阅读说明：本技术 一种花青素/pva纳米复合纤维的制备方法 (Preparation method of anthocyanin/PVA (polyvinyl alcohol) nano composite fiber ) 是由 王华林 李琳琳 郭敏 陈敏敏 于 2020-06-10 设计创作，主要内容包括：一种花青素/PVA纳米复合纤维的制备方法,包括下列步骤：步骤1：紫薯花青素的制备；步骤2：紫苏花青素的制备；步骤3：聚乙烯醇溶液的制备；步骤4：将0.5-2.0重量份的紫薯花青素、0.5-2.0重量份的紫苏叶花青素和100重量份的聚乙烯醇溶液,混合均匀得到花青素/PVA混合溶液；步骤5：对花青素/PVA混合溶液进行静电纺丝,得到纤维细丝；步骤6：将纤维细丝,在真空表压-0.09～-0.10MPa、温度30-40℃条件下,真空干燥10-14h,除去残留的溶剂,得到花青素/PVA纳米复合纤维。本发明通过提取紫薯花青素和紫苏花青素,将其封装进PVA中,得到花青素/PVA纳米复合纤维,可用于食品包装能够实时监控食品的腐败状况。(A preparation method of anthocyanin/PVA nano composite fiber comprises the following steps: step 1: preparing purple sweet potato anthocyanin; step 2: preparing purple perilla anthocyanin; and step 3: preparing a polyvinyl alcohol solution; and 4, step 4: uniformly mixing 0.5-2.0 parts by weight of purple sweet potato anthocyanin, 0.5-2.0 parts by weight of perilla leaf anthocyanin and 100 parts by weight of polyvinyl alcohol solution to obtain an anthocyanin/PVA mixed solution; and 5: performing electrostatic spinning on the anthocyanin/PVA mixed solution to obtain fiber filaments; step 6: and (3) drying the fiber filaments in vacuum for 10-14h under the conditions of vacuum gauge pressure of-0.09 MPa to-0.10 MPa and temperature of 30-40 ℃, and removing residual solvent to obtain the anthocyanin/PVA nano composite fiber. According to the invention, the purple sweet potato anthocyanin and the purple perilla anthocyanin are extracted and packaged into PVA to obtain the anthocyanin/PVA nano composite fiber, and the anthocyanin/PVA nano composite fiber can be used for food packaging and can be used for monitoring the putrefaction condition of food in real time.)

1. A preparation method of anthocyanin/PVA nano composite fiber is characterized by comprising the following steps: comprises the following steps:

step 1: adding 5-10 parts by weight of purple sweet potato powder into 100 parts by weight of ethanol water solution, and extracting at 38-43 deg.C under dark condition at stirring speed of 50-100 r/min; in the extraction process, starting ultrasonic treatment once every 10-15min, after extracting for 2-4h, centrifuging the extracting solution for 5-10min at 3000r/min for 1000-; freeze drying the filtrate to obtain dry powdery substance, namely the purple sweet potato anthocyanin;

step 2: adding 5-10 weight parts of folium Perillae into 100 weight parts of acetic acid water solution, extracting at 38-43 deg.C under stirring speed of 50-100r/min in dark condition; in the extraction process, starting ultrasonic treatment once every 10-15min, after extracting for 2-4h, centrifuging the extracting solution for 5-10min at 3000r/min for 1000-; freeze-drying the filtrate to obtain dry powdery substance, namely the perilla anthocyanin;

and step 3: dispersing 8-10 parts by weight of polyvinyl alcohol in 90-100 parts by weight of 0.8-1.2% by volume of acetic acid aqueous solution to obtain polyvinyl alcohol solution;

and 4, step 4: uniformly mixing 0.5-2.0 parts by weight of purple sweet potato anthocyanin, 0.5-2.0 parts by weight of perilla leaf anthocyanin and 100 parts by weight of polyvinyl alcohol solution to obtain an anthocyanin/PVA mixed solution;

and 5: performing electrostatic spinning on the anthocyanin/PVA mixed solution to obtain fiber filaments;

step 6: and (3) drying the fiber filaments in vacuum for 10-14h under the conditions of vacuum gauge pressure of-0.09 MPa to-0.10 MPa and temperature of 30-40 ℃, and removing residual solvent to obtain the anthocyanin/PVA nano composite fiber.

2. The method for preparing the anthocyanin/PVA nano composite fiber of claim 1, wherein the method comprises the following steps: in the step 1 and the step 2, the ultrasonic frequency is 25-35KHz, and the power density is 0.4-0.5W/cm²The treatment time is 1.5-3.0min each time.

3. The method for preparing the anthocyanin/PVA nano composite fiber of claim 1, wherein the method comprises the following steps: the volume fraction of the ethanol water solution is 75-85%; the volume fraction of the acetic acid aqueous solution is 1.5-2.5%.

4. The method for preparing the anthocyanin/PVA nano composite fiber of claim 1, wherein the method comprises the following steps: during electrostatic spinning, the relative humidity of the environment is 40-50%, and the temperature is 20-25 ℃; extruding the anthocyanin/PVA mixed solution through a thin tube with the diameter of 0.25-0.75mm at a constant speed; the electrostatic spinning voltage is 10-18KV, and the polar distance is 8-16 cm.

Technical Field

The invention belongs to the technical field of nanofiber preparation, and relates to a preparation method of anthocyanin/PVA (polyvinyl alcohol) nano composite fibers.

Background

The nano fiber is a linear material with a diameter of nano scale and a larger length and a certain length-diameter ratio, and the diameter of the material is less than 1000 nanometers. The nano fiber has wide application, for example, the nano fiber is implanted into the surface of the fabric to form a layer of stable gas film to prepare the amphiphobic interface fabric which can resist water, oil and dirt; the fabric of the high-grade protective clothing made of the nano-fiber is porous and provided with a film, so that the high-grade protective clothing not only can enable air to permeate and has breathability, but also can block wind and filter fine particles, has barrier property to aerosol, and can prevent biochemical weapons, toxic substances and the like. In addition, the nano-fiber can also be used for purification, filtration and the like of products such as chemical engineering, medicines and the like. There are many methods for manufacturing nanofibers, such as drawing, template synthesis, self-assembly, microphase separation, electrostatic spinning, etc., among which the electrostatic spinning method is widely used due to its advantages of simple operation, wide application range, relatively high production efficiency, etc.

Anthocyanins, also known as anthocyanidins, are water-soluble natural pigments widely present in plants in nature and are colored aglycones obtained by hydrolyzing anthocyanins. The major coloring substances in fruits, vegetables and flowers are mostly related to anthocyanins. Under the condition of different pH values of plant cell vacuoles, the anthocyanin enables the petals to present colorful colors. At present, anthocyanidin is mainly used for food coloring, and can also be used for dyes, medicines, cosmetics and the like.

The development of economy causes the improvement of the demand level of people, the food safety and quality guarantee become the focus of attention of people at present, and more research focuses on developing visual pH sensing intelligent food packages. The intelligent packaging is an emerging technology which can monitor the food quality and provide necessary information for consumers to ensure the safety of the consumers. The natural anthocyanin is widely available, safe, nontoxic, pH sensitive and the like, and is often used as a development material of a food freshness visual label. In addition, the natural phenolic structure of the anthocyanin has strong capacity of eliminating free radicals, and the antioxidant activity of the material can be increased to a certain extent.

Disclosure of Invention

The invention aims to provide a preparation method of anthocyanin/PVA nano composite fibers.

In order to achieve the above objects and other related objects, the present invention provides the following technical solutions: a preparation method of anthocyanin/PVA nano composite fiber comprises the following steps:

step 1: adding 5-10 parts by weight of purple sweet potato powder into 100 parts by weight of ethanol water solution, and extracting at 38-43 deg.C under dark condition at stirring speed of 50-100 r/min; in the extraction process, starting ultrasonic treatment once every 10-15min, after extracting for 2-4h, centrifuging the extracting solution for 5-10min at 3000r/min for 1000-; freeze drying the filtrate to obtain dry powdery substance, namely the purple sweet potato anthocyanin;

step 2: adding 5-10 weight parts of folium Perillae into 100 weight parts of acetic acid water solution, extracting at 38-43 deg.C under stirring speed of 50-100r/min in dark condition; in the extraction process, starting ultrasonic treatment once every 10-15min, after extracting for 2-4h, centrifuging the extracting solution for 5-10min at 3000r/min for 1000-; freeze-drying the filtrate to obtain dry powdery substance, namely the perilla anthocyanin;

and step 3: dispersing 8-10 parts by weight of polyvinyl alcohol in 90-100 parts by weight of 0.8-1.2% by volume of acetic acid aqueous solution to obtain polyvinyl alcohol solution;

and 4, step 4: uniformly mixing 0.5-2.0 parts by weight of purple sweet potato anthocyanin, 0.5-2.0 parts by weight of perilla leaf anthocyanin and 100 parts by weight of polyvinyl alcohol solution to obtain an anthocyanin/PVA mixed solution;

and 5: performing electrostatic spinning on the anthocyanin/PVA mixed solution to obtain fiber filaments;

step 6: and (3) drying the fiber filaments in vacuum for 10-14h under the conditions of vacuum gauge pressure of-0.09 MPa to-0.10 MPa and temperature of 30-40 ℃, and removing residual solvent to obtain the anthocyanin/PVA nano composite fiber.

The preferable technical scheme is as follows: in the step 1 and the step 2, the ultrasonic frequency is 25-35KHz, and the power density is 0.4-0.5W/cm²Each time of treatmentThe time is 1.5-3.0 min.

The preferable technical scheme is as follows: the volume fraction of the ethanol water solution is 75-85%; the volume fraction of the acetic acid aqueous solution is 1.5-2.5%.

The preferable technical scheme is as follows: during electrostatic spinning, the relative humidity of the environment is 40-50%, and the temperature is 20-25 ℃; extruding the anthocyanin/PVA mixed solution through a thin tube with the diameter of 0.25-0.75mm at a constant speed; the electrostatic spinning voltage is 10-18KV, and the polar distance is 8-16 cm.

Due to the application of the technical scheme, compared with the prior art, the invention has the advantages that:

1. the purple sweet potato anthocyanin, the purple perilla anthocyanin and the PVA which are used by the invention have the advantages of good biocompatibility, environmental friendliness and the like.

2. The composite fiber obtained by the invention has high porosity, can generate different color changes under different pH environments, has strong sensitivity, and can be used for food packaging to monitor the food spoilage condition in real time.

3. The composite fiber obtained by the invention has good oxidation resistance and can delay food aging and putrefaction.

Drawings

FIG. 1 is an electron micrograph of a prepared spun yarn of comparative example 1, example 2, and example 3.

FIG. 2 is the color change of anthocyanin/PVA nano-composite fiber under different pH conditions.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1-2. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.