Changes in the Polyphenol Content of Red Raspberry Fruits during Ripening

Abstract

Berry fruits that contain large amounts of polyphenol compounds are expected to exhibit health and anti-aging effects due to the antioxidant activities of these components. Among the various polyphenols, flavan-3-ol derivatives are known to have a particularly high functionality. In this study, the maturity of red raspberry fruits is classified into eight stages based on the polyphenol content at each stage. Quantification of the various compounds and investigation of the DPPH and ABTS radical scavenging activities were carried out. The total polyphenol content, including that of the flavan-3-ol derivatives, was the highest in immature fruits, gradually decreasing during fruit maturation, during which the radical scavenging activity also decreased. Based on our quantitative results, it was considered that the decrease in the flavan-3-ol derivative content due to fruit ripening was largely related to the increase in the amount of anthocyanin derivatives. Considering that the decreased contents of these compounds were related to the expression levels of polyphenol biosynthetic enzymes, quantification was performed using the semi-quantitative polymerase chain reaction, but the only change observed was the increased expression of the enzyme that synthesizes anthocyanins during maturation. Therefore, it was suggested that it is necessary to inhibit anthocyanin synthesis to increase the contents of highly functional flavan-3-ol derivatives in the mature fruit.

The Visibility of Changes in the Antioxidant Compound Profiles of Strawberry and Raspberry Fruits Subjected to Different Storage Conditions Using ATR-FTIR and Chemometrics

“…Absorption bands at about 3024 and 2985 cm −1 , as well as 2804 and 2985 cm −1 , corresponded to asymmetric and symmetric stretching vibrations of CH 2 and CH 3 groups of aliphatic compounds [ 34 ]. Additionally, bands in the range of 3000–2800 cm −1 were most likely due to stretching vibrations of C-H bonds present in hydrocarbons, O-H bonds of carboxylic acids and asymmetric stretching vibrations of C-H bonds of methyl (-CH 3 ) groups in free phenolic acids and catechins [ 35 ].…”

Raspberry polyphenols alleviate neurodegenerative diseases: through gut microbiota and ROS signals

“…During raspberry fruit ripening, catechins and epicatechin decreased to nearly 90% of their original levels, and proanthocyanidins decreased even more significantly to 30% of their original levels. 29 The scavenging activity of free radicals is significantly worse because the expression of enzymes that synthesize polyphenols is reduced. However, external factors such as light radiation can change the content of flavan-3-ols.…”

Postharvest Quality Exploration of “Crystal” Grapes in Karst Mountainous Area: Regulatory Effect of High Concentration 1-MCP Fumigation

“…The polyphenol content was determined following the method described by Kobori et al [30]. First, 10.0 mg of a crude extract of sample polyphenols was accurately weighed and diluted with 2.0 mL of methanol to create a working solution.…”