Sarhad J. Agric. Vol. 23, No. 2, 2007

STABILITY OF A (RETINOL) IN FATS/OILS

Habibullah*, Muhammad Abbas**, Hamid-Ullah Shah* and Ateeq-Ur-Rehman*

ABSTRACT The quality of locally available Ghee and oils was investigated at the department of Agricultural Chemistry, NWFP Agricultural University, Peshawar, Pakistan during May – October, 2005. Different brands of Ghee i.e. Shama Banaspati , Gulab Banaspati , Kohinoor Banaspati and Fauji Banaspati and Oil ( Handi Cooking Oil ) were analyzed for contents and quality parameters (acid and iodine values). Analysis of data revealed that Handi Cooking Oil had maximum content of vitamin A (156.5 µg.kg –1) followed by Gulab Banaspati Ghee (91.4 µg.kg –1). The lowest vitamin A content was found in Shama Banaspati (73.8 µg.kg –1). Mean values of the data indicated that the acid and iodine values were in the range of 0.9 to 2.7 mg.g –1 and 5.3 to 11.2 g.100 g –1, respectively. On exposure to ambient condition (for 7 days at 25-38 °C and 38-51 % humidity under incandescent bulb), the maximum degradation of retinol level was found in Handi Cooking Oil. Analytical analysis of free fatty acid and iodine value indicated that the exposure affected the quality of ghee especially of Fauji Banaspati , which might be due to the short chain fatty acid and unsaturation.

INTRODUCTION Vitamin A (chemically known as retinol) was the vitamin A. Since ghee or oils are exposed to air and first fat-soluble vitamin to be recognized in 1913. In humidity during various occasions of their processing nature it is found largely as an ester, and and usage, so there quality may be disrupted. The air, consequently is highly soluble in organic solvents but water and temperature are main causes for vitamin A not in aqueous solutions. The major pro-vitamin, deterioration. A regular check is indispensable for beta-, has similar solvents properties. One of quality control and to estimate the retention time of the richest sources of vitamin A is tissue. vitamin A. This study was designed to investigate the retention time and fat quality parameter (acid value Vitamin A plays an important role in vision, bone and iodine value). growth, reproduction, cell division and cell differentiation (Smith and Steinmann, 2000). Its MATERIALS AND METHODS deficiency is usually caused by prolonged dietary Sample Collection deprivation. It is endemic in areas, such as southern A number of different brands of fats and oils (Shama and eastern Asia, where , devoid of carotene, is Banaspati, Gulab Banaspati, Kohinoor Banaspati, the staple diet. Other causes of deficiency include Fauji Banaspati and Handi Cooking Oil ), packed in inadequate conversion of carotene to vitamin A or an polythene bags, were collected from different areas interference with absorption, storage, or transport of of Peshawar. The analysis was carried out at the vitamin A. For children, lack of vitamin A causes laboratory of Agricultural Chemistry department, severe visual impairments and blindness, and NWFP Agricultural University Peshawar, Pakistan significantly increases the risk of severe illness, and during May-October, 2005. A small portion of them even death, from such common childhood infections (termed as packed samples ) was taken for analysis. as diarrhea disease and (West et al . 2001). The remaining portion of these fats and oils was kept For pregnant women in high-risk areas, vitamin A exposed for 7 days at room temperature (25-38 °C deficiency occurs especially during the last trimester and 38-51% humidity) under incandescent bulb. when demand by both the unborn child and the These samples (termed as unpacked samples ) were mother is highest. The mother’s deficiency is analyzed in the same way as the packed samples to demonstrated by high prevalence of night blindness determine the difference. during this period. may also be associated with elevated mother-to-child HIV Determination of Vitamin A transmission (Cox, 1999). Vitamin A (retinol) contents were determined by colorimetric method (AOAC, 1984). Vitamin A ֿ.As the fats and oils are good carriers of vitamin A out content was expressed as µg.kg ¹ side and inside the body, so the fortification of oil/fats are taking place in many developed and under Calculation of Acid and iodine Values developed countries. Moreover, ghee or cooking oils Acid and iodine values are the main parameters used are commonly used in daily diets; therefore it is an for the quality measurement of fats. These values important way to fulfill the daily requirements of were determined according to the methods given in

* Department of Agricultural Chemistry, NWFP Agricultural University, Peshawar – Pakistan. ** Department of Human , NWFP Agricultural University, Peshawar – Pakistan. Sarhad Journal Agricultural. Vol. 23, No. 2- 2007 456

A.O.A.C. (1984). The acid and iodine values can be The iodine value of the subject Ghee and Oil was calculated by the following formulas. minimum in Gulab Banaspati (5.3 g.100g -1) and Acid value (mg g -1) = T x N x 56.1 / wt of sample maximum in Handi cooking oil (11.2 g.100g -1). The (T = titration reading in ml, N = normality of the alkali) reason was that the cooking oil contains more

-1 unsaturation and so they absorbed more iodine. The Iodine Value (g 100g ) = (B – S) x N x 12.7 / wt of sample data agreed with the result of Langewar and Badole (B = blank titration reading in ml, S = sample titration (2000). This result was also in line with Rathanam reading in ml, N = normality of Na 2S2O3). and Sail (1998) who reported that the partial RESULTS AND DISCUSSION unsaturation of ghee is due to the incomplete The analysis was conducted in the laboratory of hydrogenation of ghee. The maximum decrease in iodine value was observed in Fauji Banaspati (3.6 Agricultural Chemistry Department, NWFP -1 Agricultural University, Peshawar. The data of acid g.100g ). The iodine values decreased as the ghee value, iodine value and vitamin A content are exposed to the air because the oxygen in the air presented in Tables I, II and III, respectively. attack on the double bond and make their oxides. This causes the break down of fatty acids into short In the data regarding the acid value, a significant chain fatty acids like butyric acid which result in the difference was observed among the packed and bad smell of the ghee commonly known as rancidity exposed ghee and oils. The difference was also present (Rathanam and Sail, 1998). among different brands. The acid value of Handi cooking oil was lowest (0.9 mg.g -1) among the packed Vitamin A content among different brands was in the µ -1 samples followed by Shama Banaspati (1.0 mg.g -1), range of 73.8 to 156.5 g kg . The minimum content Kohinoor Banaspati (1.4 mg.g -1) and Gulab Banaspati was found in Shama Banaspati and maximum was (2.3 mg.g -1). The highest acid value was observed in present in Handi cooking oil. Similar result was Fauji Banaspati (2.7 mg.g -1). The maximum difference reported by Dutra-de-Oliveira et al. (1998). The due to exposure was observed in Fauji Banaspati (2.4 exposure affected the cooking oil worse and the -1 µ -1 mg.g ). This might be due to unsaturation in the Fauji difference was 47.9 g.kg . The decrease in vitamin Banaspati . The result was in good agreement with that A content may be due to the more reactive attack of of Runge and Heger, (2000), who reported the effect of air oxygen or water. air on the acid value of different ghee brands.

(Table I Acid value (mg.g¹)ֿ of different commercial brands of Ghee and cooking oil (Packed and unpacked Different brands of ghee and cooking oil* Reading A B C D E R1 1.0 2.0 1.7 3.0 0.5 Packed R2 0.7 3.0 1.2 2.7 0.9

R3 1.2 2.0 1.3 2.3 1.2 Mean 1.0 2.3 1.4 2.7 0.9 R1 1.7 4.3 3.1 4.9 2.8 R2 1.4 4.4 2.8 5.3 3.0 Unpacked R3 1.4 4.2 3.1 5.1 3.2 Mean 1.5 4.3 3.0 5.1 3.0 Difference 0.5 2.0 1.6 2.4 2.1 (of different commercial brands of Ghee and cooking oil (Packed and unpacked (¹־ Table II Iodine value (g.100g Different brands of ghee and cooking oil* Reading A B C D E R1 5.0 4.0 5.0 6.0 11.0 Packed R2 8.0 5.0 7.0 9.0 10.5

R3 7.0 7.0 9.0 11 12.0 Mean 6.7 5.3 7.0 8.7 11.2 R1 3.4 4.0 4.0 5.4 8.4 R2 3.6 4.2 4.3 5.0 8.6 Unpacked R3 3.5 4.1 4.3 4.9 8.5 Mean 3.5 4.1 4.2 5.1 8.5 Difference 3.2 1.2 2.8 3.6 2.7 (A = Shama Banaspati, B = Gulab Banaspati, C = Kohinoor Banaspati, D = Fauji Banaspati, E = Handi cooking oil) Sarhad J. Agric. Vol. 23, No. 2, 2007 457

Table III Vitamin A content (µg.kg ¹)ֿ of different commercial fortified brands of Ghee and cooking oil (Packed and unpacked) Different brands of ghee and cooking oil* Reading A B C D E R1 73.9 90.7 84.1 82.0 156.3

Packed R2 74.5 91.5 85.0 82.5 156.7 R3 73.1 92.0 84.5 83.0 156.5 Mean 73.8 91.4 84.5 82.5 156.5 R1 60.8 80.0 76.2 71.0 108.5 R2 60.9 80.4 76.5 70.5 108.3 Unpacked R3 60.8 80.2 76.2 70.0 109.0 Mean 60.8 80.2 76.3 70.5 108.6 Difference 13.0 11.2 8.2 12.0 47.9 * (A=Shama Banaspati, B = Gulab Banaspati, C = Kohinoor Banaspati, D = Fauji Banaspati, E = Handi cooking oil)

CONCLUSION It was concluded that quantity of ghee and oil varies A.O.A.C. 1984. Official methods of analysis (14 th ed.). The brand to brand because of the handling during Assoc., Arlington, Virginia, USA. processing and storage condition. The exposure to atmosphere badly affects the quality of ghee and oil Runge, F. E. and R. Heger. 2000. Use of microcalorimetry in monitoring stability studies. Example: Vitamin and affects the vitamin A content of fortified brands. A. esters. J. Agric. Food Chem. 48 (1): 47-55. So exposure should be minimize to ensure good quality of the ghee and oils. Langewar, M.M. and W.P. Badole, 2000. Chemical characteristics and fatty acid Composition of some REFERENCES mustard cultivars. J. Mah. Agric. Univ. 25(1): 114- Smith, J. and L.T. Steinmann, 2000. Vitamin A deficiency 115. and the eye. Int’1. Ophthalmology Clinics. 40(4): 91. Rathanam, K. and S.S. Sail, 1998. Physico-chemical characteristics, fatty acid composition and West, K. P., Darnton-Hill, J. R., Semba, R. D. and Bloem, nutritional evaluation of spongy gourd seed oils. J. M. W. 2001. Vitamin A deficiency. Nut. Health Oil Tech. Assoc. of India. 30(4): 173-176. developing countries. 24 (2): 267-306 Dutra, D. O. E., R. M. D., Favaro, M. V. M., Junqueira, C. Cox, S. 1999. Role of vitamin A in the immune system: G., Carvalho, A. A. Jordao, and H. Vannucchi, implications for vitamin A deficiency in the 1998. Effect of heat treatment on the biological pathology and vertical transmission of the human value of beta-carotene added to soybean cooking oil immunodeficiency virus. Nut. Abst. Rev. Series-A, in rats. J. Food Sci. Nut. 49(3): 205-210. H. Exp. 69(7): 585-598.

Sarhad J. Agric. Vol. 23, No. 2, 2007 457