Peels of thirteen (13) ripe mango genotypes were analyzed for total phenolic, total flavonoid, vitamin C, vitamin A contents, and antioxidant activity. Statistical analysis showed that the mango genotypes were significantly different in all the chemical assays performed. The total phenolic content of the genotypes ranged from 3.44-14.59% GAE while total flavonoid content ranged from 0.32 – 2.16% CE. The vitamin A and vitamin C contents of mango peels ranged from 24.66 – 92.01 IU/g and 4.55 – 6.40 mg/g, respectively. The DPPH radical scavenging activity ranged from 88.11 – 92.47%. Correlation analysis also showed that DPPH radical scavenging activity has high positive correlation with total phenolic content (r = 0.69), total flavonoid (r = 0.77) content, and vitamin C (r = 0.57). Using standards, the presence of gallic, vanillic, syringic, and ferulic acids were confirmed in Carabao mango peel by comparison of retention times using High Performance Liquid Chromatography (HPLC). The quantity of these phenolic acids was also calculated with gallic acid and ferulic acid having the highest and lowest concentrations in the peels of all the studied genotypes, respectively. The observation and data collected from this study showed that there was chemical variation in the peels of different mango genotypes that can be a basis for future breeding work. Furthermore, mango peel was can be a good source of phenolic compounds, vitamins and antioxidants which can be utilized as a functional food, and for nutraceutical, pharmaceutical and cosmeceutical purposes.

No abstract

Agriculture depends on the ability of seeds to survive until the next planting season under ambient conditions that may be averse to seed quality even when the seed is in a quiescent state. Seed priming invigorates seeds, but the impact on the longevity of seeds has limited its adoption. This study investigated the effect of the storage of primed rice seed on seed viability, vigor, and longevity. Three seed priming methods were employed on the rice cultivar New Rice for Africa (NERICA 4) seeds. Subsequently, the seeds were stored for 120 days at 25 °C and 65% relative humidity, simulating the ambient seed storage conditions of the tropics and sub-tropics. The primed seed recorded increased vigor compared to the non-primed seed until 90 days of storage. However, seed storage for 120 days reduced seed vigor and viability for all the seeds. The results indicated a significant reduction in seed vigor, increased solute leakage, generation of hydrogen peroxide, and accumulation of malondialdehyde after storage. Priming enhances cell membrane integrity and maintains seed vigor in storage at near ambient conditions long enough before reversal of its performance by the storage conditions. This assures that primed seed can either be stored until the following planting season or remain viable in the soil during delayed germination.