Aspartame

We used six sweeteners in this study: granulated sugar as the sucrose control, acesulfame potassium (MC Food Specialties Inc.), aspartame (Ajinomoto Co.), sucralose (San‐Ei Gen F.F.I.), xylitol (Nippon Garlic Co.), and Rebaudio J‐100 (Morita Kagaku Kogyo Co., LTD.). Rebaudio J‐100 was used as rebaudioside A, because it contains more than 95% rebaudioside A. All solutions were prepared via serial dilutions in Hank's Balanced Salt Solution (HBSS) (Sigma‐Aldrich) for HEK293 cell treatment or in filtered water for psychophysical evaluations by human participants.

Acesulfame-K was purchased from Nutrinova (Frankfurt, Germany). Caffeine, paracetamol, carbamazepine, saccharin, ibuprofen, and three parabens (methyl, ethyl, and butyl) were purchased from Sigma-Aldrich (St. Louis, USA). Cyclamate was obtained from Merck (Darmstadt, Germany), sucralose was purchased from Nestlè (Vevey, Switzerland), whereas aspartame was purchased from Ajinomoto (Zug, Switzerland). The internal standard (IS), sodium N-(2-methylcyclohexyl)sulfamate, was obtained by synthesis [22 (link)] (Department of Organic Chemistry, Faculty of Chemistry, Gdańsk University of Technology). Acetonitrile (HPLC grade), methanol (HPLC grade), and formic acid (> 98%) were purchased from Merck (Darmstadt, Germany). ethyl acetate (LC–MS grade) and acetone (LC–MS grade) were obtained from Sigma-Aldrich (St. Louis, USA). Methanol (LC–MS grade) and acetonitrile (LC–MS grade) were purchased from VWR Chemicals (Radnor, USA). Ultrapure water was prepared using HPL5 system from Hydrolab (Wiślina, Poland). Ammonium solution (analytical grade) was purchased from Chempur (Piekary Śląskie, Poland) and ethyl acetate (> 99%) was obtained from Sigma Aldrich (St. Louis, USA).

The passion fruit juices were prepared in the laboratory; unsweetened passion fruit pulp (DeMarchi™) was employed. The following ratio was used: one part of pulp to two parts of water. The juice samples were sweetened with sucrose (União™), aspartame (Ajinomoto™), or sucralose. Pure water was considered as reference. The samples were prepared 1 day before the experiment, stored at 4–6°C, and tested at room temperature.
The sweetener concentration in the passion fruit juice was chosen according to Rocha and Bolini’s study (11 (link), 12 (link)), who stated that 9.4/100 g was an ideal sucrose concentration according to consumer’s acceptance. They also stated that the equivalent aspartame and sucralose concentrations in passion fruit juice were 0.0547 g/100 g and 0.0159 g/100 g, respectively.