Screening of antioxidant and tyrosinase inhibition activities of spicy vegetables in Vietnam and application of Persicaria odorata leaf extract to preservative white leg shrimp (Litopenaus vannamei)

Abstract

In this study, we aimed to exploit natural extracts from the spicy vegetables, which are rich in phenolic compounds as an initial treatment step in the cold storage process for shrimp. Firstly, 40 extracts from 10 types of spicy vegetables in Vietnam were prepared and tested for their bioactivities. Among samples, the extract from Persicaria Odorata leaves (E-4) exhibited the highest potential of scavenging DPPH free radical (IC₅₀ of 7.54 µg.mL^-1) and decreasing tyrosinase activity with the inhibition percentage of 54.2 % at the concentration of 100 mg/mL. Twenty-two out of a total of 36 chemical compounds in the E-4 extract identified using HPLC-MS technique were phenolic compounds, in which four compounds (morin, quercetin, fisetin, astragalin) are flavonoids. Shrimp (Litopenaus vannamei) samples were treated with the E-4 extract having lower gray values, lipid peroxidation values, and microbiological counts than those of the control samples after 7 days of storage at 2 ^oC. These results show the potential of using the natural extract as a safe and effective alternative for commercial chemical-derived preservatives in the shrimp storage process.

Key words
Antioxidant activity; tyrosinase inhibition activity; Litopenaus vannamei; Persicaria odorata; spice vegetables

MATERIALS AND METHODS

Materials

Vegetables were purchased at the supermarkets in July 2017. Then, only leaves were collected, dried to a moisture content of about 10% and ground into fine powder using a blender. The voucher samples (number sample on Table I) were preserved at the department of food technology of the Ho Chi Minh City University of technology and education.

Table I
List of 40 extracts prepared from 10 spicy vegetables and their biological activities.

No.	Local name	Scientific name	Name Sample	DPPH assay (IC50)	TPC (mgGAE/g)	Tyrosinase Inhibition Activity (I%)
1	Húng lủi	Mentha Crispa L.	W-1	38.24	130.9 ± 2.5	45.1 ± 1.0
2			WWC-1	49.89	114.8 ± 1.9	52.6 ± 2.2
3			E-1	46.92	94.5 ± 2.8	42.9 ± 1.3
4			EWC-1	41.51	65.8 ± 2.8	40.4 ± 1.2
5	Rau ôm	Limnophila Aromatica	W-2	51.92	75.6 ± 2.3	36.2 ± 1.9
6			WWC -2	71.3	64.2 ± 2.4	37.3 ± 1.5
7			E-2	62.05	66.5 ± 2.0	33.5 ± 1.7
8			EWC -2	46.91	53.0 ± 2.3	11.9 ± 1.8
9	Húng cay	Ocimum Africanum Lour	W-3	65.91	52.3 ± 3.3	44.8 ± 2.1
10			WWC -3	71.92	132.3 ± 3.3	43.8 ± 2.0
11			E-3	65.62	51.8 ± 1.8	33.5 ± 2.6
12			EWC -3	30.44	80.2 ± 2.1	41.7 ± 2.4
13	Rau răm	Persicaria Odorata	W-4	8.36	143.9 ± 1.9	49.62 ± 0.77
14			WWC -4	9.15	143.6 ± 1.3	41.5 ± 1.9
15			E-4	7.54	155.9 ± 0.8	54.2 ± 2.9
16			EWC -4	7.85	133.8 ± 1.5	40.9 ± 1.6
17	Ngãi cứu	Artemisia Vulgaris	W-5	8.43	103.4 ± 2.4	35.7 ± 0.5
18			WWC -5	9.65	135.6 ± 2.5	34.5 ± 2.2
19			E-5	9.06	98.6 ± 2.3	32.02 ± 0.98
20			EWC -5	9.22	124.8 ± 2.4	17.02 ± 0.73
21	Diếp cá	Houttuynia Cordata	W-6	8.24	105.1 ± 2.3	50.0 ± 4.7
22			WWC -6	9.42	225.4 ± 1.9	42.2 ± 0.5
23			E-6	8.02	43.3 ± 1.0	38.9 ± 4.4
24			EWC -6	9.06	177.6 ± 2.2	34.2 ± 3.5
25	Húng quế	Ocimum Basilicum	W-7	64.78	45.9± 1.5	44.9 ± 2.4
26			WWC -7	>100	58.8 ± 2.2	37.52 ± 0.47
27			E-7	>100	31.8 ± 1.8	40.2 ± 2.8
28			EWC -7	58.08	56.9 ± 1.1	42.2 ± 0.9
29	Tía tô	Perilla Frutescens	W-8	43.8	89.4 ± 1.3	33.7 ± 3.4
30			WWC -8	43.51	66.8 ± 0.7	37.2 ± 3.7
31			E-8	56.17	62.5 ± 1.1	31.0 ± 2.2
32			EWC -8	22.65	65.8 ± 1.8	30.8 ± 1.8
33	Kinh giới	Elsholtzia Cristata	W-9	53.62	56.77 ± 1.3	38.0 ± 2.5
34			WWC -9	78.5	67.5 ± 4.8	39.3 ± 2.6
35			E-9	60.2	39.1± 1.4	31.8 ± 1.9
36			EWC -9	81.84	51.7 ± 1.3	28.6 ± 0.43
37	Ngò gai	Eryngium Foetidum	W-10	87.4	24.1 ± 1.0	37.2 ± 1.4
38			WWC -10	94.41	35.8 ± 1.3	32.2 ± 2.0
39			E-10	>100	24.4 ± 1.2	34.4 ± 3.9
40			EWC -10	>100	22.6 ± 0.9	24.6 ± 2.6

• Results presented as the mean ± SD (n=3).

White leg shrimps (L. vannamei) with the size of 30-40 shrimps/kg were purchased from Thu Duc market, Ho Chi Minh City, Vietnam, in March 2018. The shrimps were kept alive and transported to the laboratory.

Extraction procedure

Forty extracts consist of ethanol (E) and ethanol without chlorophyll (EWC) extracts, water (W), and water without chlorophyll extracts (WWC) were prepared from ten vegetable leaves (Table I). Dry powders (20-30 g) were extracted with ethanol solvent (100 mL, 65^oC) or water (100 mL, 80^oC) by the Soxhlet system. Then, the extract solutions were evaporated under reduced pressure conditions (20 hPa, 50^oC) to dry and recover the ethanol and water extracts. Similarity, EWC, and WWC were prepared after removing chlorophyll by acetone solvent (100 mL, 60-65^oC).

DPPH free radical scavenging activity

The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical was used for screening on antioxidant activity of the extracts (Molyneux 2004). Briefly, 1.5 mL of a 0.1 mM solution of DPPH was mixed with 1.5 mL of each extract solution at concentrations of 100, 50, 25, 10 μg.mL^-1 in 90 vv% ethanol. After 30 min incubation in the dark, the decrease in the solution absorbance was measured at 519 nm using Hitachi UH-530 spectrophotometer. DPPH inhibitory activity expressed as the percentage inhibition (I%) of DPPH in the above assay system, calculated as (1-B/A)×100, where A and B are the absorbance of the DPPH solution without and with the test material. IC₅₀ (inhibitory concentration, 50%) values were calculated from the mean values of data from three determinations. Gallic acid at various concentrations (1, 2.5, 5, and 10 μM) was used as a positive control.

Tyrosinase inhibition activity

The inhibitory effects of extract samples on tyrosinase inhibition activity were evaluated following the procedure of Nirmal with a slight modification by using a 96-well reader (Nirmal & Benjakul 2011). Initially, 40 µL of extract solutions (100 µg.mL^-1) were mixed with 20 µL of tyrosinase (100 U/mL). This reaction mixture was incubated for 30 min at room temperature. 140 µL of 0.714 mM L-DOPA (45^oC) was added to initiate the reaction. The reaction was conducted at 45^oC, and the absorbance at 475 nm was monitored after three min. The control was performed in the same way, except phosphate buffer (50 mM, pH 6.8) was used instead of tyrosinase. Tyrosinase inhibitory activity was the percentage inhibition (I%) and IC₅₀ value in a similar formula to DPPH assay. Kojic acid at various concentrations (1, 2.5, 5, and 10 μM) was used as a positive control.

Determination of total phenolic content

The total phenolic content (TPC) of extracts was determined using Folin-Ciocalteu reagent (Jung et al. 2008). Firstly, gallic acid solutions or extract samples were added and mixed with the reagent solution (1:5 v/v) within 5 minutes. Then, a 1.0 M solution of sodium carbonate was added to the above mixture. After 30 min of incubation in the dark at room temperature, the mixture turns to blue, whose absorbance was measured at 750 nm using Hitachi UH-530 spectrophotometer. The content of phenolics in the samples was calculated from the calibration plot of gallic acid and expressed as mg gallic acid equivalent per gram of extract (mgGAE/g). All the determinations were carried out three times.

HPLC-EIS-MS analysis

HPLC-EIS-MS technique was performed to separate and elucidate compositions in the ethanolic extract. The separation module consisted of Agilent 1200 series HPLC (USA) equipped with ESI-MS system (micrOTOF-QII Bruker Daltonic, Germany). The sample was eluted on a column ACE3- C₁₈ (4.6 150 mm, 3.5 µm, Merck, Germany) with a gradient system consisting of solvent A (0.1vv% formic acid in water) and solvent B (0.1vv% formic acid in methanol) used as the mobile phase, with a flow rate of 0.5 mL/min. The temperature of the column was maintained at 40 ^oC, and the injection volume 20 µL. For ESI-MS, full scan mass spectra were measured between m/z 150 and 2000. High purity nitrogen was used as nebulizer gas at 1.2 bar, 200 °C and at a flow rate of 0.8 mL/min.

Preservation for shrimp

The shrimp samples were immersed in 0.025 wv% extract solution, 1.25wv% SMS solution, and water (control sample) at the room temperature (32 ± 2^oC) for 5 minutes. Then, shrimps were taken out and preserved in plastic boxes at 2⁰C. Three shrimps from each treatment were tested for determining pH, melanosis development, bacterial count, lipid peroxidation inhibition assay, and microbiological analysis after 7 days of storage.

PH measurement

pH measurement was performed following the previous study with some modifications (Lopez et al. 2007). Homogenizing shrimp meat (2g) with ten volumes of deionized water for 1 min and the homogenate was kept at room temperature for 5 min. The pH values in shrimp were determined using a pH-meter (PSI pH 1200, England). All experiments were carried out in triplicate.

Melanosis evaluation

The shrimps were taken photographs using a Canon Eos M10 Kit Ef-M15-45 (Japan). Relative changes in the black spot (gray value) of the carapace at the tail, body, and head were evaluated using the following formula: % relative change =100−[(A×100)/B], where A is the actual gray value of the shrimp sample and B is the average gray value of the shrimps in the first day (Encarnacion et al. 2012). The change of gray value in images was analyzed using ImageJ software. The decrease of the % relative change corresponds to the blackening or the increase of melanosis in the carapace area of shrimp during storage. Three shrimps used for one treatment.

Lipid peroxidation inhibition assay

Thiobarbituric acid (TBA) reacts with malonaldehyde bis (dimethyl acetal) (MDA) to form a red di-adduct, which can be detected at 532 nm by spectrophotometer (Hitachi UH-530, Japan) (Singh & Arora 2007). Shrimps were ground and mixed with 10 mL of 7.5 wv% trichloroacetic acid. The mixture was filtered to collect the filtrate. Subsequently, the filtrate was mixed with 0.02 M TBA solution equal volume rate and heated at 100^oC for 15 min. Absorbance was measured at 532 nm by Hitachi UH-530 spectrophotometer. MDA content was calculated from the standard curve built at concentrations from 0.01 to 0.05 mM and reported as mgMAD/kg of shrimp.

Microbiological analysis

Enterobacteriaceae and Pseudomonas aeruginosa in shrimp samples after five days preserving at 2 ^oC were detected and determined based on bacterial count method following TCVN 5518-2:2007 (ISO 21528-2:2004) and 3347/2001/QĐ-BYT at HCM Institute Pasteur.

Statistical analysis

Results were calculated to the analysis of variance (ANOVA) whereas the Tukey’s test (p < 0.05) was applied from three determinations. Statistical calculations were carried out by SPSS 15.0 for Windows Evaluation Version (IBM Corporation, Armonk, North Castle, New York, USA).

RESULTS AND DISCUSSION

Assessment of the antioxidant and tyrosinase inhibition activities

The results of DPPH and tyrosinase assay were showed briefly in Table I. Generally, E and EWC extracts had higher IC₅₀ values than W and WWC extract. For DPPH assay, in total 40 extracts, nine samples showed IC₅₀ values from 25 to 50 µg.mL^-1, fifteen extracts with IC₅₀ values from 50 to 100 µg.mL^-1, four extracts with IC₅₀ values more than 100 µg.mL^-1, and twelve samples exhibited strong antioxidant activities with IC₅₀ values below 10 µg.mL^-1. Notably, twelve extracts that showed vigorous antioxidant activities prepared from three spice vegetables, including Persicaria Odorata, Artemisia Vulgaris, Houttuynia Cordata. Among them, E-4 extracted from P. Odorata exhibited the most potent antioxidant activity with the lowest IC₅₀ value (7.54 µg.mL^-1). IC₅₀ value of gallic acid was 4.66 µM (0.79 µg.mL^-1). The ability to quench DPPH radical of extracts can be explained due to their hydrogen donating capacity and the number of phenolic compounds present in extracts.

For tyrosinase inhibition activities of 40 ethanol extracts at concentration of 100 mg/mL, thirteen extracts showed percentage inhibition (I%) at from 40 to 50%, twenty extracts with I% from 30 to 40%, and four extracts had I% less than 30%. Three extracts (WWC-1, E-4, W-6) had percentage inhibition more than 50%, which for IC₅₀ values were suggested below 100 µg.mL^-1. IC₅₀ value of kojic acid was 49.9 µM (7.09 µg.mL^-1).

The extracts inhibited the antioxidant and tyrosinase inhibition activity due to the presence of phenolic compounds, especially flavonoids (Taherkhani & Gheibi 2014). The hydroxyl group can participate in reducing DOPA-chrome to DOPA, by giving electrons or by cross-linking with PPO via hydrogen bonding (Lopez et al. 2007).

Total phenolic content and chemical composition

The 40 ethanol extracts contained phenolic contents from 22.6 mgGAE/g (EWC-10) to 225.4 mgGAE/g (WWC-6) (Table I). In which, 12 extracts prepared from P. Odorata, H. Cordata, and A. Vulgaris showed high contents of phenolic with values more than 100 mgGAE/g. TPC value of the WWC-6 (225.4 mgGAE/g) was the highest, followed by the E-4 (155.9 mgGAE/g). Besides, the samples without chlorophyll had higher results than samples in the same solvent. It may be due to removing a part of chlorophyll by acetone solvent in WWC, EWC samples.

Many researchers indicated a positive relationship between total phenolics and antioxidant activity of plant extracts (Kim et al. 2003, Djeridane et al. 2006). The high content of phenolic compounds to scavenge free radicals may be attributed to the hydroxyl groups. The extracts of P. Odorata, H. Cordata, and A. Vulgaris exhibited not only high DPPH scavenging activity but also high phenolic contents. In brief, high DPPH and tyrosinase scavenging activity of the E-4 extract revealed that the extract has the potential to be an antioxidant and melanosis inhibitor; thus, the E-4 was collected to study on chemical constituents and preserving white leg shrimp (L. vannamei) in the cold storage.

Thirty-six compounds were determined in the E-4 extract prepared from P. Odorata leaves by HPLC-EIS-MS analysis (Table II). Twenty-two compounds belong to phenolic compounds, in which 4 compounds (morin, quercetin, fisetin, astragalin) are flavonoids. They are not only potent antioxidants but also strong antityrosinase (Taherkhani & Gheibi 2014). The flavonoids are able to produce complexes with Cu^{2 +}- a metal located at the center of activity and required for tyrosinase catalytic activity by linking the hydroxyl group to the Cu^{2 +} ion (Kim et al. 2006). Thus, the presence of phenolic compounds, especially flavonoids, may play an essential role in their antioxidant and tyrosinase inhibition activities.

Table II
Identification of 36 compounds in P. Odorata leaf extract by HPLC-EIS-MS.

No.	Compound	m/z	Predicted formula	No.	Compound	m/z	Predicted formula
1	Mitolactol	305.9128	C6H12Br2O4	19	Fisetin	286.0451	C15H10O6
2	Fipexide	388.1177	C20H11ClN2O4	20	5-Aminosalicylic acid	153.0415	C7H7NO3
3	Cefsumide	440.0796	C17H20N4O6S2	21	Fepentolic acid	224.1029	C12H16O4
4	Carbenicillin	378.0889	C17H18N2O6S	22	DPT/N,N-Dipropyltryptamine	244.1918	C16H24N2
5	Dibenzyl succinate	298.1231	C18H18O4	23	Zimelidine	316.0551	C16H17BrN2
6	Dimethadione	129.0417	C5H7NO3	24	Trinexapac-ethyl	252.0974	C13H16O5
7	Fluprednidene acetate	432.1961	C24H29FO6	25	Oxonazine	222.1239	C9H14N6O
8	Fluticasone propionate	500.1829	C25H31F3O5S	26	Butyl 4-hydroxybenzoate	194.0925	C11H14O3
9	Fluprednidene acetate	432.196	C24H29FO6	27	Usnic acid	344.0862	C18H16O7
10	Vanillin mandelic acid	198.0511	C9H10O5	28	Embelin	294.1802	C17H26O4
11	Quercetin	464.0911	C21H20O12	29	BOH	195.088	C10H13NO3
12	Astragalin	448.0964	C21H20O11	30	Lotucaine	291.2169	C18H29NO2
13	Cefatrizine	462.0765	C18H18N6O5S2	31	MAL / Methallylescaline	251.15	C14H21NO3
14	Brovincamine	432.1017	C21H25BrN2O3	32	Stearic acid	284.2688	C18H36O2
15	Cloxestradiol	418.0862	C20H25Cl3O3	33	Oseltamivir	312.2062	C16H28N2O4
16	Spironolactone	416.2007	C24H32O4S	34	Suxemerid	424.33	C24H44N2O4
17	Morin	302.0398	C15H10O7	35	Butyl 4-aminobenzoate	193.11757	C11H15NO2
18	Azelaic acid	188.1031	C9H16O4	36	Gemfibrozil	250.15744	C15H22O3

Quality changes of shrimp during cold storage

PH measurement

The changing in the pH value of white leg shrimps treated with H₂O, E-4, and SMS during the storage period shown in Figure 1. During the storage, the pH values of all investigated shrimps reported a sudden increase in the first two days and a gradual increase at lower speed from day 3 to day 5. On the first day, no noticeable difference in the pH value was observed among all samples (p>0.05). However, after five days of storage, the sample treated with water exhibited the highest pH value of 7.63, whereas those samples treated with 0.025 wt% E-4 (7.35) and 1.25 wt% SMS (7.34) displayed comparable pH value. The increase in pH was associated with the accumulation of basic compounds, mainly resulted from the microbial development. The lower increase in the pH value of shrimp treated with the E-4 extract was in accordance with the lower microbial count (Lopez et al. 2007, Montero et al. 2001). According to Shamshad, the pH values in shrimps should not exceed 7.6 during storage (Shamshad et al. 1990), this suggested that the E-4 extract could control the change of pH value similar to the commercial additive.

Figure 1
The changes of pH in shrimp during preserving at 2^oC in 5 days. Results presented as the mean ± SD (n=3). Superscript letters above each data point represent statistically significant differences (p<0.05).

Melanosis evaluation

In general, gray values change significantly after two days of the storage process at 2^oC (Figure 2). Blackening in the carapace of the shrimp in the control sample was more intensive than in shrimp immersed in 0.025 wv% E-4 solution and 1.25 wv% SMS solution. During the storage, no statistical difference in the % relative change values were obtained from the E-4 and the SMS samples (p>0.05). The considerable differences between the control sample, SMS, and E-4 sample were suggested that the E-4 is able to prevent melanosis development in shrimp during cold processing.

Figure 2
The changes of % relative change values in shrimp during preserving at 2^oC in 7 days, analyzed using ImageJ software. Results are presented as the mean ± SD (n=3). Superscript letters above each data point represent statistically significant differences (p<0.05).

Lipid peroxidation inhibition assay

The results of the lipid peroxidation inhibition assay showed in Figure 3. In general, the E-4 sample exhibited the lowest value of TBARS, followed by the SMS and the control sample, respectively. During the first day of preservation, there was no significant difference of TBARs values (p>0.05) for all studied samples. The TBARs values of the SMS and E-4 samples were found to increase from the first day to the fifth day and decrease significantly from the fifth to the seventh day of storage at 2 ^oC. While the TBARs value of the control sample reached peak value on the fourth day and reduced in the next three days. The maximum value of TBARs was obtained after five days of the sample treated with E-4, SMS, and water after four days were 4.82, 4.52, 5.08 mgMDA/kg of shrimp, respectively. The increase in the TBARs values ​​was accounted for the powerful oxidation of fat in the first stage to form hydroperoxide and oxidize hydroperoxide quickly into secondary products like aldehyde. In the second stage of fat oxidation, the secondary oxidized products continue to be converted to all other products using the effect of enzymes and microorganisms, leading to decreased TBARs value (Encarnacion et al. 2011). Shrimp samples treated by the E-4 have the lowest TBARs value among all samples. These results showed that the E-4 was able to slow the process oxidation of fat in shrimp during cold processing at 2^oC.

Figure 3
The changes of TBARs values in shrimp during preserving at 2^oC in 7 days. Results presented as the mean ± SD (n=3). Superscript letters above each data point represent statistically significant differences (p<0.05).

Microbiological analysis

Results showed that the total aerobic microorganisms of the E-4 sample (1.1x10⁶ Cfu/g) was approximately five times lower than the control sample (2.2x10⁷ Cfu/g (Table III). It was indicated that the shrimp treated with the E-4 was able to inhibit the growth of aerobic microorganisms better than that of the control sample. According to TCVN 5289: 2006 requirements of frozen seafood, total aerobic bacteria should not exceed 10⁶ Cfu/g. Thus, it can be seen that samples treated by the SMS and the E-4 are suitable, while the control sample is not acceptable. Besides, results showed that the number of P. aeruginosa and Enterobacteriaceae in the E-4 sample was lower than in the SMS sample. P. aeruginosa and Enterobacteriaceae are two pathogenic microorganisms in cryopreservation products. From this, it can be concluded that P. Odorata leaves can inhibit harmful organisms, aerobic bacteria such as P. aeruginosa and Enterobacteriaceae better than additive samples.

Table III
Microbiological analysis of shrimp samples after five days.

Criteria (Cfu/g)	Sample
	Control	SMS	E-4
Total aerobic microorganisms	2.2x107	4.7x105	1.1x106
Pseudomonas aeruginosa	<10	7.8x103	<10
Enterobacteriaceae	30	1.4x103	20

CONCLUSION

We have carried out a systematic investigation of spicy vegetables in Vietnam for DPPH inhibitory activity, tyrosinase inhibition activity. The results of screening on bioactivities of 40 extracts suggested that the ethanol extract prepared from P. Odorata leaves (E-4) was rich in phenolic content (155.9 ± 0.8 mgGAE/g) and exhibited the highest potential of the DPPH assay (IC₅₀ of 7.54 µg.mL^-1) and the tyrosinase inhibition percentage (54.2 ± 2.9%) at the concentration of 100 µg.mL^-1. In addition, this extract showed the capacity for preserving white leg shrimp (P. vannamei) by reducing melanosis development, pH value, lipid peroxidation, and scavenging harmful microorganisms. Besides, based on screening results, the extracts from H. Cordata and A. Vulgaris showed energetic activities and promises for further studies. This study shows a new capacity of using plant extract as a substitute for synthetic chemical reagents as preservatives in shrimp storage.

ACKNOWLEDGMENTS

The author would like to thank Mr. Nguyen Van Hau, Ms. Tran Thi Thanh Phuong, and Ms. Nguyen Kieu Thy Nga, Faculty of Chemical and Food Technology, Ho Chi Minh City University of Technology and Education, for their kind support on chemicals and analysis service for this work.

REFERENCES

• ANDRADE LT, ARAUJO NG, VENTURA APM, LIRA AL, MAGNANI M & CAVALHEIRO JMO. 2015. Standardization of sodium metabisulfite solution concentrations and immersion time for farmed shrimp Litopenaeus vannamei. Cienc Rural 45(3): 499-504.
• BHOBE AM & PAI JS. 1986. Study of the properties of frozen shrimps. J Food Sci Technol 23: 143-147.
• BREWER MS. 2011. Natural antioxidants: Sources, compounds, mechanisms of action, and potential applications. Comp Rev Food Sci Food Safety 10: 221-247.
• DJERIDANE A, YOUSFI M, NADJEMI B, BOUTASSOUNA D, STOCKER P & VIDAL N. 2006. Antioxidant activity of some Algerian medicinal plants extracts containing phenolic compounds. Food Chem 97: 654-660.
• ENCARNACION AB, FAGUTAO F, JINTASATAPORN O, WORAWATTANAMATEEKUL W, HIRONO I & OHSHIMA T. 2012. Application of ergothioneine-rich extract from an edible mushroom Flammulina velutipes for melanosis prevention in shrimp, Penaeus monodon and Litopenaeus vannamei. Food Res Int 45: 232-237.
• GONÇALVES AA & OLIVEIRA ARM DE. 2016. Melanosis in crustaceans: A review. LWT - Food Sci Technol 65: 791-799.
• HAIYAN S, HUA LV, GAOFENG Y & XUBO F. 2014. Effect of Grape Seed Extracts on the Melanosis and quality of Pacific White Shrimp (Litopenaeus vannamei) during Iced Storage. Food Sci Techno Res 26(2): 671-677.
• JUNG HA, JUNG YJ, YOON NY, JEONG DM, BAE HJ & KIM DW. 2008. Inhibitory effects of Nelumbo nucifera leaves on rat lens aldose reductase, advanced glycation endproducts formation, and oxidative stress. Food Chem Toxicol 46(12): 3818-3826.
• KAEFER CM & MILNER JA. 2008. The role of herbs and spices in cancer prevention. J Nutr Biochem 19: 347-361.
• KIM D, PARK J, KIM J, HAN C, YOON J, KIM N, SEO J & LEE C. 2006. Flavonoids as mushroom tyrosinase inhibitors: A fluorescence quenching study. J Agric Food Chem 54(3): 935-941.
• KIM DO, CHUN OK, KIM YJ, MOON HY & LEE CY. 2003. Quantification of polyphenolics and their antioxidant capacity in fresh plums. J Agr Food Chem 51: 6509-6515.
• LOPEZ CME, MARTINEZ AO, GOMEZ GMDC & MONTERO P. 2007. Quality of thawed deepwater pink shrimp (Parapenaeus longirostris) treated with melanosis-inhibiting formulations during chilled storage. Int J Food Sci Technol 42: 1029-1038.
• MCEVILY AJ, IYENGAR R & OTWELL S. 1991. Sulfite alternative prevents shrimp melanosis. Food Technol 45(9): 80-86.
• MOLYNEUX P. 2004. The use of the stable free radical diphenylpicrylhydrazyl (DPPH) for estimating antioxidant activity. Songklanakarin J Sci Technol 26: 211-219.
• MONTERO P, LOPEZ CME & PEREZ MM. 2001. The effect of pH inhibitors and high-pressure treatment to prevent melanosis and microbial growth on chilled prawns (Penaeus japonicas). J Food Sci 66: 1201-1206.
• NIRMAL NP & BENJAKUL S. 2011. Use of tea extracts for inhibition of polyphenol oxidase and retardation of quality loss of Pacific white shrimp during iced storage. LWT - Food Sci Technol 44: 924-932.
• NORMAN FH & BENJAMIN KS. 2000. Seafood enzyme: utilization and influence on postharvest seafood quality. CRC Press Published, 696 p.
• PEDALE AB, FUJIMOTO RY, SANTOS RF & ABRUNHOSA FA. 2012. Acute toxicity of sodium metabisulfite on mangrove crab Ucides cordatus (Decapoda, Ucididae). An Acad Bras Cienc 84: 1009-1014.
• SHAMSHAD SI, KHER-UN-NISA KU, RIAZ M, ZUBERI R & QADRI RB. 1990. Shelf life of shrimp (Penaeus merguiensis) stored at different temperatures. J Food Sci 55: 1201-1205.
• SINGH R & ARORA S. 2007. Attenuation of free radicals by acetone extract / fractions of Acacia nilotica L.) Wild Ex del. J Chin Clin Med 2: 196-204.
• TAHERKHANI N & GHEIBI N. 2014. Inhibitory effects of quercetin and kaempferol as two propolis derived flavonoids on tyrosinase Enzyme. Biotech Health Sci 1(2): e22242.
• TSIRONI T, DERMESONLOUOGLOU E, GIANNAKOUROU M & TAOUKIS P. 2009. Shelf life modeling of frozen shrimp at variable temperature conditions. LWT - Food SciTechnol 42: 664-671.
• YASHIN A, YASHIN Y, XIA X & NEMZER B. 2017. Antioxidant activity of spices and their impact on human health: A review. Antioxidants 6(70): 1-18.

Publication Dates

• Publication in this collection
  09 Aug 2021
• Date of issue
  2021

History

• Received
  31 Oct 2019
• Accepted
  16 Mar 2020