Cold atmospheric‐pressure plasma treatment of turmeric powder: microbial load, essential oil profile, bioactivity and microstructure analyses

Abstract

Turmeric powder treated by cold atmospheric-pressure plasma (CAPP) at 25 kV for various times of 3, 5 and 7 min was examined for microbial load, essential oil profile, colour parameters, total phenolic content, total flavonoid content, antioxidant activity and microstructure. CAPP treatment caused a reduction of approximately 1.5 log CFU g −1 in aerobic viable cell count of turmeric powder, which was most pronounced during the first 3 min of the treatment. The inactivation kinetic was fitted to the Weibull model with R 2 of 0.9913 and RMSE of 0.0641. Gas chromatography-mass spectrometry analysis of essential oils identified twelve different components for turmeric powder of which 1,8-Cineole, α-Terpinolene and trans-Caryophyllene were lost and ar-Turmerone and α-Zingiberene experienced considerable increases after plasma treatment. The double-edged effect of plasma treatment was also observed on bioactivity. Scanning electron microscopy showed formation of super-agglomerates in plasma-treated samples due probably to coalescence of the granules with plasma-damaged walls.

The Effect of Cold Plasma Pretreatment on Water-Suspended Herbs Measured in the Content of Bioactive Compounds, Antioxidant Activity, Volatile Compounds and Microbial Count of Final Extracts

“…Recently, a lot of research has been carried out on the effect of cold plasma on the reduction of microorganisms in food products. Most of them confirmed the antimicrobial properties of cold plasma [ 6 , 35 ]. It was proven that plasma-induced radicals attack the chemical structures of cell membranes which in consequence causes its death [ 36 ].…”

“…It has been established that the color of plasma-treated samples is determined by the treatment conditions and biological status of herbs. Its change in herb extracts might be caused by pigment oxidation or degradation initiated by active species formed by plasma generators [ 6 ]. However, color may change also due to the higher extraction rate of bioactive compounds caused by the application of plasma treatment [ 15 ].…”

“…The same effect of plasma on the reduction of the volatile compound profile was observed for lemon verbena leaves treated with plasma for 5 min [ 30 ]. Plasma treatment may disintegrate the cellular structures in the same manner as in the case of microbes [ 6 ]. However, it increases the yield of volatiles in samples but also accelerates their evaporation [ 31 ].…”

“…Reactive compounds created by plasma, oxidate microbial cell membranes while UV radiation degrades DNA, which in turn leads to the inactivation of microorganisms. There are many studies documenting that cold plasma treatment effectively decreases the growth of microorganisms in food [ 5 , 6 ]. In turn, herbs are very often microbiologically contaminated, as most of them are imported from countries of rather poor hygienic in production environments [ 7 ].…”

Effect of High Voltage Cold Plasma on Oxidation, Physiochemical, and Gelling Properties of Myofibrillar Protein Isolate from Asian Sea Bass (Lates calcarifer)

“…During this process, diverse species such as negative and positive ions, radicals, neutral and excited molecules, electrons, and quanta of electromagnetic radiation (i.e., ultraviolet and visible light) are generated [6,7]. HVCP technology has rapidly evolved as a novel non-thermal preservation technology for seafood including fish [8] and shrimps [9,10].…”