Amaranth offers natural pigments for noodles: Study
The instant noodle market is growing. According to a US Department of Agriculture emerging market project proposal, manufacturers of instant noodles are searching for “a new formula for the next noodle generation that can be higher in protein, better quality, and yet cheaper”.
The work of Harold Corke and his co-workers from the University of Hong Kong may constitute such an advance.
Addition of betacyanin pigments from Amaranthus tricolour, an approved natural colorant in China, at levels of 0.1 and 0.5 per cent led to pink-red noodles with good colour stability, without affecting the cooking and textural properties of cooked noodles, report the researchers in Food Chemistry.
“This is the first report about Amaranthus betacyanin pigments applied in Asian noodles,” wrote the researchers.
“This laboratory study may provide a basis for food technologists to develop novel coloured foods incorporating with functional natural colorants with good antioxidant capacity,” they added.
The value of colour
“Colour interferes with our judgments on flavour perception,” explained the researchers. “It plays a critical role in the attractive appearance of beverages and foods.”
The main natural red pigments currently used by the food industry are anthocyanins, betalains, and carotenoids sourced from berries and grapes, red beetroot, and red fruit, vegetables and flowers, respectively, according to Leatherhead Food International (LFI).
The most widely used natural pigments in the red-purple colour range are anthocyanins. However, these compounds are relatively unstable above pH 3. This means that betacyanins, and betalains in particular, are the natural pigments of choice to provide red-purple colour to low acid foods.
Study details
The Hong Kong-based researchers prepared Asian salted noodles with different levels of Amaranthus pigments, including 0.1, 0.5, 1.0, and 2.0 per cent. When used at the low levels, the noodles had a “more pink shade” at all stages - flour gels, dried raw noodles, and cooked noodles. At the higher levels a “more red shade” was recorded.
The lower pigment levels had no effect on the noodles’ cooking and textural properties, while at the highest level the pigments detrimentally affected the gel hardness and adhesiveness, said the researchers.
“Amaranthus pigments imparted to Asian salted noodles and flour gels a colour shade of pink or red, with great colour stability during one week storage at room temperature,” added Corke and his co-workers.
Source: Food Chemistry
Volume 118, Issue 3, Pages 663-669
“Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments”
Authors: F. Zhu, Y.-Z. Cai, H. Corke
