Use of thermally hydrolyzed feather keratin hydrolysate peptides (KHP) in enhancing yield and quality of cucumber fruits

Abstract

This invention relates to a method for improving the yield and quality of cucumber fruits using a feather keratin hydrolysate (KHP) obtained through thermodynamic hydrolysis of fresh feathers. The method involves applying the KHP to cucumber plants via foliar spraying or root irrigation. The KHP of this invention can increase leaf area and chlorophyll content, promote photosynthesis, effectively reduce the number of aborted fruits, and increase the yield of marketable fruits. Regarding fruit quality improvement, it can enhance fruit crispness and water content.

Description

Technical Field

[0001] The present invention relates to the use of thermodynamically hydrolyzed feather products for promoting the growth of cucumbers, and particularly to the use of thermodynamically hydrolyzed keratin hydrolysate for improving the fruit yield and quality of cucumbers. Prior Art

[0002] In recent years, due to global climate change, especially in Taiwan, the average temperature has risen by approximately 1.4°C in the past century. High summer temperatures have led to problems in cucumber cultivation. In Taiwan, cucumber cultivation mainly includes facility cultivation in tunnel-type greenhouses, structural screen houses, and horizontal screen houses, as well as a small number of open-field cultivation methods. Due to the poor airtightness of the screen house facilities, it is difficult to control the environment. Currently, cooling is mainly achieved by using ventilation fans, but the cooling effect is limited. Especially in hot and humid summers, the temperature often exceeds 35°C, resulting in a decline in crop yield and quality.

[0003] The impacts of high temperature in facilities on cucumber growth and yield are summarized as follows: First, high temperature makes the main roots of cucumbers grow longer and thinner, and the root system tends to become fibrous roots. The elongation of the radicle and the growth of lateral roots of cucumbers are inhibited at 42°C and completely inhibited at 45°C. Second, high temperature reduces the chlorophyll content of seedlings, decreases the ratio of chlorophyll a / chlorophyll b, and reduces the photosynthetic capacity. Third, at high temperatures, anthers are prone to abnormal development and pollen viability decreases, leading to poor pollination, which is an important reason for the decline in summer yield and quality, resulting in an increase in the number of deformed fruits such as aborted fruits, curved fruits, and small fruits at the tail end. Therefore, it is necessary to propose solutions to problems such as the decline in cucumber yield and quality caused by high temperature in facilities.

[0004] Feathers contain 85 - 91% keratin, 13 - 15% organic nitrogen, and 1.6 - 2% organic sulfur, which is higher than any other biological material. They are rich in three sulfur-containing amino acids: cystine, cysteine, and methionine. Peptides composed of sulfur-containing amino acids can activate key elements related to the physiology, development, defense, and flavor substance accumulation of crops. Currently, existing technologies use methods such as microbial fermentation, enzymes, chemical, or high-temperature and high-pressure hydrolysis to decompose feathers into keratin, peptides, amino acids, or other hydrolysis products, which are applied to feeds, fertilizers, and culture media (Ye Ruihan et al., Animal Industry Research 54(4): 259 - 272, 2021).

[0005] Nurdiawati et al. published in 2019 that after mixing feathers with water (mixing ratio 1:3), high-temperature and high-pressure hydrolysis was carried out (reaction conditions: 160 °C, 6.1 kg / cm2 or 180 °C, 9.2 kg / cm2, 30 min), and the resulting feather hydrolysis solution (containing nitrogen and amino acids) was mixed with the poultry litter hydrolysis solution to make a liquid fertilizer. It was found that this liquid fertilizer could promote the growth of Pogostemon cablin and Vigna radiata (Nurdiawati et al., International Journal of Recycling of Organic Waste in Agriculture 8:221-232, 2019). However, there are currently few successful examples of applying feather hydrolysate peptide solutions in crop cultivation.

[0006] Zhenghan Biotechnology Company (Taiwan) uses thermodynamic hydrolysis technology. Under high pressure, liquid water with a temperature not exceeding 200 °C (i.e., below the critical temperature) is used as the hydrolysis solvent to carry out hydrolysis reactions on fresh feathers (mainly containing keratin) with hundreds of different parameter combinations. Each combination will produce peptides with different sequences and lengths. Then, functional peptides suitable for crops and playing different health roles are screened out, and peptides with systematic regulation of crop health functions are analyzed to develop a feather keratin hydrolysate peptide solution by thermodynamic hydrolysis (abbreviated as KHP).

[0007] Therefore, the present invention first discovers that by applying the feather keratin hydrolysate peptide solution (KHP) to cucumbers by root irrigation or leaf spraying, the photosynthesis ability and productivity of cucumber leaves can be improved, the yield of marketable fruits can be increased, the number of aborted fruits can be reduced, and the fruit hardness and water content can be increased. Summary of the Invention

[0008] One aspect of the present invention relates to a method for improving the yield and quality of cucumber fruits by using a feather keratin hydrolysate peptide solution (KHP), which includes applying the feather keratin hydrolysate peptide solution (KHP) obtained by thermodynamic hydrolysis to cucumber seedlings after sowing and germination. In a specific embodiment of the present invention, the feather keratin hydrolysate peptide solution (KHP) is sprayed and applied to cucumber seedlings at a dilution multiple of 100-1000 (preferably 300-500).

[0009] In some specific embodiments of the present invention, the feather keratin hydrolyzed peptide solution (KHP) is obtained by a hydrolysis reaction using a thermodynamic hydrolysis technique. Under high pressure, liquid water with a temperature not exceeding 200 °C (preferably 150 - 200 °C) is used as the hydrolysis solvent, and the resulting peptide aqueous solution has a peptide concentration ranging from 2.0 x 105 to 4.5 x 105 ppm.

[0010] In some specific embodiments of the present invention, the peptides contained in the feather keratin hydrolyzed peptide solution (KHP) have a molecular weight of 500 - 4,000 Da and contain 5 - 30 amino acids.

[0011] In a specific embodiment of the present invention, the feather keratin hydrolyzed peptide solution (KHP) is used to enhance the photosynthetic capacity of cucumber leaves. In a specific embodiment of the present invention, the feather keratin hydrolyzed peptide solution (KHP) is used to increase the yield of marketable cucumbers. In a specific embodiment of the present invention, the feather keratin hydrolyzed peptide solution (KHP) is used to reduce the number of aborted cucumbers. In a specific embodiment of the present invention, the feather keratin hydrolyzed peptide solution (KHP) is used to increase the fruit hardness and water content of cucumbers. Brief Description of the Drawings

[0012] Figure 1 shows the promotion of chlorophyll content in cucumber leaves by applying the feather keratin hydrolyzed peptide solution (KHP) in Plot A (Figure 1A) and Plot B (Figure 1B). For the terminal leaflets of the seventh leaf counted from the bottom up, a chlorophyll meter (SPAD 502 plus) was used to measure the chlorophyll value, and a total of 20 cucumber leaves (N = 20) were measured. * represents a significant difference: ***p < 0.001.

[0013] Figure 2 shows the effect of applying the feather keratin hydrolyzed peptide solution (KHP) on the growth of cucumber leaves in Plot A (Figure 2A) and Plot B (Figure 2B). For the leaves of the seventh leaf counted from the bottom up, the length of the entire leaf was measured (N = 20). * represents a significant difference: ***p < 0.001.

[0014] Figure 3 shows the effect of applying the feather keratin hydrolyzed peptide solution (KHP) on the yield per plant of cucumbers in Plot A (Figure 3A) and Plot B (Figure 3B). The number of fruits collected from 20 cucumber plants was calculated, excluding fruits less than 15 cm in length, fruits with a curvature greater than 3 cm, and fruits less than 80 g and greater than 170 g to calculate the number of marketable fruits produced per plant.

[0015] Figure 4 shows the effect of applying feather keratin hydrolyzed peptide solution (KHP) in plot B on the number of aborted fruits of cucumbers. In the mid-term of cucumber fruiting, aborted fruits within 25 days were collected, and the number of aborted fruits of cucumber plants was counted.

[0016] Figure 5 shows the effect of applying feather keratin hydrolyzed peptide solution (KHP) in plot A (Figure 5A) and plot B (Figure 5B) on the moisture content of cucumber fruits. Twenty cucumber fruits were selected, and a part of their pulp was weighed for fresh weight. After drying, the dry weight was weighed, and the difference was the moisture content of the fruits. * represents significant difference: ***p < 0.001.

[0017] Figure 6 shows the effect of applying feather keratin hydrolyzed peptide solution (KHP) in plot B on the crispness of cucumber fruits. For the middle 4 cm of the fruit with a cross-sectional area of about 2.5 - 3 cm, placed upright, the breaking force was detected using a flat-ended probe P-100 of a Texture Analyzer (TA.XT Plus, Stable Micro Systems) (N = 20). * represents significant difference: ***p < 0.001. Embodiments

[0018] [Example 1. Preparation and Characterization of Feather Keratin Hydrolyzed Peptide Solution]

[0019] The feather keratin hydrolyzed peptide solution (KHP) of the present invention is obtained from Zhenghan Biotechnology Co., Ltd. (Taiwan). Its manufacturing method mainly includes: using liquid water at a high pressure of 10 - 16 kg / cm2 (not exceeding 200 °C, preferably 150 - 200 °C, i.e., below the critical temperature) as the hydrolysis solvent, and thermodynamically hydrolyzing fresh feathers (with or without adding water, the ratio of fresh feathers to water is 1:0 - 1:15) for 20 - 80 minutes to produce a group of peptides with different amino acid sequences and lengths. After selection, 253 functional peptides with a molecular weight of 500 - 4,000 Da are obtained to form the feather keratin hydrolyzed peptide solution (containing a peptide concentration ranging from 200,000 to 450,000 ppm).

[0020] [Example 2. Photosynthesis Enhancement of Cucumbers by Spraying Feather Keratin Hydrolyzed Peptide Solution on Leaves]

[0021] In this example, cucumber, Green Light (plot A) and Quanfu 212 (plot B) were used as experimental varieties. Starting 2 weeks after sowing, foliar spraying was carried out once a week for a total of four times. The chemicals applied were: CK, the water control group; KHP-1, feather keratin hydrolyzed peptide solution No. 1 (diluted 500 times), and the foliar spraying amount per plant was about 50 ml, N = 20; the test sites were Pitou, Zhanghua, Taiwan (plot A) and Tianwei, Zhanghua, Taiwan (plot B).

[0022] Increase the chlorophyll content of leaves

[0023] Leaves are the sites where crops carry out photosynthesis and store organic substances. The leaf area size and chlorophyll content represent the intensity of photosynthetic ability, so they can be important indicators of crop productivity. The frontlet lobules before the seventh leaf position were taken, and a chlorophyll meter (SPAD 502 plus) was used to measure the chlorophyll value. A total of 20 cucumber leaves were measured (N = 20).

[0024] The results in Figure 1A show that in plot A, when the feather keratin hydrolyzed peptide solution diluted 500 times (KHP-1) was foliarly sprayed, the leaf color of the cucumber plants in the treatment group was significantly darker green than that of the cucumber leaves in the control group that was only sprayed with water. The chlorophyll readings showed that the cucumber in the treatment group was 12.4% higher than that in the water control group. Similar test results were also shown in plot B. After foliarly spraying the feather keratin hydrolyzed peptide solution diluted 500 times (KHP-1), the leaf color of the cucumber leaves in the treatment group was darker green, and its chlorophyll reading was 4% higher than that in the water control group (Figure 1B).

[0025] Promote the increase of leaf area

[0026] The seventh leaf counted from the bottom up was taken, and the length of the whole leaf was measured. 20 leaves were measured for each group (N = 20). The results in Figure 2A show that in plot A, the leaves of the treatment group foliarly sprayed with the feather keratin hydrolyzed peptide solution diluted 500 times (KHP-1) were longer than those of the control group sprayed with water. After calculation, the leaf length of the treatment group could be increased by 6%, indicating that the leaf area of the cucumber plants increased after being treated with KHP. Similar test results were also shown in plot B. After foliarly spraying with the feather keratin hydrolyzed peptide solution diluted 500 times (KHP-1), the leaves were longer than those of the control group sprayed with water. After calculation, the leaf length of the KHP treatment group increased by 8% (Figure 2B), indicating that the leaf area of the cucumber plants increased after being treated with KHP.

[0027] The above results show that foliar spraying of the feather keratin hydrolyzed peptide solution of the present invention can increase the leaf area and chlorophyll content of cucumber plants, thereby enhancing the photosynthesis ability and crop productivity of cucumber plants.

[0028] [Example 3. Irrigation application of feather keratin hydrolyzed peptide solution (KHP) to increase cucumber fruit yield]

[0029] In this example, flower cucumbers, Green Light (Plot A) and Quanfu 212 (Plot B) were used as experimental varieties. Starting 2 weeks after sowing, foliar spraying was carried out once a week for a total of four times. The applied agents were: CK, water control group; KHP-1, feather keratin hydrolyzed peptide solution No. 1 (diluted 500 times), and the spraying amount per plant was about 50 ml, N = 20; Test sites: Pitou, Changhua, Taiwan (Plot A) and Tianwei, Changhua, Taiwan (Plot B).

[0030] Increase the number of marketable fruits

[0031] Calculate the total number of 20 cucumber plants and obtain the average per plant. Remove fruits less than 15 cm and fruits with a curvature greater than 3 cm, and remove fruits less than 80 g and greater than 170 g to obtain the number of marketable fruits per plant.

[0032] The results in Figure 3A show that the number of marketable fruits per plant of cucumbers treated by foliar spraying with the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times is significantly more than that of the water control group. Similar test results were also shown in Plot B. For cucumbers treated by foliar spraying with the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times, the number of marketable fruits per plant is more than that of the water control group (Figure 3B).

[0033] Reduce the number of aborted fruits of cucumbers

[0034] Aborted fruits are those in which the flowers have not fallen, the residual flowers of the young fruits have not withered, and the fruits begin to turn yellow, stop growing, and become shriveled. In this example, in Plot A, in the middle stage of the result period, two days (August 11, 2022 and August 17, 2022, with a six-day interval) were selected, and the aborted fruits of 48 plants in each treatment group were collected and counted. In Plot B, within 25 days in the middle stage of the result period, the aborted fruits of 48 plants were collected and counted.

[0035] The results in Table 2 show that after foliar spraying with the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times in Plot A, the number of aborted fruits of cucumber plants is less than that of the control group treated with water. Similar test results were also shown in Plot B. For cucumber plants treated with foliar spraying of the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times, the number of aborted fruits is less than that of the control group treated with water (the results are shown in Figure 4).

[0036] The above results indicate that foliar spraying with the feather keratin hydrolyzed peptide solution of the present invention can reduce the number of aborted fruits of cucumber plants, increase the number of marketable fruits, and improve the fruit yield of cucumbers.

[0037] [Example 4. Improving the Fruit Quality of Cucumbers by Irrigation with Feather Keratin Hydrolyzed Peptide Solution (KHP)]

[0038] In this example, the experimental varieties were flower cucumbers, Green Light (Plot A) and Quanfu 212 (Plot B). Starting 2 weeks after sowing, foliar spraying was carried out once a week for a total of four times. The applied agents were: CK, the water control group; KHP-1, the feather keratin hydrolyzed peptide solution No. 1 (diluted 500 times), and the spraying amount per plant was about 50 ml, N = 20; the test sites were Pitou, Zhanghua, Taiwan (Plot A) and Tianwei, Zhanghua, Taiwan (Plot B).

[0039] Improving the Water Content of Fruits

[0040] Twenty cucumbers were taken. The fresh weight of part of the pulp was weighed, dried, and then the dry weight was weighed. The difference was the fruit water content. The results in Figures 5A - 5B show that the water content of cucumbers treated with foliar spraying of the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times is significantly higher than that of cucumbers in the water control group.

[0041] Improving the Crispness of Cucumbers

[0042] The breaking strength of the fruit can be regarded as the crispness in taste. Take a 4-cm middle section of the fruit, with a cross-sectional area of approximately 2.5 - 3 cm², place it upright, and use a texture analyzer (Texture Analyzer.TA.XT Plus, Stable Micro Systems) with a flat-end probe P-100 to detect the breaking force. Measure 20 fruits in each group, N = 20. The results in Figure 6 show that after foliar spraying with the feather keratin hydrolyzed peptide solution (KHP-1) diluted 500 times in Field B, the breaking strength can be improved.

[0043] Based on the above results, foliar spraying with the feather keratin hydrolyzed peptide solution (KHP) of the present invention can increase the leaf size and leaf color, promote photosynthesis, effectively reduce the number of aborted fruits, increase the number of marketable fruits, and thus increase the fruit yield of cucumbers; in terms of improving fruit quality, it can increase the water content, hardness, and crispness of the fruits, showing good effects.

Claims

1. A method for improving the yield and quality of cucumber fruits using feather keratin hydrolyzed peptide solution (KHP), comprising applying a feather keratin hydrolyzed peptide solution (KHP) obtained through thermodynamic hydrolysis to cucumber plants, wherein the feather keratin hydrolyzed peptide solution (KHP) is obtained by using thermodynamic hydrolysis technology to hydrolyze fresh feathers (in a ratio of 1:0 to 1:1.5 with water) under high pressure of 10-16 kg / cm2, using liquid water at a temperature of 185-200℃ as the hydrolysis solvent, for 20-80 minutes to obtain an aqueous peptide solution; wherein the peptides contained in the feather keratin hydrolyzed peptide solution (KHP) have a molecular weight of 500-4,000 Da, contain 5-30 amino acids, and have a peptide concentration between 200,000 and 450,000 ppm.

2. The method as described in claim 1, wherein the feather keratin hydrolysate (KHP) is sprayed onto the cucumber plant at a dilution ratio of 100 to 1000.

3. The method as described in claim 2, wherein the feather keratin hydrolysate (KHP) is sprayed onto the cucumber leaf surface at a dilution ratio of 300 to 500.

4. The method as described in claim 1, wherein the feather keratin hydrolysate (KHP) is used to enhance the photosynthetic capacity of the leaves of cucumber plants.

5. The method as described in claim 1, wherein the feather keratin hydrolysate (KHP) is used to increase the commercial yield of cucumbers.

6. The method as described in claim 1, wherein the feather keratin hydrolysate (KHP) is used to reduce the number of aborted cucumber fruits.

7. The method as described in claim 1, wherein the feather keratin hydrolysate (KHP) is used to improve the crispness and water content of cucumber fruit.

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