Chemical Characteristics and Physiological Activities of Plums (Oishiwase and Formosa)

Chemical characteristics and physiological activities of plums (Oishiwase and Formosa) were evaluated. Proximate composition of plums consisted of (w/w) 1.9-6.2% protein, 2.3-7.1% fat, 3.5-4.1% ash, and 84,1-88,7% carbohydrate. Organic acids, such as oxalic, malic, succinic, and acetic acids were detected, except in Oishiwse acetic acid was not detected. Free sugars consisted of sorbitol, glucose, fructose and sucrose. Total fiber and total phenolics compounds of plum rind were higher than those of flesh. Electron-donating abilities of rind ethanol extracts were higher than those of BHA and tocopherol, and were twofold higher than those of flesh extracts. Nitrite-scavenging abilities of rind and flesh extracts were significantly higher (over 97%) at pH 1.2 and 3.0. Tyrosinase-inhibitory activities ranged 88.5 to 100%. SOD-like activities of all extracts were weak at 22.7 to 27.2%.