillus oryzae) and incubated to allow the fungus to grow. Rich in enzymes, koji is the key ingredient in all the basic foods of the traditional Japanese diet. The beneficial feature of A.oryzae is not only its potential as the source of various enzymes, but also its ability to produce these enzymes at high yields. While the history of fermented foodstuffs is long, independent production and sale of koji starter, as we still do, already existed about 500 years ago. Koji star ter is manufactured by approximately 5 special companies in our country. All breweries purchase koji starter from these companies. Koji is the base of fermented foods production and it is said that quality of products is influenced by the quality of koji. It is not too strong to say that important elements deciding the quality of koji depend on the type of koji starter.
Manufacturers of koji knew the use of wood ash to keep koji starter clean and safe a long time ago, although basic microbiological techniques such as preservation of microbes and pure cultivation were established much later in the 19th century. This is an ingenious microbiological technology established by the ancient Japanese in the 15th to 16th century. An original koji strain is the most important part of koji starter.
We improve the characteristics of the koji fungus as follows. The discovery, isolation and selection of useful microorganisms from natural environments are used to produce new excellent products as a fundamental technique, and suitable strains that are newly found are stored. Natural mutation is accelerated by the use of ultraviolet light or other methods, to produce mutant strains. Natural mutation is a normal biological phenomenon that occurs in every living organism.
Koji fungi is traditionally grown under specific stress conditions on a solid medium. Therefore, it is possible that new discoveries will be made that would not have been identified in fungi grown under standard conditions. Indeed we have already found novel antifungal agents and antiviral agents from various fungus which are grown on solid medium. Now, some of the biological control agents have reached the commercialization stage as microbial fungicides.
It is possible to modify the koji starter manufacturing method into producing the active ingredients of bio-fungicides. This technology is based on koji starter manufacturing. Now, we use antagonistic fungal spores as agrochemicals.

View full abstract

Perilla is a common kitchen herb in Japan and its characteristic scent is supposed to be the most important trait for its popularity. The author has been and still is studying perilla with various procedures for more than 20 years and experienced many cultural occurrences. Here are some discussions and statements upon those occurrences relevant to perilla from the sophisticated viewpoint of a scientist.

View full abstract