Coconut water is rich in nutrients such as sugars, minerals, and vitamins, and has been proven to have various physiological effects such as lowering blood lipids, anti ulcer, antibacterial, and blood sugar. It is a natural electrolyte beverage with an increasing market size. Hainan Tall is the main coconut variety planted in China, accounting for over 80% of the total coconut planting area. Maturity is one of the key factors affecting the nutritional flavor and functional characteristics of coconut water, but there have been no reports on the changes in nutritional and functional characteristics of coconut water from Hainan Tall variety at different maturities. Recently, the processing team of tropical woody oil products of Coconut Research Institute of Chinese Academy of Tropical Agricultural Sciences(CRICATAS) has made new progress in evaluating the nutrition and functionality of coconut water at different maturities. This study clarified the basic nutritional components, volatile flavor compounds, and  biological activity in vitro changes of coconut water Hainan Tall variety. The results can provide scientific basis for the development of standardized harvesting, storage and preservation technologies for coconut fruit.

Figure 1 Research technology route

The team used four mature stages of coconut water from Hainan Tall coconut , namely 8 months (CW-8), 10 months (CW-10), 12 months (CW-12) after pollination, and with a germination length of no more than 10cm (MCW), as raw materials. After systematic analysis, it was found that CW-8 had relatively high nutritional value, with relatively high levels of soluble sugars, reducing sugars, ash, and ester volatiles. It also had a better fatty acid composition (SFA/MUFA/PUFA value of 1.81:0.86:1, omega-6/omega-3 value of 3.98:1) and amino acid composition (EAA/TAA of 39.20%, EAA/NEAA of 64.53%), as well as the highest hydroxyl (97.31%), ABTS free radical scavenging rate (83.48%) and α - glucosidase inhibition rate (81.36%), which make it can be used as the best choice for fresh food consumption. The MCW can also be developed and utilized as a mineral element fortifier or supplement for its higher content in potassium (1969.32mg/kg), sodium (231.02mg/kg), phosphorus (143.39mg/kg), and other minerals.

Figure 2: Screening of characteristic volatile compounds in coconut water of different maturities.

The related achievements were published in Foods under the title "Chemical Components, Nutritional Value, Volatile Organic Compounds, and Biological Activities in Vitro of Coconut (Cocos nucifera L.) Water With Different Maturities". Associate Researcher Zhang Yufeng is the first author and corresponding author of the paper, and Professor Zhang Youlin from Shaanxi Normal University is the co corresponding author of the paper. This study was funded by the Central Basic Research Funds Special Project (No. 16301520220002); No. 1630142022009）、 Supported by the Science and Technology Innovation Team of the National Tropical Agricultural Science Center of the Chinese Academy of Tropical Agricultural Sciences (NO.CATASCXTD202304) and the Key Research and Development Program of Hainan Province (ZDYF2021XDNY150; ZDYF2019108).

Related paper full text link:. https://www.mdpi.com/2304-8158/13/6/863