Analysis of Wild Raspberries (Rubus idaeus L.): Optimization of the Ultrasonic-Assisted Extraction of Phenolics and a New Insight in Phenolics Bioaccessibility
- 46 Downloads
A simple and efficient ultrasonic-assisted extraction (UAE) technique was developed in order to find optimal conditions for the extraction of total phenolic compounds, flavonoids and anthocyanins in wild raspberry (Rubus idaeus L.) fruits. Several extraction variables, including methanol composition (v/v, %), solid-solvent ratio (g/mL), time (min) and extraction temperature (°C) were optimized using response surface methodology (RSM). Under optimal conditions for extraction, the total phenolics were found in the concentration of 383 mg GAE/100 g of fresh fruit weight, while HPLC-PDA analysis of the optimized extract showed the presence of cyanidin-3-glucoside, cyanidin-3-sophoroside, catechin, gallic and ellagic acid. The experimental values of DPPH and ABTS radical scavenging activities were 29.0 and 39.5 μmol Trolox/g of fresh fruit weight, respectively. In vitro simulated gastrointestinal digestion showed great raspberry phenolics stability. Our study assessed the bioaccessible phenolics in wild raspberry fruits and showed optimal conditions for the effective extraction of bioactive compounds for their analysis.
KeywordsRubus idaeus L. Extraction HPLC-PDA Cyanidin-3-glucoside Antioxidant activity In vitro digestion
Central composite design
Gallic acid equivalents
High performance liquid chromatography
Photo diode array
Response surface methodology
Total anthocyanins content
Total flavonoids content
Total phenolics content
Wild raspberry fruit
This work is supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grants no. OI 172016, III 43004 and OI 175039).
Compliance with Ethical Standards
Conflict of Interest
The authors declare no conflict of interest.
Human and Animal Studies
This article does not contain any studies with human or animal subjects.
Informed consent was obtained from all individual participants included in the study.
- 11.Ciğeroğlu Z, Aras Ö, Pinto CA, Bayramoglu M, Kırbaşlar Şİ, Lorenzo JM, Barba FJ, Saraiva JA, Şahin S (2018) Optimization of ultrasound-assisted extraction of phenolic compounds from grapefruit (Citrus paradisi Macf.) leaves via D-optimal design and artificial neural network design with categorical and quantitative variables. J Sci Food Agric 98:4584–4596CrossRefGoogle Scholar
- 14.Singleton VL, Orthofer R, Lamuela-Raventós RM (1999) Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent. In: Lester P (ed) Methods in enzymology. Academic Press, Cambridge, pp 152–178Google Scholar
- 16.Giusti MM, Wrolstad RE (2001) Anthocyanins. Characterization and measurement of anthocyanins by UV-visible spectroscopy. In: Wrolstad RE (ed) Current protocos in food analytical chemistry. John Wiley & Sons, New York unit F1.2.1−1Google Scholar
- 25.Diaconeasa Z, Ranga F, Rugină D, Leopold L, Pop O, Vodnar D, Cuibus L, Socaciu C (2015) Phenolic content and their antioxidant activity in various berries cultivated in Romania. Bull UASVM Food Sci Technol 72:99–103Google Scholar
- 29.Strugala P, Loi S, Bazanow B, Kuropka P, Kucharska AZ, Wloch A, Gabrielska J (2018) A comprehensive study on the biological activity of elderberry extract and cyanidin 3-O-glucoside and their interactions with membranes and human serum albumin. Molecules 23:E2566. https://doi.org/10.3390/molecules23102566 CrossRefGoogle Scholar
- 30.de Souza VR, Pereira PA, da Silva TL, de Oliveira Lima LC, Pio R, Queiroz F (2014) Determination of the bioactive compounds, antioxidant activity and chemical composition of Brazilian blackberry, red raspberry, strawberry, blueberry and sweet cherry fruits. Food Chem 156:362–368CrossRefGoogle Scholar