Galactomannans in disturbances of structured wax-hydrocolloid-based coatings of citrus fruit (easy-peelers)

Locust bean gum (LEC) or guar gum, both typical viscosity formers, were introduced into traditional wax formulations of two easy-peeler citrus fruit cultivars: Nova and Michal. Their performance was analyzed and compared to inclusion of the non-gelling xanthan gum in a similar formulation. Both galactomannans reduced weight loss of the fruit during respiration in a manner similar to a wax-based coating without gum. As for ethanol and acetaldehyde buildup, the viscosity-forming formulations showed no disadvantage in comparison with a commercial coating. CO2 accumulation with the xanthan coating was favored. Xanthan- and LEG-wax coatings produced the juice with the best taste quality. Inclusion of galactomannan in the formulation did not change the gloss of the coated easy-peelers, even though xanthan is known to produce better gloss. LEG showed superior performance as an addition to coating relative to guar gum, as did xanthan. Its addition changed the structure of the wax coating to a more chaotic, less ordered structure, making it beneficial in terms of fruit respiration; (C) 2000 Elsevier Science Ltd. All rights reserved.