Master 3 m

In order to determine the pH of the juice samples, a digital pH meter (EUTECH INSTRUMENTS, ION 2700, pH/mV/°C/°F meter) was used at a temperature of 25 ± 1 °C. The results of every experiment were analyzed in triplicate, and the mean was determined. A digital refractor (Master 3 m ATAGO, Tokyo, Japan) was used to determine the total soluble solids (TSSs) in the bor-thekera juice at an ambient temperature of 25 ± 1 °C. The outcomes were represented in °Brix.
The titratable acidity (TA) of the samples was assessed by titrating a 0.1 N NaOH solution against the juice in the presence of a phenolphthalein indicator (AOAC, 1999). The results were expressed as a citric acid percentage [20 (link)].

A small aliquot of honey (1 g) sample was used to determine the water activity by using an Aqualab water activity meter (Decagon Devices, Inc., Pullman, WA, USA) at 20 °C.
The total soluble solid of the sample was analysed using a handheld manual refractometer (Master-3M, ATAGO, Minato-ku, Tokyo, Japan) at 25 °C.
Each sample with a concentration of 10% (w/v) in distilled water was analysed with a pH meter (Desktop pH meter Seven Compact S220, Mettler Toledo, Chiyoda, Japan) at a temperature of 25 °C [1 (link)].
The colour of the honey was analysed using a chromameter (Konica Minolta Chroma Meter, model CR-400, Osaka, Japan) by measuring the values of L*, a*, and b*. The colour of the adulterated Kelulut honey was determined by measuring the values of values of L*, a*, and b*. L* values indicate the brightness level, a* indicates red to green, meanwhile, b* indicates yellow to blue.
The turbidity of the samples was measured with a portable turbidimeter (Orbeco-Hellige Model 966, Sarasota, FL, USA), and the reading was stated in Nephelometric Turbidity Unit (NTU).