Spatiotemporal analysis of microstructure, sensory attributes, and full-spectrum metabolomes reveals the relationship between bitterness and nootkatone in Alpinia oxyphylla miquel fruit peel and seeds

• Published in: Food research international Vol. 191; p. 114718
• Main Authors: Chen, Xiaolu, Yang, Yong, Wang, Maoyuan, Tian, Qin, Jiang, Qian, Hu, Xuan, Ye, Weiguo, Shen, Wanyun, Luo, Xueting, Chen, Xueyan, Yuan, Chao, Wang, Dan, Wu, Tianrong, Li, Yulan, Fu, Wenna, Guan, Lingliang, Li, Xingfei, Zhang, Lingyan, Wang, Zhunian, Pan, Yonggui, Yan, Xiaoxia, Yu, Fulai
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.09.2024
• Subjects: Aroma; Bitter; Chemical composition; Essential oil; Flavor; Functional food; Homologous medicinal food; Nootkatone; Oil cell; Pigment layer; Taste; Zingiberaceae; P1; P2; S7; S8; P7; P8; Bitter; Nootkatone; Flavor; Homologous medicinal food; W; Oil cell; AOF; Taste; Chemical composition; Essential oil; Aroma; Pigment layer; S1; Zingiberaceae; Functional food; S2
• ISSN: 0963-9969; 1873-7145; 1873-7145
• DOI: 10.1016/j.foodres.2024.114718

[Display omitted] •Analysis of variation in metabolites between AOF peels and seeds at various stages.•322 volatile and 1126 non-volatile components were detected. 1410 differentially accumulated metabolites among tissues were filtered based on OPLS-DA.•31 key flavor compounds were screened and nootkatone content were strongly positively correlated with bitterness intensity in AOF.•KEGG analyses were performed on differentially accumulated metabolites.•Microstructural observation and histochemistry highlighted the plastid and cytoplasm in oil cells and pigment cells were associated with essential oil accumulation in AOF. The Alpinia oxyphylla fruit (AOF) is a popular condiment and traditional Chinese medicine in Asia, known for its neuroprotective compound nootkatone. However, there has not been a comprehensive study of its flavor or the relationship between sensory and bioactive compounds. To address this issue, we examined AOF’s microstructure, flavor, and metabolomic profiles during fruit maturation. The key markers used to distinguish samples included fruit expansion, testa pigmentation, aril liquefaction, oil cell expansion, peel spiciness, aril sweetness, and seed bitterness. A full-spectrum metabolomic analysis, combining a nontargeted metabolomics approach for volatile compounds and a widely targeted metabolomics approach for nonvolatile compounds, identified 1,448 metabolites, including 1,410 differentially accumulated metabolites (DAMs). Notably, 31 DAMs, including nootkatone, were associated with spicy peel, sweet aril, and bitter seeds. Correlational analysis indicated that bitterness intensity is an easy-to-use biomarker for nootkatone content in seeds. KEGG enrichment analysis linked peel spiciness to phenylpropanoid and capsaicin biosynthesis, seed bitterness to terpenoid (especially nootkatone) biosynthesis, and aril sweetness to starch and sucrose metabolism. This investigation advances the understanding of AOF’s complex flavor chemistry and underlying bioactive principle, encapsulating the essence of the adage: “no bitterness, no intelligence” within the realm of phytochemistry.