The chemical composition of the of grape juices produced in Korea in 1969 were analyzed and the amino acids and sugars in these juices were detected by means of paper partition chromatography.
The results are summarized as follows:
1. Less sugar and amino-N and more acid were contained in Korean grape juices than those of foreign´s, and tannin content was not so different as foreign´s.
2. More sugar, amino-N and tannin and less acid were contained in the juices of Campbell Early obtained in Anyang district than in Taejon and Pohang districts.
3. Twenty-one amino acids detected in grape juices were distributed as following frequency.
Aspartic acid, serine, giycine, asparagine, lysine, arginine, threonine, alanine γ-amino butyric acid, valine, leucine, proline (in 11 varieties), glutamine, tyrosine(10), cystine(9), glutamic acid, hydroxyproline(8), isoleucine(4), phenylalanine, unknown(3).
4. Alarine was mostly abundant in all varieties and γ-amino butyric acid was next and the decreasing order were arginine, valine, leucine, proline, glutamine, threonine, etc. in the amount.
5. Number of amino acid detected in grape juices of each varieties were 20 sorts in Delaware(Anyang), 19 in Black Hamburg, and Schuyler, 18 in Campbell Early(three districts), Delaware(seedless, Taejon) and Alden, 17 in Niagara, 16 in Muscat Hamburg, and 15 in Golden Muscat.
6. Number of essential amino acids contained in Delaware(Anyang) and Black Hamburg were 6 sorts and in Campbell Early (Anyang), Niagara and Muscat Hamburg were 5 and in others 4.
7. The same number of amino acid were detected in the juices of Campbell Early obtained from three districts, but hydroxyproline was detected in that of Anyang only, while isoleucine was appeared in those of Taejon and Pohang.
8. Glucose, fructose were detected in all grape juices.
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