Method for preparing purple sweet potato concentrated clear juice

Abstract

The invention discloses a method for preparing purple sweet potato concentrated clear juice. The method comprises the following steps: pre-treating raw materials, crushing the raw materials, performing primary enzymolysis, squeezing, performing pasteurization, performing secondary enzymolysis, performing enzyme deactivation, performing ultra-filtration, concentrating, and filtering, so as to obtain a green and addition-free purple sweet potato concentrated clear juice product. The method is simple in process, vitamin C is used in the raw material crushing process so as to prevent product oxidation, nutrient substances in the raw material are extracted to the maximum extent by using enzyme, and the product clarity can be improved in a manner combining ultra-filtration and plate-frame filtration. According to the method, nutrition components in purple sweet potatoes can be extracted and maintained to the maximum extent, the concentrated juice is good in taste, and requirements of customers can be met.

Description

technical field [0001] The invention belongs to the field of food processing, and in particular relates to a preparation method of concentrated clear purple sweet potato juice. Background technique [0002] Purple sweet potato, also known as purple sweet potato, has purple to deep purple flesh. In addition to the nutritional components of ordinary sweet potatoes, it is rich in anthocyanins and has high medicinal value. It is an ideal crop that is easy to cultivate and can be used for both medicine and food. . my country is rich in purple sweet potato resources, but the utilization of purple sweet potato is seriously restricted due to relatively lagging deep processing methods. [0003] At present, purple sweet potato is mainly used for processing starch, purple sweet potato juice, purple sweet potato pigment, purple sweet potato wine, etc. As far as purple sweet potato juice products are concerned, most of the purple sweet potato sold on the market are cloudy juice drinks a...

AI Technical Summary

Problems solved by technology

[0003] At present, purple sweet potato is mainly used for processing starch, purple sweet potato juice, purple sweet potato pigment, purple sweet potato wine, etc. As far as purple sweet potato juice products are concerned, most of the purple sweet potato sold on the market are cloudy juice drinks and are not 100% pure natural purple. Sweet potato juice, its taste is poor, not conducive to drinking

And Chinese patent CN102119773B, discloses a kind of clarification type purple sweet potato concentrated juice processing technology, this technology is fresh purple sweet potato through cleaning process, crushing process, screening process, cyclone separation process, membrane separation process, membrane concentration process, three effect Evaporation process, sterilization process, aseptic filling process and other industrial operations to obtain concentrated purple sweet potato juice. The disadvantage of this method is that the raw material is easily oxidized and browned during the raw material crushing process. At the same time, a large amount of nutrients in the raw material are removed with the slag failed to enter the concentrate

Chinese patent application CN104366357A, a preparation method of purple sweet potato juice with high light transmittance, the method is through purple sweet potato raw material pretreatment, beating, liquefaction treatment, enzymatic hydrolysis treatment, flocculant treatment, ultrafiltration, instantaneous ultra-high temperature treatment, to obtain high The light transmittance of purple sweet potato juice, this method has the advantages of no precipitation and little loss of nutrients, but it also has the following disadvantages: (1) In order to avoid the raw material from being oxidized and browned when the raw material is broken, it is beaten in a vacuum state. High equipment requirements; (2) In order to obtain clarified concentrated juice, a flocculant is used, such as the flocculant polyacrylamide PAM. Polyacrylamide itself and its hydrolysis are not toxic, but its residual monomer acrylamide (AM) is neurotoxic. Toxic agent, which has a damaging effect on the nervous system. After poisoning, symptoms such as body weakness and ataxia

Although countries have strict requirements on the residual monomer AM content in food-grade PAM, it is still impossible to completely avoid the food safety risks caused by the application of additives