Internal fat is mainly used for protein coagulation and is widely used in food or daily chemical industry. Endolipid is a non-toxic white crystal, which is soluble in water and slowly decomposes at 25 degrees Celsius. Gluconolactone, the internal fat of tofu made in supermarket, is a new food additive, which is the key to determine whether tofu is shaped or not.

Production principle of lactone tofu

Glucose-δ-lactone is slowly hydrolyzed at room temperature, and the hydrolysis speed is accelerated when heated, and the hydrolysis product is gluconic acid. Gluconic acid can coagulate and precipitate protein. The hydrolysis rate is affected by temperature and ph value. The higher the temperature, the faster the solidification rate and the greater the gel strength. Although it can be cured at 70℃, the product is too tender and has low elasticity and toughness. When the temperature is close to 100℃, the soybean milk is in a slightly boiling state, and the product is easy to generate bubbles, so the temperature is generally around 90℃. When PH is neutral, the hydrolysis rate of lactone is fast, and too high or too low PH will slow down the hydrolysis rate.

How to choose the quality of lactone tofu

1. Look

Sensory recognition. The sample should be observed directly under scattered light. High-quality lactone tofu is even milky white or light yellow, with a slight luster. The color of secondary lactone tofu darkens until it is light red and dull. Inferior lactone tofu is dark gray, dark yellow or reddish brown, which is the best way for us to choose lactone tofu. It is also the most intuitive method and the first step we need to do when choosing lactone tofu.

touch

Identify the tissue state of lactone tofu. Take a sample first, look at its external situation directly, then cut it into several pieces with a knife and observe the incision carefully. Finally, gently press it by hand to test its elasticity and hardness.

High-quality lactone tofu block has complete shape, moderate hardness, certain elasticity, fine texture, uniform structure and no impurities. The shape of lactone tofu block is basically complete, the section is rough, the texture is not tender, the elasticity is poor, there is yellow liquid oozing, the surface is sticky, and it does not stick to hands after washing. The shape of inferior lactone tofu block is incomplete, the structure is rough and loose, fragile, inelastic, with impurities, and the surface is sticky, which still sticks to hands after washing.

Smell

Smell directly at room temperature. High-quality lactone tofu has the unique fragrance of lactone tofu. The aroma of secondary lactone tofu is flat. Inferior lactone tofu has bad smell such as bean smell, rotten smell or other peculiar smell. This is a very good selection method, which allows us to effectively select high-quality lactone tofu to eat.

taste

When identifying the taste of lactone tofu, you can chew a small sample carefully at room temperature and taste its taste. High-quality lactone tofu tastes delicate and smooth, pure and fragrant. The taste of lactone tofu is rough and plain. Inferior lactone tofu has bad taste such as sour taste, bitter taste and astringency. This method is very intuitive and can help us effectively choose good lactone tofu to eat.