Comparative Stability Study of Vitamin C present in Fresh Lemon Juice and Marketed Juice by Analytical Methods
Merugu Manasa*, A. Ravali, B. Bargavi, B. Mounica, V. Lakshmi Prasanna
Department of Pharmaceutical Analysis, Pulla Reddy Institute of Pharmacy, Domadugu, Gummadidala, Sangareddy, 502313.
*Corresponding Author E-mail: merugumanasa53@gmail.com
ABSTRACT:
The objective of this study is to determine the stability of vitamin c present in fresh lemon juice and marketed juice and comparison of results of iodometry and colorimetry. Fresh lemon juice (lemon juice with salt, lemon juice with salt and sugar) was prepared and marketed juice (Dabur and Freshzo) was purchased from the market and stored at two different temperatures i.e. at room temperature and refrigerator condition in glass containers. For determination of ascorbic acid present in all juices colorimetry and iodometry were performed. We have done the study for 13 days in the month of January (Stability studies) and march (reproducibility). This study reveals that the degradation of ascorbic acid is low under refrigeration conditions when compared to that of room temperature. Lemon juice prepared with salt can use 11 days under refrigerator conditions and at room temperature we can use 8 days in normal weather and 5days at moderate temperature conditions in glass containers. When comparing results of colorimetry and iodometry sensitivity was more for colorimetry, but the results of colorimetry and iodometry are near to each other. Hence we can tell that iodometry method is economic and easy method for estimation of ascorbic acid present in lemon juices.
KEYWORDS: Lemon juice, ascorbic acid, iodimetry, colorimetry, room temperature, refrigerator, storage, stability and degradation.
INTRODUCTION:
Fruits and vegetables are the best sources of vitamin C. Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors of vitamin C to the American diet. Other good food sources include red and green peppers, kiwifruit, broccoli, strawberries, Brussels sprouts, and cantaloupe. Although vitamin C is not naturally present in grains, it is added to some fortified breakfast cereals. The vitamin C content of food may be reduced by prolonged storage and by cooking because ascorbic acid is water soluble and is destroyed by heat. pH, light, humidity, other components, storage conditions, container also alter stability of ascorbic acid. According to literature review10,11,12,13,14,15,16,17,18 stability of ascorbic acid present in juices was determined by using methods like iodometry, colorimetry, UV-Visible spectroscopy and chromatography.
Structure:
Fig.1 Structure of Vitamin. C
METHODOLOGY:
Lemon with sugar:
Weigh 100g of lemon slices and separate the juice from fruit by squeezing method. Add 500mg and 500mg salt of sugar and make up to 1000ml of water.
Lemon with salt:
Weigh 100g of lemon slices and separate the juice from fruit by squeezing method. Add 300g of salt and make up to 1000ml of water.
MARKETED PRODUCTS:
Marketed juices collected dabur homemade lemoneez juice and freshzo lemon juice were collected from super market.
IODOMETRIC TITRATION:
Preparation of 0.05M iodine solution:
Weigh 1.75g of iodine in a solution of 4.5g of potassium iodide in 50 ml water and add 3 drops of hydrochloric acid (HCl) and makeup to 250ml water in volumetric flask.
Preparation of starch solution:
Titrate 1g of starch with 5ml of water and stir continuously to 100ml of boiling water containing 10mg of mercuric iodide.
Preparation of 10% Hydrochloric acid (HCl):
Measure 10ml concentrated HCl and dilute with 100ml distilled water.
Preparation of 1M sodium hydroxide:
Dissolve 10.5g of NaOH in sufficient carbondioxide free water to produce 250ml.
Standardization of 0.05m Iodine Solution:
Weigh 0.07g of arsenic trioxide, previously dried at 105◦C for 1hour and dissolve in 10ml of 1M sodium hydroxide by warming if necessary. Dilute with 20ml of water. add 0.1ml of methylene orange solution and add drop wise dilute HCl until the yellow colour is change to pink. Add 1g of sodium carbonate. dilute with 25ml water and add 3ml of starch solution. Titrate with iodine solution until a permanent blue colour is produced.
Procedure:
Measure 25ml of juice sample in a conical flask and titrate with iodine solution. Colour that persists longer than 20seconds.
COLORIMETRY:
Preparation of 0.1Noxalic acid:
Weigh 1.26g of oxalic acid and dilute with 200ml distilled water.
Preparation of acetate buffer at pH 4.2:
Weigh 0.068g of sodium acetate and add 3.85g of ammonium acetate in 250ml of distilled water and add 12.5ml of glacial acetic acid solution.
Preparation of 0.01% methylene blue:
Weigh 1g of methylene blue and dilute with 100ml distilled water.
Preparation of sample:
Pipette out 1ml of juice samples in 10ml volumetric flask and makeup to 10ml with distilled water.
Procedure:
Measure 20ml of oxalic acid and add 0.2ml of 0.01% of methylene blue and add 1ml of acetate buffer of pH 4.2 and add 1ml of sample solution and measure the absorbance at 540nm.
RESULTS:
Table No 1-Estimation of ascorbic acid at room temperature
|
Day |
Fresh with Salt and Sugar |
Fresh with Salt |
Dabur |
Freshzo |
||||
|
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
|
|
1 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
2 |
97.8 |
98.1 |
98.2 |
98.8 |
95.2 |
95.8 |
98.1 |
98.4 |
|
3 |
95 |
95.6 |
96.1 |
96.4 |
83.5 |
83.7 |
96.1 |
96.9 |
|
4 |
87 |
88.2 |
93.3 |
93.5 |
77.7 |
75 |
94 |
95.1 |
|
5 |
76.2 |
76.9 |
88 |
88.2 |
64.5 |
65.1 |
89.1 |
89.6 |
|
6 |
63 |
64 |
84 |
84.7 |
55.5 |
58.6 |
84.3 |
85 |
|
7 |
52 |
53.1 |
79.3 |
80.3 |
36.8 |
40 |
80.2 |
80.5 |
|
8 |
37.5 |
38 |
76.4 |
77.8 |
0 |
0 |
76.3 |
76.9 |
|
9 |
0 |
0 |
58.2 |
58.8 |
0 |
0 |
62.7 |
63.1 |
|
10 |
0 |
0 |
39.1 |
39.8 |
0 |
0 |
39.8 |
40.2 |
Fig.No.2 Iodometry estimation of ascorbic acid at room temperature
Fig.No.3 Colorimetric estimation of ascorbic acid at room temperature
Table No 2- Estimation of ascorbic acid under refrigerator
|
Day |
Fresh with Salt and Sugar |
Fresh with Salt |
Dabur |
Freshzo |
||||
|
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
|
|
1 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
2 |
98.8 |
99.1 |
98.8 |
99.2 |
97.2 |
97.8 |
98.5 |
98.8 |
|
3 |
97.6 |
97.9 |
97.3 |
97.5 |
88.8 |
89.5 |
97.5 |
97.9 |
|
4 |
90.5 |
91 |
94.3 |
94.8 |
84.5 |
86.5 |
95.1 |
95.3 |
|
5 |
88.2 |
89.3 |
91.7 |
92.4 |
79.4 |
80.6 |
92.4 |
93.6 |
|
6 |
80 |
80.7 |
86.6 |
87.1 |
71.6 |
71.9 |
87.3 |
87.6 |
|
7 |
76.3 |
76.8 |
82.9 |
83.3 |
62.3 |
62.6 |
83.3 |
83.5 |
|
8 |
68.7 |
68.9 |
79.04 |
80.1 |
50.4 |
50.8 |
80.2 |
80.4 |
|
9 |
60.3 |
60.9 |
74.7 |
74.9 |
30.6 |
31.2 |
75.3 |
75.4 |
|
10 |
35.5 |
36.1 |
68.1 |
68.5 |
0 |
0 |
69.2 |
69.8 |
|
11 |
0 |
0 |
60.4 |
60.7 |
0 |
0 |
62.3 |
62.5 |
|
12 |
0 |
0 |
52.2 |
52.6 |
0 |
0 |
53.5 |
53.7 |
Fig No.4 Iodometry estimation of ascorbic acid under refrigerator
Fig. No. 5 Colorimetric estimation of ascorbic acid under refrigerator
RESULTS OF REPRODUCIBILITY:
Table No 3- Estimation of ascorbic acid at room temperature
|
Day |
Fresh with Salt and Sugar |
Fresh with Salt |
Dabur |
Freshzo |
||||
|
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
|
|
1 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
2 |
92 |
92.3 |
92.1 |
92.4 |
89.1 |
89.3 |
92.4 |
92.6 |
|
3 |
71.2 |
71.7 |
85.3 |
85.6 |
73.1 |
73.4 |
86.4 |
87.1 |
|
4 |
64.3 |
66.8 |
77.5 |
77.8 |
61.3 |
62.5 |
77.4 |
77.8 |
|
5 |
39.2 |
39.9 |
69.3 |
69.5 |
40.1 |
40.5 |
70.1 |
70.4 |
|
6 |
0 |
0 |
52 |
53.5 |
0 |
0 |
53.2 |
53.5 |
|
7 |
0 |
0 |
40.2 |
40.5 |
0 |
0 |
42.3 |
42.5 |
Fig.No.6 Iodometry estimation of ascorbic acid at room temperature
Fig.No.7 Colorimetric estimation of ascorbic acid at room temperature
Table No 4- Estimation of ascorbic acid under refrigerator
|
Day |
Fresh with Salt and Sugar |
Fresh with Salt |
Dabur |
Freshzo |
||||
|
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
Iodometry |
Colorimetry |
|
|
1 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
2 |
98.2 |
98.5 |
98.8 |
98.9 |
95.2 |
95.2 |
98 |
98.2 |
|
3 |
96.3 |
96.5 |
97.1 |
97.4 |
88.2 |
88.7 |
97.1 |
97.4 |
|
4 |
91.3 |
91.5 |
94.2 |
94.3 |
84.1 |
84.3 |
94.2 |
94.4 |
|
5 |
89.4 |
89.7 |
91.6 |
91.7 |
78.7 |
79.3 |
92.1 |
92.3 |
|
6 |
81.1 |
81.5 |
86.4 |
86.6 |
71.1 |
71.3 |
86.9 |
87.1 |
|
7 |
77.1 |
77.2 |
82.7 |
82.9 |
61.8 |
62.2 |
82.4 |
82.8 |
|
8 |
68.9 |
70.1 |
79.2 |
79.04 |
49.4 |
50.2 |
79.3 |
79.5 |
|
9 |
61.1 |
61.4 |
74.4 |
74.7 |
30.1 |
30.6 |
74.8 |
75.2 |
|
10 |
36.4 |
36.7 |
68 |
68.1 |
0 |
0 |
68.8 |
69.1 |
|
11 |
0 |
0 |
59..4 |
60.4 |
0 |
0 |
61.4 |
61.9 |
|
12 |
0 |
0 |
52.1 |
52.2 |
0 |
0 |
52.9 |
53.3 |
Fig.No.8 Iodometry estimation of ascorbic acid under refrigerator
Fig.No.9 Colorimetric estimation of ascorbic acid under refrigerator
DISCUSSION:
Assay:
We have done the study for 13 days in the month of January and it was observed that:
Dabur:
Degradation of ascorbic acid was more in dabur juice because of high concentration. More degradation with microbial growth observed on 7th day at room temperature and 9th day under refrigerator conditions.
Fresh with sugar & salt:
Degradation of ascorbic acid was more in fresh juice with salt and sugar also because of presence of sugar. More degradation with microbial growth observed on 8th day at room temperature and 10th day under refrigerator conditions.
Freshzo:
Degradation of ascorbic acid was slow in freshzo lemon juice. More degradation with microbial growth observed on 10th day at room temperature and 13th day under refrigerator conditions.
Fresh with salt:
Degradation of ascorbic acid was slow in fresh juice with salt. More degradation with microbial growth observed on 10th day at room temperature and 13th day under refrigerator conditions.
Reproducibility:
To check the reproducibility of results experiment was repeated in the month of march and the results were as follows.
Dabur:
Degradation of ascorbic acid was more in dabur juice because of high concentration. More degradation with microbial growth observed on 5th day at room temperature and 9th day under refrigerator conditions.
Fresh with sugar & salt:
Degradation of ascorbic acid was more in fresh juice with salt and sugar also because of presence of sugar. More degradation with microbial growth observed on 5th day at room temperature and 10th day under refrigerator conditions.
Freshzo:
Degradation of ascorbic acid was slow in freshzo lemon juice. More degradation with microbial growth observed on 7th day at room temperature and 13th day under refrigerator conditions.
Fresh with salt:
Degradation of ascorbic acid was slow in fresh juice with salt. More degradation with microbial growth observed on 7th day at room temperature and 13th day under refrigerator conditions.
Under refrigerator conditions drugs degradation was near to the results of assay. At room temperature drug degradation was more than assay because of higher temperature.
When comparing results of iodometry and colorimetry, both signals were near to each other.
The experiment was performed in both the months i.e., in January & march. The results obtained are as follows:
CONCLUSION:
Because of higher concentration of ascorbic acid and presence of sugars degradation was more in dabur lemon juice and fresh lemon juice with salt and sugar respectively. Under refrigerator conditions degradation occurs slowly because of low temperature but degradation ascorbic acid was occurred due the exposure of humidity. Water catalyses chemical reactions as oxidation, hydrolysis and reduction reaction and promotes the microbial growth. In Freshzo lemon juice and lemon juice with salt degradation was slow because of less concentration and absence of sugar content. But ascorbic acid was affected by humidity and temperature leads to degradation.
In reproducibility studies drug degradation was more in all sample at room temperature due the change in environmental temperature degradation was more than previous study. Because, high temperature and light accelerate oxidation, reduction and hydrolysis reaction which lead to drug degradation. But Under refrigerator condition results were near to previous results. Hence the method was reproducible.
Hence we can conclude that lemon juice prepared with salt can use 11 days under refrigerator conditions and at room temperature we can use 8 days in normal weather and 5days at moderate temperature conditions in glass containers.
When comparing results of colorimetry and iodometry sensitivity was more for colorimetry, but the results of colorimetry and iodometry are near to each other. Hence we can tell that iodometry method is economic and easy method for estimation of ascorbic acid present in lemon juices.
ACKNOWLEDGEMENT:
The authors are grateful to the Management of Pulla Reddy Institute of Pharmacy for providing facilities for conducting experiment.
CONFLICT OF INTEREST:
The authors declare no conflict of interest.
REFERENCES:
1. Guredeep Chatwal and Sham Anand, Instrumental methods of chemical analysis. Himalaya Publishers,1992;7:2.624-2.639.
2. Pharmaceutical analysis by Dr. A.V. Kasture; 1:1.5-1.8.
3. Instrumental method of chemical analysis by Gurudeep R. Chatwal, 2.523.
4. Available at Wikipedia.org\Wiki\titration. Pharmaceutical analysis by Dr. A.V. Kasture, Non aqueous titrations;1:7.1-7.5.
5. C. Parameshwara murthy, redox titrations, permanganometry, new age international, 2018;1:632.
6. Available at https://en.wikipedia.org/wiki/Permanganometry.
7. W.R. Heumann, et.al, Cerimetric Titration, Analytical Chemistry, 1957; 29(8),1226-1227.
8. Available at https://en.wikipedia.org/wiki/bromatometry.
9. Jane Adams, et.al, Iodimetry titrations, Journal of the American Pharmaceutical Association;36(6).
10. Kurt. Starke, et.al, Iodometric titrations, Analytical chemistry, 1963;35 (9):1310–1311.
11. Aswathy Bose, et.al, Fluorescence spectroscopy, International journal of advances in pharmaceutical analysis, 2018;8.
12. Douglas R. Powell, et.al, X-Ray and Crystallography, Journal of chemical education, 2016;93 (4):591–592.
13. Allen C. West, et.al, Flame spectroscopy, Journal of chemical education, 1966, 43 (2), A176.
14. Robert S. McDonald, et.al, infrared spectrometry, Analytical chemistry,1986; 58 (9):1906–1925.
15. Guredeep Chatwal and Sham anand, colorimetry methods, Instrumental methods of chemical analysis, Himalaya Publishers, 1992;7:2.107-2.122.
16. Guredeep Chatwal and Sham anand, chromatographic methods, Instrumental methods of chemical analysis. Himalaya Publishers, 1992;7:566-2.700.
17. Available at C:\Users\home\Desktop\Vitamin C — Health Professional Fact Sheet.mhtml
Received on 02.04.2019 Modified on 21.05.2019
Accepted on 28.06.2019 © RJPT All right reserved
Research J. Pharm. and Tech. 2019; 12(10):4724-4728.
DOI: 10.5958/0974-360X.2019.00814.X