Fruit Quality Characteristics and Biochemical Composition of Fully Ripe Blackberries Harvested at Different Times

Abstract

We investigated how the quality of blackberry fruit changes during the ripening period. Since it is difficult to predict picking dates for blackberries, we were interested in how the quality of fully ripe fruit changed depending on the sampling date (from 28 July to 1 September). Blackberries (at full ripeness) were sampled at six weekly intervals and the contents of sugars, vitamin C, organic acids and phenolic components were analysed by high performance liquid chromatography combined with mass spectrometry. The colour parameters, total soluble solids and weight of the fruits were also measured. The results showed that the fruits at the last sampling had a significantly lower fruit weight and higher soluble solids. ‘Cacanska Bestrna’ had the highest fruit weight and vitamin C content (11.43 mg/100 g). The main sugars in blackberries were fructose (13.8–33.4 g/kg FW) and glucose (13.0–33.2 g/kg FW). ‘Loch Ness’ and ‘Navaho’ had a sweeter taste since they had the highest ratio of sugars and acids (S/A approx. 5.8) and ‘Smoothstem’ and ‘Thornfree’ had the sourest taste, with a ratio of S/A 2.5. Blackberries harvested at the first two samplings had lower anthocyanin contents than fruits from later sampling times. There were no significant differences in the content of flavonols, ellagitannins, flavanols or hydroxycinnamic acids during the ripening period. The content of vitamin C in the fruits did not change among samplings, but the fruits had a higher content of organic acids at the first two or three samplings. The results may be useful for both the processing industry and growers to set quality standards for each variety and to determine the optimal harvest time.

Postharvest quality comparison of six blackberry cultivars under two storage conditions

“…Therefore, the TSS and soluble sugar content of most samples decreased during postharvest storage. In this study, the value of TSS and soluble sugar content were approximate to that in the research of Mikulic‐Petkovsek et al (2021). However, the ripening in postharvest stage may also elevate the TSS and soluble sugar content, explaining the increase of TSS in “Arapaho” and soluble sugar content in some cultivars at the beginning of the storage (Huang et al, 2018).…”

“…Therefore, the TSS and soluble sugar content of most samples decreased during postharvest storage. In this study, the value of TSS and soluble sugar content were approximate to that in the research ofMikulic-Petkovsek et al (2021). However, the ripening in postharvest stage may also elevate the TSS and solubleF I G U R E 6 Antioxidant activity in fruit of six blackberry cultivars stored at 25°C, 55% RH for 4 days (RT) or 4°C, 90% RH for 10 days (LT).…”

Antioxidant Guided Fractionation of Blackberry Polyphenols Show Synergistic Role of Catechins and Ellagitannins

“…There were high contents of cyanidin-3- O -glucoside and cyanidin-3- O -rutinoside on either side (fractions 13–15 and 18–21) of flash fractions 16 and 17, and these two anthocyanins could be responsible for high antioxidant indices. Reyes-Carmona et al [ 35 ] have also shown that there is a significant correlation among antioxidant activities, namely FRAP and oxygen radical absorbance capacity (ORAC), and the concentration of cyanidin-3-O-glucoside and cyanidin-3- O -rutinoside in blackberries. Similarly, Gong et al [ 4 ], through boosted regression tree analysis, also showed that cyanidin-3- O -glucoside and chlorogenic acid were the main contributors in the antioxidant activity of free phenolics from different blackberry varieties.…”

THE QUANTIFICATION OF SOME BIOACTIVE COMPOUNDS IN THE FRUITS OF FOUR BLACKBERRY (Rubus fruticosus L.) CULTIVARS, PROPAGATED BY TISSUE CULTURE

“…It is well known that both sugars and organic acids are the main water-soluble substances in berries and play a crucial role in developing the taste and in the process of ripening of blackberries, as well as being a qualitative index of how they will be appreciated by consumers. Thus, organic acids together with sugars and their properties, along with various secondary and aromatic metabolites determine the taste and organoleptic properties of fruits [MIKULIC-PETKOVSEK & al. 2021].…”