Metabolic profiling of Garcinia mangostana: a new insight into quality after postharvest treatment
（Garcinia mangostanaのメタボリックプロファイリング：収穫後処理の品質への影響に関する新たな知見）
Metabolomics, the study of total profiling of metabolites, is an important tool to support postharvest fruit development and ripening studies. Monitoring the changes in the metabolome during fruit ripening is important to obtain insight into the mechanisms involved and improve postharvest management strategies. Fruit ripening process is a complex developmental process involving coordinated regulation of numerous metabolic pathways that influence color, flavor, aroma, and texture. Based on their mode of ripening, fruits are categorized into two categories such as climacteric fruit and non-climacteric fruit. The ripening of climacteric fruit is dependent on the existences of ethylene around the fruits, while non-climacteric fruit ripening is not affected by the existence of ethylene. Mangosteen, often known as the “Queen of Fruits”, is an economically important tropical fruit desired for its distinctive appearance and unique taste. Mangosteen is a climacteric fruit and the progression of ripening is indicated by changes in its peel color. Mangosteen ripening stages were categorized into seven stages based on color changes Understanding the changes that occur during ripening is necessary in order to assess optimal harvest maturity and the quality of fruit as it is marketed to the consumer as well as to devise appropriate postharvest packaging and handling strategies. For the last decade, the study of mangosteen only focused on the elucidation of bioactive compounds such as alpha-mangosteen and gamma-mangosteen. However, there is no single study that mentions about the metabolic changes during the mangosteen ripening process.
In chapter 1 provides the general introduction concerning mangosteen as an important export commodity in Indonesia and how metabolomics can be an effective tool for mangosteen researches. In Chapter 2, non-targeted GC/MS-based metabolic profiling methods were applied to obtain a general view on the metabolic changes related to the qualities during ripening process throughout mangosteen color changes. In Chapter 3, in order to investigate the effects of different cultivation area, different tree, and year of harvesting were examined to confirm the metabolic changes during mangosteen ripening process. In these experiments, all samples were evaluated based on their color changes and metabolic changes during ripening process. In Chapter 4, several postharvest treatments were applied and evaluated using metabolomics approach. At last, the conclusions revealed from this study were summarized and the future perspectives were proposed.