ねるねるねるねの魅力
Hello everyone, SCIENSPOT is a podcast that shines the spotlight on the latest scientific technology from Japan.
Your host is REN from SCIEN-TALK.
Today is a very special episode about our beloved Japanese treat, Crush's Neru Neru Nerune.
This candy has captivated generations of children with its seemingly magical transformation,
changing color and fluffing up simply by mixing powder and water.
This iconic witch character on its packaging perfectly embodies this mysterious charm.
But this magic isn't supernatural, it's a cleverly designed series of chemical and physical processes.
Crush itself positions Neru Neru Nerune as an educational snack,
making it more than just candy, it's like an edible chemistry set.
We're going to peel back the curtain on this magic and uncover the scientific mechanisms behind it.
Neru Neru Nerune is a masterpiece of full engineering, skillfully packaging fundamental scientific principles
like acid-base chemistry, gas generation, and polymer science into an interactive and delicious format.
Imagine it as a miniature science love in your hand where the ultimate goal is to eat your experiment.
So let's start by looking inside the Neru Neru Nerune kit.
It usually contains three packets, powder 1, powder 2, and powder 3 for toppings.
The scientific transformation primarily involves the first two powders.
The Neru Neru Nerune experience begins by mixing powder 1 with water.
Powder 1 contains baking soda, an alkaline component, and anthocyanin pigment,
which is responsible for the color change.
Powder 2 contains citric acid in the acidic component,
along with thickening polysaccharides and egg white powder to create that fluffy texture.
Why are these powders kept separate?
This is crucial for product stability and to ensure that dramatic chemical changes occur precisely when water is added.
If the reactive acid and alkaline components were mixed from the start,
even slight humidity from the air could initiate the reaction prematurely, compromising the product's quality.
Neru Neru Neruneの色の変化
This reflects the basic principle in chemistry experiments,
keeping reactants separate until just before the reaction.
The most iconic feature of Neru Neru Nerune is its color change.
It's based on the principle of pH indicators.
pH indicators are substances whose molecular structure and thus color changes depending on the acidity of the solution.
You might recall litmus paper from science class or how purple cabbage juice changes color with lemon juice.
At the heart of this phenomenon is anthocyanin,
a natural pigment found in many plants like purple cabbage, blueberries, and eggplants, which is highly sensitive to pH.
When you first mix powder 1 with water, the baking soda dissolves, creating a weakly alkaline solution.
In this alkaline environment, anthocyanin molecules undergo a structure change,
absorbing light in the red-orange spectrum and reflecting vibrant blue-green light, making the mixture appear blue.
Next, when you add powder 2 containing citric acid, it neutralizes the baking soda and makes the entire solution acidic.
The anthocyanin molecules then change to a different structure,
absorbing blue-green light and reflecting red-purple light, causing the color to shift.
This color change isn't a one-way magic trick.
It's a reversible shift in chemical equilibrium between the protonated and deprotonated state of the anthocyanin molecule.
Theoretically, if you added enough alkaline components to the finished red-purple, it could turn blue again.
Crush's choice of natural pigments like vegetable dyes instead of synthetic ones aligns perfectly with both the functional requirements of the pH indicator
and makes the marketing strategy appealing to parents concerned about synthetic additives.
The fluffy expansion of NNN is driven by a classical and fundamental chemical reaction, the reaction between an acid and a carbonate.
The driving force for the puffing is the chemical reaction between citric acid from powder 2 and sodium bicarbonate from powder 1.
化学反応のメカニズム
This reaction requires water as a medium to proceed.
The chemical reaction produces water and most importantly, carbon dioxide gas.
This carbon dioxide gas is what causes the mixture to expand.
It's the exact same principle that makes fizzy bath bombs bubble in water.
Interestingly, your act of NERU, NERU means mixing, directly controls the rate of this chemical reaction.
Just adding water to the powder would result in a relatively slow reaction.
However, when you vigorously mix the ingredient with a spoon, the frequency of contact between the dissolved citric acid and sodium bicarbonate ions dramatically increases.
This physical stirring accelerates the reaction and promotes the generation of carbon dioxide.
It's similar to how stirring sugar into coffee helps to dissolve faster.
Developers carefully balance the amounts of acid and base to achieve satisfactory puffing while ensuring the final product tastes good.
Simply maximizing the puffing by adding more baking soda or acid would lead to bitterness or excessive sourness, a common dilemma in food science.
The final unique fluffy texture of NERU, NERU, NERU is no accident.
It's a product of engineered physical properties created through the application of rheology, the science of how matter flows and deforms.
The main player here are hydrocolloids, long-chain polymer compounds such as thickened polysaccharides.
These polymers form viscous dispersion or gels in water, xanthan gum for instance, and wind the intervines to create a three-dimensional network that traps a significant amount of water.
This dramatically increases the liquid's viscosity, which is crucial for preventing the generated carbon dioxide bubbles from rapidly escaping.
Imagine a fine mesh sponge holding water tightly, creating a stable base that prevents bubbles from escaping.
Additionally, egg white powder plays a vital role.
The proteins in egg whites act as surfactants.
They gather around the carbon dioxide bubbles, forming elastic protective films.
Neru Neruの科学的背景
These films prevent the bubbles from collapsing into larger ones or collapsing, thus maintaining a fine and stable foam structure.
Thickening polysaccharides build the skeleton to encapsulate the foam, while egg white proteins create sturdy walls for each bubble, resulting in that special fluffiness.
The mixture is also classified as a non-Newtonian fluid.
Its viscosity changes depending on the force applied, that is, how fast you mix it.
It's very viscous when at rest, but a bigger strain causes the polymer chains to align and disentangle, reducing its viscosity.
This is the core of the Neru-Neru experience.
It feels heavy to start, but becomes smoother as you mix faster.
When you stop mixing, the polymer chains already entangle and the viscosity recovers, allowing it to hold its shape.
This property called shear thinning is like how mayonnaise or ketchup flows easily when squeezed, but holds its shape when at rest.
Scientifically, the final form of Neru-Neru can be described as a viscoelastic solid form,
a complex multi-phase substance that traps liquid and gas within the polymer network,
exhibiting both a solid-like shape, retention, and a slow liquid-like flow.
Through this scientific breakdown, I hope you can see that Neru-Neru is not just a candy, but a clever showcase of scientific principles.
Abstract scientific concepts like pH change, gas generation, and non-neutrino-fluid behavior are brilliantly translated into concrete mulch sensory experiences,
visible color changes, tangible expansion, and a delightful texture to taste.
And for those wondering, is this chemical candy safe?
So, all major ingredients used in Neru-Neru are widely approved food additives with a long history of safe use and thorough scientific evaluation.
Ingredients like citric acid, baking soda, thickening polysaccharides, and natural coloring are common and highly safe, much like what you'd find in your own kitchen.
In fact, the term chemical can be misleading in this context.
キャンディから科学教育へ
It is this foundation of unquestionable safety that Kodashi can confidently promote its educational snack branding.
Neru-Neru naturally transcends being just a snack.
It's a shining example of edible science education that stimulates intellectual curiosity and provides an intuitive hands-on introduction to fundamental chemistry and physics.
That's all for today's science thoughts.
It's truly fascinating how much science is hidden in the candy, isn't it?
In my case, I have a very great connection to the Kodashi, and I received many types of Neru-Neru, so I enjoyed everything of this educational candy.
And if you'd like to see it, please refer to the YouTube videos from the Scientalk channel.
You can see all types of Neru-Neru in this season.
So that's all.
This podcast is broadcast in both Japanese and English.
I'd love for you to listen to the podcast and post your notes and thoughts with the hashtag SciencePod.
Thank you for listening and see you next time.
