(jamilah et al., 1998) antioxidant activity of citrus hystrix peel extract in rbd palm olein during...

8/6/2019 (Jamilah Et Al., 1998) Antioxidant Activity of Citrus Hystrix Peel Extract in Rbd Palm Olein During Frying of Fish Crak

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ANTIOXIDANT ACTIVITY OF CITRUS HYSTRIX PEELEXTRACT IN RBD PALM OLEIN DURING FRYING OF FISHCRACKERSB. JAMILAH', YAAKOB B. CHE MAN and THEAN LING CHING

Department of Food TechnologyFaculty of Food Science and B iotechnologyUniversiti Putra Malaysia43400 Serdang, Selangor, Malaysia

Received for Publication December 2, 1997Accepted for Publication March 5, 1998

ABSTRACTThe Citrus hystrix peel extract (2,000ppm ) and butylated hydroxytoulene(BHT)(2OOppm) were added to t h e h i n g oil. The antioxidant activities were determ inedduring deep a t h i n g of f ish crackers o r 4 consecutive days. Each frying periodwas or 5 h and interm ittenthing at 180Cwith hal fan hour interval was carriedout. The antioxidant activities were determined by measuring peroxide va lue (PV),

p-anisidine value (A nV), totox value, iodine value (IV), percent free fat ty acids,color and viscosity of the oil. Results indicated that the ethanol extract of the citruspeel exhibited antioxidant properties and therefore has a potential as one of thenew sources of natural antioxidants.

INTRODUCTIONDeep fat frying of fish crackers in refined, bleached and deodorized (RBD )

palm olein is widely practiced in Malaysia. During frying the formation ofnumerous ox idized products with an unpleasant odor and taste affects the qualityof the fiied food. Synthetic antioxidant such as butylated hydroxytoulene (BHT)may retard lipid oxidation when added to food. However, processing techniques,method of incorporation of antioxidant, the type of oil and type o f product friedinfluence the effectiveness of antioxidants in food products (Ahm ad and Augustin1985). The interest in the activities of natural antioxidant has grown in recent years

'To whom correspondence should be addressed: T el: 03-9486101(10), Fax: 03- 9423552, E- mail:[email protected] ofFood Lipids 5 (1998) 149-157. AllRigh ts Reserved.oCopyright I998 by Food & Nutrition Press, Inc., Trumbull, Connecticut. 149


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150 B. JAMILAH,Y.B.CHEMAN and T.L.CHING

due to the possible deleterious health effects from the ingestion of syntheticantioxidants (Barbut et al. 1985). Antioxidant activities of various methanolicextracts of 180 oriental herbs (Kim et al. 1994), peanut hulls (Gow and Duh 1994),spices like sage and rosemary have been reported (Schuler 1990). Seed extracts ofCitrus rituculants and Citrus reshini have been reported to have antioxidantactivities (Pereira and M ancini 1994). The leaves of Citrus hystrix (limau purut)are popularly used as food condiments in the ASEAN region, however, the h i t sare often wasted. Furthermore, the antioxidant activity of any part of Cilms hystrixhas never been reported. Therefore, this study was carried out to determine theantioxidant activity of the peel extract in retarding the development of rancidity inRBD palm olein during intermittent frying of fish crackers.

MA TERIALS AND METHODSFish crackers and Citrus hysfrrjrwere obtained from the local markets. Fresh

RBD palm olein was purchased direct from local refinery.Extraction of Antioxidant

The fruit of Citrus hystrix was hand peeled and peels were dried at roomtemperature for 24 h. Dried peels were extracted with ethanol for 24 h in anincubator shaker (50C)at an ethanol to peel ratio of 125 (v/v). The crude extractwas then filtered, the ethanol removed using a rotary evaporator at 50C . Theconcentrated ex tract was then flushed with nitrogen and kep t at - 18C until use(Economou et al. 1990).Frying Experiment

The frying experiment was carried out in a Valentine batch fryer (M odel1020,max. apacity of 5kg) using a modified version of the p rocedure describedby Augustin et al. (1987). Four kilograms of oil were heated up to 60C for 10min, after which 200 ppm BHT or 2,000 ppm of Citrus hystrix extract were addedto the oil with slow stirring. No antioxidant was added to the oil identified a scontrol. The oil was then heated up to 180C and frying of fish crackers wasstarted 15min later. Thirty grams of fish crackers were fried for 40 s at half anhour interval for 5 h daily for 4 consecutive days. This is equivalent to 11 batchesof frying a day. After the 1 th frying,200mL of the oil was sampled for analysisafter the temperature of the oil had dropped to 60C. Two hundred milliliters offresh RE3D palm olein was added to the oil before the frying experimentproceeded for the next day.


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FISH CRACKER FRYING 1 5 1

Chem ical AnalysisThe peroxide value (PV) , p-anisidine value (AnV), iodine value (IV) andpercentage of free fatty acids (FFA) as palmitic acid were determined according to

the PO RIM Test Methods (1985). Totox value was calculated a s the AnV plusM ice the PV (Sherwin 1978; Augustin and Berry 1983). Th e composition of thefatty acids were determined for the computation of C18:2/C16:0. Th e fatty acidwas determined according to the PORIM Test Method (1 985) and analyzed usinga ga s liquid chromatograph (Hewlett Packard, model 5890A ). Th e peaks wereresolved on a STABILWAX-DA (0.53 mm i.d) column and the flow rate of thecarrier g as, helium, was at 20 mL min- and that of hydrogen was 4 4 mL min- .The oven and detector (Flame ionization detector) temperatures were 200 C and thatof the column was 18OC.Physical Analysis

The color of the oil was measured in a 1 cell in a Lovibond Tintometer(PORIM Test Method 1985). The viscosity changes of the oil was de termined byusing a computerized Brookfield DV 111Rheometer (Brookfield Engineering Labs.Inc., Stoughton, MA).Statistical Analysis

All the collected data were analyzed by analysis of variance (ANOVA) andDuncans Multiple Range Test using the programmed Statistical A nalyses System(SAS 1987). The whole experiment was repeated twice and all analysis were d onein triplicates.

RESULTS AND DISCUSSIONTh e fresh oil had an initial PV of 0.02 meq kg-, AnV of I .34, totox value o f

1.74, and IV of 56.10 g / 1 OOg oil. Thus, the oil had good initial qualities.The PV, which is an indicator of the primary oxida tion products, was found toincrease from the first day to the second day of frying for all three treatments.Similartrends for the changes in the peroxide values was observed for the control,BH T and extract-incorporated oils (Fig. 1). Significant differences (p


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I52 B. JAMILAH,Y.B. HE MAN and T.L. CHING

anisidine reactive compounds. The BHT- incorporated oil had AnV which weresignificantly higher than either the extract incorporated or the control oil. Thiscould be misleading; however, it has been shown that the an isidine test is not agood m easure of frying oil quality in potato chips w i n g since changes in theAnV values are not proportional to other parameters that could depict thedeterioration rate of frying oil (Augustin and Berry 1983).

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0 1 2 3 4Frying Time (days)FIG. . CHANGES TO PEROXIDE VALUES OF OILS DURING FRYING

The totox value which is defined as the sum of the AnV and 2 times the PV isa measure of the total oxidation occurring in the oil. The totox values of controlare significantly different from BHT and extract incorporated oil throughout thefrying experiment (Table 1). Hence, this could indicate that there is no differentin the effectiveness of the extract in retarding the deterioration process of thecooking oil.


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FISH CRACKER FRYING 153

180

70

60

20

10

0

+control

+extract

FIG. 2. CHANGES IN ANISIDINE VALUES OF O ILS DURING FRYING

Iodine value is an ind icator for the degree of unsaturation of the fatty acids inthe oil and therefore, the more the oxidation and polymerization occur, the loweris the value (IUPAC 1979). How ever, a significant change in the iodine value willonly be observed when there is excessive deterioration o f the oil (Augustin andBerry 1983). Significant differences among the oils were distinct on the secondand the third day of frying only. Thus indicating that BHT incorporated oil wasonly slightly less oxidized than that of extract incorporated oil. N o significantdifference was obtained among treatments throughout the study. The increase inFFA of all samples indicated that these were formed during the frying process andthat neither BHT nor the ex tract was capab le in retarding their formation.


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154 B. JAMILAH,Y.B. CHE MAN nd T.L. CHINGTABLE 1 .THE TOTOX VALUE, IODINE VALUE AND FFA VALUESOF OILS DURING FRYING

Characteristics Days Control* BHT* CitrushystrixExtract*Totox value 0 1.74iO.02" 1.74i0.02' 1.74i0.02'

I 68.17*0.32' 59.69*0.95' 59.99j~0.84~2 83.93i0.87' 8 1.48iO.18b 82.2O~k0.48~3 94.73i0.69' 90.28i1.08' 91.55*00.95b4 95.75i0.29" 91.22i1.35' 92.05i0.24'

Iodine value 0 56.1W0.01" 56.10*0.01" 56.10-+0.01"(g of I,lOOg-'oil) 1 54.303~0.07~ 55.8%0.25' 55 02i0.26"2 52.50k0.23' 55.57i0.38' 54.22iO.18'3 5 1.4Oi0.06' 54.15i0.74" 52.95i0.49'4 5 1.21k0.53' 53.17*0.26' 52.0WO.18"'

% FFA 0 0.089;tO.OO" 0.08W0.00' 0.08W0.00'1 0.175i0.01" 0.16W0.00' 0.17W0.00'2 0.335i0.02 0.32M.00' 0.315*0.02'3 0.432i0.00' 0.395%0.03' 0.4200.03'4 0.432i0.00' 0.5 15*0.01' 0.535*0.03'0.545i0.01' 0.515*0.01' 0.535i0.03'

* Means and standard deviations were from 6 analyses and 2 replicates of each. Means within eachrow follow by the same letter are not significantly different (P


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TABLE 2.THE RATIO O F C 18:2 / C 16:O FOR OILS DURING FRYING~

Days of Frying Control* BHT* Citrus hystrixExtract*0 0.288i0.01" 0.288i0.01" 0.228i0.01"1 0.20510.01' 0.22010.00" 0.21 5i0.0 2a2 0.165i0.02' 0.2 13i o.o " 0.205i0.02"3 0.095iO.O 1' 0.160*0.Ola 0.135*0.Ola4 0.085i0.01' 0.120+0.01" 0.1o oio.0 0"

* Means and standard deviations were from 6 analyses and 2 replicates of each. Means withineach row w ith the same letters are not significantly different (p


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I56 B. JAMILAH, Y.B. CHE MAN and T.L. CHING

The viscosity of the oil is related to the presence of polym eric materials in it(Berger 1984). The BHT incorporated oil was found to be slightly less viscousthan extract incorporated oil.

CONCLUSIONFrom the results above, it could be concluded that the ethano l extract of the

Citrus hystrix peel has a potential as a new source of natural antioxidant. Itsantioxidan t properties could possibly be improved by further purification of theextract.

REFERENCESAHMAD, S. and AU GUSTIN, M.A. 1985. Effect of tertiarybutylhydroquinoneon lipid oxidation in fish crackers. J. Sci. Food Agric. 36, 393-401.ASAP, T. and AUGUSTIN, M.A. Effects of TBHQ on qualitycharacteristics of RBD palm olein during frying. J. Am. Oil Chem. SOC.63,AUGUSTIN, M.A., ASAP, T. and LEE, K.H. 1987. Relationsh ips betweenmeasurements of fat deterioration during heating and frying in RBD olein. J.

Am. Oil Chem. SOC. 4,1670-1675.AU GU STIN, M.A. and BERRY, S.K. 1983. Efficacy of the an tioxidants BHAand BH T in palm olein during heating and frying. J. Am. Oil Chem. SOC . 0,AUGUSTIN, M.A., LEE, K.H. and IDRIS, N.A. 1989. Frying experiments w ithhydrogenated vegetable shortenings and palm olein. Pertanika I2 , 167-172.BARBUT, S., JOSEPHSON, D.B. and MAURER, A.J. 1985. Antioxidantproperties of rosemary oleoresin in turkey sausage. J. Food Sci. 50, 1356 -1359, 1363.BERGER, K.G. 1984. The practice of frying PORIM Technology No. 9.PORIM , Bandar Baru Bangi.ECONOM OU, K.D., OREOPOULO U, V. and THOMO POUL OS, C.D. 1990.Antioxidant activity of some plant extracts of the family labiatae. J. Am . OilChem. SOC.68, 109-1 13.GOW , C.Y. and DUH, P.D. 1994. Antioxidant properties of m ethanolic extractsfrom peanut hulls. J.Am. Oil Chem. SOC . 0,383-386.IUPAC. 1979. Standard methods for the analysis of oils, fats and derivatives. In

IUPAC, 6th Ed. (C. Paquot, ed.) Applied Chem. Div., Comm ission on oil, fatsand derivatives.

1986.1169-1171.

1520-1523.


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KIM, S.Y., JUNG, M.Y. and OH, M.J. 1994. Antioxidant activities of selectedoriental herb extracts. J.Am. Oil Chem . SOC.71,633-640.PEREIRA, R.B. and MANCINI, F.J. 1994. Antioxidant activity evaluation ofcitrus h i t s seeds. Ciencia-e Tecnologia-de Alimentos (English abstract). 14,PORIM TEST METHOD. 1985. In PORIM Test Methods of Palm Oil and PalmOil Products. PORIM Dept. of Information. Bandar Baru Bangi.SAS. 1987. Statistical analysis system for data analyses. SA S Inst. Inc., Cary,NC.SCHULER, P. 1990. Natural antioxidants exploited commercially. In FoodAntioxidants. (B.J.F. Hudson, ed.) pp. 99-71, Elsevier Appl. Sci., London.SHERWIN, E.R. 1987. Oxidation and antioxidants in fat and oil processing. J.Am. O il Chem. SOC.55,809-814.VEKIARI, S.A., OREOPOULOU, V., TZIA, C. and THOMOPOULOS, C.D.1993. Oregano flavonoids as lipid antioxidants. J. Am. Oil Chem . SOC.70,

160-167.

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(jamilah et al., 1998) antioxidant activity of citrus hystrix peel extract in rbd palm olein during...

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