Yam has high nutritional value and can strengthen the spleen and stomach. However, there may be some problems when eating yam. Sometimes you may find that the inside of the yam has turned purple. Whether it can be eaten depends on the specific situation. If it is caused by short-term oxidation, it can generally be eaten. If it is rotten due to deterioration, it cannot be eaten.

Can purple yam be eaten?

It is normal for yam to turn purple inside because it contains a kind of polyphenols. After peeling, it is exposed to the air, and the polyphenols react with oxygen to produce o-quinone, which is further oxidized and polymerized into brown pigment and melanin. Therefore, it will turn purple. This purple color is generally seen only in winter and becomes rare when the weather gets hotter. However, it should be noted that if the yam is stored for too long, a large amount of water will be lost, or some parts will start to decay, resulting in the phenomenon of purple yam heart. This kind of yam contains certain toxins and is not suitable for consumption.

How to prevent yam from turning purple

Soak the peeled yam in cold water to isolate it from the oxygen in the air to prevent discoloration; or soak the sliced yam in salted water immediately after cutting to prevent oxidation and blackening, or put it in cold water with oil and vinegar; it can also be soaked in lemonade and then taken out when frying the yam.

Precautions for eating iron stick yam

1. Yam is rich in starch and should not be eaten with gas-producing foods such as sweet potatoes, potatoes, soybeans, and black beans to avoid bloating and hiccups.

2. Yam should not be eaten with alkaline drugs because it contains amylase, and alkaline drugs will deactivate the amylase in yam and reduce its nutritional value, such as drugs that reduce gastric acid secretion.

3. Yam is rich in starch, and diabetic patients should control their intake of starch to avoid rapid blood sugar rises. It is recommended to eat yam cautiously.