J. Sci. Food Agric. 1982, 33, 576578

A Comparison of Seed Phosphatides and Synthetic Compounds as Antioxidants for Cow and Buffalo Ghee (Butter Fat)

Narinder Kaur, Pritam S. Sukhija and Iqbal S. Bhatia

Department of Biochemistry, Panjab Agricultural UniversirjJ, Ludhiana, India

(Manicscript received 26th May 1981)

The antioxidant capacity of seed phosphatides and synthetic antioxidants when com- pared in cow ghee was found to be in the order: phosphatidyl ethanolamine > propyl gallate > palmitoyl ascorbate > butylated hydroxy anisole > phosphatidyl choline. Phosphatidyl ethanolamine was found to be the most effective antioxidant. Cow ghee had less peroxide development than buffalo ghee. The ghee prepared at 100°C was more stable against peroxide development compared with that prepared at 50°C. These observations were supported by the analysis of ghee samples for peroxide values and for fatty acids. The phosphatides imparted more antilipolytic activity to ghee then to synthetic antioxidants.

1. Introduction

An earlier investigation' showed that when seed phosphatides are added to ghee they impart signifi- cant protection against both oxidative and lipolytic deterioration. Commercial antioxidants such as propy I gallate (PG), palmitoyl ascorbate (PA) and butylated hydroxy anisole (BHA) are widely used to control autoxidation in vegetable oils and fats2. However, in addition to their antioxidative effects, they adversely affect the flavour of the 0iL3 Natural antioxidants, such as seed phosphatides, if equally effective in retarding the oxidative and hydrolytic spoilage of ghee, would be advan- tageous over commercial antioxidants for use on a large scale.

Therefore, the present study was undertaken to compare the antioxidative and antilipolytic properties of seed phosphatides with commercial antioxidants in ghee.

2. Experimental 2.1. Materials The creams from cow and buffalo milks were obtained from the Department of Food Science and Technology, Panjab Agricultural University, Ludhiana. Butter was prepared using an electric churner, and ghee obtained by heating butter at 50 and 100°C.

2.2. Seed phosphatides and other antioxidants Phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) from sunflower seed (Helianthus unnuus) oil were isolated as described previously.1 The amount of phosphatides was estimated by the methods of A r n e ~ . ~ The concentration in ghee of PE and PC was 0.05 mg g-l while that of PG, PA and BHA was 0.1 mg g-1. The samples were mixed thoroughly in capped tubes and stored at 37°C for a period of 90 days. The peroxide value was determined by the method of Sallee.5 The triglycerides were isolated by preparative thin-layer chromatography.

2.3. Fatty acid analysis The fatty acid esters were prepared by the method of Luddy et al.6 and analysed by gas-liquid

0022-S142/82/06O(M576 $02.00 0 1982 Society of Chemical Industry

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Antioxidants for cow and buffalo ghee 511

chromatography. The column conditions, id-ntification of fatty acids and the calculation of peak area were as described previous1y.l

3. Results and discussion

The peroxide values of the cow and buffalo ghee samples, prepared by heating butter at 50 and 100"C, were determined after storage at 37°C for periods of 30, 60, and 90 days in the absence of

Figure 1. The effect of storing ghee at 37°C on peroxide development: 0, buffalo ghee (50°C); 0 , buffalo ghee (100°C); 111, cow ghee (50°C); a, cow ghee (100°C); A, cow ghee (100°C) plus phosphatidyl choline; A, cow ghee (IOOT) plus butylated hydroxy anisole; V, cow ghee (100°C) plus palmitoyl ascorbic acid; V , cow ghee (100°C) plus propyl gallate; and cow ghee (100°C) plus phosphatidyl ethanolamine.

Figure 2. The effect of storing ghee at 37°C on the ratio of saturated to fatty acids: 0, buffalo ghee (50°C); 0 , buffalo ghee (1OO'C); 0 , cow ghee (50°C); a, cow ghee (IOOT),; '1, cow ghee (100°C) plus phosphatidyl choline; A, cow

ghee (100°C) plus butylated hydroxy anisole; V , cow ghee (IOO"C) plus palrnitoyl ascorbic acid; v , cow ghee (100°C) plus propyl gallate; and - - -. cow ghee (100°C) plus phos- phatidyl ethanolamine.

, 0 30 60 90

Time of incubation (days)

t

1.0 - 30 60 90

Time of incubation (days)

antioxidants (Figure 1). It was observed that in the cow ghee the peroxide development was less than in the buffalo ghee. This may be due to the higher amount of phospholipids in cow ghee.7 The ghee prepared at 100°C had a better keeping quality than that prepared at 50T, possibly due to the higher phospholipid content in ghee heated to 100°C.7 The higher phospholipid content of ghee prepared at 100°C can be attributed to the increased liberation of phospholipids from lipopro- tein complexes and the increased efficiency of removal of moisture.

578 N. Kaur et 4l.

For comparison of the antioxidant efficiency of phosphatides and synthetic compounds, cow ghee prepared by heating butter at 100°C was used. The antioxidant potential of these compounds was found to be in the order: PE > PG > PA > BHA > PC (Figure I). PE was found to be the most effective antioxidant for ghee. This was also evident from the analysis of the fatty acid composition of stored ghee. The ratio of saturated : unsaturated fatty acids increased during storage due to the oxidation of unsaturated fatty acids. This increase was higher in buffalo ghee and ghee prepared at 50°C than in cow ghee and ghee prepared at 100°C (Figure 2). In the presence of antioxidants, the increase in the ratio was in the order: PC > BHA > PA > PG > PE, indicated an antioxidant capacity in the order: PE> PG > PA > BHA > PC (Figure 2). These observations are in agreement with the peroxide values obtained (Figure 1).

Figure 3. The effect of antioxidants on the triglyceride content of cow ghee (100°C) stored at 37°C: e, phos-

propyl gallate; - .. - .. -, palmitoyl ascorbic acid ; -, butylated hydroxy anisole; and - - -, control.

e phatidyl choline; A, phosphatidyl ethanolamine;

30 60 90

Time of incububation (days)

The effect of these antioxidants on lipolysis was studied by measuring the triglyceride contents of the ghee samples after storage for 30, 60 and 90 days. In each treatment a decrease in triglyceride content was observed. The decrease was almost the same in the control, PG, BHA and PA, but significantly higher than PE and PC (Figure 3). The effectiveness of PE and PC as antilipolytic agents could be due to their interaction with the lipase system.8 These results suggest that seed phosphatides are more effective in the control of oxidative and lipolytic deterioration of ghee during storage than many synthetic antioxidants used commercially.

References 1 .

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Bhatia, I. S.; Kaur, N. ; Sukhija, P. S. Role of seed phosphatides as antioxidants for ghee (butter fat). J. Sci. Food Agric. 1978, 29, 747-752. Sedlacek, B. A. J. Use of certain antioxidants in the stabilisation of oils. 1. Initial and other non-volatile products of autoxidation. Fette, Seifen, Anstrichm. 1968, 12, 721-725. Ramanskaya, N. N.; Valeeva, A. H. Effect of synthetic antioxidants on the stability of milk fat during storage. Trudy. Frimzensk. Politekh. Inst. 1962, 7, 17-21. Ames, B. N. Assay of inorganic phosphate, total phosphate and phosphatases. In Methods in Enzymology (Neufeld, E.; Ginsberg, V., Ms), Vol. 8, Academic Press, New York, 1960, pp. 115-118. Sallee, E. M. Peroxide value. In Oficial and Tenfarive Melhods of American Oil Chemists' Society (Method Cd 8-53) Chicago, 1960. Luddy, F. E.; Barford, R. A.; Herband, S. F.; Paul, M. J. A rapid and quantitative procedure for the pro- duction of methyl esters of butter oil and other fats. J. Amer. Oil Chern. Soc. 1968, 45, 549-552. Rama Murthy, M. K.; Narayanan, K. M.; Bhalerao, V. R. The role of ghee residue as an antioxidant in ghee. Indian J. Dairy Sci. 1969, 22, 57-58. Campbell, L. €3.; Watrous Jr, G. H.; Keeney, P. G. Induced lipolysis in milk as affected by adding some phos- pholipids and a cerebroside. J. Dairy Sci. 9167, 50, 963.