Taste and flavor compounds in box thorn ( Lycium chinense Miller) leaves

• Published in: Food chemistry 1997-04, Vol.58 (4), p.297-303
• Main Authors: Kim, S.Y., Lee, K.H., Chang, K.S., Bock, J.Y., Jung, M.Y.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Coffee, tea and other stimulative beverage industries; Food industries; Fundamental and applied biological sciences. Psychology; Lycium chinense
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/S0308-8146(96)00099-4

Contents of selected taste components in box thorn leaves collected at different seasons (from mid-May to mid-October) were determined. Volatile flavor compounds in the box thorn leaves were extracted using a simultaneous steam distillation-extraction apparatus, and the compounds were isolated and identified by gas chromatography/mass spectrometry. Box thorn leaves contained fructose (0.58–1.54%), glucose (0.33–1.33%), sucrose (0.23–0.68%) and maltose (0.60–0.98%). Non-volatile organic acids identified were citric acid (162.3–361.3 mg%), oxalic acid (61.1–130.9 mg%), malonic acid (44.9–59.4 mg%), malic acid (15.6–34.3 mg%), succinic acid (3.7–5.1 mg%), fumaric acid (1.3–2.9 mg%), and lactic acid (0.0–1.1 mg%). Eighteen free amino acids were found in the leaves and their contents varied greatly with season. Proline (52.6–267 mg%), histidine (162–244 mg%) alanine (99.5–198 mg%), leucine (51.4–149 mg%), valine (54.5–125 mg%), isoleucine (37.0–119 mg%) and aspartic acid (46.7–111 mg%) were major amino acids in the leaves. Total tannin contents were 0.90–2.10%, showing the highest amount in October. Forty-five volatile flavor components were identified in the leaves for the first time. These included four acids, 15 alcohols, seven aldehydes, two esters, three furans, nine hydrocarbons, two ionones, and three other compounds.