Screening of cladodes from 42 South African spineless cactus pear cultivars for morphology, mucilage yield and mucilage viscosity

M. De Wit, A. Du Toit, H.J. Fouché, A. Hugo, S.L. Venter
In South Africa, the cactus plant is mainly used as a fodder crop, and therefore its application as a human food, especially the cladodes, should be further explored. Mucilage extracted from cladodes could be used in many different ways in food products, since it can absorb large quantities of water. It has properties similar to those of other hydrocolloids such as xanthan and guar gum. It can be used to stabilize and thicken beverages and soups, as well as being used as a foaming and suspension agent. Forty-two cultivars (Opuntia ficus-indica and Opuntia robusta) were evaluated in terms of cladode morphology (size, weight, volume, width, length, diameter and surface area), cladode moisture and solid contents, mucilage yield and mucilage viscosity. These tests were done to identify cultivars with ideal characteristics in terms of cladode dimensions and mucilage yield and viscosity. The average cladode weight was 578.53 g (ranging from 400 to 800 g), surface area 2852.96 mm2, volume 682,070.96 mm3, length 347.93 mm, width 188.95 mm and diameter 10.37 mm. The average mucilage yield was 17%, and yield ranged between 5 and 25%. The average moisture and solid contents were 87.08 and 12.92%, respectively. Cultivars were categorized into five groups in terms of mucilage viscosity, namely low, medium-low, medium, medium-high and high. Correlations between cladode size and weight, mucilage yield and viscosity as well as cladode moisture content and mucilage viscosity were determined for each cultivar. No correlation was found between size and weight of cladodes and mucilage yield (r=-0.06). Positive correlations between cladode moisture content and mucilage yield (r=0.55) and mucilage viscosity (r=0.33) were observed, while the strongest positive correlation was observed between the mucilage yield and mucilage viscosity (r=0.7). Cladode dimensions and properties were linked with mucilage yield in order to select cultivars for further analysis in food applications.
De Wit, M., Du Toit, A., Fouché, H.J., Hugo, A. and Venter, S.L. (2019). Screening of cladodes from 42 South African spineless cactus pear cultivars for morphology, mucilage yield and mucilage viscosity. Acta Hortic. 1247, 47-56
DOI: 10.17660/ActaHortic.2019.1247.7
https://doi.org/10.17660/ActaHortic.2019.1247.7
mucilage, Opuntia ficus-indica, Opuntia robusta, viscosity, yield
English

Acta Horticulturae