Nh2 column

Fructose, glucose, maltose, and saccharose values in the fermented radish roots were determined according to the GB 5009.8-2016 national food safety standard. This method was previously reported by our group, with slight modifications (24 (link)). Radish sample (2.0 g) extraction was conducted by ultrasonic extraction for 30 min by adding 25 mL of water, and then the mixture was passed through 0.22 μm polytetrafluoroethylene filters. The mixture was then analyzed with an Agilent 1,200 HPLC system (Agilent, Palo Alto, CA, USA) with an NH2 column (250 × 4.6 mm, i.d. × 5 μm; Agilent). The available sugars were separated at 30°C using a mobile phase acetonitrile aqueous solution (70%, v/v) with a flow rate of 1.0 mL/min. The compounds were then quantified using external standards and expressed as g/100 g of sample.

First, 45 products (26 gluten-free and 19 gluten-containing) were homogenized in a grinder (Sinbo SCM-2934, Istanbul, Turkey) for an average of 20–30 s. Then, 5 g of finely ground samples was weighed and placed in 50 mL falcon tubes. The volume was adjusted to 50 mL by adding distilled water, and the samples were homogenized in an ULTRA-TURRAX mixer (IKA, Staufen, Germany) for 1 min. After centrifugation at 13,000 rpm for 5 min, the samples were filtered through a 0.45 µm cellulose acetate membrane and analyzed using a HPLC system. The system consisted of a Shimadzu RI-20A detector (Shimadzu Corporation, Kyoto, Japan) and a Shimadzu LC 20AT pump. The flow rate was set to 2 mL/min using a mobile phase comprising acetonitrile and deionized water (80:20 v/v). Separation was carried out using an Agilent NH2 column (250 × 4.6 mm², 5 μm) with the column furnace temperature set to 40 °C [19 (link)].