Studies on Storage Methods of Agricultural Products

On the Actual Conditions of Citrus Storage in Kagoshima Prefecture

Abstract

From October 1966 to March 1968, research and investigation on the actual condition of storge are carried out to gain the engineering data for improving citrus storage technique. We selected and researched six natural simple storages in A section and five mechanical cooling storages in B and C section in Fig. 1, Kagoshima prefecture, Japan. Investigation results were summarized as follows:
(1) In natural simple storages such as underground type, barn type and watering under-floor type, the ratio of evapotranspiration weight loss to the total weight loss was smaller than the ratio in PRECON, mechanical cooling storage.
(2) In the later term of storage in the natural type, green mold and stem-end-rot of citrus fruit incresed and the total weight loss also increasd exponentially.
(3) In mechanical cooling storage (PRECON), considerable and a certain weight loss by evapotranspiration in the total weight loss continues through the storage term.
(4) During storage, contents of acid (mainly, citric acid) (%) in citrus fruit unshu gradually decreased, especially normal temperature (natural) storage allows contents of citric acid to decrease more rapidly than the low temperature storage.
(5) No significant tendency was recognized in the change of contents of total sugar (%) in the citrus fruits. Measurement degree by sugar refractometer to determine the sugar contents is not to be relied upon, because citrus as well as other fruits are constituted by complex ingredients which have a different index of refraction, respectively.