Polyphenols from Mango Peel – Why the Extraction Method Matters

Published on: 2024-02-28

In the quest for healthier living, scientists are constantly exploring new ecological sources and efficient methods to extract beneficial compounds from natural sources. Food waste such as fruit by-products such as mango peels are rich in polyphenols and be used as source to obtain high-quality phenolic compounds. A such technique gaining traction in recent years is ultrasonic extraction, a process that applies high-frequency sound waves to efficiently extract bioactive compounds from plant materials. Among these compounds, polyphenols have emerged as star players due to their numerous health benefits, including antioxidant and anti-inflammatory properties. Join us on a deep delve into polyphenol extraction from mango peels and learn how different ultrasound equipment makes a significant difference for extraction efficiency and polyphenol yield.

What are Polyphenols?

Mango peels are rich in health-promoting compounds such as polyphenols and carotenoids. Ultrasonic probes are highly efficient for the extraction of valuable phytochemicals from fruit by-products such as mango peel.Polyphenols are a diverse group of naturally occurring compounds found in fruits, vegetables, tea, coffee, wine, and other plant-based foods. They are known for their antioxidant properties, which help combat oxidative stress in the body, reducing the risk of chronic diseases such as cardiovascular disease, cancer, and neurodegenerative disorders. Additionally, polyphenols exhibit anti-inflammatory, anti-microbial, and anti-cancer effects, making them valuable components of a healthy diet. Phenolic compounds from plant-based food by-products are a low cost source that can be used as food additives or supplements contributing to a healthier diet.
Mango peels are a great source of phenolic compounds (14.85–127.6 mg/gDW). Additionally, they offer high amounts of fiber (36–78 g/100 g of DW); vitamins (C and E); and carotenoids (0.1–51 mg/gDW).

The scientific study of Aznar-Ramos and colleagues gives compelling insights into the fascinating world of phenolic compound extraction from mango peel by-products and the relevance of the right extraction equipment. The results in the study shed light on the superior performance of probe-type sonication in extracting phenolic compounds compared to traditional ultrasonic baths.

Convincing Results: A Tale of Efficiency and Precision

As the data unfolded, it became evident that probe-type sonication held the key to unlocking nature’s bounty with unmatched efficiency and precision. The values obtained for total phenolic content (TPC) showcased a remarkable difference between the two extraction methods. While the ultrasonic bath yielded TPC values ranging between 1.6 and 8.7 mg GAE/g dw, the sonotrode extraction boasted higher values ranging from 3.9 to 9.4 mg GAE/g dw. These results underscored the potency of probe-type sonicators in maximizing phenolic compound extraction from mango peel by-products.

But the advantages of probe-type sonication did not stop there. Delving deeper into the analysis, the researchers discovered a fascinating trend – the probe-type sonication extracted a greater variety of compounds compared to the ultrasonic bath. With a total of 22 quantified compounds in sonotrode extracts versus 15 in ultrasonic bath samples, the superiority of probe-type sonication was further underlined.

Ultrasonic probe (sonotrode) UP400St as used in the mango peel extraction study by Aznar-Ramos et al. 2022

Ultrasonic probe (sonotrode) UP400St as used in the mango peel extraction study by Aznar-Ramos et al. 2022

Unlocking Phenolic Compounds from Fruit Waste: A Triumph of Probe-Type Sonication

Among the myriad compounds unearthed, flavonoids emerged as the stars of the show. The probe-type sonication extract reported the highest amounts of flavonoids, showcasing its unparalleled ability to unlock nature’s pharmacopeia in all its glory. In particular, a higher content of methylgallate was detected in sonotrode extracts—more than eight times higher than in bath ultrasound extracts—while the sum of galloylglucose isomers and methylgallate was significantly higher in sonotrode samples.

Scaling to Commercial Production: From Lab to Industry

Important to note that the advantages of probe-type sonication extend beyond the laboratory walls. With its scalability at both pilot and industrial levels, the probe-type sonication opens doors to a world of possibilities. From small-scale experiments to large-scale production, the efficiency and reliability of probe-type sonicators pave the way for transformative innovations in the extraction industry.

In the realm of extraction science, where every drop counts, probe-type sonicators stand as beacons of efficiency and precision. Through their remarkable performance in extracting phenolic compounds from mango peel by-products, these sonic marvels have reshaped our understanding of extraction methodologies. As we look to the future, the sonic revolution sparked by probe-type sonication promises to unlock new horizons of scientific discovery, one sonic wave at a time.

Traditional Extraction Methods vs. Ultrasonic Extraction

Traditionally, polyphenols have been extracted using methods such as maceration, Soxhlet extraction, and steam distillation. While effective, these techniques often require lengthy extraction times, high temperatures, and the use of organic solvents, which can degrade sensitive compounds and compromise the quality of the extract.

Enter ultrasonic extraction – a non-thermal, eco-friendly, and highly efficient alternative. This method harnesses the power of ultrasonic waves, typically in the range of 20 kHz to 100 kHz, to disrupt cell walls and release bioactive compounds from plant matrices. The process involves immersing the plant material in a solvent (usually water or a water-ethanol mixture) and subjecting it to ultrasonic waves, which create cavitation bubbles. These bubbles implode near the plant cells, generating intense shear forces and microjets that facilitate the extraction process. As a result, ultrasonic extraction offers several advantages over traditional methods, including shorter extraction times, lower solvent consumption, and higher extraction yields.

Benefits of Ultrasonic Polyphenol Extraction:

The use of ultrasonic extraction for polyphenol isolation offers numerous benefits:

  1. Enhanced Extraction Efficiency: Ultrasonic waves penetrate plant tissues more effectively than mechanical methods, leading to higher extraction efficiencies and greater yields of polyphenols.
  2. Reduced Processing Time: Compared to traditional techniques, ultrasonic extraction significantly reduces extraction times, allowing for faster production and increased throughput.
  3. Preservation of Bioactivity: The gentle nature of ultrasonic extraction minimizes thermal degradation and oxidation of polyphenols, preserving their bioactive properties and enhancing the quality of the extract.
  4. Environmentally-Friendly: Unlike solvent-intensive methods, ultrasonic extraction requires minimal solvent usage and eliminates the need for toxic organic solvents, making it environmentally sustainable and economically viable.

Applications of Ultrasonic Polyphenol Extraction:

The versatility of ultrasonic extraction has led to its widespread adoption in various industries, including pharmaceuticals, nutraceuticals, food and beverage, cosmetics, and herbal medicine. Some common applications include:

  • Production of polyphenol-rich extracts for dietary supplements and functional foods
  • Development of natural antioxidants for use in food preservation and cosmetics
  • Extraction of bioactive compounds from medicinal plants for pharmaceutical formulations
  • Optimization of extraction processes for specific polyphenol subclasses, such as flavonoids, phenolic acids, and tannins




Industrial-grade ultrasonic probe-type extractor for the inline processing of fruit by-products in order to isolate bioactive compounds such as polyphenols.

Sonicator MSR-4 with 4x 4kW ultrasonic probes (total 16kW ultrasound power) for industrial extraction of bioactive compounds from mango peel.

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