Title: Why is purple sweet potato porridge blue? Revealing the scientific truth behind food discoloration
Recently, a short video about "Purple Sweet Potato Porridge Turned Blue" went viral on social platforms, sparking heated discussions across the internet. After many netizens tried to reproduce it, they also discovered that purple sweet potato porridge does appear strangely blue. What scientific principles are hidden behind this phenomenon? We combine the hot data and expert interpretations of the past 10 days to reveal the answer for you.
1. Statistics of hot discussions on the entire network
| Platform | Related topic readings | Number of discussions | Hot search highest ranking |
|---|---|---|---|
| 230 million | 187,000 | TOP3 | |
| Douyin | 180 million | 532,000 | No. 1 on the challenge list |
| little red book | 68 million | 91,000 | Food list TOP5 |
2. Three key factors that cause purple potatoes to turn blue
1.Acid-base reaction of anthocyanins: Purple sweet potato is rich in anthocyanins that change from purple to blue in an alkaline environment. Experimental data shows:
| pH value | Color performance | Common trigger conditions |
|---|---|---|
| ≤6 (acidic) | Purple red | Add lemon juice/white vinegar |
| 7-8 (neutral) | Purple blue | boil tap water |
| ≥9 (alkaline) | dark blue | Add edible alkali/hard water |
2.water quality differences: The water quality in northern areas is alkaline (pH7.5-8.5), which is more likely to cause discoloration. Netizens’ actual measurement comparison:
| area | Water pH | porridge color |
|---|---|---|
| Beijing | 8.2 | blue purple |
| Guangzhou | 6.8 | Purple red |
3.Effect of cooking methods: Cooking at high temperature for a long time will accelerate the color change. Laboratory tests show that the color difference ΔE of purple potato porridge after boiling for 30 minutes can reach 15.7 (obvious difference visible to the naked eye).
3. Expert answers and safety tips
Professor Li from the School of Food, China Agricultural University, pointed out: "This phenomenon is completely normal, and the discoloration properties of anthocyanins are also widely used in the food industry. The blue purple potato porridge is not only safe and edible, but its antioxidant activity is higher than the purple state."
4. Collection of creative eating methods from netizens
| creative approach | Number of likes | Key steps |
|---|---|---|
| Starry Purple Sweet Potato Ice Powder | 245,000 | Add lemon juice to create gradient color |
| Blueberry and Purple Sweet Potato Porridge | 182,000 | Add ingredients with different pH in batches |
| Dream Purple Potato Latte | 128,000 | Brew purple sweet potato powder with soda water |
5. Extend scientific knowledge
The color-changing properties of anthocyanins are ubiquitous in nature, such as:
- Morning glory is blue in the morning and red in the evening (the pH of the cell fluid changes day and night)
- Black wolfberry turns blue/purple when soaked in water (affected by different water quality)
- Red cabbage as pH indicator (pH 1-14 displays 7 colors)
Through this "Purple Sweet Potato Porridge Discoloration" incident, we not only gained interesting kitchen experiments, but also gained a deeper understanding of the scientific mysteries behind food. Next time you encounter food that has "discolored", you might as well check the ingredient list first, you may be able to unlock new scientific knowledge!
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