The Nutritional Composition and Health Benefits of Lincang Walnuts

Abstract

Background
Although there is considerable information on the nutritional composition of the common walnut, information on the iron walnut
is scarce.
Aim
To analyze the nutritional composition of Lincang walnuts (which belong to the species Juglans sigillata L., also known as the iron
walnut) and if they confer any advantages over Xinjiang or Californian walnuts (both Juglans regia L. or common walnut).
Results
Nutrients of particular nutritional significance in Lincang walnuts (both regular and old tree) were protein (5.9 and 5.6 g/30 g
serve), dietary fiber (6.5 and 6.7 g/30 g serve), vitamin B6 (0.87 and 0.93 mg/30 g serve), copper (1.65 and 1.63 mg/30 g serve),
magnesium (158 and 142 g/30 g serve), manganese (7.33 and 8.41 mg/30 g serve) and phosphorus (437 and 427 g/30 g serve).
Despite a high fat content, the fatty acids profile was predominantly polyunsaturated and monounsaturated types. The Lincang
walnuts were similar in macronutrient composition to the Xinjiang and Californian-sourced samples, but the Lincang ones were
higher in some of the B vitamins (niacin, thiamin, and vitamin B6) and minerals (manganese and to a lesser extent copper, iron,
phosphorus, and potassium). The serotonin concentration in Lincang walnuts (7.6 and 7.2 mg/30 g serve) was over double that
found in Californian walnuts (2.9 mg/30 g serve) and higher than Xinjiang walnuts (5.5 mg/30 g serve).
Conclusion
The nutrients present in Lincang walnuts confer a range of well-established health benefits. One area of particular interest is the
role that walnuts may play in brain function owing to the combination of nutrients and phytochemicals present. In addition to
direct consumption of walnuts, there are many options for the development of functional food products, including walnuts as
ingredients, to promote regular consumption of walnuts for improvement of health.