Phan Anh Dao Thi, Zhang Jiale, Seididamyeh Maral, Srivarathan Sukirtha, Netzel Michael E, Sivakumar Dharini, Sultanbawa Yasmina
ARC Industrial Transformation Training Centre for Uniquely Australian Foods, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Indooroopilly, QLD, Australia.
Department of Crop Sciences, Phytochemical Food Network Research Group, Tshwane University of Technology, Pretoria, South Africa.
Front Nutr. 2022 Jul 29;9:961679. doi: 10.3389/fnut.2022.961679. eCollection 2022.
Exell., also known as Kakadu plum, is a wild-harvested native Australian fruit with limited information on how maturity is affecting the phytonutritional properties and bioactivities of the fruit. Thus, this study investigated changes in hydrolysable tannins, phenolic acids, sugar profile, standard physicochemical parameters, and antioxidant-scavenging capacity of wild-harvested Kakadu plum fruits at four different maturity stages, from immature to fully mature. Fruits harvested <25, 25-50, 50-75, and 75-100% degree of fullness were classified as highly immature (stage 1), immature (stage 2), semi-mature (stage 3), and fully mature (stage 4), respectively. Results showed that chebulagic acid, geraniin, chebulinic acid, castalagin, punicalagin, and gallic acid continuously decreased during fruit maturity, while elaeocarpusin, helioscopin B, corilagin, 3,4,6-tri--galloyl--glucose, and ellagic acid increased at the beginning of fruit growth (from stage 1 to 2), but decreased when the fruits reached their full maturity (stage 4). The levels of hydrolysable tannins and phenolic acids in fully mature fruits (stage 4) were significantly ( ≤ 0.05) lower than that in their immature counterparts (stages 1 and 2). Total phenolic content (TPC) and DPPH antioxidant radical-scavenging activity did not vary significantly between different maturity stages. Pearson's correlation coefficient test indicated that TPC and DPPH positively ( ≤ 0.05) correlate with most of the studied tannin compounds. Sugars (glucose, fructose, and sucrose), total soluble solid content, and titratable acidity increased during the fruit development. Furthermore, principal component analysis (PCA) revealed the difference between the immature and mature samples, based on their nutritional profile and bioactive compounds. The PCA results also suggested a considerable variability between the individual trees, highlighting the challenges of wild-harvest practice.
阿育吠陀果，也被称为卡卡杜李，是一种野生采集的澳大利亚本土水果，关于成熟度如何影响其植物营养特性和生物活性的信息有限。因此，本研究调查了野生采集的卡卡杜李果实从未成熟到完全成熟的四个不同成熟阶段中可水解单宁、酚酸、糖谱、标准理化参数以及抗氧化清除能力的变化。收获时饱满度<25%、25 - 50%、50 - 75%和75 - 100%的果实分别被归类为高度未成熟（阶段1）、未成熟（阶段2）、半成熟（阶段3）和完全成熟（阶段4）。结果表明，诃子酸、老鹳草素、诃子次酸、卡斯塔拉金、石榴皮苷和没食子酸在果实成熟过程中持续减少，而杜英素、半日花素B、柯里拉京、3,4,6 - 三 - 没食子酰 - β - 葡萄糖和鞣花酸在果实生长初期（从阶段1到2）增加，但在果实达到完全成熟（阶段4）时减少。完全成熟果实（阶段4）中可水解单宁和酚酸的含量显著（≤0.05）低于未成熟果实（阶段1和2）。不同成熟阶段之间总酚含量（TPC）和DPPH抗氧化自由基清除活性没有显著差异。皮尔逊相关系数检验表明，TPC和DPPH与大多数研究的单宁化合物呈正相关（≤0.05）。糖（葡萄糖、果糖和蔗糖）、总可溶性固形物含量和可滴定酸度在果实发育过程中增加。此外，主成分分析（PCA）揭示了未成熟和成熟样品在营养成分和生物活性化合物方面的差异。PCA结果还表明单株树木之间存在相当大的变异性，突出了野生采集实践的挑战。
