Yamato Tachibana (Tachibana; Citrus tachibana) is an endemic fruit and represents one of the oldest citrus species in Japan; it is grown in the Mie Prefecture. It has been attracting attention for its cultural heritage and unique scent. To evaluate biological activities of Tachibana, we fed several parts of the Tachibana fruit (whole fruit, pulp [albedo and segment wall], and flavedo) to adult zebrafish and found that Tachibana increased body weight and plasma triglycerides besides increasing overall food intake. We then created a simple fluorescence-based feeding assay using dried rotifer sheets and larval zebrafish (6 days postfertilization) to screen the various extracts of Tachibana parts. We found that water extracts of Tachibana pulp increased feeding volume in zebrafish. Although citrus species are believed to prevent obesity and obesity-associated diseases in general, our findings showed that water extracts of Tachibana increase food intake in zebrafish and lead to an increase in body weight. We suggest that Tachibana might reverse appetite loss in lean populations and may prove beneficial in aiding fish cultivation.

Hydrophobic materials extracted from citrus wastes, both peel of mandarin fruits and leaf of mandarin trees were used to treat food-grade Kraft paper. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy and infrared spectroscopy, and their antioxidant activities were determined using a free radical scavenger agent (2,2-diphenyl-1-picryl-hydrazyl-hydrate, DPPH). Water vapor permeability, air transmission rate, peroxide value, and microstructure of treated and original papers were also determined. The experimental results showed that: (i) most components of the peel or peel/leaf extracts were terpenes; (ii) free volume existed among cellulose macromolecule chains of the original paper, occupied by a part of extract materials, and another part of the extracts was formed a thin layer on the paper surfaces; and (iii) air and water barrier properties and antioxidant activity of the treated papers were improved, indicating that the extracts were efficient materials for food packaging applications.