Journal of Food Processing & Technology

Betalains from Hylocereus polyrhizus: A potential natural red food colourant

4^th International Conference and Exhibition on Food Processing & Technology

August 10-12, 2015 London, UK

Ashwini Gengatharan, Gary A Dykes and Wee Sim Choo

Scientific Tracks Abstracts: J Food Process Technol

Abstract:

The current trend in food colouring research is the discovery and use of natural food colourants to overcome the potential adverse
effects of synthetic colourants. Hylocereus polyrhizus (red pitahaya) is rich in betalains, a potential source of natural red colourant.
The betalain extracts from Hylocereus polyrhizus can contain up to 80% of fermentable sugars. These free sugars result in diluted
colourant preparation and possible caramelization during food processing at high temperatures. Fermentation using Saccharomyces
cerevisiae is a simple technique to remove these free sugars and to concentrate the betalains from Hylocereus polyrhizus. This
studyoptimized the fermentation conditions (temperature, duration, inoculum size and agitation speed) using Response Surface
Methodology (RSM) to achieve the maximum recovery of betalains. A Box-Behnken design was performed to analyse the effects of
fermentation conditions on the yield, Betacyanin Content (BC) and total sugar content of betalains. The study revealed that agitation
speed had a significant influence on the yield of betalains while temperature, duration and agitation speed were the key factors for
the removal of sugars from betalain extracts. The BC was significantly influenced by temperature and agitation speed. The optimized
conditions obtained were as follows: Temperature of 36°C, duration of 16.5 hr, inoculum size of 2.7% and agitation speed of 107 rpm.
Under these fermentation conditions, at least 48.8% of betalains with a BC of 132.5 g kg-1and 2.57% of sugars will be recovered.
These optimized fermentation conditions are useful for the production of betalains with low sugar content as potential natural red
colourants for the application in the food industry.

Biography :

Ashwini Gengatharan is in her final year of PhD degree under the supervision of Dr. Wee Sim Choo and Prof. Gary A Dykes at the School of Science, Monash University
Malaysia. She completed her BSc (Hons) Biotechnology at AIMST University, Malaysia with a First-Class Honours and obtained her Masters in Biotechnology from
Macquarie University, Australia. Her areas of research interest are mainly on the production of functional foods, application of plant secondary metabolites in food processing
and to improve consumer food products.