One of the problems encountered in the food industry is that some additives are toxic, particularly the synthetic food colourings used in that king of summer desserts, ice cream.
Intensely pink in colour, Gomphrena globosa L. flower extract can be used as a food colouring in ice cream, safe in the knowledge that it is not toxic according to research involving the Complutense University of Madrid (UCM).
A study published in LWT-Food Science and Technology reports that its main advantage is that it is rich in betacyanins, which besides adding colour possess bioactive properties that would functionalise any food to which the extract is added.
"Although there are already some natural betacyanin-rich food colourings on the market, mainly obtained from beetroot, this natural food colouring extracted from Gomphrena globosa flowers represents a more stable alternative from a physico-chemical standpoint", announced Patricia Morales Gómez, a researcher in the Department of Nutrition and Food Science at the Complutense University of Madrid and a member of the ALIMNOVA research group.
As well as its impressive colouring capacity, the extract possesses bioactive, antioxidant and antimicrobial properties, and can therefore also be considered a functional ingredient.
IDEAL FOR DAIRY PRODUCTS
The aim of the research project, Morales explained, had been to seek natural alternatives to synthetic additives in the food industry and thus eliminate problems of toxicity or adverse reactions.
For the experiment, the researchers first separated the pigmented parts of the flower using two mechanical processes: milling and sieving. They then optimised three extraction techniques: maceration, microwave-assisted extraction and ultrasound-assisted extraction, selecting the latter because of its better extraction performance.
Like many other natural additives, this betacyanin-rich extract presents a few limitations for use because the stability of these compounds can be affected by factors such as extraction time, temperature, pressure, the solid-liquid ratio and the proportion of ethanol in aqueous mixtures.
However, thanks to its physico-chemical properties, this extract is an ideal natural food colouring for use in “dairy derivatives and products such as ice cream, drinks or yoghurt, and in frozen products or bread and cakes with a short shelf life”, added the experts.
This study formed part of a doctoral thesis being carried out at the UCM Faculty of Pharmacy in collaboration with the Polytechnic Institute of Bragança (Portugal).
References:
Custódio Lobo Roriz et al., 2018. Gomphrena globosa L. as a novel source of food- grade betacyanins: Incorporation in sice-cream and comparison with bee-root extracts and comercial betalains. LWT-Food Science and Technology 92. DOI: 10.1016/j.lwt.2018.02.009
