Abstract: The present invention relates to a method for constructing a recombinant bacterium with high production of ?-elemene and germacrene A. Firstly, ?-elemene and germacrene A are synthesized from scratch through the screening of germacrene A synthase and the overexpression of the mevalonate pathway; then, the availability of acetyl-CoA, pyruvate, and glyceraldehyde-3-phosphate in the farnesyl diphosphate pathway is ensured by deleting competing pathways in the central carbon metabolism; next, the present invention uses lycopene color as a high-throughput screening method and obtains an optimized NSY305N through error-prone PCR. Finally, in shake flasks, strain ?-EL-4 constructed through key pathway enzymes, efflux engineering, and translation engineering produced 1161.09 mg/L of ?-elemene and 852.36 mg/L of germacrene A, which is the highest reported yield at shake flask level. In 4-L fed-batch fermentation, the production of ?-elemene and germacrene A reached 3.52 g/L and 2.13 g/L, respectively.

Abstract: The disclosure relates to a preparation method of a amylodextrin and belongs to the technical field of starch chemical modification. According to the method, de-clustering and complexation effects of ultrasonic waves are used to achieve de-clustering of a starch chain and complexation of an amorphous region and an emulsifier, and then ?-amylase and pullulanase are used to achieve complex enzymolysis. Because the amorphous region and the emulsifier form a complex which is resistant to enzymolysis, the amorphous region is prevented from being destroyed. Finally, dextrins of different molecular weights are separated by a membrane separation method, so as to obtain a amylodextrin product with low polydispersity coefficient and narrow molecular weight distribution, and the starch comprehensive utilization efficiency is increased to 70% or above.

Abstract: The present disclosure discloses a preparation method of low-glycemic index slowly digestible starch-based reconstituted instant rice, and belongs to the technical field of food processing. The preparation method is based on high-temperature fluidization technology to carry out non-crystallization treatment on a solid phase broken rice raw material in a short period of time, and then the material is subjected to a one-step reactive extrusion technology combining enzymatic hydrolysis and esterification treatment to prepare the reconstituted instant rice with high content of slowly digestible starch and low glycemic index. The reconstituted instant rice prepared by the one-step molding extrusion technology is suitable for type II diabetes patients to eat, and at the same time increases the added value of agricultural and sideline products, reduces production cost, and improves production efficiency.

Abstract: The disclosure discloses a preparation method of slowly digestible starch, and belongs to the technical field of starch modification. In the disclosure, ordinary rice starch and corn starch are used as raw materials, and the starch is fully de-clustered through dry-heat amorphization treatment, instead of traditional hydrothermal gelatinization; then ultrasonic treatment is used to induce complexation of amino acids and starch milk to form VI-type crystal; and finally through an extrusion technology, the VI-type crystal is transformed into VII-type crystal, and the content of the slowly digestible starch is significantly increased to 55%-60%. The disclosure is highly efficient, simple and environmentally friendly, and the prepared product can be used as a drug sustained-release carrier or a low-glycemic index food ingredient, and has important practical value for the regulation of chronic diseases such as diabetes and cardiovascular diseases.

Abstract: The present disclosure discloses a production method of normal-temperature instant cooked rice and belongs to the technical field of food processing. The method of the present disclosure comprises the main steps of rice washing and soaking, flavor blending, sub-packaging, cooking, sterile vacuum sealing, cooling and crystallization and normal-temperature storage, wherein an aqueous solution containing flavor substances is adopted to perform flavor blending, and a fast cooling mode is adopted to perform cooling and crystallization. The normal-temperature instant cooked rice obtained through the production method provided in the present disclosure can keep the original flavor after being stored for 90 days.

Abstract: The disclosure discloses a preparation method of slowly digestible starch, and belongs to the technical field of starch modification. In the disclosure, ordinary rice starch and corn starch are used as raw materials, and the starch is fully de-clustered through dry-heat amorphization treatment, instead of traditional hydrothermal gelatinization; then ultrasonic treatment is used to induce complexation of amino acids and starch milk to form VI-type crystal; and finally through an extrusion technology, the VI-type crystal is transformed into VII-type crystal, and the content of the slowly digestible starch is significantly increased to 55%-60%. The disclosure is highly efficient, simple and environmentally friendly, and the prepared product can be used as a drug sustained-release carrier or a low-glycemic index food ingredient, and has important practical value for the regulation of chronic diseases such as diabetes and cardiovascular diseases.

Abstract: The disclosure relates to a preparation method of a amylodextrin and belongs to the technical field of starch chemical modification. According to the method, de-clustering and complexation effects of ultrasonic waves are used to achieve de-clustering of a starch chain and complexation of an amorphous region and an emulsifier, and then ?-amylase and pullulanase are used to achieve complex enzymolysis. Because the amorphous region and the emulsifier form a complex which is resistant to enzymolysis, the amorphous region is prevented from being destroyed. Finally, dextrins of different molecular weights are separated by a membrane separation method, so as to obtain a amylodextrin product with low polydispersity coefficient and narrow molecular weight distribution, and the starch comprehensive utilization efficiency is increased to 70% or above.

Abstract: The present disclosure discloses a rice conditioning process and a production method of instant rice, and belongs to the technical field of food processing. According to the present disclosure, rice conditioning pretreatment is realized on the basis of an instantaneous high-temperature fluidization technology, and a conditioning liquid containing compounded soft rice flour, edible oil and rice soup is prepared through a rice soup backfilling technology. A technology of rapid cooling for film forming is adopted to increase a water-retaining film on the surface of rice, so as to enhance the water-retaining property, viscoelasticity and luster of the rice. The method mainly includes the steps of rice washing and draining, conditioning, cooking, aseptic packaging and rapid cooling for film forming. According to the present disclosure, industrialized continuous production can be realized, and the obtained instant rice is sticky but not adhesive after being stored for 60 days, and has a good taste.

Abstract: The disclosure discloses a preparation method of rice noodles with low glycemic index, and belongs to the technical filed of food processing. According to the disclosure, by adding debranching enzymes and an emulsifying agent into rice starch, resistant starch is prepared and obtained through one-step extrusion, and then, other food raw materials are compounded to form the low glycemic index rice noodles through secondary extrusion. By using the characteristic that V-type crystals are formed by complexing the emulsifying agent and amylose, the disclosure adds the debranching enzymes and the emulsifying agent into a rice starch raw material for extrusion processing. The debranching enzymes added in a first-step extrusion processing process perform limited hydrolysis on starch to reduce starch branching and improve a content of the amylose.

Abstract: The present disclosure discloses a preparation method of low-glycemic index slowly digestible starch-based reconstituted instant rice, and belongs to the technical field of food processing. The preparation method is based on high-temperature fluidization technology to carry out non-crystallization treatment on a solid phase broken rice raw material in a short period of time, and then the material is subjected to a one-step reactive extrusion technology combining enzymatic hydrolysis and esterification treatment to prepare the reconstituted instant rice with high content of slowly digestible starch and low glycemic index. The reconstituted instant rice prepared by the one-step molding extrusion technology is suitable for type II diabetes patients to eat, and at the same time increases the added value of agricultural and sideline products, reduces production cost, and improves production efficiency.

Abstract: The present disclosure disclosed is a preparation method for low glycemic index resistance starch recombinant rice, which belongs to the technical field of food. The method of the present disclosure is as follows: after starch and lipid in an alcohol aqueous system are complexed under low temperature, variable-temperature crystallization is performed, so that a low glycemic index resistance starch is prepared, and then, with the low glycemic index resistance starch as a main material, low glycemic index recombinant rice is prepared by the extrusion technique. The low glycemic index resistance starch prepared by utilizing the method of the present disclosure has the functions of controlling postprandial blood glucose, protecting and transporting fatty acid, retarding starch retrogradation and so on. The low glycemic index recombinant rice prepared by utilizing the method of the present disclosure is suitable for being eaten by patients with type II diabetes.

Abstract: The present disclosure discloses a production method of normal-temperature instant cooked rice and belongs to the technical field of food processing. The method of the present disclosure comprises the main steps of rice washing and soaking, flavor blending, sub-packaging, cooking, sterile vacuum sealing, cooling and crystallization and normal-temperature storage, wherein an aqueous solution containing flavor substances is adopted to perform flavor blending, and a fast cooling mode is adopted to perform cooling and crystallization. The normal-temperature instant cooked rice obtained through the production method provided in the present disclosure can keep the original flavor after being stored for 90 days.