It has been demonstrated that the three most important factors which determine the rate of breakdown of pelargonidin-3-glucoside, the major anthocyanin of strawberries, are pH, temperature and the presence of oxygen (6,9). Ascorbic acid has a marked effect and sugars also contribute to the breakdown of this pigment (9).Since sugars are present at such high concentration in many strawberry products and since there is a variety of sugars available for use in the preparation of these products, it was considered advantageous to study the effects of sugars on the rate of pigment breakdown. Meschter (9) has observed the rate of strawberry pigment degradation in the presence of different sugars at 38" C. Sugars such as arabinose, levulose and sorbose, which are relatively labile, produced a higher rate of pigment degradation than the more stable sugar maltose and the sugar alcohol sorbitol. The sugar degradation

Skin Pigments of the Cabernet Sauvignon Grape and Related ProgenyThe skin pigments of the Cabernet Sauvignon grape have been separated by paper chromatography and identified as malvidin, two glucosides of malvidin, a petunidin glucoside, a delphinidin glucoside, and a complex diglucoside of malvidin. Evidence is presented to indicate that the two malvidin glucosides are the 3-glucoside and the 3,5-diglucoside, and that the delphinidin and petunidin pigments are the 3,5-diglucosides. The malvidin diglucoside was the most abundant. The pigments of progeny of Cabernet Sauvignon and Carignane grapes were qualitatively identical with those of the Cabernet Sauvignon. The order of appearance of the anthocyan pigments in the maturing Cabernet Sauvignon grape was: malvidin diglucoside, malvidin monoglucoside and delphinidin glucoside, petunidin glucoside, and free malvidin, contrary to the hypothesis that in the developing fruit or flower anthocyanins are formed at the expense of the corresponding anthocyanidin.

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As part of a study on the breakdown of strawberry anthocyanin in model systems, the effects of various normal constituents of strawberry juice on pigment loss were studied. Since Mackinney, Lukton and Chi-Chester (5) have demonstrated that the rate of breakdown of the major anthocyanin of strawberries, pelargonidin-3-glucoside, in sugar or ascorbic acid systems was accelerated by the presence of glycine, it seemed reasonable to incorporate the effect of the amino acids of the strawberry into the experimental design. In order to determine the extent of this effect in strawberry products, it was necessary to know the identity and approximate concentration of the free amino acids present in the strawberry juice as it might be used under manufacturing conditions.The only references to the amino acids of strawberry products are those of Casimir and Jakovliv (3) and Casimir (2). These studies were made on acid hydrolysates and hence do not represent the free amino acids present in strawberry juice. This paper reports, therefore, the separation, identification and quantitative estimation of the free amino acids of the juice of the Marshall strawberry. EXPERIMENTAL PROCEDUREThese experiments were carried out on a sample ,of juice obtained from Marshall strawberries which had been frozen and held for six months at 0" F. After thawing the juice was expressed through cheesecloth; a clear sample was obtained by further filtration through a sintered glass filter.Qualitative studies. Hackman and Lazarus ( 4 ) have described a procedure for isolation of amino acids using one dimensional paper chromatography and a series of solvent systems. This procedure was followed using Whatman No. 1 filter paper.Using the single phase n-butanol/acetic acid/water system (77 : 6 : 17, v/v) and running the chromatogram twice in the same direction, the amino acids leucine and/or isoleucine, d i n e and alanine and sometimes glutamine were separated. Although not clearly separated in this solvent system the presence of aspartic acid and asparagine was also established by virtue of the characteristic colors produced with ninhydrin. Asparagine gave a brown color, while aspartic acid gave a blue-green color which turned purple on standing.A single phase phenol/water system (74 :26, phenol : buffer v/v) buffered with borate buffer at pH 10.0 gave a good separation of aspartic acid, glutamic acid, asparagine and threonine on paper buffered at pH 10.0. Alanine and glutamine were not separated in this system but alanine was separated in a preparation in which the glutamine and asparagine had been hydrolysed to glutamic and aspartic acids. '