There are no defined maturity parameters for berry fruit which often results in harvesting and marketing of inedible, immature or over ripe berries. In the present study the changes in quality characteristics of different white-, red-, and black-currant cultivars as well as gooseberry and jostaberry fruit were investigated at three maturity stages. Colour parameters, berry juice pH level and the content of sugars, organic acids and phenolic compounds have been evaluated. A total of 65 different phenolic compounds were detected by HPLC–PDA/MS. The results indicate that, during the last 2–4 weeks of fruit ripening, significant changes occur in colour parameters, primary and secondary metabolites and radical scavenging activity. The results suggest that the average content of specific phenolic groups and sugars/acids ratio can be used as a simple and reliable maturity index for optimisation of harvest time.
COBISS.SI-ID: 8056697
Watercore is a physiological disorder affecting fruit of some apple (Malus domestica Borkh.) cultivars. Intercellular spaces are filled with fluid, which reduces intercellular air space volume. In this study individual phenolic content, sugars and organic acids in watercore affected flesh have been identified and quantified. Peroxidase activity was also measured, as a potential stress indicator. The study was performed on three cultivars prone to watercore development ‘Delicious’, ‘Gloster’ and ‘Fuji’. Total phenolic content was higher in flesh of fruit without watercore in all three cultivars, which was mainly due to higher individual and total flavanol content. In contrast, total and individual dihydrochalcone content was higher in watercore flesh, where it was up to 2.4 times higher from the flesh of fruit without watercore. Also, peroxidase activity was higher in watercore flesh. Higher peroxidase activity and total and individual dihydrochalcone content leads us to believe that oxidative stress occurred. These results show that watercore has an influence on apple fruit sugar and phenol content even before any visual signs of internal breakdown and browning. With the development of non-destructive techniques for phenol content determination, the knowledge about phenolic changes in watercore affected fruits could aid with apple fruit sorting.
COBISS.SI-ID: 8275065
Apple trees (Malus domestica Borkh.) develop an abundance of flowers and shed the majority of fruitlets in the first developmental stages. In this study the process of abscission was monitored in cultivar ‘Golden Delicious’ and linked with the position of fruitlets in the cluster, focusing on differences among central or king flower/fruit (K1), flowers/fruit nearest to the king flower (lower on the peduncle; L2) and flowers/fruit located at different positions near the base of the peduncle (L3-L6). Individual clusters consisted of 3–7 flowers the most frequent were clusters with 5 flowers. Abscission was biphasic with the first peak 29 days after full bloom (DAFB) and the second peak 48 DAFB. At the end of the abscission process approx. 70% of all fruitlets shredded. Fruitlets at the central position (K1) were frequently unaffected by this process and developed to fruit in 70% of the analyzed clusters. The ratio between subsisting and shedded fruitlets was the opposite for lateral positions in the cluster; approx. 70% of fruitlets abscised in the clusters with 4/5 flowers. No significant differences in the level of abscission have been observed between the lateral positions in the cluster (L2-L6). A tendency to abscission has been detected for L2 position (lateral fruitlet nearest to the king flower) in clusters consisting of 6 flowers. This was further confirmed at harvest. Fruit from the lateral position nearest K1 were smaller and firmer in comparison to K1, L3 and L4. This demonstrates the obvious dominance of the central fruit in comparison to lateral fruit, especially those nearest to the king fruit. This is particularly evident in clusters with many flowers.
COBISS.SI-ID: 8222073
Persimmon is a seasonal fruit and only available in fresh form for a short period of each year. In addition to freezing, drying is the simplest substitute for the fresh fruit and accessible throughout the year. The effect of mellowing and drying was evaluated in ‘Tipo’ persimmon, an astringent cultivar. ‘Tipo’ firm fruit contained high levels of tannins (1.1 mg g−1 DW), which were naturally decreased to 0.2 mg g−1 DW after mellowing. The drying process greatly impacted the contents of carotenoids, total phenols, individual phenolics, tannins, organic acids, sugars and colour parameters in firm and mellow fruit. The reduction of tannins, phenolic compounds and organic acids were accompanied by the increase of sugars and carotenoids, improving the colour of the analysed samples. These results showed that the drying process improved the quality of persimmon products and extended their shelf life.
COBISS.SI-ID: 8290681
Traditional elderflower beverages are very popular due to their pleasing taste and pro-health properties. Phenolics were quantified in three elderflower extracts (methanolic extraction and two water extracts prepared as fresh drinks according to local recipes) with HPLC-MS. Chromatographic patterns of methanolic and water extracts were quite similar; however, content levels of individual compounds differed between the two extraction solvents. Two feruloylquinic acids and two p-coumaroyl-caffeoylquinic acids and different flavonol glycosides have been identified in elderflowers for the first time. Hydroxycinnamic acids and flavonol glycosides were the major phenolic constituents in elderflowers. Methanolic extract contained higher levels of all phenolic groups compared to water-extracted samples. The yield of elderflower extracts depended on extract solution and time of extraction. Elderflower beverages were characterized by high total phenolic content (91.09 to 746.63 mg GAE/L). The results confirmed that elderflower beverages (sabesa, syrup) should be recommended as a good source of phenolics in human diet.
COBISS.SI-ID: 8100729