Little information is available on either the proximate analysis or vitamin content of the different varieties of avocado. Changes in the concentration of these nutrients with crop year, season, and period of refrigeration or ripening after refrigeration are also largely unknown. This study included such comparisons for seven B vitamins as well as the usual proximate analyses in samples from four crop years of Fuerte, two of Anaheim, and one of Hass avocados. HE AVOCADOS grown in California

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Vitamin content of grapes, musts, and wines has been examined frequently but the losses or gains produced by the processes of crushing and fermentation have not been determined systematically. A study of the thiamine, riboflavin, vitamin Be, and pantothenic acid (filtrate factors) of several California grown grape juices and wines was reported in 1939 (14) and of the stability of added portions of these four vitamins in similar preparations in 1945 (15). Castor ( 6 ) noted the changes in B vitamin content of fermenting grapes musts and wines with special reference to the effect of the yeast action and of aging. A parallel study of the whole grapes and their musts has not been reported. The literature on vitamins in wines has recently (1) been reviewed.I n this experiment five varieties of grapes of the vintages of 1952, 1953, and 1954 were used, the juices expressed in various ways and the wines produced under varying conditions. Two varieties of white and three of red grapes were employed and the wines made from them were of the dry white, sherry, sweet red, dry red, and dry rose types. A description of the products is given in Table 1. EXPERIMENTAL PROCEDUREDuring September and October 1952, 1953, and 1954 samples of fresh grapes and freshly pressed musts were prepared and stored at once in the freezing room (-10°C.). The grapes were sampled both as the whole fruit and as a slurry after the stems had been removed. Samples of the wines made from the musts were also stored a few days after fermentation when the yeast had settled and the supernatant liquid could be removed. Finished wines, aged i n the usual cellar fashion, and stored at 53"F., were examined 4 to 6 months later. The musts were fermented with a pure yeast culture (Montrachet strain of Saccharomyces cereoisiae var. ellipsoideus) and in all cases except one, 75 p.p.m. 902 were added before fermentation. I n one sample of White Riesling wine no sulfiting was used and in another 135 p.p.m. SOz were added before fermentation and 100 p.p.m. 6 weeks later. The red wines were produced by fermentation of the crushed grapes, the pink and white wines by fermentation of the expressed juices.Analytical methods. A modification of the thiochrome method was used for thiamine (7) and both the fluorometric procedure (12) and the usual microbiological method by use of L. casei were applied for riboflavin. Results of the fluoronietric method agreed fairly with those of the microbiological only in the musts and wines. Much larger values were obtained by the former with all the grape samples. Obviously non-riboflavin fluorometric substances were present i n considerable amounts in the skins and seeds, thus invalidating the method. I n general the values obtained by fluorometry were larger even for the musts and wines than were those obtained by the usual microbiological procedure. I n consequence only the values from the microbiological tests are used in the summaries and comparisons.Niacin was determined by the microbiological method of Snell and Wright (19) and pantot...

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A report on the thiamine, riboflavin, and niacin content of 3 varieties of California-grown walnuts of 4 successive crops was published in 1949 (8). Further studies in this laboratory have now been completed which have included analyses for pantothenic acid, folic acid, and vitamin B, as well as repetitions of the analyses for the three B vitamins previously studied.The new samples of Juglans regia were grown in the same districts and were shipped to the laboratory in the shells in the same manner previously described." The 3 varieties, Payne, Placentia, and Franquette, were the same used in the first study and samples of the 1950 and 1951 crops were examined. METHODSThe nuts were shelled, ground thoroughly twice, and divided into representatire samples which were packaged in pliofilm and stored in the freezer. All samples were made up of mixed light, amber, and dark kernels.The proximate analysis and vitamin determinations were done by the methods described by Hall, Morgan, and Wheeler ( 4 ) . The f a t content was expressed as total petroleum ether soluble content of the dry pulrerized samples.The thiochrome procedure, a combination of the Hennessey and Cerecedo ( 5 ) and Conner and Straub (3) methods, was used for thiamine with omission of the heating before the enzyme digestion with clarase. This produced a more rapid filtering, clearer filtrate than was found when the heating was done. The usual microbiological proeedures were used for riboflavin and niacin. There was, howerer, a change in the