Evaluation of Terpene Decomposition in Kaffir Line Juice during Storage Using Gas Chromatography-Mass Spectrometry and Proton Transfer Reaction-Mass Spectrometry  
[PERSON]  
1 Department of Analytical Chemistry, Faculty of Chemistry, Gdatsk University of Technology,  
80-233 Gdatsk, Poland; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Analytical Chemistry, Faculty of Chemistry, Gdatsk University of Technology,  
80-233 Gdatsk, Poland; [EMAIL_ADDRESS]  
[PERSON]  
2 Department of Chemistry and Food Analysis, National Agricultural and Food Centre-Food Research Institute,  
824 75 Bratislava, Slovakia; [EMAIL_ADDRESS] (B.T.) [EMAIL_ADDRESS] (M.P.) [PERSON]  
1 Department of Analytical Chemistry, Faculty of Chemistry, Gdatsk University of Technology,  
80-233 Gdatsk, Poland; [EMAIL_ADDRESS]  
[PERSON]  
2 Department of Chemistry and Food Analysis, National Agricultural and Food Centre-Food Research Institute,  
824 75 Bratislava, Slovakia; [EMAIL_ADDRESS] (B.T.) [EMAIL_ADDRESS] (M.P.) [PERSON]  
3 Department of Agronomy, Faculty of Agriculture, Kasestant University, Chathach  
properties of fruit (degradation products may have different bioactive and sensory properties). This is important since their profiles in fruits vary depending on growing conditions, degree of maturity, or storage conditions [4]. Regarding citrus waste, the problem of management is particularly important in the case of kaffir lime (_Citrus hystrix_). An overview of the production, post-harvest, and marketing of kaffir lime was provided by [PERSON] et al. [5], who reported that kaffir lime is a popular citrus fruit in Southeast Asia, mainly because of its leaves and outer part of the peel, which are used as spices and as an ingredient in many dishes. Despite its culinary uses, the peel is considered waste after the leaves have been picked [6]. In Thailand, it is sometimes used as a detergent for clothes and hair [7]. In Cambodia, it is common to add kaffir lime pieces to holy water during religious ceremonies. However, these are occasional applications. Kaffir lime juice is also used in folk medicine in some Asian countries [8]. The juice is not consumed because of its bitter taste, so there is no commercial production. In the case of kaffir limes, 80% of the fruit crops are industrial waste. In the literature, there are studies on the chemical composition of kaffir lime juice and its aromatic and health-promoting properties [3; 4; 9]. However, to the best of our knowledge, no one has ever investigated kaffir lime juice in terms of the compositional changes that occur under different storage conditions. [PERSON] et al. studied changes in aroma compounds in orange juice during storage [10], but there are no similar studies for kaffir lime juice. As kaffir lime juice can have many uses, as indicated in the abovementioned articles, this study may be crucial in the context of importing kaffir limes from the area where they are grown. Kaffir lime fruits are harvested from June to July [5]; therefore, the maximum temperature in the harvesting areas is 35 \({}^{\circ}\)C. The high temperature of fruit storage in non-refrigerated conditions contributes to numerous changes in the terpene profile of the fruit, resulting in changes in functional, health-promoting, and sensory properties. So far, the decomposition/degradation products of terpen have been studied using nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), ultraviolet (UV) analysis, gas chromatography (GC) [11], and, mainly, gas chromatography-mass spectroscopy (GC-MS) [12]. In general, the degradation of terpen occurs in four ways including (1) epoxidation; (2) oxidative cleavage of carbon-carbon double bonds; (3) allylic oxidation into alcohols, ketones, and aldehydes; and (4) dehydrogenation into aromatic systems [13]. In the context of shelf-life determination, where quick and robust methods are often required, high-throughput methods are sought. Separation in the GC column is a factor that prolongs and causes low throughput of the analysis.