Hydrolysable tannins, physicochemical properties, and antioxidant property of wild-harvested Terminalia ferdinandiana (exell) fruit at different maturity stages

Abstract

Terminalia ferdinandiana 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-O-galloyl-S-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 (p ≤ 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 (p ≤ 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.

The Health-Promoting Quality Attributes, Polyphenols, Iridoids and Antioxidant Activity during the Development and Ripening of Cornelian Cherry (Cornus mas L.)

“…Similar trends have been observed in many other fruits, e.g., plum [38], bilberry [39], blackberry [34], or blueberry [27]. According to the literature, the value of TSS is positively correlated with sugar accumulation and it can be used as a marker of fruit maturity [40].…”

Quality Assessment of Burdekin Plum (Pleiogynium timoriense) during Ambient Storage

“…The concentration of organic acids is the result of organic acid synthesis, catabolism and tissue storage [ 49 ]. The increase in TA in some fruit samples may be caused by a ‘simple’ concentration effect due to the moisture loss of the samples during ambient storage [ 50 ], and/or a change in the respiratory metabolism, leading to an increased TA [ 51 ], and/or the inherent variation in the wild harvested fruits [ 52 ].…”

Multivariate Analysis among Marker Compounds, Environmental Factors, and Fruit Quality of Schisandra chinensis at Different Locations in South Korea

“…Ma et al (2023) reported that goji berry contains the highest number of flavonoids when it is a green fruit, but as it matures, the content of flavonoids decreases [37]. Phan et al (2022) reported that total soluble solid and titratable acidity increased depending on the ripening stage of Kakadu plum fruits, but the content of phenolic compounds, including tannin, tended to decrease [38]. In addition, our previous study [39] showed that the content of active compounds in the fruit of Cudrania tricspidata decreases as the size of the fruit increases.…”