REACTIVE OXYGEN SPECIES SCAVENGING ACTIVITY AND DNA PROTECTING EFFECT OF FRESH AND NATURALLY FERMENTED COCONUT SAP

ABSTRACT Coconut sap is consumed as a juice or used as raw material for fermentation to produce beverages with various health benefits. To understand the underlying mechanisms of the health benefits of coconut sap, we investigated the in vitro reactive oxygen species scavenging activities and DNA protecting effects of fresh and naturally fermented coconut sap using a flow-injection chemiluminescence method. The results show that the fresh sap scavenges superoxide anion, hydroxyl radical and hydrogen peroxide better than the naturally fermented sap; in contrast, the fermented sap shows a more powerful ability to prevent damage to DNA than the fresh sap. The naturally fermented sap had a higher polyphenol level but a lower ascorbic acid content than fresh sap, suggesting that fermentation is beneficial for improving the polyphenol content of coconut sap. PRACTICAL APPLICATION Reactive oxygen species (ROS) are reported to be related to many diseases, such as cancer and Alzheimer's disease. Antioxidants are vital substances that possess the ability to protect the body from damage caused by ROS. There is an increasing interest in natural antioxidants, e.g., polyphenols, present in medicinal and dietary plants, which might help prevent oxidative damage. Coconut sap is obtained by tapping the unopened spadix of the coconut palm, and also used as the resource of sugar and alcoholic beverages by local people. Our experimental results testify that the coconut sap has powerful ROS scavenging activity and can be potentially used as the ingredients of functional food.