Experimental materials:

Bamboo shoot segment

bamboo shoots

table vinegar

Cooking wine

refined sugar

sodium bicarbonate

salt

Clean water

rice-rinsing water

Different varieties of bamboo shoots

Bamboo shoots of Phyllostachys praecox-blanched after slicing 1 min, without astringency.

Bamboo shoots-blanch for 5 minutes after slicing, without astringency.

Common bamboo shoots:

Bamboo shoots:

The content of astringent substances is small, and pretreatment is basically unnecessary. If you buy older thunder shoots, blanch them for 1-2 minutes.

Bamboo shoots:

Compared with other bamboo shoots, there are more astringent substances. Bamboo shoots and winter bamboo shoots in Wenzhou are all bamboo shoots. Because most of the winter bamboo shoots have not been unearthed, they are less exposed to light and have low astringency. Most bamboo shoots grow underground, which is influenced by light and has a high astringency.

Horseshoe bamboo shoots:

The content of astringent substances is small, and pretreatment is basically unnecessary. If you buy older horseshoe bamboo shoots, blanch them 1-2 minutes.

Slicing method of bamboo shoots:

Slice:

The required blanching time is short, about 1-2 minutes.

Cut:

It takes a long time to blanch, about 10- 15 minutes.

Soaking pretreatment:

Shimizu: It's still astringent.

2% sugar water: almost no astringency.

2% salt water: astringent and salty.

10% wine: slightly astringent, with residual wine flavor.

10% vinegar: no astringency, too sour.

Soak the cut bamboo shoots overnight 12 hours or more.

Taomi water: slightly astringent.

Baking soda: slightly astringent.

Boiling pretreatment: clear water: still astringent.

Boiling pretreatment: 2% sugar water, not astringent, fresh and sweet. 2% salt water, slightly astringent and salty. 10% wine, slightly astringent and slightly alcoholic. 10% vinegar, slightly astringent, crisp and sour with white. Taomi water is not astringent and has the smell of bamboo shoots. Baking soda, not astringent, turns yellow, softens the taste and loses its umami flavor.

In the season when bamboo shoots are in full bloom, spring seems to be wasted if you don't eat a few bamboo shoots. While enjoying the delicious bamboo shoots, you will also encounter this situation: your mouth is astringent, your throat is itchy, and you feel poisoned, which is inevitable to be disappointed. Use common kitchen materials, soak and blanch to eliminate the throat feeling of bamboo shoots, and see which method is more convenient and useful.

experimental result

1, different varieties

Bamboo shoots of Phyllostachys praecox: blanched 1 min after slicing, not astringent.

Bamboo shoots: slice and blanch for 5 minutes, not astringent.

2. Different cutting methods (bamboo shoots)

Slice: Zhuo 1-2 minutes.

Cutting: precooking 10- 15 minutes.

3, soaking pretreatment (bamboo shoots)

Sugar and vinegar have obvious effects, but vinegar destroys the flavor of bamboo shoots.

4, blanching pretreatment (bamboo shoots)

Sugar water, rice washing water and baking soda have obvious effects. Salt, vinegar and wine can remove astringency to a certain extent, but also affect the flavor of bamboo shoots. Baking soda will discolor bamboo shoots and lose their flavor.

Conclusion: Different varieties of bamboo shoots have different astringent substances. Slicing is easier to remove astringency than cutting. The astringency can not be completely removed by soaking for a long time; The blanching effect is better. Boil bamboo shoots with sugar water, rice washing water and baking soda for 10- 15 minutes to remove astringency.

Experimental principle

What is the astringent substance in fresh bamboo shoots?

The astringency of bamboo shoots and thunder shoots mainly comes from tannin and oxalic acid. The astringent taste is different from the five tastes of sweet and salty perceived by taste buds, and is mainly perceived by central nervous receptors, so it has a certain delay and lag; The perception time is about 15s, and then the intensity gradually decreases until it disappears. The sensory evaluation of astringency is difficult to describe, and it is a feeling of convergence and numbness, which is often referred to as astringency, throat stabbing and throat pulling.

How to avoid/remove the astringency of bamboo shoots?

Choose bamboo shoots with less astringency.

1, select varieties. Among common bamboo shoots, the content of astringent substances is bamboo shoot > horseshoe shoot > thunder shoot, so try to choose fresh bamboo shoots with less astringent substances such as thunder shoot.

2. Distinguish between old people and young people. Compared with old bamboo shoots, fresh bamboo shoots are less prone to sore throats. When selecting, it is better to have many and dense bamboo shoots and bright yellow color; If it is a bamboo shoot with a shell, the whiter the bamboo shoot, the more tender it is.

3. Seasonal. Winter bamboo shoots are not easy to astringent. Light will affect the accumulation of astringent substances, and reducing light intensity can reduce its content. Most of the winter bamboo shoots have not been unearthed, and there is less light; Most of the spring bamboo shoots have grown out of the ground and accumulated more astringent substances under the light.

Pretreatment before eating: blanch with sugar water or rice washing water. Sliced bamboo shoots can be blanched in water 1-2 minutes. Bamboo shoots, uncovered and boiled in sugar water or rice 10- 15 minutes.

Oxalic acid and tannic acid (tannic acid) which affect astringency are two kinds of acids. Rice washing water is weakly alkaline and is removed by acid-base neutralization. The bitter taste of bamboo shoots mainly comes from cyanide, which will volatilize continuously when boiled, so there is no need to cover the pot when blanching.

Baking soda can also remove astringency, but too high pH also neutralizes the umami amino acids of bamboo shoots, losing umami taste and having a slight soapy taste, while Taomi water does not.