Kiwifruit, with its high nutritional quality, good taste and aromatic scent, has an important commercial value. In recent years, the demand for fruit quality has been increased gradually, and studies have shown that fruit nutritional value is critical to fruit quality.

To investigate the nutritional profile of each kiwifruit variety, researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences (CAS) selected 14 kiwifruit varieties, covering red-fleshed, green-fleshed and yellow-fleshed kiwifruits wildly cultivated in China. They detected and compared the pectin, moisture, chlorophyll, carotenoid, flavonoid, energy, carbohydrates, protein, lipid, dietary fiber, soluble sugar, organic acid, vitamin and aroma compound contents.

The physical and chemical properties, nutritional properties and aroma varied in different flesh color and species groups. The green-fleshed kiwifruits showed the highest content of pectin compared with the red- and yellow-fleshed kiwifruits. The green-fleshed kiwifruits, such as A. eriantha had the highest chlorophyll a content, chlorophyll b content and total carotenoid content. The green- and yellow-fleshed kiwifruits with low energy and carbohydrates were suitable for people with "three highs" and poor stomachs.

Red-fleshed kiwifruits had the highest sugar:acid ratio and total flavonoid content, giving them a particularly sweet flavor and a bright red color. However, the energy and carbohydrate contents were much higher in red-fleshed kiwifruits, and the lipid and dietary fiber contents were lower in red-fleshed kiwifruits than yellow- and green-fleshed kiwifruits. VE and VB1 contents were higher in red-fleshed kiwifruits. Moreover, 1-pentanol, trans-2-hexen-1-ol, n-hexane and styrene were only presented in red-fleshed kiwifruits.

Principle component analysis revealed that among the 14 varieties, 'Huate', 'MHYX', 'Jinkui', and 'Xuxiang' ranked as the four highest-ranking varieties. 'MHYX' and 'Huate' could be developed to provide processed kiwifruit products for consumers, while, 'Jinkui' and 'Xuxiang', as major commercial cultivars, could be developed to utilize their nutritional value for human health.

This work facilitates selecting kiwifruits for consumers and provides scientific evidence for kiwifruit processing and utilization.

The results have been published on Foods entitled "Comparative study on physicochemical and nutritional qualities of kiwifruit varieties."

This study was funded by the National Key R&D Program of China and the Strategic Leading Science and Technology Project of CAS.