B Vitamin Content of Avocados

Three varieties of California-grown avocadodFuerte, Anaheim, and Hassof four crop years, were examined for content of most of the B vitamins. The fat and water contents, and the effect of various periods of refrigeration and ripening at room temperatures also were given attention. Avocados grown in California are of two races of Mexican and Guatemalan origin. The Fuerte-comprising about 80% of the state's avocado crop-is a hybrid of the two races. The Anaheim and the Hass are of the Guatemalan race. The Fuerte ripens from October to June. The Anaheim-the most prominent of the low-oil avocado varieties-ripens from June to September and the Hassa sturdy variety-ripens from May to October. The samples analyzed for each crop year were obtained from the same area. Boxes of the fruit were shipped at intervals during the twoto three-month tree ripening periods. All fruits were stored at once in the refrigerator at 39.2"F to 41°F and samples removed at intervals of one to 61 days. The removed samples were kept at room temperature from none to five days to determine the effect of any further ripening. Then fruits were peeled and ground, packed in Pliofilm, and stored at freezer temperature of -50°F until the analyses were completed. Analyses were carried out on representative samples of each variety, and water and fat determinations were made on most of the individual fruits used for the vitamin assays. The vitamin analyses were done by microbiological and fluorometric methods. Bioassays which generally yield a higher apparent concentration of vitamins in foods than do the other types of analyses were made to validate the effectiveness of the extraction procedures preceding the chemical or microbiological tests. Comparisons of this type have also been made in prunes, figs, turkey tissues, and walnuts in this laboratory. Bioassays for thiamine, riboflavin, pantothenic acid, and vitamin B, were carried out on Fuerte samples of four different crop years. A vitamin B, bioassay was also made on H a s samples. In the thiamine and one of the pantothenic acid biological assays the values were greater-36% thiamine and 40% pantothenic acid-than those obtained by other means. The other bioassay for pantothenic acid and that for vitamin Be on the Hass sample yielded excellent agreement with the results of the microbiological analysis, 101% and 109% of the latter values. This was true also of the riboflavin assay. In the other vitamin Be assay, on the Fuerte fruit, the bioassay showed about one third smaller value than that obtained by microbiological procedure. This may reflect the improved extraction procedures used in the microbiological analyses. Also, it might reflect poor absorption of the rather large avocado test doses-one to three grams-fed daily to young rats used in the rat-growth bioassay. The proximate analyses indicated the variability of the water and fat content of the fruits because increased fat was usually accompanied by decreased moisture. The Anaheim variety had little more than half to two thirds of the fat