Abstract
Yield and chemical property of Yuzu (Citrus junos Sieb. ex Tanaka) juice produced using tree extractors such as a continuous Centrifugal-type extractor (spiral separator), a Belt-press extractor and an In-line extractor were examined. The yield of juice from the Centrifugal-type extractor was increased apparently about 10 percent more than that from the Belt-press extractorbecause of higher pulp volume. Juice from the Centrifugal-type extractor (CT juice) and the In-line extractor (IL juice) had lower acidity and higher soluble solid content than that extracted by the Belt-press extractor (BP juice). CT juice showed a higher b value on a color differential meter compared to BP juice although the recoverable oil from CT juice was one-half of that from BP juice, and this phenomenon should be attributed to the higher pulp volume. The total free amino acidsand the major free amino acids including asparatic acid, glutamic acid and asparagine were greater in CT and IL juice than in BP juice. The major volatile components of CT, IL and BP juice were terpene hydrocarbons (d-limonene, γ-terpinene and myrcene etc.). The terpene alcohol such as linalool in CT juice was higher in concentration than that in IL and BP juice. As mentioned above, the yield and quality of juice extracted by the three extractors were different from one another. The results of this investigation would suggest that the Centrifugal-type extractor as well as the Belt-press extractor could apply for extracting Yuzu juice because of high juice yield whereas large pulp volume.
