Consistency labels of thickened liquids in Hong Kong and the effects of thickening product, temperature and time

Abstract

This study objectively examined the consistency (thickness) labels that are commonly used in Hong Kong for describing the thickness of thickened liquids in dysphagia management. Water samples were thickened to achieve the four consistency levels (Slightly Thick, Mild Thick, Medium Thick, and Extra Thick) according to the manufacturer’s instructions of two commercial thickeners. IDDSI Flow Test and consistometric measurements were obtained and compared across two thickening products (starch-based and gum-based thickeners) and three temperature levels (cold, room temperature, and hot), and between different standing times (standard [5 min], +10 min, + 30 min and + 60 min). Results showed that the thickness of thickened liquid across consistency levels was highly dependent of the type of thickening product, temperature of liquid medium, and amount of standing time. Thickened samples prepared using ThickenUp, a starch-based thickener, were typically thinner at lower concentration under room temperature, and demonstrated an increase in consistency over time when compared with a gum-based thickener. A decrease in consistency was observed in samples prepared using both products with an increase in temperature. The compatibility between the Hong Kong norms and IDDSI consistency labels, and the relationship between the two objective measurements were discussed.