Ultrasonic Capsaicin Extraction from Hot Chili Peppers

• Capsaicin is the main flavour and spice compound in hot peppers, also known as chilies.
• To produce high-quality capsaicin as aromatic flavour and medicinal ingredient, an efficient, yet mild extraction technique is required to prevent degradation.
• Ultrasonic extraction is a mild mechanical extraction method, which gives high yields of capsaicin in a very short extraction time.

High-Performance Ultrasonics for High-Quality Capsaicin Extracts

Ultrasonic extraction of capsaicinoids from hot chilli peppers (e.g. Capsicum frutescens) improves the extraction yield significantly. Power ultrasound promotes the perforation and disruption of cell walls, as well as swelling and hydration by pushing the solvent into the plant cells. This results in an increased mass transfer of the intracellular substances (including capsaicinoids) from the plant cells into the solvent.
As a purely mechanical, non-thermal processing technique, ultrasonic extraction prevents the thermal degradation of thermo-labil compounds. Ultrasonic cavitation intensifies the extraction process, resulting in high yields of superior extract quality. The investment and operational costs of ultrasonic extraction equipment are relatively low and allow for a fast RoI.

Ultrasonic Capsaicinoid Extraction – in Batch or Continuous Flow Mode

Batch: Ultrasonic extraction processes can be operated as simple batch processes or as inline treatment, where the medium is continuously fed through an ultrasonic flow-through reactor.
Batch processing is an easy procedure, where the extraction is performed lot by lot. Hielscher Ultrasonics offers ultrasonic processors for small to large batches, i.e. 1L to 120L.
For processing batches of 5 to 10L, we recommend the UP400ST with sonotrode S24d22L2D. (see pic. left)
For processing batches of approx. 120L, we recommend the UIP2000hdT with sonotrode RS4d40L4. (see pic. top right)

Flow-through: For larger volumes and full-scale commercial capsaicin extraction, a continuous liquid stream containing hot pepper flakes is fed through an ultrasonic reactor, where the solvent/botanical slurry is intensely sonicated.
For a volume of approx. 8L/min., we recommend the UIP4000hdT with sonotrode RS4d40L3 and pressurizable flow-cell FC130L4-3G0.

Case Study of Ultrasonic Capsaicin Extraction

Olguín-Rojas et al. (2019) report the isolation of capsaicinoid yield higher than 96% using three Capsicum chinense Jacq. cultivars (‘Bode’, ‘Habanero’, and ‘Habanero Roxo’ peppers). They used the Hielscher probe-ultrasonicator UP200S (200 W, 24 kHz) with the sample immersed in a temperature-controlled water bath was used. 0.25g of Capsicum chinense sample was put in contact with 25mL of methanol for 10 minutes, and was then transferred to the water bath at 50ºC, 200 W output amplitude, and 0.5sec duty cycle. Afterwards, the extracts were filtered through a nylon syringe filter and analyzed via chromoatography. In the analysis, all five principal capsaicinoids (n-DHC, C, DHC, h-C, and h-DHC) were found. Ultrasonic extraction gives a full spectrum extract with a broad flavour profile.

Sganzerla et al. (2014) found that ultrasonic extraction is an excellent method for the quantitative and reproducible extraction of capsaicinoids from chili peppers using methanol as solvent. Due to its simplicity and efficiency, ultrasonic extraction can be applied for the fast routine analysis of capsaicinoids in chili peppers.

Ultrasonic Extraction Equipment

Hielscher Ultrasonics is specialized in manufacturing high-performance ultrasonic processors for the production of high-quality extracts from botanicals.

The broad product portfolio of Hielscher Ultarsonics ranges from compact, powerful lab sonicators to robust bench-top and fully industrial systems, which deliver high intensity ultrasound for the efficient extraction and isolation of bioactive substances (e.g. quercetin, caffeine, curcumin, terpenes etc.). All digital sonicators from 200W to 16,000W feature an intuitive menu with programmable settings, a coloured touch display for digital control, an integrated SD card for automatic data recording, browser remote control and many more user-friendly features. The sonotrodes and flow cells (the parts, which are in contact with the medium) can be autoclaved and are easy to clean. All our ultrasonicators are built for 24/7 operation, require low maintenance and are easy and safe to operate.
A digital colour display allows for a user-friendly control of the ultrasonicator. Our systems are capable to deliver from low up to very high amplitudes. For the extraction of polyphenols and other bioactive phytochmicals such as capsaicinoids, we offer special ultrasonic sonotrodes (also known as ultrasonic probes or horns) that are optimized for the sensible isolation of high-quality active substances. The robustness of Hielscher’s ultrasonic equipment allows for 24/7 operation at heavy duty and in demanding environments.
The precise control of the ultrasonic process parameters ensures reproducibility and process standardization.

The table below gives you an indication of the approximate processing capacity of our ultrasonicators: