Evolution of the Volatile Organic Compounds, Phenols and Antioxidant Capacity during Fruit Ripening and Development of Rubus ulmifolius Schott Fruits

Abstract

Nowadays, a growing interest in consumers’ fruit with a high content of health-promoting compounds has been observed. In this sense, wild berries have received special attention based on their high accumulation of phenolic compounds, as well as their characteristic and pleasant aroma. In this work, we characterize the color development, antioxidant capacity, phenolic contents, and volatile profile of Rubus ulmifolius Schott fruit at different ripening stages during two seasons on the same orchard. Four stages were established based on the color parameter, which was consistent with changes in the weight and size of the fruit. In addition, total phenolic and flavonoid content showed a decrease during the fruit ripening, in contrast with the total anthocyanins content that increased at the final stages of ripening. In addition, the antioxidant capacity was evaluated through two approaches: FRAP and DPPH, which consistently displayed higher levels at the final stages in the two different seasons. Finally, the VOCs analysis showed an active synthesis of volatile compounds during the late stage of ripening, with alcohols being the most abundant compounds for each ripening stage. These results allow us to propose a classification of different ripening stages of the wild blackberry to have a better knowledge of this interesting fruit with higher healthy- and nutraceutical compounds.

Taxonomic, physicochemical, phenolic and antioxidant comparison in species of high Andean wild fruits: Rubus and Hesperomeles

“…Similar studies in other wild berries support this trend. For example, wild blackberries (Rubus ulmifolius) exhibited higher levels of phenols and flavonoids and higher antioxidant activity in ripe fruits compared to immature fruits (Castro et al, 2022). Johnson and Mejía (2012) mentioned that there is a positive correlation between the content of phenolic compounds and the antioxidant capacity, which would indicate that the content of polyphenols and the maturity indexes in the studied fruits directly influence their antioxidant activity.…”

Blackberries and Mulberries: Berries with Significant Health-Promoting Properties

“…Additionally, the metabolism of fruits produces volatile compounds during the ripening, harvesting, post-harvesting, and storage. As a result, the volatile composition of blackberries is affected by the genotype, origin, technological treatment (freezing, drying, among others), ripening stage, harvest, and storage conditions [61][62][63][64]. Therefore, the analysis of volatile compounds is critical for understanding the components responsible for their flavour and aroma, as well as the best harvest period for higher quality and phytosanitary qualities [4,61].…”

“…On the other hand, R. ulmifolius possesses around 33 different volatile compounds: nine aliphatic alcohols, three branched alcohols, six aldehydes, two ketones, six terpenoid compounds (including β-myricene, D-limonene, β-linalool, L-α-terpineol, sulcatol, and sulcatone), four compounds containing a benzene-ring (including methoxyphenyl oxime, methyl salicylate, benzyl alcohol, and phenylethyl alcohol), and ethyl octanoate (an ester), 2-methylbutanoic acid (a carboxylic acid), and 2-ethylfuran (a cyclic ether). This species of blackberry contains high amounts of benzenoids, aldehydes, and alcohols (Table 6) [62,66].…”

“…Blackberries are considered one of the richest sources of natural antioxidants due to their high content of phenolic compounds, such as anthocyanins, ellagitannins, flavonols, and flavanols [13,41,44,49,51,62]. In fact, they present an extraordinary capacity to scavenge chemically generated radicals, thus preventing a wide range of human disorders and maintaining a healthy balance between free radicals and antioxidant systems.…”