14 results about "Polyphenol oxidase activity" patented technology

The invention provides a sweet potato leaf powder processing technology with a high nutrition retention rate, which comprises the following steps: S1, putting sweet potato leaves into a dynamic fixation roller, and mixing nitrogen and carbon dioxide by adopting a nitrogen and carbon dioxide mixing generator to form nitrogen and carbon dioxide mixed gas, the nitrogen and carbon dioxide mixed gas is heated to 95 DEG C through a heat exchanger and sprayed out, the oxygen concentration in the dynamic fixation roller is maintained to be smaller than or equal to 0.5%, and the chlorophyll degradation rate of the sweet potato leaves is monitored through a near-infrared sensor by inhibiting the activity of polyphenol oxidase of the sweet potato leaves; according to the method, a weak acid environment is formed through CO2 dissolution to inhibit the activity of polyphenol oxidase and reduce the requirement for fixation temperature, active ingredients are reserved through three-area gradient variable-temperature drying and rapid dehydration and freeze-drying sublimation, energy consumption is reduced by 37%, heat stability is improved through polyphenol glycosylation, the bioavailability of beta-carotene is improved to 80% through nano embedding, and therefore nutrient loss is avoided, and the method is suitable for industrial production. The drying efficiency, color and flavor are improved.

This invention discloses a plant-derived preservative for Akebia quinata, its preparation method, and its application, belonging to the field of fruit and vegetable preservation technology. The preservative uses young Akebia quinata fruit as the main raw material, combined with Sophora flavescens, Phellodendron chinense, and Zanthoxylum bungeanum, and is prepared through primary yeast fermentation and secondary fermentation with Lactobacillus plantarum and Bacillus amyloliquefaciens. The preservative significantly reduces polyphenol oxidase (PPO) activity, effectively inhibiting enzymatic browning in Akebia quinata; after 14 days of storage at room temperature, the rot rate decreases to 64%-66%, with effects comparable to imazalil; it delays fruit cracking, reduces the cracking rate, and decreases the length and width of the ventral suture; it also has a significant inhibitory effect on Escherichia coli and Staphylococcus aureus. The product of this invention is purely plant-derived, with no chemical residues, and possesses four functions: inhibiting browning, preventing rot, preventing fruit cracking, and broad-spectrum antibacterial activity. The process is stable, and the application is simple, making it suitable for post-harvest green preservation of Akebia quinata and showing good industrialization prospects.

The application discloses a kind of continuous production line for preparing yeast black tea by biological fermentation, including quantitative impurity removal feeder conveyor, withering fermentation machine, kneading and twisting block fermentation machine and hot air drying aroma and vacuum freeze drying all-in-one machine.By this production line, the continuous processing of yeast black tea can be realized, and the temperature of each step in tea processing can be accurately controlled, thereby reducing the loss of polyphenol oxidase activity in tea, and completing the final drying of tea by freeze-drying, and retaining a higher activity of polyphenol oxidase.Therefore, the yeast black tea processed by this production line not only tastes good, but also can be used for fermentation with other plants, and the fermentation of other plants is promoted by polyphenol oxidase in tea, thereby used for the production and processing of composite black tea.It can be widely applied in the field of black tea processing technology.

The invention relates to improvements in reduction of tuber browning in potato (Solanum tuberosum) varieties utilising endonuclease-directed gene editing technologies In particular, the invention provides a Solanum tuberosum plant cell comprising a mutation which generates a phenotype of reduced or eliminated polyphenol oxidase activity when compared to a Solanum tuberosum plant cell without the mutation. The invention further provides ribonucleoprotein complexes comprising an endonuclease and a guide RNA that hybridises with a target sequence comprised within a polyphenol oxidase 2 (StPPO2) gene of a Solanum tuberosum variety, and methods of using the same.

The application discloses a NtPPO gene homozygous mutant and application thereof, and the application is: (1) reducing polyphenol oxidase activity of tobacco leaves; (2) reducing browning degree of tobacco in curing; the NtPPO gene mutant comprises mutant types of NtPPO1, NtPPO2, NtPPO3 and NtPPO4; the NtPPO gene mutant comprises mutant types of NtPPO1, NtPPO2, NtPPO3 and NtPPO4; the nucleotide sequence of the NtPPO1 gene mutant type is shown in SEQ ID NO. 1; the nucleotide sequence of the NtPPO2 gene mutant type is shown in SEQ ID NO. 2; the nucleotide sequence of the NtPPO3 gene mutant type is shown in SEQ ID NO. 3; and the nucleotide sequence of the NtPPO4 gene mutant type is shown in SEQ ID NO. 4.

The present application relates to the processing technology field of Rhizoma Polygonati, in particular to a low-temperature tumbling system and process for directional softening and browning inhibition of Rhizoma Polygonati fibers; the system comprises a tumbling barrel, a collection box, a cooling circulation module and an ultraviolet-ultrasonic synergistic treatment unit. The tumbling barrel breaks Rhizoma Polygonati cells and releases juice during rotation, the juice is filtered by the collection box, cooled to 0-10 DEG C by a cooling device, and then recycled and sprayed onto the surface of Rhizoma Polygonati to realize dynamic temperature control; the ultraviolet lamp inhibits the reproduction of microorganisms, the ultrasonic wave destroys the activity of polyphenol oxidase, and the low-temperature environment blocks the browning reaction; the process realizes directional softening of Rhizoma Polygonati fibers under low-temperature conditions by alternating tumbling and standing, synergistically controls the softening rate of fibers and the inhibition efficiency of enzyme activity, and significantly reduces the browning risk. The system takes into account the quality and processing efficiency of Rhizoma Polygonati, is suitable for the industrialized processing of different varieties such as Rhizoma Polygonati and Rhizoma Polygonati, and can be widely applied to the processing technology field of Rhizoma Polygonati.

The present application provides a wheat grain polyphenol oxidase activity major site and SNP marker and application, the SNP molecular marker Marker149631 is located on the 3A chromosome of wheat, the nucleotide sequence of the molecular marker is as shown in SEQ ID NO.1 or SEQ ID NO.2; the SNP molecular marker Marker149773 is located on the 3A chromosome of wheat, the nucleotide sequence of the molecular marker is as shown in SEQ ID NO.3 or SEQ ID NO.4; the SNP site provided by the present application is of great significance for detecting wheat grain low PPO activity variety, strain, breeding material, and molecular markers can be developed according to it, and the efficiency of wheat quality breeding is accelerated.

The invention discloses a nano antibody combined with polyphenol oxidase and application of the nano antibody. The nucleotide sequence of the nano antibody is as shown in SEQ ID NO.1, and the amino acid sequence corresponding to the nano antibody is as shown in SEQ ID NO.2. The nano antibody prepared by the invention has good stability, high specificity and high affinity, and can accurately inhibit the activity of polyphenol oxidase, thereby fundamentally preventing enzymatic browning; the prepared nano antibody is mainly used as a natural biological preservative and a processing aid, can be widely applied to quality maintenance of aquatic products and various easily browning foods, effectively blocks the enzymatic browning process by specifically inhibiting the activity of polyphenol oxidase, remarkably prolongs the shelf life and maintains the sensory quality of the product.

The invention provides a preparation method of soybean protein isolate with low beany flavor and high water solution transparency, which comprises the following steps: carrying out hot steam heat treatment on defatted soybean meal to obtain defatted soybean meal subjected to heat treatment; desalted water is added into the degreased soybean meal subjected to heat treatment for protein extraction; after extraction, centrifuging to remove bean dregs, adding sodium pyrosulfite into the extract, adjusting the pH value, centrifuging, and precipitating to obtain protein curd; redissolving the protein curd with water to obtain protein liquid; and mixing the protein liquid with compound protease, performing sterilization, flash evaporation and homogenization treatment, and performing spray drying, thereby obtaining the product. The defatted soybean meal is subjected to superheated steam pretreatment and high-temperature instantaneous treatment to inactivate lipoxygenase and the like, so that beany flavor substances generated by oxidation in the subsequent process are greatly reduced; the added sodium pyrosulfite inhibits the activity of polyphenol oxidase to realize soybean protein bleaching, and the whiteness of the product is improved; the protein solubility and emulsification stability are improved through a compound proteolysis process, and the transparency of the product is improved.

This invention provides the major active site of wheat grain polyphenol oxidase activity and the SNP marker Marker 149773, as well as their applications. The SNP molecular marker Marker 149631 is located on wheat chromosome 3A, and its nucleotide sequence is shown in SEQ ID NO. 1 or SEQ ID NO. 2. The SNP molecular marker Marker 149773 is located on wheat chromosome 3A, and its nucleotide sequence is shown in SEQ ID NO. 3 or SEQ ID NO. 4. The SNP sites provided by this invention are of great significance for detecting wheat varieties, lines, and breeding materials with low PPO activity. Molecular markers can be developed based on these sites to accelerate the efficiency of wheat quality breeding.

The invention relates to the technical field of fruit preservation, in particular to color protection liquid and a low-temperature freshness locking technology thereof. The invention relates to a composite color protection solution and a low-temperature fresh-keeping technology based on the composite color protection solution, and the specific technical content is as follows: 1, the composite color protection solution comprises two functional mixed solutions which are respectively used for blanching color protection and soaking color protection, and the specific formula is as follows: a first color protection blanching solution is prepared by mixing 0.2-0.5% of sodium alginate and 0.1% of citric acid, and a second color protection blanching solution is prepared by mixing 0.2-0.5% of sodium alginate and 0.1% of citric acid; sodium alginate can form a primary protective film on the surface of litchi, and citric acid can adjust the pH value of the system and inhibit the activity of polyphenol oxidase. The method has the beneficial effects that the preservation cost is low: the composite color protection liquid adopts low-cost raw materials such as sodium alginate and citric acid, the process steps are simple and easy to operate, complex equipment is not needed, and the method is suitable for large-scale industrial production; the fresh-keeping effect is good: through a dual color protection mechanism of blanching color protection and soaking color protection, and in combination with a nitrogen-filling oxygen-isolating and low-temperature quick-freezing technology, browning and rotting of the litchis can be effectively inhibited.

The invention discloses a cultivation method for improving the postharvest preservation quality of agaricus bisporus based on coco coir-turf composite covering soil. The soil covering material is formed by mixing coco coir with the volume ratio of 40% and domestic turf with the volume ratio of 60%, and preferably, coco coir blocks with the specific particle size range and the turf produced in northeast China are selected. After the soil covering material is stirred by adding water and the pH is adjusted to 7.5 + / -0.3, the water content of the soil covering material reaches 71.2% + / -3%, and the soil covering material can be used for soil covering cultivation of agaricus bisporus. According to the method, the postharvest fresh-keeping quality of sporocarps is remarkably improved on the premise that the total yield of agaricus bisporus is not affected through the soil covering material with a specific proportion, and the specific performance is that the weight loss rate in the storage period is reduced by 50%-75%, the activity of polyphenol oxidase (PPO) is inhibited by 26.4%-33.9%, the accumulation of malondialdehyde (MDA) is reduced by 48.7%-64.3%, and the hardness retention rate is increased by 10% or above. The industrial problems that traditional turf resources are non-renewable, imported turf is high in cost and poor in quality after harvesting are solved, and an innovative soil covering solution is provided for green, efficient and high-quality production of agaricus bisporus.

The invention discloses a method of a Xinjiang early yellow fig tissue culture and rapid propagation system, and belongs to the technical field of plant tissue culture. The method comprises the steps of explant selection and treatment, induction culture, subculture, rooting culture and domestication and transplanting. In the explant pretreatment, a bacitracin-ursolic acid-abamectin conjugate is used for disinfection, so that the bacitracin and abamectin cooperate to resist bacteria and prevent microbial infection, and ursolic acid is used for inhibiting the activity of polyphenol oxidase to prevent explant browning; hormone-enriched microspheres with chitosan as a core layer and calcium alginate-lignosulfonate as a shell layer are added into the culture medium, BA or NAA can be stably stored and accurately released, nutrient substances can also be adsorbed, meanwhile, mannitol, L-proline and betaine loaded on the microspheres can adjust osmotic pressure, enhance cell stress resistance and reduce vitrification, and the hormone-enriched culture medium is suitable for being used as a culture medium. The rapid propagation of the fig explant can be efficiently promoted, and a feasible technical path is provided for the tissue propagation of the fig explant.

According to the waxberry regeneration tissue culture method taking the waxberry endosperm as the explant, the endosperm is taken as the explant, so that the problems that the conventional explant only grows callus, does not grow regeneration buds and is quickly browned are effectively solved, the endosperm is positioned in the seed, direct contact of disinfectant such as alcohol and sodium hypochlorite (NaCLO) is avoided during disinfection, and the explant can be quickly browned. The browning rate is reduced, the activity of polyphenol oxidase (PPO) of endosperm is low, the total phenol content is low, the initial browning degree is natural and light, and the browning rate is lower than that of a traditional method with waxberry leaves and pulp as explants. And performing induced culture under the screened optimal hormone concentration and illumination condition, and performing differentiation culture to generate callus and waxberry regenerated tissue. Compared with the traditional method using leaves or pulp as explants, the browning rate of the method provided by the invention is reduced by 100%, and the generation rate and differentiation rate of calluses are respectively improved by 80%-90% and 2%-4% by virtue of the screened optimal endosperm sampling period and optimal culture environment.