Origin of Homochirality of Amino Acids in the Biosphere

Discussions are made concerning realistic mechanisms for the origin of L-amino acids in the biosphere. As the most plausible mechanism, it is proposed that a mixture of racemic amino acids in the prebiotic sea caused spontaneous and effective optical resolution through self crystallization, even if asymmetric synthesis of a single amino acid has never occurred without the aid of an optically active molecule. This hypothesis is based on recrystallization of a mixture of D,L-amino acids in the presence of excess of D,L-asparagine (Asn). The enantiomeric excess (ee) of each amino acid in the resulting crystals indicates that crystallization of co-existing amino acids with the configuration same as that of Asn took place, although it was incidental whether the enrichment occurred in L- or D-amino acids. In addition, the resulting ee was sufficiently high (up to 100%) to account for the predominance of L-amino acids on the earth

Racemic D,L-asparagine causes enantiomeric excess of other coexisting racemic D,L-amino acids during recrystallization: a hypothesis accounting for the origin of L-amino acids in the biosphere.

When recrystallizations were performed using a mixture of 12 D,L-amino acids (alanine, aspartic acid, arginine, glutamic acid, glutamine, histidine, leucine, methionine, serine, valine, phenylalanine, and tyrosine) with excess D,L-asparagine, all amino acids with the same configuration as asparagine were preferentially co-crystallized, indicating that it is the nature of a mixture of racemic amino acids to produce a spontaneous high enantiomeric excess.When recrystallizations were performed using a mixture of 12 D,L-amino acids (alanine, aspartic acid, arginine, glutamic acid, glutamine, histidine, leucine, methionine, serine, valine, phenylalanine, and tyrosine) with excess D,L-asparagine, all amino acids with the same configuration as asparagine were preferentially co-crystallized, indicating that it is the nature of a mixture of racemic amino acids to produce a spontaneous high enantiomeric excess

栄養士コースの短大生を対象にした和風だしの味覚に関する調査

　世界的にも和食が注目されているが，近年，わが国では食の欧米化が加速している．そんな中，若い世代を対象 に和食に対する調査を行うことは，これからの和食への関心の継続に繋がるだけでなく，将来的な食育の発展にも 寄与することが期待できる． 　本研究では，和食の中でも日本古来の「和風だし」に焦点を絞り，短大生の味覚について官能評価・アンケート調 査を用いて現状の把握と課題の抽出を行った．四種類の「和風だし」の官能評価において，「A：昆布1％・かつおぶし 2％だし」の天然だしと既製品の「C：かつおだし（顆粒）」及び「D：混合だし（顆粒1：1）」の3つに好みが分かれる結果と なった．既製品の「B：昆布だし（顆粒）」の官能評価は「まずい」が半数を超えていた．だしの嗜好に関する調査では， 既成の「顆粒だしの素」が日常の調理では73％の家庭で，味噌汁を作る際は63％の家庭で使用されていた． 　Japanese food is gaining attention globally, but in recent years the Westernization of food is accelerating in Japan.　In such circumstances, conducting a survey on Japanese food for young people will not only lead to continued interest in Japanese food in the future, but also to contribute to the development of food education in the future. 　In this research, we focused on traditional Japanese “dashi soup” among Japanese cuisine, and conducted sensory evaluation and questionnaire survey on the taste of junior college students to grasp the current situation and extract problems.　In organoleptic evaluation, it was resulted the college students preferred three dashi soup such as “A: 1％ kelp and 2％ onion”, “C: bonito (granule)” and “D: mixed (granule 1: 1)”.　The most unfavorable dashi soup was stock “B: kelp soup (granule)” in over half of students.　In the survey on the preference of soup stock, 73％ of homes were cooked in daily life and 63％ of households were using“ granulated noodles” when making miso soup

高校調理科生徒を対象にした和風だしに関する調査研究

高校の調理科は文部科学省のデータで職業学科（家庭）に属し，日本の全高校生の中で1.3％しか学んでいないと 報告されている1）．それ故，食を中心にした特徴的学習をしている調理科に通う高校生を対象にした和食に関する 調査研究は貴重である．さらに，高校生という若い世代を対象に和食に対する調査を行うことは，これからの和食 への関心の継続に繋がるだけでなく，将来的な食育の発展にも寄与することが期待できる． 　本研究では，和食の中でも日本古来の「和風だし」に焦点を絞り，調理科生徒の味覚について官能評価・アンケー ト調査を用いて現状の把握と課題の抽出を行った．官能評価において，Cだし「かつおだし（顆粒）」が最も好まれる 結果で，一番まずかっただし汁はBだし「昆布だし（顆粒）」で半数を超えていた．今回調査を行った調理科生徒の家 庭では，一般的な料理を作る際「顆粒だしの素」を使用している割合が55％，味噌汁を作る際は53％，と「顆粒だし の素」を使用している割合が高かった．家庭で使用している‘だし’が生徒の好みに影響していることが考えられた．　　　　　　　　　　　It is reported that the cooking course of high school belongs to the vocational department (family) with the data of the Ministry of Education and Science, and only 1.3％ of all Japanese high school students have learned 1).　Therefore, there are a few research on Japanese food for high school students who attend to the cooking course learning mainly about food.　Furthermore, conducting a survey on Japanese food for young people who are high school students will not only lead to continued interest in Japanese food, but also to contribute to the development of food education in the future. 　In this research, we focused on traditional“ Japanese dashi”, and conducted the taste of cooking class students by a sensory evaluation and questionnaire survey, and we grasped the current situation and extracted problems.　In the organoleptic evaluation,“ C: bonito (granule)” was the most favorable result, the most disappointing soup was“ B: kelp soup (granule)” exceeding half. 　In the family of the students of cooking course who conducted the survey this time, the percentage using “granule soup stock” was 55％ when making common dishe