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IMPROVEMENT THE STABILITY OF FRIED SUNFLOWER OIL BY

USING DIFFERENT LEVELS OF POMPOSIA (SYZYYGIUM CUMINI)

Rehab F.M. Ali

Department of Biochemistry, Faculty of Agriculture, Cairo University, 12613, Giza,Egypt.

[email protected]

ABSTRACT

Pompozia fruits ( Syzyygium Cumini) is rich sources of phenolic components. The aim of the current

investigation was to evaluate the efficiency of pomposia extract as natural antioxidant compared

with BHT as synthetic antioxidant .Total polyphenols of pomposia extract was 0.49 %.

Concentrated extract of pomposia at levels 200, 400, 800 and 1200 mg kg-1

were mixed with

sunflower oil. Sunflower oil samples were heated at 180 °C + 5 °C. Then frozen French fries potato

were fried every 30 min. during a continuous period of 12 h. Oil samples were taken every 2, 4, 8

and 12 h. Some physical and chemical parameters were determined for fresh and fried samples. Theresults of the current study indicate that the natural polyphenolic compounds of pomposia extract at

level 800 and 1200 ppm exhibited antioxidant effect similar to that of synthetic antioxidant BHT at

level 200ppm.

KEYWORDS

Pomposia fruits [ Syzyygium Cumini] , BHT, sunflower oil, frying and Quality assurance tests.



Rehab F.M. Ali. et al. EJEAFChe, 9 (2), 2010. [396-403]

397

INTRODUCTION

Deep frying is widely used for the preparation of many types of foods. The high temperaturesreached during food frying lead to a complex series of reactions that result in hydrolysis, oxidation

and polymerization of the oil [1]. During deep fat-frying hydroperoxide, which is the majoroxidation product, decomposes to secondary products, such as esters, aldehydes, alcohols, ketones,

lactones and hydrocarbons. These secondary products adversely affect flavour, aroma, taste,nutritional value and overall quality of foods. Additionally, certain oxidation products are

potentially toxic at relatively low concentrations [2-3]. The synthetic antioxidants, i.e. butylatedhydroxyanisole (BHA) and butylated hydroxytoluene [ BHT] are very cost-effective given a high

stability. The use of BHT and BHA in food has been decreased due to their suspected action as promoters of carcinogenesis, as well for the general consumer rejection of synthetic food additives

[4]. Therefore, the importance of replacing synthetic antioxidants with natural ingredients fromoilseeds, spices and other plant materials has greatly increased. Some components isolated from

fruits and vegetables have been proven in model systems, being effective as antioxidants assynthetic antioxidants [5- 8].

Fruits and vegetables are rich sources of phenolic components that include simple phenols,flavonoids and anthocyanins. Besides enormous benefits, phenolic components affect theorganoleptic qualities of several foods and food products primarily through affecting their color and

taste known as astringency [9]. Jamun (Syzyygium Cumini)which is also known as pompozia fruitsis an important fruits of India. Generally two types of pomposia, the first one Rajamun is big

oblong, deep purple or bluish in colour having pink to grey is juice, sweet flesh with small seeds.The second type is known as "Kaatha" which has small fruits with comparatively big seed and flesh

acidic in taste pompozia fruit is known to have therapeutic properties as it considered to preventdiabetes and help in its control [10]. The fruit is consumed fresh, however little information about

processing of this fruit [11]. Utilization of anthocyanin the dominant pigment of pompozia fruits asnatural colorant for dairy products and jelly products was carried out by [12]. The bark of the jamun

is astringent, sweet, refrigerant, carminative, diuretic, digestive, antihelmintic, febrifuge,constipating, stomachic, antibacterial, antioxidant, anti-inflammatory, antidiabetic and

gastroprotective [13-14]. The fruits and seeds of jamun are useful in treating diabetes, pharyngitis,splenopathy, urethrorrhea and ringworm infection [15].

Thus, the purpose of the current investigation was to evaluate the efficiency of pompoziaextract as natural antioxidants during frying process of sunflower oil in comparison with BHT as

synthetic antioxidant.

MATERIALS AND METHODS

Source of pomposia .

Ripened and freshly harvested pomposia, ( Syzyygium Cumini) season, July 2008 was obtained

from the farm of Faculty of Agriculture, Cairo University, Giza, Egypt.Chemicals.

Catechin and BHT were purchased from Sigma ( St. Louis, MO, USA) . Folin-Cioculteau reagentwas obtained from Gerbsaur Chemical Co (Germany).

Sunflower oil.

Freshly refined sunflower oil without synthetic antioxidants was obtained from Sila edible oil Co.

S.A.E., Kom Osheim, El-Fayoum Governorate Egypt.Preparation of pomposia ( Syzyygium Cumini ) juice

The fruits were cleaned, cut into pieces and then pressed by means of the hydraulic laboratory pressmodel C S/N 37000-156 Freds from Carver (WI, USA) . The resultant crude juices were




398

centrifuged at 4000 rpm for 30 min, the supernatant was concentrated using a freeze- dryer

(Labconco corporation Kansas city, Missouri 64132 USA ) .The concentrated juice was kept in a brown bottle at 5°Cuntil use.

Frying process

Sunflower oil (30 kg) was divided into six portions. Four of them were mixed with 200, 400, 800

and 1200 mg kg-1

of concentrated pomposia juice the fifth portion was mixed with the syntheticantioxidant BHT at level of 200 mg kg-1 and the last portion, without antioxidant, was used as a

control. Each portion of abovementioned treatments was placed in a was placed in a stainless steel pan of electric fryer [ 25 cm depth x 30 cm length x25 cm width, Univest Co., 6

thof October city,

Industrial zone NO. 3, Giza, Egypt ] and heated at 180°C ± 5°C. Then 500 g of frozen French fries potato were fried every 30 min. during a continuous period of 12 h. Oil samples were taken every 2,

4, 8 and 12 h. The oil samples were left to cool down then stored at -10°C for subsequentdeterminations.

Determination of chemical composition of pomposia ( Syzyygium Cumini )

Moisture, crude oil, crude protein (N x 6.25) and total ash of pomposia juices were determined asdescribed in the A.O.A.C [ 16] . Total soluble Carbohydrates was calculated by difference.

Determination of total polyphenols.

Total polyphenols were determined according to the method of [17]. An aliquot from pomposia

juices ( 0.1 mL) were dissolved in a 10 mL mixture of acetone and water [ 6:4 v/v] . Sample (0.2mL) was mixed with 1.0 mL of ten-fold diluted Folin-Ciocalteu reagent and 0.8 mL of 75 g L-1

sodium carbonate solution. After standing for 30 min at room temperature, the absorbance wasmeasured at 765 nm. The results were expressed as (+) catechin equivalents.

Quality assurance tests

These tests were conducted on fresh and fried oil samples. Refractive index, acid value and peroxide

value were determined according to the methods 977.17, 969.17 and 965.33 of the AssociationOfficial of Analytical Chemists [16].

Thiobarbituric acid value (TBA) and insoluble polymers content were determined accordingto the methods of [18-19], respectively. Lovibond tintometer from Tintometer Limited (Solstice

Park, Amesbury, UK) was used to measure the color of the oil samples under investigation, theyellow glass filter was fixed at 30 and the intensity of red glass color was measured [20]. Relative

flow time was measured as an indication of oil viscosity. The relative flow times of the various samplesof oils were measured using an Ostwald viscometer according to [21].

Statistical analysis

The data of the present work were subjected to analysis of variance and the least significantdifference test, in order to compare the mean values of the investigated parameters [22].RESULTS AND DISCUSSION

Chemical composition and mineral contents of pomposia, ( Syzyygium Cumini) juices [ Based

on dry basis]

The data presented in Table [1] show the proximate composition of pomposia, (Syzyygium Cumini) juice. The moisture content of pomposia juice was 79.82%.

Pomposia juice had high levels of soluble Carbohydrates, and total polyphenols were 85.65and 0.49%, respectively. These data are in good agreement with those obtained by [ 12 and 23] .




399

Influence of pomposia extract on some physico-chemical properties of sunflower oil:

Refractive Index:

The data presented in Table [2] show that the refractive indices increased gradually with increasingthe time of frying period .However mixing sunflower oil with 800 and 1200 ppm of pomposia

extract or 200 ppm of BHT caused a significant (P<0.01) decrease in the refractive indices in friedsunflower oil compared with control sample without antioxidant. It is well known that frying

process caused conversion of some of the non-conjugated double bonds into conjugated ones. Thisreaction led to an increase in the refractive index. Data also show that the efficiency of pomposia

extract at levels 800 and 1200 in lowering the increase of refractive indices were similar to theefficiency of synthetic antioxidant BHT at level 200 ppm. The obtained results are in a good

agreement with the findings of [24, 6- 8] who found that the mixing of fried oils with variouslevels of phenolic compounds caused significant decrease in refractive index values.

Viscosity

Changes in the viscosity of sunflower oil samples under investigation are shown in Table[2].Generally, viscosity values were gradually and significantly increased with increasing the periodof frying. Adding 400,800 and 1200ppm of pomposia extract led to significant (P<0.01) decrease

the viscosity values during frying periods. Control sample without adding antioxidants hadsignificantly the highest value of viscosity at the end of frying period was 108(min) whereas

sunflower oil samples mixed with 800 and 1200 ppm of pomposia extract as well as 200ppm ofBHT had significantly the lowest values of viscosity at the end of frying period were 86.2 ,86.0and

86.3(min)., respectively. One would report that mixing sunflower oil with 800 or 1200ppm of pomposia extract led to decrease the changes of viscosity values during frying process.

It means that the highest level of polyphenols mixed with oil induced the lowest change onoil viscosity. The obtained results are in a good agreement with the findings of [24, 6- 8] who

found that the mixing of fried oils with various levels of phenolic compounds caused significantdecrease in oil viscosity during frying process.

Colour

The colour of the fried potatoes and potato chips is one of the most significant quality factors ofacceptance for fried products. .Frying process caused a significant increase of darkness which was

measured as red slid by using a Lovibond tintometer. The results present in Table [2] show thatthe values of red glass slides for fried sunflower oil were gradually and significantly increased with

the increasing the period of frying .Meanwhile, mixing sunflower oil with 800 and 1200 ppm of pomposia extract caused a significant (P<0.01) decrease in colour values compared with contro

sample. Sunflower sample mixed with 1200 ppm of concentrated of pomposia extract hadsignificantly (P<0.01) the lowest value at the end of frying period .In this respect, several studies

indicated high correlations between darkening of the colour of fried oils and oil degradation duringfrying [ 25- 27 ] . The obtained results are in a good agreement with the findings of [24, 6- 8]

who found that the mixing of fried oils with various levels of phenolic compounds causedsignificant decrease in oil oxidation.

Acid value

Acid value is one of the indicators used to access oil quality. Changes in acid value of sunflower oilsamples under investigation are shown in Table [2]. The acid value of non-fried sunflower was

0.12mg KOH/g. Generally, the values of free fatty acids of sunflower oil samples increasedsignificantly (P<0.01) with increasing the period of frying. Mixing sunflower oil samples with




401

reduction increased with the increasing the concentration of pomposia extract. Fried sunflower oil

mixed 1200 ppm of pomposia extract had significantly the lowest level of polymer was 1.66 %followed by those samples mixed with 200ppm of BHT and 800ppm of pomposia extract ranged

from 1.78 to 1.80 %. One would recommend to add pomposia extract at level 800 or 1200 ppm tooils to act as polymerization inhibitor.

Several studies indicated the effect of frying process on the physico-chemical and sensory properties of fried oil. In this respect 31; 26; 32 reported that frying oils used continuously or

repeatedly at high temperatures in the presence of oxygen and water from the food being fried, aresubject to thermal oxidation, polymerization, and hydrolysis, and the resultant decomposition

products adversely affect flavour and colour. Deterioration of frying oils is generally followed bychanges in free fatty acid [ FFA] level, colour of the used oil, or an increase in polarity of the oil [

33; 34;25; 26; 35; 27].The presence of air and water introduced as steam during the frying process can accelerate

the deterioration of frying oil [ 31] . The results of the current study are in harmony state with thedata of previous works.

Table[ 1] Chemical composition [ %] of pomposia, [ Syzyygium Cumini]

juices [ Based on dry basis]

Component pomposia juices

Moisture 79.82 b

Crude proteins [ Nx6.25] 4.66c

Crude lipids 1.76d

Crude fiber 5.29c

Ash 1.85d

soluble Carbohydrates 85.65a

Total polyphenols 0.49e

LSD 1.078

Table [ 2] Changes in some physical properties of sunflower oil mixed with different levels of pomposia juice,

200ppm of BHT and Sunflower oil without antioxidants [ control] .

Frying period [ h] 200 ppm 400ppm 800 ppm 1200 ppm BHT 200 ppm Control

Refractive index

0 1.4725a 1.4725a 1.4725a 1.4725a 1.4725a 1.4725a

2 1.4726a 1.4725a 1.4725a 1.4725 a 1.4726 a 1.4726a

4 1.4733a 1.4729 a 1.4728 a 1.4728 a 1.4732 a 1.4734a

8 1.4739a

1.4737a

1.4737a

1.4737a

1.4738a

1.4748a

12 1.4749 b 1.4748 b 1.4740a 1.4741a 1.4746a 1.4910c

LSD= 0.01633

Viscosity [ min]

0 83.5f 83.5f 83.5f 83.5f 83.5f 83f

2 90.0d

85.0f

84.0f

84.0f

84.0f

94c

4 95.1c 86.0 ef 84.83 f 84.67f 85.0 f 100 b

8 100 b

89.0de

85.17f

85.13f

85.20f

106a

12 107a 90.0d 86.2ef 86.0ef 86.3ef 108a

LSD= 2.811

Color [ Red slide ]

0 2.4 j 2.4 j 2.4 j 2.4 j 2.4 j 2.4 j

2 4.5hi

4.0hi

3.0ij

3.0ij

3.6ij

5.0gh

4 7.5e 6.0fg 3.5ij 3.4ij 4.0hi 10.0c

8 10c

9.0cd

4.5hi

4.5hi

4.5hi

12.0 b

12 13.0ab 12.0 b 8.0de 7.0ef 7.5e 14.0a

LSD= 1.332

Values are expressed as the mean of three determinations.

Values followed by different letter are significantly different at [ P<0.01] .




402

Table [ 3] Changes in some chemical properties of sunflower oil mixed with different levels of pomposia juice,

200ppm of BHT and Sunflower oil without antioxidants [ control] .

Control BHT 200 ppm 1200 ppm 800 ppm 400 ppm 200 ppm Frying period [ h]

Acid value [ mg KOH/g oil]

0.12t 0.12t 0.12t 0.12t 0.12t 0.12t 0

0.39o 0.28or 0.23s 0.26rs 0.31pq 0.34p 2

0.64k 0.46m 0.42no 0.45mn 0.57L 0.62L 4

0.98d 0.71

d 0.66k 0.76

i 0.88gh 0.91

fg 8

1.62a 0.94ef 0.87h 0.96de 1.17c 1.23 b 12

0.03072 LSD=

Peroxide value [ meq. Peroxides/Kg oil]

1.71m

1.71m

1.71m

1.71m

1.71m

1.71m

0

4.02 jk 3.74

k 2.88L 3.68

k 3.72k 4.02

JK 2

6.21f 5.16hi 4.72ij 5.25hi 6.21f 6.46f 4

11.32c 8.52

d 7.36e 8.75

d 9.01d 9.31

d 8

15.00a 11.21c 10.75c 11.65c 12.40 b 12.47 b 12

0.6444 LSD=

Thiobarbituric acid value [ Absorbance at 535 nm] 0.02k 0.02k 0.02k 0.02k 0.02k 0.02k 0

0.21ij 0.06 jk 0.06 jk 0.09 jk 0.10 jk 0.10 jk 2

0.75 bcd 0.37

chi 0.29hi 0.35

ghi 0.42gh 0.48

fgh 4

0.91ab 0.64def 0.52efg 0.63def 0.70cde 0.79 bcd 8

0.98a 0.73

bcd 0.66cdef 0.70

cde 0.79 bcd 0.84

abc 12

0.1683 LSD=

Polymer content [ %]

0.24t 0.24

t 0.24t 0.24

t 0.24t 0.24

t 0

0.99m 0.52r 0.46s 0.65q 0.82p 0.86o 2

1.68h 0.95n 0.84op 1.00m 1.49j 1.54i 4

2.19c 1.46k 1.39L 1.55i 1.88f 1.93e 8

2.64a 1.78g 1.66h 1.80g 2.08d 2.23b 12

0.02379 LSD=

Values are expressed as the mean of three determinations.

Values followed by different letter are significantly different at [ P<0.01] .

REFERENCES

1-Rossell, J. B. [ 2001] . Frying. Improving quality. In J. B. Rossell [ Ed.] . Cambridge [ England] : Woodhead

Publishing Limited.

2-Min, D. B., & Boff, J. F. [ 2001]. Lipid oxidation of edible oil. In C. Akoh & D. B . Min [ Eds.] , Food lipids [ pp.

335–363] . New York: Marcel Dekker.

3-Nawar, W. W. [ 1996]. Lipids. In O. R. Fennema [ Ed.] , Food chemistry [ 3rd ed., pp. 225–319] . New York:

Marcel Dekker.

4-Namiki, M . [ 1990]. Antioxidants/Antimutagenes in Food Crit: REV. Food Sci.Nutr.29, 273-279

5-Mansour, E. H. and Khalil, A. H. [ 2000]. Evaluation of antioxidant activity of some plant extracts and their

application to ground beef patties .Food Chemistry ,69,135-141

6-Shaker E. S. [ 2006]. Antioxidative effect of extracts from red grape seed and peel on lipid oxidation in oils of

sunflower. LWT 39 ,883–892.

7- Farag, R. S. ;Mohamoud, E. A.; Basuny ,A. M. and Rehab,F. M. Ali [ 2006]. Influence of crude olive leaf juice on

rat liver and kidney functions. International Journal of Food and Technology ,41,1-10.

8- El Anany, A.M. [ 2007]. Influence of Pomegranate [ Punica granatum] peel extract on the stability of

sunflower oil during deep-fat frying process. Electronic Journal of Food and Plants Chemistry 2 [ 1] , 14-19




403

9- Shahidi, F., and Naczk, M. [ 2005]. Phenolic in food and nutraceuticals. Book Reviews in Trends in Food Science &

Technology, 16, 171–176.

10- Shrotri, D. S.; Keller, M. ;Deshmukh, V. K. And Ramita Amiman[ 1963] Investigation of the hypoglyscemic

properties of Vinca Rosa Cassia Auriculate and E. Jambolana. Indian J. Med. Res., 51 :464.

11- Amba Dan, [ 1973]. Some new fruit beverages. Indian Hort., 18:5.

12- Hamed, H.S. Mattuke, Hemmat I. and Attia, E.A.[ 2001]. Production of anthocyanins from pompozia fruits

Egyptian Journal of Agricultural Research, 79,[ 1].

13- Teixeira, C.C, Blotta, R.M, Costa, A.P, Mussnich, D.G, Ranquetat, G.G and Fuchs FD.[ 1992] .

Plants employed in the treatment of diabetes mellitus results of an ethnopharmacological survey in Porto Alegre.Brazil: Fitoterapia LXIII;: 4: 320-322.

14-Ravi ,K.; Ramachandran, B.and Subramanian S.[ 2004]. Effect of Eugenia Jambolana seed kernel on antioxidant

defense system in streptozotocin-induced diabetes in rats. Life Sci; 75:2717-31.

15- Warrier PK, Nambiar VPK, Raman Kutty C.[ 1996]. Indian medicinal plants. Hyderabad India: Orient Longman

Ltd; 1996:225 -228. 16- A.O.A.C [ 2000]. Official Methods of Analysis of the Association of Analytical Chemists 17th. Washington, D.C.,

U.S.A.

17- Jayaprakasha, G., Selvi, T., & Sakariah, K. [ 2003]. Antibacterial and antioxidant activities of grape [ Vitis

vinifera] seed extracts. Food Research International, 36, 117–122.

18- Sidwell , C. G.; Harold, S.; Milado, B. and Mitchell ,J .H .[ 1954] .The use of thiobarbituric acid as a measure of fat

oxidation. J. Am. Chem. Soc.31: 603-606.

19- Wu, P.F. and Nawar W.W. [ 1986]. A technique for monitoring the quality of used frying oils.

J. Am. Oil Chem. Soc. 63: 1363-1367 20- Nielsen, S. S. [ 1998]. Food Analysis. Second edition, An Aspen publication, Aspen publisher Inc. Gaithersburg,

Maryland pp 222-223.

21- Joslyn MA [ 1950]. Methods in Food Analysis. Academic Press, New York.

22- Cochran, WG. And Cox, GM. [ 1992]. Experimental Designs, 2nd Ed, New York. Wilely.

23- Chowdhury, P. and Ray, R.C. [ 2007]. Fermentation of Jamun [ Syzgium cumini L.] Fruits to Form Red Wine

ASEAN Food Journal 14 [ 1] : 15-23.

24- Farag R.S., El-Baroty, G.S. and Amany, M. Basuny [ 2003]. The influence of phenolic extracts obtained from the

olive plants [ cvs. Picual and Kronakii] on the stability of sunflower oil. J. Food Sci. Technology .38,81-87.

25- Orthoefer, F. T. [ 1988] . Care of food service frying oils. Journal of the American Oil Chemists’ Society, 65[ 9] ,

1417–1419.

26- White, P. J. [ 1991]. Methods for measuring changes in deep-fat frying oils. Food Technology, 45[ 2] , 75–80.

27- Orthoefer, F. T. and Cooper, D. S. [ 1996]. Evaluation of used frying oil , in deep-frying Chemistry, Nutrition and

practical Application, edited by E. G. Perkins and M. D. Erickson, AOAC Press, Champaign, PP. 285-296.

28-Barthel, G. and Grosch, W. [ 1974]. Peroxide value determination comparison of some methods .

J. Am. Oil Chem. Soc. 51, 540.

29- Azuma, K.; Ippoushi.K.;Higasio,H and Terao, J.[ 1999]. Evaluation of antioxidative activity of vegetable extracts in

linoleic acid –emulsion and phospholipids bilayers. J,Sci. Food Agri.,79,1-7

30- Orthoefer, F. T., Gurkin, S., and Liu, K. [ 1996]. Dynamic of frying. In E. G. Perkins, & M. D. Erickson [ Eds.] ,

Deep frying. Chemistry, nutrition, and practical applications [ pp. 223–244] . Champaign, IL: AOCS Press 31- Clark, W. L. and Serbia, G. W. [ 1991]. Safety aspects of frying fats and oils. Food Technology, 45[ 2] , 84–89,

94.

32- Tyagi, V. K., and Vasishtha, A. K. [ 1996] . Changes in the characteristics and composition of oils during deep-fat

frying. Journal of the American Oil Chemists’ Society, 73[ 4] , 499–506.

33- Paradis, A. J., and Nawar, W. W. [ 1981]. Evaluation of new methods for the assessment of used frying oils.

Journal of Food Science, 46, 449–451.

34- Tan, Y. A., Ong, S. H., Berger, K. G., Onn, H. H., and Poh, B. L. [ 1985]. A study of the cause of rapid color

development heated refined palm oil. Journal of the American Oil Chemists’ Society, 62[ 6] , 999–1006.35- Melton, S. L., Jafar, S., Sykes, D., and Trigiano, M. K. [ 1994]. Review of stabilitymeasureme nts for frying oils

and fried food flavor. Journal of the American Oil Chemists’ Society, 71[ 12] ,1301–1308.

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