Effect of UV-C radiation and vapor released from a water hyacinth root absorbent containing bergamot oil to control mold on storage of brown rice

Abstract

The aims of this study were to develop absorbent material from a water hyacinth root containing bergamot oil and to improve its antifungal activity by using ultraviolet C (UV-C) against the growth of A. flavus on the brown rice. Process optimization was studied by the immersion of a water hyacinth root into a water and bergamot oil (300, 500 and 700 μl ml −1 ). The root (absorbent material) was dried at 50, 70, and 90°C for 10 min. Then, ultraviolet C (UV-C) was used for enhancing the antifungal activity of bergamot oil for 10, 15, and 20 min. The shelf-life of the brown rice with the absorbent after incubation at 25°C with 100 % RH for 12 weeks was also investigated. A microscope and a Fourier transform infrared spectroscopy (FTIR) were used to find out possible mode of action. Results indicated that the absorbent material produced from the water hyacinth root containing bergamot oil at 500 μl ml −1 in the water solution, dried at 70°C and UV for 15 min showed the highest antifungal activity in a vapor phase against A. flavus on the brown rice. A microscopy investigation confirmed that the water hyacinth root could absorb bergamot oil from an outside water solution into root cells. Limonene in vapor phase was shown to be a stronger inhibitor than essential oil after UV-C radiation and should be the key factor in boosting bergamot oil antifungal activity. A vapor phase of bergamot oil could be released and inhibit natural mold on the surface of the brown rice for up to 12 weeks; without the absorbent, mold covered the brown rice in only 4 weeks.

Enhancement of antibacterial activity of essential oil vapor released from a paper egg tray in combination with UV‐C radiation against pathogenic bacteria on chicken eggs

“…However, clove oil alone in vapor phase only has a low antimicrobial activity, so it is often used in combination with other essential oil vapors, such as mustard (Aguilar-González, Palou, & López-Malo, 2015) and cinnamon (Goni et al, 2009), or UV-C radiation. has the shortest wavelength of the highly energetic UV spectrum and has been used to inhibit the growth of spoilage and pathogenic bacteria (Koutchma, 2009) and molds (Songsamoe, Matan, & Matan, 2016) and inactivate microorganisms in fruit juice (Keyser, Műller, Cilliers, Nel, & Gouws, 2008).…”

“…UV‐C radiation (200–280 nm) has the shortest wavelength of the highly energetic UV spectrum and has been used to inhibit the growth of spoilage and pathogenic bacteria (Koutchma, 2009) and molds (Songsamoe, Matan, & Matan, 2016) and inactivate microorganisms in fruit juice (Keyser, Műller, Cilliers, Nel, & Gouws, 2008). Therefore, chicken eggs are one of the foods in the world that contain high‐quality protein.…”

The effects of Michelia alba oil against mould on brown rice and assessing the brain response using electroencephalogram (EEG)

“…The results from this experiment confirmed that M. alba in the vapour phase (≥ 450 μl/L) could completely inhibit the growth of A. flavus . By performing a comparison with the M. alba oil from the leafy part of the plant, it was found that oil from the flowering part is less effective against A. flavus than that from the leafy part (Songsamoe et al 2016 ). Linalool (the major component of M. alba oil), a monoterpene alcohol, is widely known as a highly effective antimicrobial compound (Suppakul et al 2011 ).…”

“…A. flavus are a major cause of postharvest losses and diseases in brown rice and its products with a high frequency worldwide (Suhem et al 2015 ). Recently, has been discovered that the application of essential oils such as that of Litsea cubeba (Suhem et al 2015 ), bergamot (Songsamoe et al 2016 ) and Michelia alba (Songsamoe et al 2017 ) can suppress the growth of A. flavus in brown rice.…”

Controlled Release of Peppermint Oil from Paraffin‐Coated Activated Carbon Contained in Sachets to Inhibit Mold Growth During Long Term Storage of Brown Rice

“…Unfortunately, it has low shelf life because it is susceptible to fungal contamination. Accordingly, various methods have been used to detect and reduce fungal growth on the surface of BR (Chen, Chen, & Chang, ; Songsamoe, Matan, & Matan, ).…”