Investigation on the Determination of Chemical Compositions of Subtropical Fruits in Taiwan

This experiment was carried out in the Department of Horticulture, College of Agriculture, National Taiwan University, from July.1952 to June 1963, The results of this experiment may be summarized as follows:1.Sixteen families with twenty-four kinds of subtropical fruits produced in Taiwan were chosen for st tidy. The chemical composition of those fruits was analyzed as the contents of moist11ire, ash,reducing sugar, sucrose or starch, protein, fat, fiber,Pectin substance, organic acids and tannin. The fruit pulp was commonly adopted as the analyzed samples, only the coffee, cacao and Macadamia nut seeds were sampled by this investigation. 2.The more content of pectin substance was found in the Voa vanga, Florida cherry, strawberry guava and mountain-soursop with about 3% in their edible portions. It is learnt that pectin substance was the good material to prepare jam, jelly, candy or to extract the powder by Commercially. 3.The crude protein was largest presented in Macadamia nut than other kinds of subtropical fruits as shown by the results obtained from this work. Coffee, Cacao and Java almonda came to the next with 13.54% , 8.29%, and 6.4% respectively, It is failed to obtain a more cacao protein content so as indicated by some foreign raferences due to the fact that cacao seeds could not develop we!l in this island. 4.It is surprlsed that Macadamia nut contained so abundantly, fat content in its seed with about 72.14% was more than any, agricultural products including of planut or soybean. Simu1taneouslyi, the nut contained a very deiicious taste. and flavour as famous as cashew-nut, one of tropical nut, but its yield always was more than the latter. 5.The crude fiber of fruit has been used to measura a fruit quality combined wlth suger, While the more fiber and low sugar content, the fruit ordinarly, called a low value in the commerial market. Strawberry guava and Java almonda have a higher fiber content than other subtropical fruits shown by table 3 of this paper. Coffee through had a high fiber content, but its soluble matter was to be drunk only.6.Different kinds of non-nitrogenous organic acids were commonly, found in various subtropical fruits obtained by this work. The more abundant organic acid Was found in Gandaria with about 2.3% of its edible portion. Strawberry guava with 1.84% came to the next. The more oxlic acid was indicated in carambola fruit with about 0.42% of its fresh portion.7.The astringency taste in a fruits was ordinarily caused by the presenting of the soluble tannin, Many kinds of subtropical fruits contained more than 0.5% tannic acid was shown in table 4, which would be making our tongue and mouth with a astringency taste.8.In order to measure a fruit economical value, It must take a complete consideration such as the nutritional value, taste and color, cultivation and harvesting, and the fruit solid matter content, especially the latter is the more important factor to a harvested fruit to be used both for processing purpose and for export.