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CN-121970873-A - Method for improving sulforaphane content in broccoli by magnetic field assisted blanching

CN121970873ACN 121970873 ACN121970873 ACN 121970873ACN-121970873-A

Abstract

The invention discloses a method for improving the content of sulforaphane in broccoli by magnetic field assisted blanching, belonging to the technical field of food processing. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching comprises the following steps of (1) raw material preparation, (2) magnetic field assisted blanching pretreatment, (3) cooling and structure maintaining treatment, (4) enzymatic incubation based on a magnetic field assisted blanching regulation state, and (5) obtaining a broccoli product with high sulforaphane content. Exogenous enzymes, chemical reagents or additives are not introduced in the process, and the regulation of the activity of endogenous myrosinase and the catalytic hydrolysis path thereof is realized by synchronously applying a physical regulation means in the blanching pretreatment process, so that the generation level of sulforaphane in a treated sample is improved. The method is suitable for a food processing system, has the advantages of mild process conditions, strong controllability, high safety and easiness in industrial amplification, and has wide application prospect in the field of food processing.

Inventors

  • Wu Muci
  • HU WENQI
  • CHENG JIAWEI
  • HE JINGREN
  • ZHANG RUI
  • ZHOU WANGTING

Assignees

  • 武汉轻工大学

Dates

Publication Date
20260505
Application Date
20260126

Claims (10)

  1. 1. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching is characterized by comprising the following steps of: (1) Raw material preparation, namely selecting fresh plants as samples to be treated; (2) The method comprises the following steps of performing magnetic field assisted blanching pretreatment, namely placing a sample to be treated in a liquid blanching medium, performing blanching treatment at 50-70 ℃ for 5-20 min, and synchronously applying a magnetic field with the strength of 0.1-10 mT to the whole blanching system in the thermal action process of the blanching treatment; (3) Cooling and structure maintaining treatment, namely collecting a broccoli sample subjected to magnetic field assisted blanching pretreatment, and cooling to stop further heat action; (4) Enzymatic incubation based on a magnetic field assisted blanching regulation state, wherein the cooled and crushed broccoli sample is subjected to enzymatic incubation under a certain condition so as to promote hydrolysis reaction of glucoraphanin; (5) And obtaining the broccoli product with high sulforaphane content, namely obtaining the broccoli product with obviously improved sulforaphane content after incubation.
  2. 2. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching method according to claim 1, wherein in the step (2), the liquid blanching medium comprises a buffer solution or a liquid medium meeting the food processing safety requirements, no metal salt, organic solvent or enzyme preparation is additionally added into the liquid medium, the buffer solution comprises at least one of a phosphate buffer solution, a citric acid-sodium citrate buffer solution and an acetic acid-sodium acetate buffer solution, the pH value of the buffer solution is 5.5-7.5, and the liquid medium comprises at least one of water, deionized water, softened water and a low-ionic-strength aqueous solution.
  3. 3. The method for improving the sulforaphane content of broccoli by using the magnetic field as defined in claim 1, wherein in the step (2), the magnetic field is one of a static magnetic field, a low-frequency alternating magnetic field and a pulsed magnetic field.
  4. 4. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching according to claim 3 is characterized in that the frequency of the low-frequency alternating magnetic field is 0.1-50 Hz, the pulse width of the pulse magnetic field is 0.1-5 s, the pulse interval is 0.1-10 s, and the pulse duty ratio is preferably 10% -90%.
  5. 5. The method for improving the sulforaphane content of broccoli by using the magnetic field assisted blanching as set forth in claim 1, wherein in the step (2), the variation mode of the magnetic field intensity comprises one of continuous adjustment, staged adjustment and gradient adjustment within a set range.
  6. 6. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching according to claim 5, wherein the number of stages of the staged adjustment is 2-4, the magnetic field intensity variation range between adjacent stages is 0.1-1.5 mT, and the gradient adjustment variation rate is 0.05-1.0 mT/min.
  7. 7. The method for improving the sulforaphane content of broccoli by using the magnetic field assisted blanching according to claim 1, wherein in the step (2), the magnetic field is applied in a manner of continuous application or intermittent application.
  8. 8. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching according to claim 7, wherein the intermittent application mode comprises the steps of enabling single magnetic field application time to be 0.5-10 min, enabling blank time between two adjacent magnetic field applications to be 0.5-10 min, enabling the magnetic field application and the blank time to be circularly repeated for 1 or more times, and enabling total magnetic field action time to be controlled within a blanching treatment time range.
  9. 9. The method for improving the sulforaphane content in broccoli by using the magnetic field assisted blanching as claimed in claim 1, wherein in the step (4), the incubation temperature is 30-45 ℃ and the incubation time is 30-120 min.
  10. 10. The use of the method for increasing the sulforaphane content in broccoli by using the magnetic field assisted blanching according to any one of claims 1 to 9, characterized by comprising the treatment of cruciferous vegetables containing glucosinolates and having endogenous myrosinase for broccoli or other glucosinolates to increase the sulforaphane content.

Description

Method for improving sulforaphane content in broccoli by magnetic field assisted blanching Technical Field The invention relates to the technical field of food processing, in particular to a method for improving the content of sulforaphane in broccoli by magnetic field assisted blanching. Background The sulforaphane is an important isothiocyanate type active substance derived from cruciferous vegetables, has remarkable biological functions of resisting oxidation, inflammation and tumor, regulating the activity of detoxification enzyme and the like, and has wide application prospect in functional foods, nutrition intervention and health industry. Broccoli, which is a direct precursor of Glucoraphanin-rich Glucoraphanin (Glucoraphanin) in thioglucosides, is considered to be one of the main sources of Glucoraphanin in the diet. In broccoli tissue, the sulforaphane is not present in free form, but is produced by the hydrolysis of glucoraphanin catalyzed by endogenous myrosinase. During the enzymatic reaction, firstly an unstable thiohydroxamic acid intermediate is formed, and then the thiohydroxamic acid intermediate is rearranged under the physiological pH condition of plants to generate the sulforaphane. However, the hydrolysis system is highly complex during actual processing and consumption, and is susceptible to a variety of factors such as temperature, pH, metal ions, and skin specific sulfur proteins (Epithiospecifier protein, ESP). The existence of the epidermis specific sulfur protein can obviously change the hydrolysis reaction path, so that the intermediate preferentially generates nitrile byproducts, thereby reducing the production efficiency of the sulforaphane. In order to increase the formation level of sulforaphane in broccoli, heat treatment (e.g., blanching, cooking, etc.) is widely used to regulate enzymatic reaction systems. Moderate blanching can promote the generation of sulforaphane. However, the traditional blanching process has strict requirements on temperature and time window, and slight deviation can lead to the inactivation of myrosinase or the massive loss of sulfadiazine, and the process stability and controllability are insufficient. In addition, studies have been made to attempt to increase the production of sulforaphane by exogenously adding myrosinase, adjusting pH conditions, or supplementing metal ions, etc. For example, the Chinese patent publication No. CN110066776A discloses a method for extracting sulforaphane and a myrosinase magnetic microsphere, and the invention hydrolyzes sulforaphane into sulforaphane by exogenously adding the solidified myrosinase magnetic microsphere as a catalyst so as to improve the content of the sulforaphane. The Chinese patent publication No. CN117137098A provides a preparation method of broccoli sprout powder rich in glucoraphanin and glucoraphanin, and the sprout is treated by steaming, zinc sulfate soaking, and enzymolysis during the treatment process, so that the content of glucoraphanin in the sprout is increased. However, the method has the problems of high cost, complex process, insufficient food application safety or industrialization feasibility and the like. Specifically, for exogenous addition of myrosinase, the price of high-quality food-grade myrosinase is high, and the cost is obviously increased by further combining magnetic nano materials, functional modification reagents and equipment and conditions required by immobilization reaction. And the process chain flow of introducing magnetic separation and recovery is long, the control nodes are increased, and the microspheres are easy to pollute and inactivate due to the adsorption of impurities such as grease, protein and the like in the food matrix. In real production, the exogenously added enzymes and their immobilized carriers need to be subjected to strict safety assessment, which also restricts the wide application of the process. For the mode of adjusting process parameters or supplementing metal ions, the metal ions such as zinc and the like are required to be strictly controlled within the safety limit of the food additive standard, and the burden of raw material detection and process control is increased. And the metal ions are easy to deteriorate the flavor of broccoli, or react with other ingredients in food to generate precipitation and color change, so that the sensory quality of the product is seriously affected. The existing method for improving the content of the sulforaphane brings extra cost and process complexity which far exceed the market value created by the method, and is difficult to popularize and apply in the actual food processing process. In view of the above, there is a need to develop a technical means with simple process, strong controllability and suitability for food processing conditions, which can significantly improve the production efficiency of sulforaphane in broccoli on the premise of ensuring the product safety, so as to meet the requirem