Optimization of Ultrasound-Assisted Extraction of Chlorogenic Acid from Potato Sprout Waste and Enhancement of the In Vitro Total Antioxidant Capacity

Abstract

Potato sprouts, an underutilized by-product of potato processing, could be exploited for the recovery of caffeoyl-quinic acids (CQAs), a family of polyphenols with well-recognized biological activities. In this work, the predominant compound of this class, 5-CQA, was extracted by Ultrasound-Assisted Extraction (UAE) under conditions optimized by an Experimental Design. The investigated variables solid/solvent ratio (1:10–1:50 g/mL), water content in ethanol (30–100% v/v) and UAE time (5–20 min) highlighted a critical influence of the last two factors on the extraction efficiency: extracts richer in 5-CQA were obtained with lower water content (30%) and time (5 min). The addition of ascorbic acid (1.7 mM) as anti-browning agent to the extraction solvent improved the extraction efficiency of 5-CQA compared to acetic and citric acids (3158.71 μg/mL, 1766.71 μg/mL, 1468.20 μg/mL, respectively). A parallel trend for the three acids and an increase in 5-CQA recovery was obtained with the use of freeze-dried sprouts (4980.05 μg/mL, 4795.62, 4211.25 μg/mL, respectively). Total antioxidant capacity (TAC) in vitro demonstrated UAE being a more valuable technique than conventional maceration. Furthermore, three-times-higher values of TPC (7.89 mg GAE/g) and TAC (FRAP: 24.01 mg TE/g; DPPH: 26.20 mg TE/g; ABTS 26.72 mg TE/g) were measured for the optimized extract compared to the initial one. An HPLC-DAD method was applied to monitor 5-CQA recovery, while an LC-HRMS/MS investigation allowed us to perform analyte identity confirmation along with detection of the glycoalkaloids α-solanine and α-chaconine. This evidence underlines the necessity to develop purification strategies in order to maximize the potential of potato sprout waste as a source of 5-CQA.

Therapeutic Potential of Chlorogenic Acid in Chemoresistance and Chemoprotection in Cancer Treatment

“…This process involves utilizing water content (30%), a time duration of 5 min, and ascorbic acid (1.7 mM) as an anti-browning agent. [58]. Chen et al evaluated various ultrasound conditions for CGA extraction from burdock (Arctium lappa L.) roots.…”

NADES-Assisted Extraction of Polyphenols from Coriander Seeds: A Systematic Optimization Study

“…This finding could be fruitfully exploited by creating ad hoc NADES-based systems when the attention is focused on a leading compound whose obtainable amount needs to be enhanced. The use of CA or Ur-based NADES, respectively, coupled with MAC or UAE for 20 min, allowed us to obtain high amounts of chlorogenic acid, a compound that is gaining great attention for its outstanding pro-health properties including antioxidant, radical scavenging, anticancer, antiobesity and antidiabetic activity [2,23]. Through the same approaches, high levels of rutin (also known as vitamin P) were extracted, a flavonoid highly recognized for its pharmacological activities and variously used in food, cosmetic and chemical industries [46].…”

“…The major challenge today is represented by the reduction in volatile and flammable organic solvents, harmful to both human health and the environment, conventionally used in all of the analytical phases [1], among which the extraction is the most crucial for the isolation of the desired chemical components. In this context, numerous efforts have been made to improve extraction protocols and technology-supported approaches that would allow for a much more efficient recovery of valuable compounds than the conventional ones [2]. The ideal alternative is a low toxicity, easy to remove and environmentally friendly solvent, which could be combined with a low-energy and cost-effective, innovative technology.…”