18 Station Bulletin 372 



food constituents, tested in amounts which would be found in normal plant 

 tissues, which were capable of giving "ascorbic acid values" were malic, 

 tartaric, fumaric, and succinic acids (the last two, only slight activity). Ox- 

 alic and citric acids do not react with the dye. These are often used as tissue 

 extractants for ascorbic acid. 



Further studies are needed in order to obtain quantitative data on the 

 sugars in fresh and preserved foods and bo obtain "ascorbic acid equivalents" 

 of these substances. The nature, as well as the degree of reaction, of these 

 naturally occurring interfering substances will have to be ascertained before 

 actual ascorbic acid values can be known, especially for foods with high sug- 

 ar content. 



Supplement No. 2, The Determination of Carotene in Certain Foods. 



In previous studies, it was noted that yellow wax beans contained some 

 carotene, although most literature records this food as lacking in carotene. 

 According to the purpose of this project (i.e., to investigate the various exist- 

 ing methods for determining carotene in foods), it was thought that studies 

 of this variety of bean might show up differences in chemical methods. For 

 this year's work, two plantings of Pencil Pod Wax beans were made. In or- 

 der to study the distribution of carotene, if it were found present, some of 

 the whole young plants were analyzed just prior to blossoming (34 days af- 

 ter planting) from each row and again after the plants were through bear- 

 ing. Following the carotene determination of the plant, the whole beans 

 were sized and similarly analyzed at various stages of development. 



In using the Zscheile carotene method, saponification of tissue prior to 

 extraction was compared to non-saponification. From the results so obtained, 

 it seems that whereas saponification appears to aid in the extraction of caro- 

 tene from the bean plants, it is not necessary for the purpose of extracting 

 carotene from the beans. 



Carotene was found to an appreciable extent in the small beans. Al- 

 though still present in the more mature beans, the concentration of carotene 

 decreased with age. The fresh beans averaged from 0.2 mg. to 0.5 mg. beta 

 carotene per 100 gms., as determined with the colorimeter (green peas, last 

 year, 0.08 mg. to 0.3 mg. per 100 gms.) . 



H. J. Purinton 



AGRICULTURAL ECONOMICS 



Seasonal Milk Pricing and Supplies 



During the war years, consumption of fluid milk increased more rapidly 

 than the supply in the metropolitan Boston market as well as in most of the 

 milk markets in the United States. At the same time, the seasonality in milk 

 deliveries became wider. As a result, during three of the last four years, pro- 

 ducers in the Boston milkshed failed to deliver enough milk to meet require- 

 ments in the short months of November, December, and January. The high 

 cost of bringing in milk from the Midwest encouraged the addition of several 

 plants formerly in the New York milkshed. To prevent an overexpansion 

 of the Boston milkshed, it is important to develop a price plan that will en- 

 courage the production of a larger proportion of milk in the fall months of 

 short supply. 



