IndianJ.DairySci.
67(4),2014
RESEARCH ARfICLE
Antacid properties of milk and milk products in comparison to other foods and commonly available antacid pharmacological preparations Renuka Malik, B.S. Beniwal, Hari Om and RenuArora Received:
April 2014 / Accepted:
July 2014
Abstract
Hydrochloric acid (HCl) is the major constituent of gastric fluid and when its secretion is increased beyond optimal, it causes lot of discomforts. This study was planned to find out antacid properties of milk and milk products in comparison to other foods and commonly available Antacid Pharmacological Preparations (APP). 100 ml of HCl having pH similar to gastric fluid (l.5) was mixed with one serving of various food items and the recommended dosage (lOml) of the APP. It was found that milks/milk products increased the pH to higher levels in comparison to Vegetables, Fruits, Carbonated Beverages, other foods and APPs studied. The pH of HCl was increased from 1.5 to 5.61, 5.45, 5.33, 5.32, 5.29, 5.24, 4.48, 4.24,4.23, 4.20, and 1.86 in JO min by Burfi (50g), Peda (50g), FCM (lOOml), DTM (lOOml), TM (lOOml), Rasmalai (lOOg), Paneer (50g), APP-B, APP-C, APP-A and APP-D, respectively. Additional 50 ml HCl was mixed with milks/milk products and APPs after 30 min. The pH at 60 min was 5.14, 5.12, 4.65, 4.63, 4.59, 4.32, 4.06, 4.04, 3.99, 3.81 and 1.60 for Peda, Burfi, FCM, DTM, TM, Rasmalai, Paneer and APP-A, APP-C, APP-B and APP-D, respectively. In this experiment also milks/milk products showed higher increase in pH as compared to the APPs. The study indicates that in in vitro acid conditions, milk/milk products resist changes in pH better than Antacid Pharmacological Preparations and other foods. The per unit protein content in milks and milk products showed differential effects on the increase in pH, which was higher in liquid milks as compared to desiccated and coagulated milk products.
Renuka Malik (~), 8.S. 8eniwal, Hari Om and Renu Arora General Manager, Analyst, Delhi Milk Scheme, Delhi-I I 0 008. Associate Prof., Institute of Home Economics, Delhi-I I 0 016. Renuka Malik Ph.D Student, Dept. of Resource Economics,
Delhi-I
Management,
I 0 016.
E-mail:
[email protected]
Institute
of Home
Keywords: Buffering Capacity, Milk Products, Antacid Pharmacological Preparations, Non Ulcer Dyspepsia (NUD)
Introduction Food is broken down in the stomach by the action of gastric fluid. The gastric fluid consists of a variety of enzymes, salts with Hydrochloric acid (HCl) as the major constituent. The pH of gastric fluid is around 1.5-3.5. The total secretion of HCl in a healthy adult is around 2-3 liters per day (http:// tera.chem.ut.ee/e-koit/arstpr/ph _ en.pdf). However, because of wrong food habits, life style, emotional disturbances and some other reasons the secretion of HCl is increased beyond requirements. This situation is known as hyper acidity and it causes a lot of discomforts which may include heart burn, flatulence, nausea and vomiting etc. It is also known as nonulcer dyspepsia (NUD) and 20-40% of the adult population in the Western world suffers from it (Berkow, 1997). Persons suffering from such maladies resort to antacid tablets or liquid gels to get relief. Other options are available in the form of hydrogen ion blockers. The antacid preparations and the hydrogen ion blockers are not without side effects and may cause harm to human health. Some of the foods that we eat may also resist changes in pH upon ingestion due to their buffering capacity (BC)/neutralizing ability. Choosing suitable food items may ward off the requirement of pharmacological preparations in such cases. Milk and milk products are not only good source of quality nutrients but may offer antacid value also because of their protein and other constituents. Various authors have different views on use of milk in ulcer conditions. While Materia et at. (1984), opined that prostaglandins in commercial milk preparations may be responsible for the presumed beneficial effects of milk in the prevention and treatment of peptic ulcer, Ippoliti et al. (l976), say that there is reason to question the frequent ingestion of milk by patients with peptic ulcer, because milk contains both protein and calcium, and each are stimulants of gastric-acid
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secretion. As per Marotta and Floch (1991), also frequent milk ingestion as previously prescribed is not encouraged. This is owing to the transient buffering effect and significant gastric acid secretion effect of milk. There is no evidence to suggest any such harmful effect of milk in non-ulcer dyspepsia (NUD) or hyperacidity. Rather Lutchman et al. (2006) have suggested that the good buffering capacity of milk is ideal in the treatment of NUD. They found that powdered cow's milk provided a better buffering capacity than either powdered goat's or soy milk. Park (1991), had also found that buffering capacity of the soy based infant formulas were lower than those of natural milks. On these lines this work was undertaken to assess the antacid properties of milk and milk products in comparison to other foods and commonly available Antacid Pharmacological Preparations (APP).
aluminum hydroxide gel LP. (830 mg). The APP-B per 10 ml (Recommended Dose) contained Activated Dimethicone LP. (100 mg), Magnesium Hydroxide LP. (500 mg added as Magnesium Hydroxide paste), Dried Aluminum Hydroxide Gel LP. (500 mg added as Aluminum Hydroxide paste) and Sorbitol solution (70%) LP.(non crystallizing) 2.5 gm. The APP-C per lO ml (Recommended Dose) contained Oxetacaine B.P. (20 mg), Aluminum Hydroxide (0.582 g added as aluminum hydroxide paste equivalent to 0.760 g of dried aluminum Hydroxide gel LP.) and Magnesium Hydroxide LP. (196 mg added as magnesium hydroxide paste). The APP-D per 10 ml (Recommended Dose) contained powders of Yavakshar (75.0 mg) and Shwet Parpati (250 mg). It also contained extracts of Tribudus terrestris (500 mg), Contra drum sativum (320 mg) and Cuminum cymimum (200 mg).
Materials
Quantity of Food Preparations (APP)
and methods
The experiment was carried out in the Quality Control Laboratory of Delhi Milk Scheme, Govt. of India, New Delhi. Procurement
of Food Materials
Various food materials which included milk and milk products, fruits, vegetables, carbonated drinks and some other food items were procured from the local market. The milk procured was pasteurized Toned Milk (TM), Double Toned Milk (DTM) and Full Cream Milk (FCM). Milk products studied were Paneer (a product obtained from cow or buffalo milk or a combination thereof by precipitation with sour milk, lactic acid or citric acid and having maximum 70.0 % moisture and minimum 50.0010 milk fat on dry matter basis. -De Sukumar, 2007), Ice-cream, Sweet Yogurt, Plain Yogurt, Chhach (Butter milk), Rasmalai, Rasgulla, Peda and Burfi. The base material used in preparation of Rasgulla and Rasmalai is Chhana. Chhana is similar to Paneer but is generally prepared from cow milk. In Rasgulla the Chhana balls are soaked in sugar syrup while Rasmalai is marketed as flattened Chhana patties in concentrated sweetened milk (Aneja et al. 2002). The base material in Burfi and Peda is khoya which is a heat desiccated milk product containing minimum 30% fat on "dry weight basis (FSSAl, 2013). Procurement
of Antacid Pharmacological
Preparations
(APP)
A total of four no of commonly used APP were procured from medical stores in the local market and all were either Gel/ Liquid or Syrup. Instead of their original names they have been denoted as APP-A, APP-B, APP-C and APP-D in this paper. The APP-A per 10 ml (Recommended Dose) contained Magnesium hydroxide LP. (185 mg), Simethicone LP. (50 mg), Sodium carboxymethylcellulose I.P. (100 mg) and Dried
Items
& Antacid
Pharmacological
The quantity of various food items that was used in the study was the quantity that is generally taken in one helping/ serving of that food item. This quantity is given against each food item in the tables. 10 ml of the APP in each case (which is the dosage recommended by the manufacturer) was used as the experimental quantity for the mixing with HCl (pH 1.5). Procurement of HCl: HCI was procured from Mls Thermofisher Scientific India Pvt. Ltd., Hiranandani Business Park, Pawai, Mumbai -400076 with specific gravity 1.18 and molecular weight 36.46. To prepare the experimental HCl having pH 1.5, 9.0 ml of this acid was added to one liter of double distilled water. The fmal sample was tested to confirm the desired pH i.e.l.5. Measurement of pH of Milk! Foods/ Antacid Pharmacological Preparations (APP) The pH meter used was Model No. pH 700, Mls Eutech Instruments; Singapore. In case of milk and milk products the pH was taken by mixing/mashing the milk/milk product and immersing the electrode directly into the milk /milk products. Fruits and vegetables were peeled and mashed and then pH was taken by directly immersing the electrode in the mashed fruit/vegetable. Similarly peeled egg, bread, cooked rice and chocolate were also mashed and their pH was measured by immersing the electrode directly into them. The pH of carbonated drinks and APP was also measured by direct electrode immersion. The temperature of these foods was maintained optimal before recording the pH. The milk and milk products, except ice cream, were maintained at 5°C in a refrigerator. Ice cream was stored at -20°C. Fruits and vegetables, bread, chocolate, carbonated drinks and the APP were also stored at 5°C while egg and cooked rice were stored at room temperature before pH measurement. The experimental HCl was stored at body temperature i.e. 37°C.
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'. Table 1 pH of Milk & Milk Products and Antacid Pharmacological Preparations (APP) up to Ju Min. Sr. No.
Food Item & Quantity
Initial pHof Food Item
pH of the mixture (Milks & milk Products + HCl) at various time intervals Omin
lOmin
20min
30min
5.22 5.18 5.22 3.32 2.45 3.49
5.33 5.29 5.32
5.34 5.30 5.33 3.08 2.44 3.59
5.35 5.31 5.35 3.10 2.44 3.56
3.91 4.70 5.05 5.62 3.91 5.47 4.26 4.29 4.27 1.85
3.95 4.76 4.86 5.64 3.99 5.49 4.29 4.28 4.26 1.86
CD
Milk & Milk Products FCM100ml lM100ml DlM100ml Chhach 100ml Ice Cream 100 ml Yoghurt (plain) 100g Yoghurt (Sweet) 1OOg Paneer50g Rasmalai 100g Burfi 50g Rasgulla50g Peda50g APP-A APP-B APP-C APP-D
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Mixing of HCl and Food Items/ Antacid Preparations (APP)
6.67 6.69 6.71 3.86 6.94 3.96 4.35
3.90 4.46 5.12 5.44 3.59 5.37
5.70 6.28 6.61 6.19 6.12 8.10
4.06 4.11 4.15 1.83
8.02 7.95 5.99
Pharmacological
of Protein Contents
Protein contents of the food samples were determined AOAC methods (AOAC, 1990). Statistical
by
Analysis
The data obtained during the present investigation were suitably analyzed by employing statistical designs (Snedecor and Cochran, 1967). The result values are mean of three replications.
Results
and
3.61 3.89 4.48 5.24 5.61 3.83 5.45 4.20 4.24 4.23 1.86
and other food items studied. This can be attributed to the higher content of protein i.e. casein in milk & milk products. Previous studies have reported that in normal cow's milk, protein and organic acids content and solubilization of colloidal calcium phosphate are responsible for its acid reducing properties (Salaun et al. 2005; Lucey et al. 1996, Lucey et al. 1993; Krichmeier, 1980). Al-Dabbas et al. (2010) also found in their study that cow milk offered high buffering capacity in comparison to licorice, lettuce stem, peanut, almond, lupine, lentils, bean, kidney bean and chick pea. They further opined that high buffering capacity of cow's milk is related to its high protein content (28.9% dw) glutamic (5.8% dw) aspartic (2.0% dw) acids, phosphates, organic acids and ash. The increase in pH brought about by liquid milks (FCM, TM & DTM) and Milk Products (Burfi, Peda, Rasmalai & Paneer) was higher even than the APPs studied. Yoghurt (Plain and Sweet) and Chhach didn't increase the pH to a substantial extent because their own initial pH was quite low in comparison to various types of milks (Table-l ). The low increase in pH by Rasgulla and Ice cream can be attributed to the low protein content of these products. It may be noted that though Rasgulla is basically prepared from Paneer/ Chhana, it additionally contains sugar syrup thus the total protein in Rasgulla is less in comparison to Paneer. Moreover, Chhana/Paneer is a coagulated product, therefore, the increase brought about in pH of HCl is less. Salaun et al. (2005) noted that the pasteurization of cheese milk causes denaturation of whey proteins and insolubilization of calcium phosphate that
On an average about 100 ml of HCl is secreted per hour in an adult's stomach. Therefore, in each case 100 ml of the HCI was mixed with the thoroughly mixed/mashed food item/APP. The pH was measured at 0, 10, 20 and 30 min. of mixing. Estimation
3.08 2.45
0.083 0.071 0.074 0.211 0.010 0.082 0.030 0.124 0.079 0.081 0.108 0.067 0.072 0.081 0.062 0.021
discussion
Effect of Milk, Food Items and Antacid Pharmacological Preparations (APP) on the increase in pH of HCI up to 30 min It can be concluded from Table-l and 2, that the maximum increase in pH of HCI was brought about by Burfi followed by Peda and then liquid milks i.e. DTM, FCM and TM. After Burfi and Peda other milk products Rasmalai and Paneer were found to bring about more increase of pH in HCI in comparison to all the Vegetables, Fruits, Carbonated Beverages
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Table 2 pH of Common Food Items up to 30 Min. Sr.No.
Food Item & Quantity
Initial pH of Food Item
pH ofthe mixture (Food
+ HCI) at various time intervals
CD
Omin
IOmin
20min
30min
5.56 4.36 5.41
2.57 2.73 2.98
2.77 2.75 3.02
2.77 2.75 3.02
2.77 2.75 3.02
0.055 0.020 0.023
4.68 3.86 5.13 6.32
3.60 2.21 3.22
3.64 2.23 3.28
3.64 2.24 3.30
3.65 2.26 3.31
2.86
2.88
2.90
2.90
0.022 0.018 0.031 0.022
2.62 3.03 3.10
1.76 1.76 1.76
1.77 1.78 1.76
1.76 1.78 1.76
1.77 1.78 1.76
O.oII O.oI2 0.000
7.86 5.27 6.17 5.57
3.32
3.50 4.01 2.14 3.28
3.59 4.03 2.19 3.45
3.67 4.04 2.14 3.53
0.033 0.061 0.121
Milk & Milk Products Cucumber 100 g I 2 Tomato 100 g Onion 100 g 3 Fruits Banana 100 g 1 Apple 100 g 2 3 Papaya 100 g Muskmelon 100 g 4 Carbonated Beverages I Thumsup 100 ml Limca 100ml 2 Dew lOOml 3 Other Food Items I Whole Boiled Egg (Hen) 2 Bread 100g Cooked Rice 100 g 3 4 Chocolate 50 g
3.97 2.21 2.75
0.071
Table 3 pH of mixture at 30 min and after addition of additional 50 ml HCI up to 60 min Sr. No.
I 2 3 4 5 6 7 8 9 IO II
Milk!Milk
pHofMilkl Milk Products
TM 100ml DTM100ml FCMml Burfi 50 g Peda 50 g Ras Malai 100 g Pane er 50 g APP-A APP-B APP-C APP-D
6.77 6.69 6.67 6.31 6.13 6.69 5.63 8.10 8.05 7.93 5.92
pH ofthe mixture (MilklMilk Products + HCI) at various time intervals after addition of additional 50 ml HCI of pH 1.5
pH of the mixture
5.30 5.31 5.31 5.39 5.44 4.98 4.49 4.25 4.31 4.29 1.87
30min
40min
50min
4.51 4.56 4.58 4.94 4.97 4.06 3.82 3.80 3.73 3.85 1.62
4.55 4.61 4.63 5.07 5.1 4.19 3.94 3.89 3.81 3.97 1.61
4.58 4.63 4.64 5.12
will be lost during pressing and the buffering capacity of cheese is decreased. The lower contribution of Ice cream in increase of pH can also be attributed to its lower protein content. It can be seen from Table-2 that the increase in pH of HCI brought about by Fruits, Vegetables and Carbonated Beverages are also less which may be because of their lower
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5.12 4.26 4.04 4.01 3.83 3.95 1.62
CD
60min 4.59 4.63 4.65 5.12 5.14 4.32 4.06 4.04 3.81 3.99 1.60
0.063 0.082 0.051 0.101 0.082 0.088 0.083 0.061 0.062 0.103 0.021
total solid contents. The pH measured at 20 and 30 min is similar to the pH at 10 min in case of vegetables, fruits, carbonated beverages, bread and cooked rice. It indicated that the reaction equilibrium had reached within 10 min. But in case of boiled egg and chocolate, the pH of the mixture continued to increase up to 30 min and 20 min, respectively,
Indian
J. Dairy
Sci. 67(4), 2014 !.
"
Table 4 Total Milk Protein of Milk! Milk Products vs pH of the Mixture (Milk! Sr. No.
Milk/Milk Products
I 2 3 4 5 6 7
Th1 DTM FCM Burfi Peda Rasmalai Paneer
Quantity
100rnl lOOml lOOml 50g 50g lOOg 50g
% Protein
3.233 3.447 3.424 12.061 13.503 9.560 15.901
indicating these food items were still resisting change in pH. This may be because of the high protein contents in egg and chocolate which continue to act as buffer. Effect of Milks/ Milk Products and Antacid Pharmacological Preparations (APP) on the increase in pH of additional HCl It is revealed in Table-I that with addition of liquid milks and milk products Burfi, Peda, Rasmalai & Paneer, the increase in pH of HCI was very high. So, the experiment was repeated using these items and after 30 min. additional 50 m!. HCI (pH1.5) was added. This was done to simulate the continuous secretion of acid in the stomach and to see how these products behave with the addition of acid with respect to change in pH. It can be seen from Table-3 that even with the additional 50 ml acid, the pH did not go much below the pH that was observed at 30 min prior to addition in respect of all these products. In case of liquid milks and APP-D, the pH at 40 min is similar to that at 30 min indicating that the reaction equilibrium had reached immediately; while in Burfi, Peda, Ras Malai, APP-A, APP-B and APP-C the pH continued to increase up to 40 min. In case of Paneer it further rose up to 50 min indicating that these products had further resisted change in pH. The pH at 60 min. was found to be 5.14, 5.12, 4.65, 4.63, 4.59, 4.32 and 4.06 in case of Peda, Burfi, FCM, DTM, TM, Rasmalai and Paneer, respectively. These figures of pH are not too much on the acidic side as far as stomach conditions are concerned where the pH generally ranges from 1.5-3.5. Another significant observation in this experiment that can be made from Table-3 is that all the liquid milks and milk products brought about a higher increase in pH as compared to all the APPs studied. Therefore, it can be safely said that these milks and milk products are likely to prove highly beneficial in hyperacidity/non-ulcer dyspepsia conditions, even better than the Antacid Pharmacological Preparations (APP). Effect of protein Content in Milk! Milk Products on increase in pH of HCI Al-Dabbas
et al. (2011) observed that with dairy products,
Milk Products + HCI) at 10 min
Total Milk Protein (g)
pH of Mixture at 10min
% increase from pH of HCI(I.5)
% increase in pH/Total Milk Protein
3.233 3.447 3.424 6.03 6.75 9.56 7.95
5.29 5.32 5.33
352 355 355 374 363 349 299
108.8 102.9 103.6 62.0 53.7 36.5 37.6
5.61 5.45 5.24 4.48
the high protein content ensures a relatively high buffering capacity due to the buffering effect of amino groups present and to the formation of the casein network which reduces dry matter loss during draining. However, it can be observed from Table-4 that the protein content in liquid milks and milk products have differential effects on the increase in pH of HCI per unit of protein. All the liquid milks show similar increase in pH which seems proportional to their protein content but the increase in pH by Burfi and Peda exhibit a different behavior as compared to liquid milks; but when compared between them Burfi and Peda show proportional increase with respect to their protein content. Same is the case with Rasmalai and Pane er with regard to the increase in pH. This can be explained as per the observations of Salaun et al. (2005), who found that with the denatur ition of whey proteins and insolubilization of Calcium Phosphate that will be lost during pressing of cheese, the buffering capacity of cheese is decreased. The highest increase in pH brought about by liquid milks may be because of the fact that casein present in them is in natural state and offers highest buffering capacity while in case of Burfi, Peda, Rasmalai and Paneer, the structure of the casein has changed and so it is offering less buffering capacity.
Conclusions Milk and milk products resist changes in pH better than Antacid Pharmacological Preparations and other foods in acid medium and hence can safely be recommended in hyperacidity/ Non Ulcer Dyspepsia (NUD) conditions. The per unit protein content in liquid milks shows higher buffering ability against HCI as compared to desiccated and coagulated milk products.
References AI-Dabbas, M. M. AI-Ismail, K. and AI-Abdullah, M. M. 2011. Effect of Chemical Composition on the Buffering Capacity of Selected Dairy Products. Jordan 1. of Agril. Sci. 7(4):690 - 699. AI-Dabbas, M. M. AI-Ismail, K. Abu-Taleb, R. and Ibrahim, S. 2010. Acid-
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