Table 2.

Composition of staining solutions investigated in the study.

Staining solution	Ingredients	Manufacturer	Concentration
Coco-based drink (CHO)	Extract of malted barley, maltodextrin, cow milk, sugar, cocoa, palm oil, minerals, vitamin	Milo, Nestlé, Malaysia	33 g of Milo/200 ml boiling distilled water
Coffee (COF)	Sugar, glucose, syrup, hydrogenated palm kernel oil, instant coffee, skimmed milk powder 4% (cow milk), sodium caseinate (milk protein), salt	Nescafé Blend & Brew™, Nestlé, Malaysia	20 g of Nescafe/180 ml boiling distilled water
Chinese tea (CHI)	Pu-erh tea leaves	Pu-erh tea (M) SDN BHD, Malaysia	2 g of pu-erh tea/40 ml boiling distilled water
Milk tea (MT)	Nondairy creamer, sugar, instant tea, stevia leave extract	Teh tarik original, BOH, Malaysia	27 g of teh tarik/180 ml boiling distilled water
Distilled water	—	Hamilton Laboratory Glass Ltd, UK	As supplied