A kind of preparation method of bean curd with high yield and no beany smell

Abstract

The invention relates to a method for preparing bean curd with high yield and no beany smell. The method comprises the steps of drying and crushing soybeans; softening step; The step is to use indirect steam to soften the broken soybeans stepwise. The method of the present invention greatly reduces the amount of bean dregs, reduces the total amount of protein adsorbed by bean dregs, improves the yield of products, and at the same time inactivates the activity of lipoxygenase, so that Tofu has no beany smell and eliminates the bitter and astringent taste. However, the traditional preparation method will produce a large amount of bean dregs after soaking, refining, boiling, stewing, molding, and pressing processes, resulting in a large loss of total protein, resulting in a low product yield. At the same time, the process directly uses soybeans as raw materials without passivation treatment of lipoxygenase, and the tofu has a severe beany smell and has a bitter taste.

Description

technical field [0001] The invention relates to a preparation method of tofu with high yield and no beany smell, and belongs to the technical field of food processing. Background technique [0002] The production of traditional tofu is made from soybeans, which are made by soaking, refining, boiling, marinating, molding, pressing and other processes. The processing of traditional tofu has the following defects and deficiencies: 1) Soybeans need to be cleaned and soaked before processing, which consumes a lot of water, produces waste water that pollutes the environment, and soaks for a long time, generally 10-15h, resulting in low production efficiency; 2) Since the soybean seed coat accounts for 8% of the whole soybean seed grain weight, the main component of soybean seed coat is fiber. After soaking, it is directly refined with the skin on. During the refining process, the fiber will be combined with protein and be filtered and removed in the form of bean dregs. , taking a...

AI Technical Summary

Problems solved by technology

The processing of traditional tofu has the following defects and deficiencies: 1) Soybeans need to be cleaned and soaked before processing, which consumes a lot of water, and the waste water produced has great environmental pollution, and the soaking time is long, generally 10-15 hours, resulting in low production efficiency; 2) Because the soybean seed coat accounts for 8% of the total soybean seed weight, the main component of the soybean seed coat is fiber. After soaking, the skin is directly refined. During the refining process, the fiber will bind protein and be filtered out in the form of bean dregs. , take away part of the protein, reduce the utilization rate of protein, and cause the yield of tofu to be low, about 250%-330%, and the water content of tofu is high and easy to break, which brings a lot of inconvenience to processing, eating and transportation; Lipoxygenase is always active during the soaking and refining process of soybeans. The lipoxygenase oxidizes fat to produce fatty acid hydroperoxide, which is then decomposed by lyase to produce volatile alcohols, ketones and aldehydes with short carbon chains. Substances, volatile substances such as alcohols, ketones and aldehydes combine with proteins or amino acids to make tofu produce beany and bitter tastes, and at the same time interrupt the hydrophobic group interactions between protein chain segments, making the protein structure lose stability. , the high concentration of soybean isoflavones in soybean navel is also an important factor for the bitter taste of tofu

However, this method needs to soak the soybeans with 2 to 3 times the volume of water for 8 to 10 hours, and the soaked soybeans need to be screened again to remove the hard beans and soybeans with incomplete soaked skin wrinkles. Beans, the refining process is complex and cumbersome, not suitable for large-scale production

Secondly, this method uses blanching treatment to inactivate the activity of lipoxygenase, reduce the beany smell, and soften the fiber. Because the moisture content of soybeans is high after soaking, under the treatment conditions of 50-100°C and 1-50min, the soybean center Part of the temperature is difficult to reach the temperature for lipase inactivation, resulting in incomplete inactivation, poor improvement of bean flavor and bitter taste, which in turn affects the softening effect of the fiber

[0004] Chinese patent document CN102524418 B discloses the production method of bean curd and bean curd, and this method crushes soybean, removes germ and bean skin, and makes bean curd with this as raw material, although this method crushes soybean, shortens soaking time to 30 -45min, but the fibrous tissue inside the watercress did not change, and the activity of lipoxygenase in the watercress was still high, which affected the dissolution effect of protein, the yield of tofu and the beany smell of tofu

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