TWI692312B - Method for increasing anti-oxidation of banana pseudo-stem extract - Google Patents

Abstract

The invention relates to a method for increasing anti-oxidation of a banana pseudo-stem extract comprising steps of (a) blanching and squeezing a banana pseudo-stem tender core to acquire a residual crude extract; (b) drying and grinding the residual crude extract to acquire a powder; and (c) extracting the powder by an ethanol solution to acquire a banana pseudo-stem extract. Accordingly, the banana pseudo-stem extract prepared by the method according to the present invention has a high antioxidant capacity.

Description

Method for increasing antioxidant capacity of banana fake stem extract

The present invention relates to a method for increasing the antioxidant capacity of a banana pseudostem extract, in particular, it refers to extracting a pseudo-stem tender core by a specific processing condition to obtain a better antioxidant capacity The method of extracting, by this, can increase the economic value of the banana stem.

Bananas are annual fruit trees and one of Taiwan's important cash crops. The average output from 2010 to 2012 reached 296,300 metric tons (Council of Agriculture, 2014). The amount of waste produced by banana production is very large, which also causes great problems for the environment. According to Bello et al. (2014), when producing a ton of bananas, the waste generated includes: banana-stem (pseudo-stem) Three tons, banana stem 160 kg, banana leaf 480 kg and 440 kg banana peel. Among the banana waste, the proportion of banana stalks is the highest. Only a few in Southeast Asia use the stalks in combination with other ingredients as soups.

At present, some scholars have studied making fake banana stems into biomass alcohol. Some scholars have found that the fake banana stems often have a tissue juice content of more than 80%, and have higher organic acid and electrolyte content, so they try to use the fake banana stem juice as Plant battery material.

The fibers of the fake banana stems can also be made into paper. For example, Patent Publication No. I359891 of the Republic of China discloses a "thin sheet used to remove fibers from banana plants and a method and equipment for making base paper from the thin sheet." Has a longitudinal axis, which is used for The equipment for making thin stems of banana plants in the Musaceae family includes: (a) a work station that can feed a fake stem into it; (b) a support member for supporting the fake stem in the work station Making it rotate around the longitudinal axis of the pseudostem; and (c) a fiber separation device that contacts the rotating pseudostem substantially along the entire length of the pseudostem: where in rotation, a continuous fiber The sheet is removed from the false stem by the fiber separation device. In addition, the method for manufacturing base paper from a sheet made from a fake stem of a banana plant in the Musa family includes the following steps: (a) feeding the fake stem into the workstation; (b) supporting in the workstation The pseudostem, causing it to rotate about the longitudinal axis of the pseudostem; and (c) contacting the rotating pseudostem substantially along the entire length of the pseudostem with the fiber separation device, wherein during rotation, a continuous sheet Removed from the pseudostem, the sheet having fibers with substantially parallel directions; (d) stacking two or more sheets together so that the direction of the substantially parallel fibers in at least two adjacent sheets is misaligned; and (e) Curing these adjacent sheets to form base paper.

Japanese Patent No. 4125065 discloses "Banana fiber and its preparation method, blended yarn and fiber structure using it", which is characterized by drying peeled fake stems of bananas belonging to the banana family of the Musa family for consumption. Split the fiber and make the average fiber length from 10mm to 50mm and the average fineness from 0.5dtex to 80dtex; because the fiber structure has the advantages of light weight, excellent hygroscopicity, richness and coolness, it can be used Used as general clothing such as underwear, shirts, or short coats.

Other farmers use the fake banana stem as a base for planting; however, most of them still discard the fake banana stem as an inactive part.

The main object of the present invention is to provide a method for preparing a banana pseudostem extract, which extracts a banana pseudostem by a specific condition to enhance the antioxidant power of the extract.

In order to achieve the above-mentioned implementation objective, the present invention provides a method for increasing the antioxidant capacity of banana pseudo-stem extract, which includes the following steps: (a) take the banana (scientific name Musa paradisiaca) pseudo-stem tender core to kill cyanine and extract juice to obtain a crude Extract; (b) drying the crude extract and grinding into a powder; and (c) extracting the powder with an ethanol solution to obtain a banana pseudostalk extract.

In one embodiment of the present invention, the ethanol solution preferably uses 95% (V/V) ethanol.

In one embodiment of the present invention, step (a) is preferably to kill the cyanine by using hot water at 80°C for 1-20 minutes.

In one embodiment of the present invention, step (b) is preferably dried at 75°C-100°C for at least 24 hours; more preferably, dried at 100°C for 36 hours.

In an embodiment of the invention, step (c) preferably further includes a reduced pressure concentration step.

In this way, the banana pseudostem extract prepared by the method of the present invention has high antioxidant capacity, and the banana pseudostem that is often discarded as an ineffective part can be developed into a healthy food.

Figure 1: Flow chart of the steps of the preferred embodiment of the present invention.

Figure 2: The flow chart of the steps of a specific embodiment of the present invention.

Figure 3: Composition analysis of phenolic acid and flavonoids in the ethanol extract of the banana core of the untreated (U) group.

Figure 4: Composition analysis chart of the phenolic acid and flavonoids of the ethanol extract of the banana pseudostem tender core of the cyanidin (B) group.

Fifth figure: Composition analysis chart of phenolic acid and flavonoids of the ethanol extract of banana pseudo-stem tender core of juice extraction (S) group.

Figure 6: Composition analysis chart of phenolic acid and flavonoids of ethanol extract of banana pseudo-stem tender core of cyanidin and juice extraction (B+S) group.

Figure 7: Step flow chart of the second specific embodiment of the present invention.

The purpose of the present invention and its structural and functional advantages will be explained based on the structure shown in the following drawings and in conjunction with specific embodiments, so that the reviewing committee can have a more in-depth and specific understanding of the present invention.

Please refer to the first figure, which is a flowchart of steps of a preferred embodiment of the present invention. The present invention relates to a method for increasing the antioxidant capacity of a banana pseudostem extract, which includes the following steps: (a) taking a tender core of a banana pseudostem for cyanine killing and squeezing juice to obtain a crude extract, wherein the cyanidin killing effect may be, for example Kill the cyanine with hot water at 80°C for 1-20 minutes; (b) Dry the crude extract, preferably at 75°C-100°C for at least 24 hours, more preferably at 100°C for 36 hours, and Grinding into a powder; and (c) extracting the powder with an ethanol solution (which may be, for example, 95% (V/V) ethanol) to obtain a banana pseudostalk extract. Preferably, step (c) may further include a reduced pressure concentration step.

In addition, through the following specific embodiments, the scope of the present invention can be further proved to be practical, but it is not intended to limit the scope of the present invention in any form.

Banana fake stems are one of the considerable wastes of banana harvest and the highest proportion of banana waste. Therefore, if the potential effects of banana fake stems can be developed, it will solve environmental problems and increase the value of banana fake stems. Increase farmers' income. The present invention mainly adopts different processing procedures for the tender core of banana fake stems, if there are, no killing cyanine, or un-treated (abbreviated as "U"), Blanched (abbreviated as "B"), juice extraction (Squeezed, referred to as "S") and squeezed and juice (Blanched-and-Squeezed, referred to as "BS") treatment, and the samples with better activity after these treatments use water, ethanol, acetone, ethyl acetate and Extraction with n-hexane, with a view to developing a preparation method that can enhance the antioxidant effect of banana pseudostalk extract.

Example 1: Detecting the effect of different pretreatments on the antioxidant activity of the extract of banana pseudo-stem tender core

Please refer to the second figure, which is a flowchart of steps of a specific embodiment of the present invention, which will Banana pseudo-stem tender cores are divided into direct freeze-drying, freeze-drying after cyanine killing, freeze-drying after squeezing juice, and freeze-drying after squeezing citrus juice. The effects of different pre-treatment methods on the antioxidant activity of the samples are discussed.

(1) The sample of this experiment is the tender stem core of Musa paradisiaca provided by Taiping Farmhouse in Taichung City in August 2004. After removing the outer leaf sheath and cutting, the sample pretreatment methods are as follows : Untreated group (U; direct freeze-drying): After cleaning and cutting the fresh banana stems, the banana stems are placed in a -20℃ refrigerator for freezing, taken out and placed on an iron plate and spread Flat, put in a freeze dryer to dry. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use.

Killing Jing group (B; killing Jing freeze-dried): after washing and cutting the fresh banana pseudo-stem tender cores, killing Jing with hot water at 80℃ for 1 minute, and slicing the banana pseudo-stem tender cores, Put it in the refrigerator at -20℃, take it out, place it on the iron pan and flatten it, put it in the freeze dryer to dry it. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use.

Juicing group (S): After washing and cutting the fresh banana pseudo-stalk tender core, put it in a juicer to squeeze juice, and store the residue and juice separately in a -20 ℃ refrigerator to freeze, take out the residue and juice separately Spread it on the iron pan and put it in a freeze dryer to dry it. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use.

Jingjing and Juicing Group (BS; Jujing Juicing): After washing and cutting the fresh cores of fresh banana fake stems, kill the Jing in hot water at 80℃ for 1 minute, and tenderize the banana fake stems after killing Jing Cut the core into pieces, put it into a juicer to squeeze the juice, and separate the residue and juice in a -20℃ refrigerator for freezing. Take out the residue and juice separately on an iron pan and flatten it, put it in a freeze dryer to dry. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use.

Moisture content analysis: Put the sample in an oven, heat and dry at normal pressure (1atm) and specific temperature (105℃), the weight loss before and after drying the sample is the moisture content of the sample. Determination method (AOAC, 1984), after drying and weighing the aluminum foil dish, 1 to 2 grams of the sample appropriately crushed by the precision scale, placed in a 105°C oven for 2 hours, then transferred to a glass drying dish and placed at room temperature Allow to cool for 30 minutes before weighing. After weighing, put the sample into the oven to dry for about 30 minutes, remove and weigh. Repeat the above operation until the weight reaches a constant weight, and the sample detection is repeated three times. The calculation formula is as follows: moisture (%) = (W ₁ -W ₂ )/(W ₁ -W ₀ )×10, where W ₀ : weight of aluminum foil dish (g), W ₁ : weight of aluminum foil dish plus sample (g ), W ₂ : weight (g) when the aluminum foil dish plus the sample is dried to constant weight.

Water activity (AW) analysis: Weigh 1-2 grams of appropriately crushed samples into a plastic dish and measure them with a Hygrometer. The samples are tested in triplicate.

Total soluble solids (°Brix) analysis: Drop the sample to be tested on the calibrated sugar degree tortuosity meter, and observe the indicated sugar degree at room temperature. Expressed in °Brix, the sample detection is repeated in triplicate.

Total acid analysis: For the determination method, refer to CNS 3736 and modify it. Organic acids (weak acids) in foods are neutralized to form salts with standard alkali droplets. Use phenolphthalein and pH meter as the end point indicator for titration. When the titration reaches the end point (pH=8.1, the indicator is pink), the total acid content of the sample is calculated according to the volume of standard lye consumed, and the sample detection is repeated three times. Take 5mL of the sample, add 20mL of secondary water, titrate the sample solution with 0.1N NaOH standard alkali, and add two drops of phenolphthalein indicator until the pH meter has been calibrated to determine that the sample solution is pH=8.1, record 0.1N NaOH The consumption and sample testing are all repeated three times. The calculation formula is as follows: [total acidity (100%)=a×F×b×100÷S×dilution multiple], where a: consumption of 0.1N NaOH standard solution (mL), b: equivalent to 1 mL of 0.1N NaOH standard solution The amount of organic acid (g), S: the weight of the sample (mL), F: the force value of 0.1N NaOH standard solution.

Volatile acid analysis: add about 300mL of secondary water to a triangular flask, place 10mL of sample in the Sellier tube, and use a magnetic stirrer to heat it. When the water in the triangular flask rolls and the pipe emits white smoke, clamp the tube to make The steam enters the Sellier tube, drives out the volatile acid, and collects 100mL of distillate. First open the clamp piston, then turn off the magnet stirrer, add two drops of the collected distillate to the phenolphthalein indicator, and titrate with 0.1N NaOH Until the calibrated pH meter determines that the sample solution is pH=8.1, the consumption of 0.1N NaOH is recorded, and the samples are tested in triplicate. The calculation method is as follows: volatile acid (100%) = a × F × b × 100 ÷ S × dilution factor, where a: 0.1N NaOH standard solution consumption (mL), b: equivalent to 0.1N NaOH standard solution 1mL Amount of organic acid (g), S: weighed amount of sample (mL), F: force value of 0.1N NaOH standard solution.

Total sugar analysis: using phenol-H ₂ SO ₄ method (Dubois, 1956). Take 2 mL of the sample, add 1 mL of 5% phenol and 5 mL of concentrated sulfuric acid, let stand for 10 minutes, mix evenly and place in a 25°C water bath for 15 minutes, and measure its absorbance at 480 nm. Finally, the glucose solution is used as the calibration line for calculation, and the sample detection is performed in triplicate.

Reducing sugar analysis: using the DNS method to determine the content of reducing sugars (referring to sugars that can generate aldehyde groups and ketone groups in alkaline solutions) in food. The use of DNS has the characteristic of reducing power, so as long as the carbohydrate has free or free aldehyde groups or ketone groups, it can have a reducing ability under alkaline conditions, so the reaction proceeds. Take 0.5mL of sample, add 0.5mL of DNS reagent and mix well, heat the reaction in a 100°C water bath for 10 minutes, then add 2.5mL of secondary water to dilute, measure the absorbance at 540nm, and then calculate the reducing sugar content from the standard curve. Repeat for three.

Crude fat quantitative (Soxhlet Method) analysis: Place the round bottom flask in a 105°C oven and dry to constant weight for use. The sample to be tested is also placed in an oven to dry for 1 hour to avoid moisture affecting the measurement results. After weighing the sample, place it on the filter paper, put it into the cylindrical filter paper after being coated, plug the hole with absorbent cotton, and move it into the cable extractor. After drying, the round bottom flask was transferred to a drying dish and cooled to room temperature. The weight was accurately weighed and about two-thirds of n-hexane was added. After assembly, the cable-type extractor is placed in a constant temperature water tank at 50~60℃ for 6 hours for extraction. After the extraction is completed, the n-hexane is recovered to dryness under reduced pressure, dried in a 105°C oven for 1 hour, placed in a drying dish to cool to room temperature, weighed to a constant weight, and the samples are tested in triplicate. The calculation method is as follows: crude fat (%)=[(W ₁ -W ₀ )÷S]×100, where W ₀ : weight of round bottom flask (g), W ₁ : weight of round bottom flask after lipid extraction (g ), S: sample weighed amount (g).

Low protein assay (Lowry assay) analysis: Lowry method was used to analyze protein content. Under alkaline conditions, peptide bonds in proteins combine with copper to form complexes. Phosphomolybdate-phosphotungstate in Folic-ciocialten phenol reagent is reduced by tyrosine and phenylalanine residues in protein, which is dark blue. Under certain conditions, the blue depth is proportional to the amount of protein. Put 0.5mL sample in a test tube, add 2.5mL Solution C, mix and stand for 10 minutes, then add 0.25mL Solution D and mix for 30 minutes, measure and calculate the absorbance at 750nm using a spectrophotometer. The BSA solution is used as the calibration line for calculation, and the samples are tested in triplicate.

Please refer to Table 1 for the analysis of the composition of the juice of banana tender cores treated with cyanidin and cyanidin, where "-" stands for unmeasured. The measured water content of unkilled cyanine juice and cyanided sap water is quite high, both about 97%. The larger difference between the two is the total sugar, reducing sugar, and trace protein content. The content of cyanine juice is high; this result is opposite to the expected reaction, and usually can inhibit the occurrence of browning when killing cyanine, but this example found that the browning reaction after cyanidation caused the color to deepen and the content of reducing sugar and protein was significant Sexuality is reduced. If you try to use other temperatures such as 100 ℃ to kill cyanine, the color is darker and the browning is more serious.

(2) Test the content and antioxidant activity of total phenolic compounds and total flavonoids in banana tender core juice treated with cyanidin and non-cyanidin.

Determination of total phenol content: For the determination method, refer to the method of Julkunen-Tiitto (1985) and modify it. As Take 50 μ L sample tube, was added 1mL of deionized water and 0.5mL 100% Folin-Ciocalteu's phenol reagent evenly mixed, was added 2.5mL 10% (w / w) sodium carbonate uniformly mixed again, left to stand in the dark for 20 minutes, The absorbance was measured at a wavelength of 735nm. This measurement method uses gallic acid as the standard curve, and the total phenolic compound content in the sample is expressed in milligrams of gallic acid equivalent/g of dry weight per gram of sample dry weight.

Determination of total flavonoid content: For the determination method, refer to the methods of Zhishen et al. (1999) and Barreira et al. (2008) and modify them. Take 250 μ L samples were placed in a test tube, was added 1.25mL deionized water, and 75 μ L 5% (g / ml) NaNO 2, homogeneous reaction mixture was allowed to stand for 6 minutes and then was added 150 μ L 10% (g / ml) AlCl _3, mixed stand for 5 minutes, finally adding 0.5mL 1M NaOH was added and mixed well 275 μ L of deionized water to make a final volume of 2.5 mL, the absorbance was measured at 510nm wavelength. This determination method uses Catechin as a standard curve, and the total flavonoid content of the sample is expressed in mg catechin equivalent/g of dry weight per gram of sample dry weight.

DPPH (2,2-Diphenyl-1-picrylhydrazyl hydrate) free radical scavenging ability determination: For the determination method, refer to Shimada et al. (1992) and Espin et al. (2000) and modify them. Sample was added 200 μ L of various concentrations in 96 well ELISA plat in (on the sample was dissolved in methanol), methanol, and the control group (+) - Catechin methanol solution was added 50 μ L of methanol 1mM DPP, mixing was allowed to stand Avoid light for 30 minutes, and measure its absorbance at 517nm. When the DPPH radicals are cleared more, the absorbance value at 517nm is lower. The clearance rate of the blank positive control group can be used to judge the strength of DPPH radicals removal ability of various banana pseudo-stem tender core extracts. The calculation method of DPPH free radical scavenging rate is as follows: Scavenging effect(%)=[Ab-(A-As)]/Ab×100, where A: 517nm absorbance of the sample plus DPPH methanol solution, As: 517nm absorbance of the sample , Ab: 517nm absorbance of the blank group.

Determination of total antioxidant capacity (ABTS ⁺ ): For the determination method, refer to the experimental methods of Arnao et al. (1990) and Miller et al. (1995) and modify them. Peroxidase (Peroxidase), H ₂ O ₂ and ABTS were mixed evenly in the ratio of 1:1, so that the final concentrations were 4.4unit/ml, 100 μ M and 50 μ M, respectively, and reacted at room temperature It produces stable blue-green ABTS ⁺ cationic free radicals, adjust the absorbance of its reagent at a wavelength of 734 nm to 0.7 ± 0.02, take 30 μ L samples of different concentrations, positive control group Trolox, add 270 μ L ABTS ⁺ reaction 1 After a minute, the absorbance was measured at a wavelength of 734 nm, and the degree of blue-green discoloration was observed. In addition, the ability of different concentrations of Trolox to scavenge ABTS ⁺ cationic free radicals was used as a standard curve for the clearance rate, and the ratio of Trolox to the sample concentration at the same inhibition rate was calculated. The calculation method of ABTS+cation radical scavenging rate is as follows: Scavenging effect(%)=[Ab-(A-As)]/Ab×100, where A: 734nim absorbance of sample plus ABTS ⁺ reagent, As: 734nm absorbance of sample , Ab: 734nm absorbance of the blank group.

Determination of reducing power: The measuring method refers to the experimental method of Oyaizu (1986) and Yen and Chung (1999) and is modified. Samples with different concentrations of 250 μ L were removed, the positive control (+) - Catechin, were placed in a microfuge tube, and then were added sequentially 250 μ L 0.2M phosphate buffer solution _{(Na 2 HPO 4 -NaH 2 PO} 4 ) pH 6.6,250 μ L 1% Potassium ferricyanide, containing traces of the sample and the reagent into the centrifuge tube 50 deg.] C water bath for 20 minutes, 250 μ L 10% Trichloroacetic aicd solution is rapidly cooled, after centrifugation at 4 ℃ 3000 rpm for, 10 minutes, and the supernatant 100 L, 100 L of deionized water was added and 25 μ L 0.1% Ferric chloride solution was allowed to stand for 10 minutes, measured at a wavelength of 700nm absorbance.

The results are shown in Table 2. As shown in Table 2, the total phenolic compounds and total flavonoids content of the banana pseudo-stem tender core juice after the cyanidin treatment is higher than that of the non-killed cyanine juice. However, banana pseudostem soft core juice have shown that both the DPPH radical scavenging ability, EC ₅₀ value of the total antioxidant capacity and neither high reducing ability, a further comparison, blanching juice which DPPH radical scavenging antioxidant capacity than the results Unkilled cyanine juice is still poor, and the total antioxidant capacity and reducing ability are slightly better than unkilled cyanine juice. Therefore, if you want to commercialize the banana pseudo-stem tender core juice, it is recommended that the banana pseudo-stem tender core should be in hot water at 80℃ Kill Jing for 20 minutes.

In addition, since the results of this example show that the juice of the banana pseudo-stem tender core is not good in oxidation resistance and reducing ability, the residue of the banana pseudo-stem tender core is subsequently used for testing.

Example 2: Detecting the resistance of different extracting solvents to the extract of banana stalk tender core Effect of oxidation activity

In order to understand the influence of the polarity of the solvent on the extraction rate and components of the banana pseudostem tender core, it was extracted with water, 95% ethanol, acetone, ethyl acetate and n-hexane. Because water is prone to spoilage when it is extracted at room temperature, it is changed to low temperature (4℃) for extraction. The detailed extraction steps are as follows: Room temperature extraction: Weigh 33g of banana stems with different pretreatments in a serum bottle, respectively with 1000mL (sample to solvent ratio is about 1:30) four different polar solvents (95% ethanol, acetone, ethyl acetate (Ester and n-hexane) were stirred and extracted at room temperature in the dark for 24 hours. The extract was filtered through Whatman NO.1 filter paper, and the residue was collected into a serum bottle, and the second extraction was performed according to the above steps. The obtained extract was collected twice, the organic solvent was removed by concentration under reduced pressure, and the water was removed by freeze-drying. The obtained dry crude extract was stored in a sample bottle and placed in a -20°C refrigerator for use.

Low-temperature extraction: Weigh 33g of banana pre-stem tender cores of different pretreatments in a serum bottle, and extract with 1000mL of deionized water (sample to solvent ratio of about 1:30) under 4℃ environment in the dark and stir for 24 hours The extraction solution is filtered with Whatman NO.1 filter paper, and the residue is collected into a serum bottle, and the second extraction is performed according to the above steps. Collect the obtained extract twice, and remove the deionized water through a freeze dryer to obtain a crude extract, store it in a sample bottle, and place it in a -20°C refrigerator for use.

Analytical extraction rate: Pour the washed and dried sample bottle precision scale, pour the sample extract obtained above into the sample bottle, respectively, concentrate under reduced pressure or freeze-dry, after the organic solvent and deionized water are removed Extraction rate. The calculation method is as follows: extraction rate (%)=((W ₁ -W ₀ )-W ₂ )×100%, where W ₀ : weight of sample bottle (g), W ₁ : weight of sample bottle plus extract ( g), W ₂ : weight of the sample weighed during extraction (g).

Please continue to refer to the second figure, and combine the "direct freeze-dried group (U)", "killed lyophilized group (B)", "juiced group (S)" and "killed squeezed group (BS)" in the first embodiment. ''Further extraction of different pre-treatments with five solvents of cold water, 95% ethanol, acetone, ethyl acetate and n-hexane To study the effect of different pretreatments and different solvents on the extraction rate and antioxidant activity of the banana pseudo-stem tender core.

(1) Using five solvents to extract the banana pseudo-stem tender core with different pretreatments, the results of extraction rate, total phenolic compounds and total flavonoid content are shown in Table 3. The extraction rate is higher in the cold water extraction group and the ethanol extraction group, and the extraction rate in other pretreatments is quite low, indicating that most of the banana pseudo-stem tender cores are compounds of higher polarity; the highest extraction rate is the cold water extraction. The cyanine-treated group (B) and the ethanol-extracted untreated group (U) are 22.43±0.84 and 22.44±0.03, respectively, so it is recommended to use water or ethanol for extraction. In the content of total phenolic compounds and total flavonoids, the content of total phenolic compounds and total flavonoids in the ethanol extraction group was higher than that of the other treatment groups, followed by the cold water extraction group and the acetone extraction group, and then ethyl acetate The content in the n-hexane extraction group was the lowest; the total phenolic compound content in the cold water extraction group was slightly higher than that in the acetone extraction group, but the total flavonoid content in the acetone extraction group was significantly higher than that in the cold water extraction group.

In addition, in the ethanol extraction group, the content of total phenolic compounds and total flavonoids in the juice extractor (BS) after killing cyanine was higher, which were 11.34±0.62mg/g and 9.41±0.20mg/g, followed by The juice extraction group (S), the unkilled group (B), and finally the untreated group (U). Generally speaking, heat treatment (cyanocide killing) should destroy phenolic compounds, but in this example, it was found that cyanide killing and juice extraction can increase the content of phenolic compounds, also in the cold water extraction group and acetone extraction group There is a similar trend, but there is no similar phenomenon in the ethyl acetate extraction group and n-hexane extraction group.

(2) Test the antioxidant activity of extracting the banana tender stem core with five solvents

Using five solvents to extract the tender cores of banana pseudo-stems with different pretreatments, the antioxidant activity results are shown in Table 4, where "-" stands for unmeasured. The DPPH free radical scavenging ability test results show that the extract of banana pseudo-stem tender core using solvent extraction has better antioxidant capacity than the juice of banana pseudo-stem tender core (without solvent extraction), indicating the extraction of banana pseudo-stem tender core The extract has better antioxidant capacity, and the EC ₅₀ value of the BS group extracted with ethanol is the lowest, which means that the banana pseudo-stem tender core extract with the best DPPH free radical scavenging ability can be obtained by this method, which in turn is In group S, group B and group U, this change trend and the content of total phenolic compounds and total flavonoids were similar. In other solvent extraction parts, the acetone extraction group is next, and the water extraction group and the acetone extraction group are similar, followed by the ethyl acetate extraction group, and the n-hexane extraction group is the worst; these four solvent extractions are not the same as the ethanol extraction group. The same trend, however, the BS treatment group (except the n-hexane extraction group) has better DPPH free radical scavenging ability. Therefore, if the stalks of the banana pseudo-stem are treated with juice after squeezing the cyanidin, then ethanol extraction can be used to obtain better The DPPH free radical scavenging ability.

The results of ABTS ^+. radical scavenging ability test showed that the ethanol extraction group was also the one with better scavenging ability ^. The sequence of the ABTS ^+. radical scavenging ability and DPPH radical scavenging ability in different solvent treatment groups were similar, and all were treated with BS Group is the best, followed by Group S, Group B and Group U. In the U treatment group, the removal ability is ethanol/ethyl acetate, water and acetone in order; in the BS treatment group, the removal ability is ethanol, acetone, ethyl acetate and water in sequence; in the B treatment group, the removal ability is ethanol/ Water and acetone/ethyl acetate; in the S treatment group, the removal capacity is ethanol/acetone, ethyl acetate and water in order; therefore, if the stalks of the banana pseudostalk are processed by juicing after squeezing the cyanidin, then extracting with ethanol can get better ABTS ^+. Free radical scavenging ability. In the determination of the ABTS ^+. radical scavenging ability of the n-hexane extraction group, precipitation and turbidity continued to occur. Repeating the test many times still failed to solve this problem. In order to make the results of the study consistent, it indicates that its scavenging ability cannot be measured.

The results of reducing power test are slightly different from those of the previous two. The effect of extracting BS treatment group with water is the best. Its reducing power is BS group, B group, U group and S group in order; the ethanol extraction group has its reducing power The order of BS group, S group, B group and U group and DPPH and ABTS ^+. removal ability are the same. The reducing power of acetone extraction group is S group, BS group, B group and U group in order; In the ethyl ester extraction group, the reducing power is BS group, U group, B group and S group in order; n-hexane extraction group is significantly worse than other extraction groups, and the reducing power is U group, B group, S group in order And BS group. In the U treatment group, the strength of the extraction solvent's reducing power is water, ethyl acetate, ethanol, acetone, and n-hexane in order; in the B treatment group, the strength of its extraction solvent's reducing power is water, ethanol, acetone, ( Ethyl acetate) and n-hexane; in the S treatment group, the strength of the extraction solvent reducing power is water, ethanol, acetone, ethyl acetate and n-hexane in order; in the BS treatment group, the strength of the extraction solvent reducing power is in order It is water, ethanol, acetone (ethyl acetate) and n-hexane. From this result, it can be seen that the reducing power is related to the polar component substances in the tender core of the banana pseudo-stem. The higher the polar component of the extraction solvent, the reducing power is significantly increased. Extraction with water can obtain better reducing power.

Compared with the test results of the antioxidant capacity of the banana pseudo-stem tender core juice in Example 1, Table 4 extracts obtained by extracting the residue from the juice of the banana pseudo-stem tender core did have better antioxidant capacity, and their EC ₅₀ The values are lower.

Example 3: Detecting the composition of phenolic acid and flavonoids in ethanol extract of banana pseudo-stem tender core with different pretreatments

Determination of anti-oxidant content in the tender core of banana pseudo-stem: The standard products are respectively equipped with a series of different concentrations, and the solutions of different concentrations are measured with analytical C18 columns (250×4.6mm, 5 μm ) at a column temperature of 30℃ , The mobile phase solution is methanol (A) and water (B) (containing 6% acetic acid), take 21 kinds of standard products to measure, standard products include 1: gallic acid (Gallic acid), 2: catechin (Catechin ), 3: Chlorogenic acid, 4: epicatechin, 5: Caffeic acid, 6: Vanillic acid, 7: Syringic acid, 8 : Ρ-Coumaric acid, 9: Ferulic acid, 10: Sinapic acid, 11: Myricetin, 12: Hesperidin, 13: Querce Quercitrin, 14: Neohesperidin, 15: Diosmin, 16: Quercetin, 17: Hesperetin, 18: kaempferol ( Kaempferol), 19: Rutin, 20: Naringin, 21: p-Anisic acid, a total of 9 kinds of phenolic acids, 12 kinds of flavones, the solvent gradient analysis conditions are as follows: The phase solution is methanol (A): water (B) (containing 6% acetic acid) = 15:85 (v/v), linearly increasing to methanol (A): water (B) (containing 6%) within 5 minutes Acetic acid) = 23: 77 (v/v), linearly increased to methanol (A) in 17 minutes: water (B) (containing 6% acetic acid) = 26: 74 (v/v), linear in 30 minutes Increase to methanol (A): water (B) (containing 6% acetic acid) = 42:58 (v/v), linearly increase to methanol (A): water (B) (containing 6% acetic acid) within 42 minutes ) = 48: 52 (v/v), linear increase to methanol (A) in 50 minutes: water (B) (containing 6% acetic acid) = 60: 40 (v/v), linear increase in 55 minutes To methanol (A): water (B) (containing 6% acetic acid) = 70:30 (v/v), elute with 100% methanol for 10 minutes, equilibrate for 10 minutes after returning to the initial mobile phase conditions, total analysis time 75 min, flow rate setting 1mL / min, the sample injection volume was 20 μ L, and then to detector Waters UV-VIS or Waters 2996 Photodiode array detector for single spectrum (280 nm) or the full scan spectrum (210 ~ 450nm).

The standard product is configured with different concentrations of Gallic acid (0~70ppm), Catechin (0~110ppm), Chlorogenic acid (0~90ppm), Epicatechin (0~80ppm), Caffeic acid (0~120ppm), Vanillic acid (0~50ppm) , Syringic acid (0~120ppm), ρ-Cumeric acid (0~120ppm), Ferulic acid (0~70ppm), Sinapic acid (0~70ppm), Rutin (0~120ppm), Naringin (0~120ppm), ρ -Auisic acid (0~110ppm), Myricetin (0~110ppm), Hesperidin (0~1000ppm), Quercitrin (0~120ppm), Neohesperidin (0~80ppm), Diosmin (0~100ppm, Quercetin (0~120ppm), Hesperetin (0~120ppm), Kaempferol (0~120ppm), using gradient conditions for analysis, and a standard curve of concentration versus integral area, the banana pseudostem tender core was dissolved back in methanol, filtered with a 0.45μm filter membrane After analysis, the relative residence time and the full spectrum are compared with the standard product, and the integrated area is taken into the standard curve to convert the content of the main antioxidant components in the tender core of the banana pseudo-stem, and the content of individual compounds can be obtained.

Please refer to the third picture to the sixth picture, which are HPLC charts of the phenolic acid and flavonoid compounds of ethanol extracts from different pre-treated banana pseudo-stem tender cores, in which the standard products of phenolic acid and flavonoid compounds tested a total of 21 phenols Acids and flavonoid compounds, respectively 1: Gallic acid, 2: Catechin, 3: Chlorogenic acid, 4: Epicatechin; 5: Caffeic acid, 6: vanillic acid (Vanillic acid), 7: Syringic acid, 8: Coumarinic acid (ρ-Coumaric acid), 9: Ferulic acid, 10: Sinapic acid, 11: Myricetin ( Myricetin), 12: Hesperidin, 13: Quercitrin, 14: Neohesperidin, 15: Diosmin, 16: Quercetin, 17: Hesperetin, 18: Kaempferol, 19: Rutin, 20: Naringin, 21: p-Anisic acid.

According to the results in the figure, there are many components, such as 8.5 minutes, 19 minutes, 57 minutes, and 58.5 minutes, all of which have obvious peaks. After comparing the delay time and wavelength of the standard products, it is found that the peak and the standard appear only at 19 minutes. Same product, namely ρ-Coumaric acid.

The ρ-Coumaric acid content of the extracts of banana pre-stem tender cores in different pretreatments was tested. The results are shown in Table 5. There was no ρ-Coumaric acid in the water extraction group, and the ρ-Coumaric acid content in the ethanol extraction group was treated with BS The highest group was 0.75±0.01mg/mL, followed by S group, B group and U group was the worst. The trend of the acetone extraction group was the same as that of the ethanol extraction group, but their contents were slightly lower than those of the ethanol extraction group.

Example 4: Examining the effects of extracts of banana pseudo-stem cores with different pretreatments and different solvents on the inhibition of copper ion-induced oxidation of human LDL

Since ethanol extracts have higher phenolic compounds, total flavonoids, and antioxidant capacity than other extracts, ethanol extracts are used to inhibit copper ion-induced human LDL oxidation (Cu ²⁺ -induced LDL oxidation△t _lag ¹ ) Of determination.

Inhibition of copper ion-induced human LDL oxidation reaction analysis: This experiment refers to the method of Puhl (1994). The LDL obtained by dialysis was adjusted to an appropriate concentration with phosphate buffer solution (PBS). 100 μ L of the taking of LDL (final cholesterol concentration of 50 μ g / mL) was placed porous silica plate 96, after sequential addition of 10 μ L of sample and 130 μ L of a phosphate buffer solution, and finally rapidly added 10 μ L the 125 μ M copper sulfate solution (final concentration of 5 μ M), once the absorbance every 5 minutes at 234nm detection, and finally calculates the oxidation lag phase (lag time). Calculation method of lag period: the time obtained by the intersection of the tangent of the horizontal axis of the initial absorbance value and the maximum slope of the oxidation phase (Propagation phase) is the oxidation lag period.

The results are shown in Table 6. The U treatment group can extend LDL oxidation by 23.00±0.34 minutes, while the B treatment group can extend LDL oxidation by 40.73±9.11 minutes, the S treatment group can extend LDL oxidation by 11.67±2.66 minutes, and the BS treatment group can extend LDL. Oxidation up to 67.50±14.81 minutes. From this result, it can be seen that the ethanol extract of the banana stems tender core can extend its LDL oxidation under different treatments, indicating that the ethanol extract of banana stems tender core can be used to add to food, which can increase the antioxidant capacity of oils and fats. Since the inhibition ability of the BS treatment group is the best, it can be extended for about 68 minutes. Therefore, if the better ability to inhibit the oxidation of fats and oils, the juice should be squeezed after killing the cyanine.

Example 5: Detect the effect of different drying temperature and time on the antioxidant activity of the extract of the tender core of banana pseudo-stem

Please refer to the seventh figure, which is a flow chart of the steps of the second specific embodiment of the present invention; in short, this embodiment is the hot air drying of the best pretreatment conditions (ethanol extraction BS group) of the foregoing embodiment, and measuring different drying Whether the condition affects the antioxidant activity of the extract of the tender core of banana pseudo-stem.

(1) First kill the saplings of the banana pseudo-stalks and then squeeze the juice, and then dry the residues by freeze drying (Freeze-dried), 50°C, 75°C and 100°C to discuss the changes in the antioxidant capacity of the ethanol extract to determine Its optimum drying temperature. The detailed steps are as follows: Preparation of freeze-dried banana pseudo-stem tender cores: Fresh banana pseudo-stem tender cores, after washing and slitting, kill the cyanine with hot water at 80°C for 1 minute, and remove the cyanided banana pseudo-stem tender cores Cut into pieces, put in a juicer to squeeze juice, freeze the slag in a -20℃ refrigerator, take it out and place it on an iron plate, spread it out, and put it in a freeze dryer to dry it. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use.

Preparation of tender core of banana pseudo-stem dried by hot air at 50℃, 75℃ and 100℃: fresh tender core of banana pseudo-stem, after washing and slitting, kill the cyanine with hot water at 80℃ for 1 minute, and kill the banana after cyanidation Cut the tender stem core into pieces, put it in a juicer to extract juice, and put the residue in -20 Freeze in refrigerator at ℃, take it out and place it on an iron pan and spread it, put it in a hot air dryer at 50 ℃, 75 ℃ or 100 ℃ for 24 hours. The dried samples are crushed and homogenized by a crusher, packed separately in vacuum bags and vacuum-packed, and placed in a -20°C refrigerator for later use

Please refer to Table 7. The 100 ℃ drying group has significantly more total phenol and total flavonoid content, and DPPH and ABTS ^{+. The} radical scavenging ability and reducing power are obviously better; although the ability to inhibit LDL oxidation is worse than the 75 ℃ drying group, But overall, the performance of the 100 ℃ drying group is still the best, so 100 ℃ is the most suitable drying temperature.

(2) First remove the saplings of the banana pseudo-stem core and squeeze the juice. The residue is then dried at 100°C and taken out regularly to discuss the change in the antioxidant capacity of the ethanol extract to determine its optimal drying time.

Please refer to Table 8 for the change of the composition of the banana pseudo-stem tender core when it is dried at 100°C. It can be found that the content of total phenol and total flavonoids increases with the drying time, and the content of ρ-coumaric acid is also; dry to 36 After an hour, although its content has increased or decreased, it has not changed much.

Please refer to Table IX. In the change of antioxidant capacity, the results are similar to the trend of the change of total phenol and total flavonoid content. As the drying time increases, the antioxidant capacity increases, so the better antioxidant period is considered. Capacity and energy considerations have found that it is the most suitable The drying temperature and time are 100°C and 36 hours, respectively.

It can be seen from the above implementation description that the present invention has the following advantages compared with the prior art:

1. The present invention can not only extract banana pseudo-stalks with antioxidant properties With specific extraction conditions, the antioxidant power of the banana pseudostem extract can be enhanced.

2. The present invention proves that the banana pseudo-stem tender core, which is often regarded as waste, has a fairly good antioxidant capacity. Both the juice part and the residue part have the antioxidant capacity, although the juice part has a lower antioxidant capacity than the residue part. However, it can still be used as an antioxidant additive for beverages or foods, and can also be developed into a healthy food, so it can greatly increase the economic value and industrial utilization of banana fake stems.

In summary, the method of the present invention for increasing the antioxidant capacity of banana pseudo-stalk extract can indeed achieve the expected use effect by the embodiments disclosed above, and the present invention has not been disclosed before the application. Fully comply with the provisions and requirements of the Patent Law. I filed an application for a patent for invention in accordance with the law, pleaded for the review, and granted the patent.

The illustrations and descriptions disclosed above are only the preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention; those who are familiar with this art, and other equivalent changes made according to the characteristic scope of the present invention Or modification should be regarded as not departing from the design scope of the present invention.

Claims (3)

A method for increasing the antioxidant capacity of banana pseudo-stem extract, which includes the following steps: (a) taking the tender core of banana pseudo-stem and using 80°C hot water to kill cyanine for 1-20 minutes and squeezing juice to obtain a residue; (b) The residue was dried at 100°C for 36 hours and ground into a powder; and (c) the powder was extracted with an ethanol solution to obtain a banana pseudostalk extract. The method as described in item 1 of the patent application scope, wherein the ethanol solution is 95% (V/V) ethanol. The method as described in item 1 of the patent application scope, wherein the step (c) further comprises a reduced pressure concentration step.

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