The TPC and AAC of the ripe and unripe guava fruits (Kampuchean variety) are summarised in Table 1. As the fruit ripens, TPC decreases but AAC increases. According to Taylor (1993), the decrease in polyphenol content of guava fruit causes a loss in astringency during ripening of the fruit. The increase in AAC as the fruit matures is due to the breakdown of starch to glucose which is used in the biosynthesis of ascorbic acid. The DPPH scavenging activity of the unripe guava as measured by the AEAC value is primarily due to its higher TPC relative to AAC. Decrease of AEAC during ripening suggests that the antioxidant activities of guava fruit declined during fruit ripening.