Comparison Of The Polyphenols Composition And Contents Change During Fruit Development In Pomegranate

In this dissertation, using four pomegranate varieties as materials, including Taishanhong,Shuijingtian, Hongbaoshi and Lvbaoshi, the contents of total phenolics in the peel, juice andseed were determined by FC during development of fruits. On this basis, this article alsodetermined the polyphenols composition and contents by HPLC, and further proved theirDPPH radical-inhibition and reducibility by means of DPPH and PB methods. This articlereveals the varieties and organ differences of pomegranate polyphenols and the change trendof polyphenols composition, contents and antioxidant activity during fruit development. Toprovide a theoretical basis and data support for the development and utilization ofpomegranate phenolics, to explore phenolic substances in pomegranate fruit development inthe process of the formation, accumulation and transformation and dynamic tracking researchto provide certain theoretical basis. The main experimental results were as follows:1. The HPLC method successfully separated18phenolic compounds in pomegranatefruit. The experimentally determined chromatographic conditions I: Column temperature wasset at30℃with flow rate1.1mL·min-1and280nm wave length. The mobile phase wasacetonitrile and1%acetate acid solution on gradient elution. The chromatographic conditionsII: Column temperature was set at30℃. The mobile phases were acetonitrile and2%acetateacid solution on isocratic elution at a flow rate of1.0mL·min-1. Chromatograms were recordedat280nm.2. Pomegranate maturity, polyphenols composition and contents have obviousdifferences in the organ. The total phenol content in order to: peel＞juice＞seed. HPLC resultsfor: peel polyphenols composition and content in the most abundant, identified18phenoliccompounds. The polyphenols content of pomegranate juice in the second, from whichidentified16kinds of polyphenols, epicatechin and luteolin not detected. Lowest polyphenolscontent in pomegranate seeds, from which identified17kinds of phenolics, luteolin notdetected. Pulicalagin was the main pomegranate polyphenols component.3. Pomegranate maturity, polyphenols composition and contents have obviousdifferences in the varieties. The order of the total phenolic contents of the four varieties:Lvbaoshi＞Hongbaoshi＞Taishanhong＞Shuijintian. HPLC results as follows: in the peel,Taishanhong and Lvbaoshi detected18phenolic compounds, benzoic acid not detected in Shuijingtian, phloretin not detected in Hongbaoshi. The order of the total phenolic monomerscontents of the four varieties: Lvbaoshi＞Hongbaoshi＞Taishanhong＞Shuijintian. In the juice,epicatechin and luteolin were not detected in four varieties, taxifolin not detected inShuijingtian. Highest amount of phenolic monomers content is Lvbaoshi, followed byHongbaoshi, Taishanhong and Shuijintian. In the seed, luteolin were not detected in fourvarieties, benzoic acid not detected in Shuijingtian. Highest amount of phenolic monomerscontent is Shuijintian, followed by Taishanhong, Lvbaoshi and Hongbaoshi.4. During fruit development, total phenolic contents at different positions of the differentvarieties of pomegranate have not completely the same change trend, the overall decline. Thetotal phenol contents in the peel and juice of four varieties decreased gradually. The totalphenolic contents in the seed of Shuijingtian continued to decline, total phenol contentsdecreased at the other three pomegranate cultivars rise followed by a sharp decline.5. In pomegranate growth process, the18phenolic monomers contents in the peel, juiceand seed of four varieties change were different, but overall is a downward trend. The changesof main phenolic monomers content in the peel as follows: Pulicalagin and catechin contentgradually decreases in four varieties. Protocatechuic acid and ellagic acid content inTaishanhong and Shuijingtian continues to decline, the contents in Hongbaoshi and Lvbaoshiwere increased before they are falling fast. Epicatechin continued to decline in Shuijingtian,other varieties were’∽’ type change trend. The changes of main phenolic monomers contentin the juice as follows: Pulicalagin in Hongbaoshi and Lvbaoshi juice were ‘∽’ type changetrend, Shuijingtian and Taishanhong were decreasing. Parahydroxybenzoic acid andprotocatechuic acid content in four pomegranate cultivars were declining. Catechin contentsin Shuijingtian and Taishanhong were decline, in the Hongbaoshi and Lvbaoshi wereincreased increased first and then decreased slightly. The changes of main phenolicmonomers content in the seed as follows: Pulicalagin contents in Taishanhong and Lvbaoshiwere ‘M’ type change trend, in Hongbaoshi were ‘∽’type change trend, in Shuijingtian weregradually decreased. Ellagic acid contents decreased in four the pomegranate varieties,phlorizin contents first increased and then decreased in four the pomegranate varieties.6. Vitro antioxidant tests showed that four pomegranate cultivars peel, juice and seedspolyphenols with a strong clear DPPH radical scavenging and reducibility. Fourpomegranate varieties peel, juice and seeds polyphenols DPPH radical scavenging abilityand reducibility decreased as the fruit matures.