OYSTER PEPTIDE CAPABLE OF ENHANCING SEXUAL FUNCTION, AND PREPARATION METHOD AND APPLICATION THEREOF
20170362629 · 2017-12-21
Assignee
Inventors
- Xiaochun XIAO (Jiangmen, Guangdong, CN)
- Xufeng ZHAI (Jiangmen, Guangdong, CN)
- Xiaolei GUO (Jiangmen, Guangdong, CN)
- Yongjun LOU (Jiangmen, Guangdong, CN)
- Chung Wah MA (Jiangmen, Guangdong, CN)
Cpc classification
C12P21/06
CHEMISTRY; METALLURGY
International classification
Abstract
An oyster peptide capable of enhancing a sexual function, and a preparation method and application thereof are provided. In the method, oyster meat is pre-treated by using calcium salt before enzymatic hydrolysis, so as to activate and release endogenous enzymes of oysters, such that enzymatic preparations consumed in subsequent enzymatic hydrolysis can be reduced.
Claims
1. A method for preparing a sexual function-improving oyster peptide, comprising: 1) grinding oyster flesh, calcium salt and water to obtain oyster flesh pulp; 2) enzymatic hydrolyzing oyster flesh pulp, centrifuging and collecting the supernatant to obtain an oyster enzyme-hydrolyzed raw solution; 3) decoloring the oyster enzyme-hydrolyzed raw solution and removing impurities to obtain a fine oyster peptide solution; and 4) concentrating and spay drying the fine oyster peptide solution to obtain the oyster peptide.
2. The method according to claim 1, wherein the calcium salt is food grade calcium chloride, calcium lactate, calcium carbonate, calcium hydrogen phosphate or calcium citrate.
3. The method according to claim 1, wherein the amount of the calcium salt in step 1) is 0.1%˜0.3% of the oyster flesh mass.
4. The method according to claim 1, wherein the step 2) comprises: enzymatic hydrolyzing the oyster flesh pulp by neutral proteases or alkaline proteases; adding flavourzyme for further hydrolyzation; inactivating enzymes after enzymatic hydrolyzation; and centrifuging and collecting the supernatant to obtain an oyster enzyme-hydrolyzed raw solution.
5. The method according to claim 4, wherein the step 2) comprises: stirring the oyster flesh pulp at 35° C.˜45° C. for 1 h˜2 h; adding neutral protease or alkaline protease; adjusting the pH and heat to 50° C.˜60° C. to continue hydrolysis for 5 h˜8 h; adjusting the pH to 5.0 to 5.5 and adding flavourzyme to continue hydrolysis at 50° C.˜60° C.; inactivating the enzymes 2 h—3 h after the hydrolysis; and centrifuging and collecting the supernatant to obtain an oyster enzyme-hydrolyzed raw solution.
6. The method according to claim 4, wherein the neutral protease is one or more of papain, bromelain, animal proteolytic enzyme and complex protease Protamex; the alkaline protease is one or more of Alcalase alkaline protease, FoodPro Alkaline Protease alkaline protease and trypsin.
7. The method according to claim 4, wherein the amount of the neutral protease or the alkaline protease is 0.3‰˜0.8‰ of the oyster flesh pulp mass.
8. The method according to claim 4, wherein the amount of the flavourzyme is 0.5‰˜1.0‰ of the oyster flesh pulp mass.
9. An oyster peptide prepared by the method according to claim 1.
10. A method for improving sexual function and/or antioxidant in a subject in need thereof comprising administering to the subject the oyster peptide according to claim 9.
Description
DETAILED DESCRIPTION
[0027] The present invention provides a preparation method for sexual function-improving oyster peptide. One of ordinary skill in the art can use this disclosure for reference and improve the technological parameter to reach the same result. In particular, all similar replacements and changes are obvious for those skilled in the art, so they will be considered within the scope of the present invention. The method and use of the oyster peptide have been described in preferred embodiment. It is apparent that others can use the technology in the present invention through reasonable changes, modifications and combinations within the scope of the present invention.
[0028] In the embodiments, the method of detecting the antioxidant activity (reducing capacity, DPPH IC.sub.50) of oyster peptide in vitro and the method for enhancing sexual function of adult male mice are described in the following steps.
[0029] 1. Reducing capacity of the samples was measured at 700 nm using a potassium ferricyanide reduction system. The prepared sample was diluted at a gradient protein concentration; 2 ml of the sample solution was added to the test tube and mixed with 2 ml 0.2 ml/L phosphate buffer (PBS, pH 6.6) and 2 ml 1% (m/V) potassium ferricyanide; mixed evenly in the 50° C. constant temperature water bath for 20 min; 2 ml 10% TCA was added and mixed thoroughly. 2 ml supernatant was taken from the test tube, 2 ml distilled water and 0.4 ml 0.1% FeCl3 solution were added, mixed well and stood for 10 min, absorbance at a wavelength of 700 nm was measured. Each sample was operated in the same manner as described above and measured three times in parallel (reducing capacity IC.sub.50 value is the protein concentration (mg/ml) when A700 nm=0.5).
[0030] 2. Adult male mice (weight 18˜22g) were randomly divided into blank control group, sample group and comparative sample group. Each group has 12 mice. All mice were treated for 28 days continuously.
[0031] 48 hours before the experiment, female rats were injected subcutaneously with estradiol benzoate (0.02 mg/mouse) to reach the same estrum. The test was carried out at 7 to 11 pm. After 30 min of the last administration, male mice were placed in the cage for 5 min to suit the environment. Then, one female was added to each cage. The following indexes were recorded:
[0032] 1) interval time between the female mouse was put into the cage and the male tried to capture the female (capture latency);
[0033] 2) within 20 min, the times male mouse caught the female or climbed the back of the female (number of capture);
[0034] 3) within 20 min, the number of licking penis after male mouse caught the female or climbed the back of the female (ejaculation times);
[0035] 4) interval time between climbing back and licking penis of male mouse (ejaculation latency).
[0036] 5) percentage of capture and ejaculation within 20 min:
[0037] Capture percentage=mouse who has capture behavior/total mice
[0038] Ejaculation percentage=mouse who has ejaculation behavior/total mice
[0039] Data analysis: experimental data were analyzed by SPSS19.0 software. The experimental data of each group were expressed by mean value. If the variance homogeneity condition of each group was satisfied, one-way ANOVA was used to compare the variance. If not, the comparison between the groups was analyzed by Welch method, and the difference was significant with p<0.05.
[0040] The method for preparing the sexual function-improving oyster peptide in the present invention is further described below.
EXAMPLE 1
Method for Preparing the Oyster Peptide
[0041] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium chloride (0.1% of the flesh mass) and water (same amount as the flesh) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0042] 2) Oyster flesh pulp was stirred at 45° C. for 1 h. After adding papain at a amount of 0.3‰ of the oyster flesh pulp, the pH of the system was adjusted to 6.5; hydrolysis was carried out at 55° C. for 6 hours; then the pH of the system was adjusted to 5.5 by using 0.1 mol/L HCl solution; flavourzyme (1.0‰ of the flesh mass) was added and hydrolysis was carried out for 2 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0043] 3) Activated carbon (0.6% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 50° C. for 1 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0044] 4) The fine oyster peptide solution was concentrated to a solution containing more than 35% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 1.
EXAMPLE 2
Method for Preparing the Oyster Peptide
[0045] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium lactate (0.3% of the flesh mass) and water (half amount as the flesh) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0046] 2) Oyster flesh pulp was stirred at 35° C. for 2 h. After adding Alcalase at a amount of 0.8‰ of the oyster flesh pulp, the pH of the system was adjusted to 8.0; hydrolysis was carried out at 60° C. for 5 hours; then the pH of the system was adjusted to 5.0 by using 0.1 mol/L HCl solution; flavourzyme (0.7‰ of the flesh mass) was added and hydrolysis was carried out for 2.5 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0047] 3) Activated carbon (0.3% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.5 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0048] 4) The fine oyster peptide solution was concentrated to a solution containing more than 45% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 2.
EXAMPLE 3
Method for Preparing the Oyster Peptide
[0049] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0050] 2) Oyster flesh pulp was stirred at 40° C. for 1.5 h. After adding papain at a amount of 0.6‰ of the oyster flesh pulp, the pH of the system was adjusted to 7.0; hydrolysis was carried out at 50° C. for 8 hours; then the pH of the system was adjusted to 5.3 by using 0.1 mol/L HCl solution; flavourzyme (0.5‰ of the flesh mass) was added and hydrolysis was carried out for 3 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0051] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0052] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 3.
EXAMPLE 4
Method for Preparing the Oyster Peptide
[0053] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0054] 2) Oyster flesh pulp was stirred at 40° C. for 1 h. After adding bromelain at a amount of 0.4‰ of the oyster flesh pulp, the pH of the system was adjusted to 6.0; hydrolysis was carried out at 52° C. for 7 hours; then the pH of the system was adjusted to 5.1 by using 0.1 mol/L HCl solution; flavourzyme (0.9‰ of the flesh mass) was added and hydrolysis was carried out for 2 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0055] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0056] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 4.
EXAMPLE 5
Method for Preparing the Oyster Peptide
[0057] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0058] 2) Oyster flesh pulp was stirred at 35° C. for 2 h. After adding animal proteolytic enzyme at a amount of 0.5‰ of the oyster flesh pulp, the pH of the system was adjusted to 6.5; hydrolysis was carried out at 50° C. for 8 hours; then the pH of the system was adjusted to 5.2 by using 0.1 mol/L HCl solution; flavourzyme (0.8‰ of the flesh mass) was added and hydrolysis was carried out for 2.5 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0059] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0060] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 5.
EXAMPLE 6
Method for Preparing the Oyster Peptide
[0061] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0062] 2) Oyster flesh pulp was stirred at 45° C. for 1 h. After adding complex protease Protamex at a amount of 0.7‰ of the oyster flesh pulp, the pH of the system was adjusted to 7.0; hydrolysis was carried out at 57° C. for 6 hours; then the pH of the system was adjusted to 5.4 by using 0.1 mol/L HCl solution; flavourzyme (0.5‰ of the flesh mass) was added and hydrolysis was carried out for 3 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0063] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0064] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 6.
EXAMPLE 7
Method for Preparing the Oyster Peptide
[0065] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0066] 2) Oyster flesh pulp was stirred at 38° C. for 1.5 h. After adding trypsin at a amount of 0.5‰ of the oyster flesh pulp, the pH of the system was adjusted to 8.5; hydrolysis was carried out at 55° C. for 7 hours; then the pH of the system was adjusted to 5.5 by using 0.1 mol/L HCl solution; flavourzyme (0.6‰ of the flesh mass) was added and hydrolysis was carried out for 2 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0067] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0068] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 7.
EXAMPLE 8
Method for Preparing the Oyster Peptide
[0069] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium citrate (0.2% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0070] 2) Oyster flesh pulp was stirred at 42° C. for 2 h. After adding FoodPro Alkaline Protease at a amount of 0.3‰ of the oyster flesh pulp, the pH of the system was adjusted to 7.5; hydrolysis was carried out at 53° C. for 6 hours; then the pH of the system was adjusted to 5.3 by using 0.1 mol/L HCl solution; flavourzyme (0.5‰ of the flesh mass) was added and hydrolysis was carried out for 2.5 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0071] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0072] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide sample 8.
COMPARATIVE EXAMPLE 1
Method for Preparing the Comparative Oyster Peptide
[0073] 1) The oysters were shelled; the flesh was cleaned and minced. Water was added at the same amount as the flesh to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0074] 2) After adding papain (1.0‰ of the flesh mass) and flavourzyme (1.0% of the flesh mass) to the oyster flesh pulp, the pH of the system was adjusted to 6.5; hydrolysis was carried out at 55° C. for 8 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was an oyster enzyme-hydrolyzed raw solution.
[0075] 3) Activated carbon (0.6% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 50° C. for 1 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0076] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide comparative sample 1.
COMPARATIVE EXAMPLE 2
Method for Preparing the Comparative Oyster Peptide
[0077] 1) The oysters were shelled; the flesh was cleaned and minced. Calcium chloride (0.1% of the flesh mass) and water (80% of the flesh mass) were added to the oyster flesh and passed colloidal mill to get oyster flesh pulp.
[0078] 2) Oyster flesh pulp was stirred at 40° C. for 1.5 h. After adding Alcalase (1‰ of the flesh mass) and flavourzyme (1‰ of the flesh mass) to the oyster flesh pulp, the pH of the system was adjusted to 8.0; hydrolysis was carried out at 50° C. for 11 hours; enzymes were inactivated by heating at 95° C. for 15 min; finally, centrifuged and collected the supernatant. This was the oyster enzyme-hydrolyzed raw solution.
[0079] 3) Activated carbon (0.5% of the solution mass) was added to oyster enzyme-hydrolyzed raw solution; stirred at 55° C. for 0.7 hour; filtered the mixture. The filtered solution was a fine oyster peptide solution.
[0080] 4) The fine oyster peptide solution was concentrated to a solution containing more than 40% of the solid and spray dried by vacuum concentration method to obtain the oyster peptide comparative sample 2.
EXAMPLE 9
Recovery Rate of Enzymatic Protein and Antioxidant Activity in Vitro of Different Peptide Samples
[0081] Test samples: oyster peptides from examples 1 to 3, comparative samples from comparative examples 1 and 2.
[0082] Results were shown in table 1.
TABLE-US-00001 TABLE 1 Recovery Rate of Enzymatic Protein and Antioxidant Activity in Vitro of Different Peptide Samples Protein Recovery Reducing DPPH IC.sub.50 Samples Rate (%) Capacity* mg/ml Oyster Peptide 1 79.95 0.52 3.12 Oyster Peptide 2 82.41 0.56 3.64 Oyster Peptide 3 80.43 0.51 3.05 Comparative Sample 1 71.24 0.40 5.61 Comparative Sample 2 83.01 0.38 4.99 *The absorbance at A700nm when the solid matter concentration in the sample is 1 mg/ml.
[0083] From the data analysis of Table 1, it can be seen that the method for hydrolysis of oyster flesh in the present invention resulted in a high protein recovery rate (79.95-82.41%), while in comparative example 1, even a larger amount of enzyme was added, the protein recovery rate was only 71.24%. This was mainly due to the fact that the method in the present invention activates the endogenous enzyme of the oyster flesh by adding the enzyme activator (calcium salt); hydrolysis is carried out at the optimum temperature of the endogenous enzyme (35° C.˜45° C.) for a period of time to promote the self-dissolving of oyster flesh, thus reducing the usage amount of commercial enzymes but still get better hydrolysis efficiency. Protein recovery rate in comparative example 2 was also as high as 83.01%, verifying the importance of endogenous enzymes in hydrolysis.
[0084] At the same time, the in vitro antioxidant values (reducing capacity and DDPH clearance rate) of the oyster peptide prepared by the method of the present invention were superior to those of the comparative examples. The higher reducing capacity and lower DPPH IC.sub.50 value of oyster peptide samples are mainly due to the specific enzyme combinations and two-step enzymatic hydrolysis, which are more conducive to the release of antioxidant activity.
[0085] Although comparative example 2 has a pretty high protein recovery rate, its in vitro antioxidant value (reducing capacity and DPPH) was low, whereby it was demonstrated that the enzyme combination of the present invention was an optimum enzyme combination for hydrolyzing oysters to obtain ingredients having antioxidant activity.
[0086] According to the methods in embodiments, tests were carried out on samples 4 to 8. Results showed that the protein recovery rate of samples 4 to 8 was about 82%, significantly higher than comparative sample 1 but not obviously different with comparative sample 2. The reducing capacity of samples 4 to 8 was about 0.55, higher than comparative samples 1 and 2; DDPH clearance rate of samples 4 to 8 was less than 3.5mg/ml, even lower in comparative sample 1 and 2. Taken together, the oyster peptide sample provided by the present invention has a higher reducing capacity and a lower DPPH IC.sub.50 value while having a higher protein recovery rate, compared to comparative samples.
EXAMPLE 10
Effect on Male Mice Mating Ability of Different Oyster Peptide Samples
[0087] Test samples: oyster peptide from examples 1 to 3, comparative samples from comparative examples 1 and 2.
[0088] Results were shown in table 2 and 3.
TABLE-US-00002 TABLE 2 Effect on Male Mice Mating Ability of Different Oyster Peptide Samples (
TABLE-US-00003 TABLE 3 Effect on Male Mice Mating Ability of Different Oyster Peptide Samples (
[0089] Data analysis from table 2 and table 3 showed that: compared with the blank control group, oyster peptide samples (oyster peptide samples 1, 2, 3) have significant improvement (p<0.01) in the number of capture and ejaculation; the oyster peptide samples (oyster peptide samples 1, 2, 3) have significant difference (p<0.01) at capture latency and ejaculation latency compared with the blank control group and significant increase in capture rate and ejaculation rate.
[0090] Compared with comparative samples (comparative samples 1 and 2), mice administrated the oyster samples (oyster peptide samples 1, 2, 3) have a significantly higher (p<0.01) number of capture and ejaculation and a higher capture rate and ejaculation rate.
[0091] According to the methods in embodiments, tests were carried out on samples 4 to 8. Results showed that, compared to blank control group and comparative samples, samples 4 to 8 have a significant improvement (p<0.01) in the number of capture and ejaculation; a significant increase (p<0.01) in the capture rate and ejaculation rate; a obvious difference (p<0.01) on the interval time of capture latency and ejaculation latency.
[0092] At present, although the literature has not directly proved that antioxidant and sexual function has a direct relationship, the present invention found that there is a certain correlation between these two, that is, the oyster peptide samples prepared by the present invention have a good anti-oxidation effect in vitro and also a good effect on the improvement of mice sexual function.