1064 nm Raman Excitation of Fluorescent Pumpkin Seed Oil

Happy Halloween! Jack-O-Lanterns, pumpkins with ghoulish faces placed in front of homes, have been a symbol of Halloween for centuries¹. Because of their popularity, the pumpkin industry in the USA is geared towards supplying for this annual festival². On the contrary, pumpkins are more commonly used for medicinal cuisine in Asia as they reduce swelling by promoting diuresis^3,4.

Although pumpkins are not an easy ingredient to handle, you can enjoy the full benefits by simply cooking with the oil extracted from their seeds. Pumpkin seed oils have high oxidative stability (cooking oil can oxidize at high temperatures, generating harmful compounds), making them ideal for cooking⁵.

Raman spectroscopy is routinely used to monitor the quality of foods, and we have explored the Raman spectra of olive oils using the B&W Tek i-Raman^® Plus-785 system previously (Fast Ingredient Analysis of Edible Oils Using a Portable Raman Spectrometer). Nevertheless, the same system is not optimal for evaluating pumpkin seed oils which are deeply colored and have strong fluorescence (Figure 1). This problem can be resolved by using 1064 nm handheld systems like B&W Tek’s NanoRam^®-1064 or 1064 nm portable systems like B&W Tek’s i-Raman EX and i-Raman Prime-1064.

Meanwhile, Figure 2 shows Raman spectra of different plant-based oils collected with our NanoRam-1064 system. The peaks for the pumpkin seed oil can be clearly characterized like other types of oil. All plant-based oils have similar Raman peaks since they essentially have the same content⁶. However, the pumpkin oil had a distinct peak at 1528 cm^-1, corresponding to carotenoids – a bright yellow pigment in plants known to mitigate degenerative disease^7,8.

For more information about B&W Tek’s 1064 nm Raman systems, visit https://bwtek.com/technology/raman/.