The approach, which utilizes high-throughput screening – a technique top flavor houses use for rapidly identifying potentially exciting new flavor ingredients or combinations with certain properties (eg. sweetness, or bitter blocking) by firing them at taste receptors – will help SGF identify combinations of glycosides and other natural ingredients at specific ratios with the most promise.
These can then be passed on to human sensory panels for more traditional testing, SGF chief science officer Mel Jackson, PhD, told FoodNavigator-USA.
“The technology utilizes something called patch clamping, where you’re taking a cell, and pressing a tube against the cell [to isolate a small ‘patch’ of cell membrane that contains one or more ion channels, pore-forming proteins in cell membranes that mediate neurophysiological reactions, such as taste perception], then putting a liquid on the tube side and then you can measure the voltage difference across the cell [ion channels transmit electrical signals to the brain].
“We’re interested in sweetness, so we’re using cells that express proteins called sweetness receptors, which are really gates, which allow sweeteners to interact with them, and when they do, the gate opens, and there is a voltage change across the cell, which signals to the brain that that [the stimuli] is sweet. We can also look at bitter receptors as well.”
The rapid screening is helping SGF identify taste modulators that work synergistically with stevia, he added: “We already know steviol glycosides are sweet, but we don’t know how other compounds or ingredients work in tandem with steviol glycosides to affect their overall sweetness or bitterness.
“If you can put in modifiers or mixtures of different ingredients to get a more sugar-like response you are really advancing the field and this screening approach just lets us to do this combinatorial work much more quickly.”
Historically, he said, stevia producers have employed human sensory panels and electronic tongue technology to assess combinations of steviol glycosides to find optimized blends. However, humans cannot evaluate the countless possible combinations of ingredients quickly enough, while electronic tongue technologies cannot imitate the neurophysiological reaction of the human taste buds accurately.
“It would take decades to screen this many ingredients and combinations with a sensory panel,” said Dr Jackson.