Kogakuin University, which was founded in 1887 (Meiji 20), has promoted academic exchange with the National University of Namibia in Africa. We are aiming to promote human resource development by accepting foreign students from Namibia, in order to increase industrialization in Namibia that enables effective use of resources, conserves the natural environment, and establishes a sustainable global society through inter-university cooperation. I hope this contribution will serve as an impetus for many people who are involved in food and food research to become interested in Namibia and Africa at large.

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Wheat is one of the major crops worldwide. Why does wheat succeed for human food and livestock feed? There are two aspects to its success. One is its environmental adaptability. And the other is the gluten protein fraction which shows the visco-elastic properties that allow dough to be processed into bread, noodles, and other various food products. For the point of view of the first one, as wheat evolved in the desert region of the highland gives ears with awns and the crease on the wheat grains in itself, these unique organs resulted in wide environmental adaptability.
The major components of wheat flour is starch and protein. Wheat starch consists of the lenticular granules of approximately 20μm mean size and spherical granules of approximately 5μm mean size. The granule is organized in concentric alternating semi-crystalline and amorphous layers. The semi-crystalline layer mainly consists of amylopectin. On the other hand, the amorphous layer almost consists of amylose. The amylose is a linear polymer consisting of approximately 1000 molecules of glucose linked by α 1-4 bonding. The amylopectin is a dendritic polymer branched by α 1-6 bonding every 20–25 molecules of glucose. The ratio of the content of amylose to that of amylopectin in starch strongly affects the texture of final food products. Hydrated protein, called gluten, confers the visco-elastic properties. The cross-linking of amino acid residues among domains gives a macro polymer. Because cross-linking is a chemical reaction, the three part requirements of chemical reactions (temperature, space, time) are of importance. In addition, increasing the pH of dough causes the de-amidation of the glutamine and asparagine, and the de-amidation generates glutamic and aspartic acid and ion bonding cross-linking takes place, as a result, the dough becomes hard. The unique properties mentioned above have produced a wide variety of foods such as bread and noodles.
Finally, based on the above findings, this article shows the interesting processing technique of food products, such as the batter of tempura and Japanese thin noodle (somen), which were featured in several television programs in Japan.

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Many studies of wheat glutenin subunits have provided novel details of their molecular structures and interactions which allow the development of a model to explain their role in determining the visco-elastic properties of gluten and dough. The present review summarises the knowledge from the sequence of formation (the degree of polymerization) of glutenin, from genes via the polypeptides to large disulfide-linked polymers.

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Improving our national food self-sufficiency ratio is a big issue in Japan, and increasing use of domestic wheat is one of the effective means. We have conducted studies for increased use of domestic wheat. Saitama prefecture has three wheat varieties for noodles and one variety for bread. “Norin61” (N61), a popular wheat cultivar for making Japanese Udon noodles, remains a perennial favorite because of its sensory characteristics, including its unique taste and flavor compared with Australian Standard White (ASW). Currently, N61 is being replaced by “Satonosora”, which is one of the successors of N61. Satonosora has good disease resistance, good color and crop yield like ASW but is inferior in Udon making and has less unique taste and flavor compared with N61. “Ayahikari” is one of the low-amylose wheat varieties, and it gives a glutinous texture for noodles. Ayahikari and Satonosora give good color to noodles, but color fading of boiled Udon is observed. “Hanamanten” is a wheat variety for bread cultivated in Saitama.
The noodle-making quality of N61, Ayahikari and satonosora is inferior to that of ASW because of the weakness of Gluten formed in the noodle dough. Glutenin unextracted with Sodium Dodecyl-Sulfate (SDS) solution contributes to the improvement in noodle-making quality. Hanamanten includes a lot of glutenin unextracted in SDS solution. An addition of Hanamanten to N61, Ayahikari and Satonosora improved the Udon making process. From observation of boiled noodles using Magnetic Resonance Imaging (MRI) and the fluorescence microscope, it was shown that the characteristics of the gluten affected not only the noodle-making process but also the texture of boiled noodles.
Hanamanten had an uneven gluten component ratio (gliadin/glutenin), therefore, it was difficult to make bread using only Hanamanten. Meanwhile, the gluten component ratio of Ayahikari was higher than Hanamanten. Blending Hanamanten and Ayahikari had a good effect for ease of bread-making.
Color fading of boiled Udon using Ayahikari was one of the issues. It was caused by Lipoxygenase (LOX) included in wheat flour. Some antioxidative ingredients such as ferulic acid trapped lipid radicals and inhibited the degradation of lutein. An addition of these antioxidative ingredients improved the color fading of boiled Udon.
We carried out an investigation about the taste and flavor of Udon. The result showed the existence of a preference between N61 and ASW. And also, the results of the sensory evaluation showed these differences.
Ongoing studies on the use of domestic wheat may lead to increased use and improve our national food self-sufficiency ratio.

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Food-Kansei Engineering provides consumer-oriented technologies by applying mathematical models based on the communication of the five senses in a human being. The latest information on hyper-strong wheat, bread surface color, as well as aroma have been thought of as the transformative factors in remotely-stimulating the communication of the five senses and thus food preference. The branding technologies to provide effective usage of these factors are presented by utilizing the results obtained from a field survey on hyper-strong wheat and also experimental research in bread baking processes.
The effect of heating conditions on crust color formation was investigated during the baking of white bread. The surface temperatures were monitored with the thermocouples attached on the rear surface of a loaf pan cover. The trajectory pattern of the surface color in the L^∗a^∗b^∗ color coordinate system was defined as the “characteristic coloring curve”. The curve demonstrated that a^∗ and b^∗ have a specified value for a certain L^∗ value. A linear relationship was observed between the L^∗ depression and the rise of weight loss of the samples. The surface color could be predicted from the relationships among the database of ingredient composition, air temperature, weight loss ratio, and sensory evaluation score.
The potent odorants in the crust and crumb of white bread were identified and quantified by gas chromatography-mass spectrometry and gas chromatography/ olfactometry. The weight loss ratio of the samples baked at 220 °C was controlled in the range of 0–28 %. The odorants were classified into 5 types by their transfer characteristics: 1) All odorants transferred from the crust to external space. 2) All odorants transferred from the crust to the crumb and external space. 3) A certain amount of odorants remained in the crust and the rest transferred to the crumb and external space. 4) All odorants transferred from the crumb to the external space. 5) A certain amount of odorants remained in the crumb and the rest transferred to the crust and external space. The results indicate that the crust could be a barrier to prevent the odorants from being transferred to external space. The optimum control period was found to be at the stage where crust formation starts, for creating aroma which gratified the consumer most. Coupling the stepwise PLS-VIP and the ANN modeling successfully provides the tools to analyze and design the optimum final products contributing to the palatability of white bread.

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Increased public awareness about negative health effects associated with excessive sugar consumption has triggered increasing interest in plant-derived natural zero-calorie sweeteners. Three plant species containing natural sweeteners, Stevia rebaudiana, Siraitia grosvenorii, and Glycyrrhiza plants have been the subject of extensive phytochemical studies to identify compounds with marked sweetening properties. Steviol glycosides are a group of highly sweet diterpene glycosides contained in the leaves of the Paraguayan shrub Stevia rebaudiana (Bertoni). Mogrosides, extracted from fruits of Siraitia grosvenorii (Swingle), a herbaceous perennial plant of the Cucurbitaceae family native to southern China, are a group of cucurbitane-type triterpenoid glycosides that can be more than 300 times sweeter than sucrose. Glycyrrhizin, an oleanane-type triterpenoid glycoside derived from underground parts of Glycyrrhiza plants of the Fabaceae family, is more than 150 times sweeter than sucrose. It has been used as a natural sweetener and also as a medicinal material because of its various pharmacological potential with anti-inflammatory and hepatoprotective properties.
The recent availability of inexpensive and high-throughput sequencing technologies has allowed plant scientists to conduct deep transcriptome analyses of non-model plants, including the above-mentioned species. As a result, many of the genes encoding enzymes related to the production of plant secondary metabolites have been identified. This review summarizes recent progress in gene discovery and elucidation of the biochemical functions of enzymes active in the biosynthesis of steviol glycosides, mogrosides, and glycyrrhizin. A special focus is placed on the functions of cytochrome P450 monooxygenases (P450s) and UDP-dependent glycosyltransferases (UGTs) as enzymes contributing to the biosynthesis of these natural sweeteners.
Recently, remarkable progress has been made in engineering the production of various plant secondary metabolites in microbial hosts such as yeast species, through the introduction of biosynthetic genes. Perspectives on the use of these latter for the microbial production of plant-derived natural sweeteners are also discussed in detail.

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In the course of screening food materials for anticancer activity, we found that a Thelephora aurantiotincta ethanol extract decreased viability of human hepatocellular carcinoma cells. Mushrooms of the Thelephoraceae family are widely distributed in America, Australia, New Zealand and Japan, and are a rich source of biologically active compounds. Previous phytochemical investigations conducted on the genus Thelephora revealed that it is an abundant source of p-terphenyl compounds. Some of these latter have been reported to feature biological activities such as scavenging of 2,2-diphenyl-1- picrylhydrazyl (DPPH) radicals, neuroprotection, and immunosuppression.
We have studied bioactive components responsible for anticancer activity of T. aurantiotincta and isolated a new p-terphenyl compound, thelephantin O, as well as a known compound, vialinin A, as the principal agents in ethanol extracts. In addition, we were able to elucidate underlying mechanisms and structure-activity relationships.
T. aurantiotincta, which grows in symbiosis with pine trees, is sold as an edible mushroom whose unique flavor is greatly appreciated in the Yunnan province of China. Although mushrooms belonging to the genus Thelephora are rich sources of biologically active compounds, culture systems for large scale production have yet to be established. Therefore, we have focused on chemical synthesis as an essential alternative and have reported synthetic routes to various p-terphenyl compounds. In this review, we detail various biological activities of p-terphenyl compounds, and discuss structure-activity relationships.

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Introduction
“Green Odor” emitted by leaves is composed of six unsaturated C6 alcohols and aldehydes with Z- or E-double bonds and two saturated compounds. In response to environmental stimuli, neutral fat, phospho-and galacto-lipids in chloroplasts are hydrolyzed by lipolytic acyl hydrolase to yield α-linolenic and linoleic acids. Then, by lipoxygenase and the hydroperoxide lyase, these acids yield (Z)-3-hexenal and n-hexanal via unstable (S)-13-hydroperoxide intermediates. Finally, by alcohol dehydrogenase these aldehydes are reduced to corresponding alcohols. On the other hand, pyrethrin activity is induced by an original blend of “Green Odor” and (E)-β-farnesene and is formed finally by Lipase/Esterase from chrysanthemoyl CoA and pyrethrolone, respectively. Namely, the pyrethrin forming activities are exactly controlled by the blend ratio of “green odor” and the terpene. This unexpected original finding means that the “Green Odor” is a very important messenger of plant origin.

“Green Odor”
This article describes components, biosynthesis and seasonal changes of the green odor. Green odor emitted by leaves is composed of six unsaturated C6-alcohols, -aldehydes with Z- or E-double bond and two saturated compounds. In these homologues, (E)-2- hexenal is named “leaf aldehyde”, whereas (Z)-3- hexenol is referred to as “leaf alcohol”. Leaf aldehyde was found in fresh green leaves of certain bushes by Curtius T. at Heidelberg University in 1912. Meanwhile, Leaf alcohol was found in fresh tea leaves by my teacher Takei S. at Kyoto University in 1933. In 1960 and 71, I found ｓ(E)-3- and (E)-2-hexenols and then in 1973 and 81, I found (Z)- and (E)-3-hexenals from fresh tea leaves. These eight compounds are collectively regarded as “Green odor”. Until today I have investigated them from a multi disciplinary approach of organic chemistry, biochemistry, molecular biology, aroma-physiology and -psychology.
At first, in the biosynthetic pathway of green odor it should be noted for the unexpected findings that the precursor of green odor does not possess six carbons, such as glucoses, but eighteen carbons; α-linolenic (1) and linoleic acids (2). In response to various environmental stimuli, neutral fat, phospho- and galacto-lipids in tea chloroplasts are hydrolyzed by lipolytic acylhydrolase to result in (1) and (2). Then, by lipoxygenase (LOX) these acids are converted to unstable (S)-13-hydroperoxide-intermediates. Following that, by hydroperoxide lyase (HPO lyase) the cleavage of the single bond between carbon-12 and -13 of these intermediates results in (Z)-3-hexenal and n-hexanal. By alcohol dehydrogenase these aldehydes are reduced to corresponding alcohols. It should be noted that the pathway from lipids to (Z)-3-hexenal is a one way reaction, whereas the alcohol-aldehyde redox reaction is an equilibrium. By this equilibrium the concentration balance between six unsaturated alcohols and aldehydes should result in induced bioactive function. Particularly, the lipoxygenase reaction passes through the complex stereochemical steps, that is the removal of a H proton from C11 in α -linolenic acid to form an (S)-13-hydroperoxide-intermediate. This stereochemical coordination is left rotation of R1->R2->R3- bound to asymmetric carbon-13. (Z)-3- and (E)-2-hexenals produced by LOX and HPO lyase differ largely by plant species.
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