Functional properties and sensory evaluation of mucilage from South-African cactus pear cladodes

The demand for functional foods is expanding as more consumers become obese or allergic to dairy, eggs and gluten. Functional food products could increase well-being, yet the undesired ingredients need to be replaced to restore the textural properties. Mucilage is a hydrocolloid gum, extracted from cactus pear cladodes that could transfer its function in plants to foods and be developed into a profitable functional ingredient. The investigation of the functional properties of extracted freeze-dried powders was necessary to predict the potential of South African cultivars as healthy ingredients. Freeze-dried powders of four cultivars (Opuntia ficus-indica ‘Algerian’, ‘Morado’, ‘Gymno-Carpo’ and Opuntia robusta ‘Robusta’) were dissolved in water or oil. After centrifugation (10 min at 5938.816 × g) and oven drying at 102°C for 24 h, the solubility-, swelling power, water and oil holding- and absorption capacity of the mucilage powders were determined. Emulsification capacity was determined by homogenizing freeze-dried powder with equal amounts of water and oil. The Leco Nitrogen analyzer was used to determine the crude protein content. Freeze-dried mucilage powders had a very high solubility index (78.8%), water (0.89 mL g(‑1)) and oil absorption (3.56 mL g(‑1)) as well as water (8.04 mL g(‑1)) and oil holding (1.22 g g(‑1)) capacities. It displayed high emulsification capacity (98.31%) and stability (87.79%). The protein content for the three O. ficus-indica cultivars was not significantly different (2.74-3.23 g 100 g(‑1)), but significantly higher in O. robusta (4.79 g 100 g(‑1)). None of the cultivars possessed significantly better functional properties. Native mucilage was applied in fat-, dairy and egg-replacement products. Mucilage showed promise as emulsifier and fat-replacer in mayonnaise products and was described as creamy with a highly acceptable mouthfeel. Mucilage is a natural, health improving product that the food industry could benefit from. It showed strong potential as a functional ingredient.