Citric acid may boost retention of natural colouring, says research

By Nathan Gray

- Last updated on GMT

Related tags Vinegar

The addition of one per cent citric acid to rice flour prior to extrusion cooking may reduce the amount of colourant needed by 25 per cent, according to new research.

The study, published in Food Research International​, evaluates the suitability of the natural food colouring anthocyanin as a pre-extrusion colouring for rice flour, noting that its retention as a pre-extrusion colour is mainly dependant on the extrusion cooking parameters.

The authors, led by Professor Rekha Singhal from the Institute of Chemical Technology, India, also reported that sodium carbonate reduced the retention of anthocyanin in the rice extrudates, and recommended metallized polyester as the most suitable packaging for the coloured extrudates.

“These attractive natural colouring pigments are water-soluble and this property facilitates their incorporation into numerous aqueous food systems,”​ said Singhal and her colleagues.

​[However], to the best of our knowledge, stability of added anthocyanins as pre-extrusion colouring has not yet been reported in literature,”​ they added.

Study details

Prof. Singhal and her team reported that the retention of anthocyanin colourant in rice extrudates coloured prior to extrusion improved with an increase in the moisture content of feed material, and screw speed and decreased with an increase in dye temperature.

They added that the addition of one per cent citric acid increased retention of anthocyanin by 20 per cent, but sodium bicarbonates decreased retention by 50 per cent.

They said that the amount of the natural colourant needed for extrusion cooking was reduced by 25 per cent with the addition of one per cent citric acid to rice flour prior to extrusion.

Natural prominence

The demand for natural colourings has been intensified “with increasing public concern on the safety of synthetic colourants,” ​said Singhal and her team.

Such increased prominence in the use of natural colours has been also strengthened by the requirement that all food products containing the six colours so-called Southampton colours – cocktails of which were linked to hyperactivity in children – carry a warning label, which came into force on 20 July last year.

The researchers noted that anthocyanins are natural colouring compounds, widely found in fruits, berries and flowers. The research findings may help to reduce the amount of the natural colourant needed in foods.

Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2011.05.017
“Stability of anthocyanins as pre-extrusion colouring of rice extrudates”
Authors: A.V. Durge, S. Sarkar, R.S. Singhal

Related news

Show more

Related products

show more

Flavor technology for bold, bright citrus flavors

Flavor technology for bold, bright citrus flavors

Content provided by ADM: Gain an Edge with Global Consumer Trends | 10-May-2023 | Case Study

Our collaborative global team of expert citrus flavorists combines technology and experience to make ADM the full-service partner you need to shape your...

Future of Functional Beverages in Europe

Future of Functional Beverages in Europe

Content provided by Glanbia Nutritionals | 05-May-2023 | Insight Guide

The strong appeal of functional beverages to support health is changing the RTD landscape in Europe. Here’s a look at Europe’s functional beverage trends...

Create Better-for-Everyone Reduced-Sugar Products

Create Better-for-Everyone Reduced-Sugar Products

Content provided by SweeGen | 04-May-2023 | Product Presentation

Consumers are growing wiser about wellness. Create reduced-sugar products that are better tasting and better for your consumers with Sweegen’s expertise...

Drinking with our eyes first

Drinking with our eyes first

Content provided by Lycored | 28-Apr-2023 | Product Brochure

Whether flavored waters, sports drinks, juices, mocktails or low alcoholic beverages, the beauty behind coloration doesn’t just lie in visual appeal, but...

Related suppliers

Follow us


View more