Printer Friendly

Stabilisation of some vegetable oils by sugarcane leaf extract at ambient temperature.

Introduction

The auto-oxidation and photo-oxidation susceptibility of vegetable oils is one of the biggest problems of vegetable oil processing industry (Choe and Min, 2006). Health apprehensions of rancid vegetable oils are even worse than bad fats because of the absorption of several oxidation products in the body (Quiles et al., 2002). Auto-oxidation of fats and oils leads to the generation of potentially toxic oxidation products which have been connected in a large number of health related disparities such as atherosclerosis, carcinogenesis etc. (Turner et al., 2006). The conversion of primary oxidation products into highly reactive and toxigenic secondary oxidation products such as 4-hydroxy-2-alkenals has led to the great deal of concerns regarding the consumption of oxidized fats, the toxicity of oxidation products for L6 muscles has also been scientifically proven (Pillon et al., 2010; Zarate et al., 2009). Further, the nutritional and sensory characteristics of oxidized fats and oils are on the lower side due to the generation of a wide range of disagreeable flavouring compounds, loss of fats soluble vitamins and essential fatty acids (Kanner, 2007). Degree of unsaturation, processing conditions, metal ions, antioxidants, light and heat greatly influence the oxidation of vegetable oils. The undesirable activities of reactive oxygen species (such as superoxide, hydrogen peroxide and hydroxyl radicals) can cause oxidative damage to the cells, the unrestrained free radicals in body can lead to the damage of DNA, lipids, proteins, lipoproteins, carcinogenesis, cardiovas-cular diseases, diabetes, stroke and accelerated ageing (Adedapo et al., 2008;Yazdanparast and Ardestano, 2007). The role of phytochemicals as biologically active compounds in the neutralisation of free radicals, protective against oxidative damage and inhibition of lipid peroxidation has been well established (Valantina et al., 2009).

Sugarcane (Sacchrum of ficinarum L.) is one of the most widely cultivated cash crops in the world and recent studies have reported the presence of phenolic acids, flavonoids with diuretic, anti-anaemic, anti-ulcer and live protective properties. Although some work has been previously conducted to assess the antioxidant characteristics of sugarcane leaves, the detailed work is the need of hour to explore its antioxidant potential for the stabilisation of some commercially important vegetable oils. The oxidative stabilisation of vegetable oils through natural antioxidants has been extensively studied (Nadeem et al., 2014) but the antioxidant activity of sugarcane leaf extract for the stabilisation of sunflower (SFO), soybean (SBO) and canola (CO) has not been previously investigated. This study aimed to stabilise SFO, SBO and CO through ethanolic sugarcane leaf extract at room temperature by the assessment of oxidative stability through some conventional and advanced analytical techniques.

Materials and Methods

Refined, bleached and deodorized (RBD) sunflower, soybean and canola oils (SFO, SBO and CO) without any additives were obtained from United Industries Ltd. Kashmir Road, Nishatabad, Faisalabad, Pakistan and their chemical camposition was noted (Table 1). Sugarcane leaves were obtained from Ayub Agricultural Research Institute, Faisalabad. All the reagents used in this work were HPLC grade and obtained from Sigma Aldrich, UK.

Preparation of antioxidant extract. Fresh leaves of surgarcane were washed with tap water, dried in the shade and ground to 100 mesh size. The sample (20 g) was mixed with 100 mL ethanol in a Pyrex beaker, mixed at 200 rpm for 8 h at room temperature (20-22 [degrees]C), filtered over Whatman filter paper and the residue was again extracted in a similar manner, pooled, evaporated on a rotary evaporator at 45[degrees]C (Buchi, Japan) till 10 mL, preserved in amber bottles and stored at 65[degrees]C (Sanyo) till further use in this study.

Experimental plan. SFO, SBO and CO were added with 600 ppm sugarcane leaf extract, filled in transparent PET bottles, stored at ambient temperature for 180 days, sampled at 0, 60, 120 and 180 days for the assessment of oxidative stability.

Total phenolic contents. For the determination of total phenolic contents 5 mL Folin-ciolcalteu and 10 mL distilled water were mixed then 5 mL of this solution was mixed with 1 mL extract and sodium carbonate (7.5%), vortexed at 2200 rpm for 2 min and incubated at room temperature for the development of colour for 1 h and measured on a double beam spectrophotometer at 760 nm (Shimadzu, Japan). The concentration of total phenolic contents were calculated from the calibration curve ([R.sup.2]=0.994) and expressed in terms of GAE/ 100g (Wolf et al., 2003).

Determination of antioxidant activity in linoleic acid system. To a solution containing 0.13 mL linoleic acid, 10 mL 99.8% ethanol and 7 mL phosphate buffer (0.2 M; pH 7), 5 mg SLE was added, distilled water was added to make the volume of mixture to 25 mL, incubated at 4[degrees]C. The extent of oxidation was determined as per thiocyanate method, 10 mL 75% ethanol, 30% ammonium thiocyante (0.2 mL), 0.2 mL SLE and 0.2 mL ferrous chloride solution (20 mL in 3.5% HCl) were added in a sequence. The absorption was read at 500 nm after 3min of stirring and compared with a control (without SLE). Butytated hydroxyl anisole (BHA) and butylated hydroxyl toluene (BHT) were employed as positive controls. The inhibition of linoleic acid peroxidation was calculated by the following expression to assess the antioxidant activity of extract (Yen and Duh, 1993).

100- [(Absorbance of sample at 336h/ absorbance of control at 336 h)]

DPPH free radical scavenging activity. DPPH solution (2,2,diphenyl-2 picrylhydrazyl) 1.95 (6x[10.sup.-5]; 50 [micro]L) was mixed with sugarcane leaf extract at different concentrations, left at room temperature for 60 min and absorbance was measured on double beam spectrophotometer at 515 nm (Mansouri et al., 2005). DPPH free radical scavenging activity was calculated by the following expression

% DPPH free radical scavenging activity = (AB-AS)/ AB x 100

where:

AB and AS is the absorbance of blank and sample, respectively.

Experimental plan. Sugarcane leaf extract (SLE) was incorporated into RBD SFO (winterized), SBO and CO at 600 ppm concentration, compared with the controls (SFO, SBO and CO without SLE as positive controls). Filled in PET bottles, stored at ambient temperature and oxidative stability was measured at 0, 60, 120 and 180 days of storage period.

Analysis. Peroxide, anisidine and iodine values were determined by the standard methods (AOCS, 1995). Specific extinctions at 232 and 280 nm were measured on a double beam spectrophotometer (Shimadzu, Japan) as per method (IUPAC, 2006). Two methods were used to assess the antioxidant potential of sugarcane leaf extract in the accelerated oxidation conditions; in the first method Schaal oven test was performed by exposing the vegetable oils added with SLE and controls to 63[degrees]C for 5 days, extent of peroxide value was determined as an adequacy of the antioxidant capacity of SLE (AOCS, 1995). Induction period was determined on a Rancimat 679 as per instructions prescribed in the instruction manual of Metrohm Corporation, Switzerland (Metrohm, 1993). Colour was checked in 5.25" quartz cell (Lovibond Tintometer Salisbury, England). The fatty acid methyl esters were prepared by sodium methoxide trans esterification technique in iso-octane, the supernatant FAME layer was injected at a 1[micro]L concentration into the GC (Perkin Elmer Instrument, Auto system XL) using SP-2380 fused silica capillary column (30 m x 0.25 mm Supelco Bellefonte, PA) using nitrogen (1.5 mL/min) as a carrier gas (Qian, 2010). Fatty acids were identified and quantified by using FAME Mix GLC30, Supelco). The results of triplicate treatments and three time analysis of each samples were expressed as Mean[+ or -]SD and Duncan Multiple Range Test was used to determine the significant difference among the treatments (Steel et al., 1997).

Results and Discussion

Total phenolic contents. Total phenolic contents in ethanolic extract of SLE were 724.3 (mg GAE/100 g). Souza-Sartori et al. (2013) observed that the concentration of flavonoids in sugarcane leaf extract was 50.98 mg/100 mL. The antioxidant activity of sugarcane leaves is due to luteolin-8-C-(rhamnosyl glucoside) (Fabiana et al., 2008). The beneficial effects of polyphenols as antimicrobial, antimutagenic, antiproliferative, and vasodilatory activities has been well established in vitro studies (Lazarou et al., 2007; Taguri et al., 2006). Polyphenols can prevent tooth decay by inhibiting the activities of Streptococcus mutans, improve memory and lack of concentration disorders (Magdalini et al., 2009; Sasaki et al., 2004). The strong antioxidant activity of methanolic extract of sugarcane leaves has also been reported in Chinese sugarcane. In current investigation, the ethanolic extract of sugarcane top leaves also revealed the higher extent of phenolics. The literature suggest the better antioxidant activity of plant based antioxidants, but from the safety view point methanolic extracts for the stabilisation of food substrates could have a high degree of concerns due to its toxicity. Abbas et al. (2013) reported a great deal of neutralization of free radicals by the leaves of sugarcane from seven different cultivars of Pakistan.

DPPH free radical scavenging activity. DPPH free radical scavenging activity is a useful assay to determine the antioxidant activity of antioxidants. The scavenging of DPPH is based on the hydrogen donating ability of the antioxidant which leads to the formation of non-radical DPPH-H (Al-Farsi et al., 2005). The DPPH free radical scavenging activity of SLE was 76% (1mL) as compared to 88% in BHT (Fig. 1). The strong free radical scavenging activity of SLE could be connected to the occurrence of a wide range of phenolic and polyphenolic compounds in SLE. The results of this investigation are corroborated with the earlier finding of Abbas et al. (2013) on the antioxidant activity of various sugarcane genotypes. The antioxidant and prophylactic activity of sugarcane has also been reported by Koge et al. (2000). Plant based natural antioxidants possess the capability of neutralizing free radicals, can safeguard the body from the damage caused to the cardiovascular system and oxidative stresses by the free radicals. DPPH free radical scavenging activity of sugarcane juice (60%) and detoxification of free radicals has been reported by Zamir et al. (2012). Li et al. (2010) studied the phenolics in sugarcane tip, stem, peel and leaves, the flavonoid content of the leaves 3700-[micro]g/g was significantly higher over other parts of the plant (P<0.05).

Antioxidant activity in linoleic acid system. The antioxidant activity of SLE in linoleic peroxidation system is given in Fig. 2. SLE inhibited 82% peroxidation oflinoleic acid as compared to 85% and 90% inhibition by BHA and butylated hydroxyl toluene (BHT) after 360 days of incubation. The percentage of inhibition of SLE was almost similar to BHA and comparable to (BHT). The great antioxidant activity of SLE can be connected to the higher concentration of phenolics. The antioxidant activity of Moringa oleifera leaf, fruits and vegetables for the inhibition of peroxidation of linoleic acid has been described by Anwar et al. (2006) and Siddhuraju and Becker (2003).

Peroxide value. The results regarding peroxide value of SFO, SBO and CO supplemented with SLE are given in Table 2. The addition of SLE in substrate oils considerably inhibited the generation of peroxides. Peroxide value of all the experimental samples and their controls increased throughout the storage period of 6 months but to varying extents. The rise of peroxide value during ambient storage period was dependent upon two factors, (i) the kind of oil i.e., degree of unsaturation and (ii) the addition of antioxidant. Polyphenolic compounds of SLE provided a great deal of protection to the oil samples added with SLE. Vegetable oils (controls) which were not added with SLE suffered a high degree of oxidation. The pattern of rise of peroxide value in the supplemented and non-supplemented vegetable oils was in the order of SFO> SBO > CO. The inhibition of lipid peroxidation phenomenon in the supplemented vegetable oils could be connected with the neutralization of free radicals by the antioxidant. The oxidizability of SFO was the highest followed by SBO and CO. The better inhibition of peroxidation could have been achieved by the application of higher dose of SLE however, this aspect needs to be further investigated. Assessment of peroxide value delivers a worthwhile evidence of the oxidative breakdown in fats and oils (Pritchard, 1991). Greater values are frequently interrelated with inferior storage stability (Fereidoon, 2005). The storage stability of vegetable oils through the phenolics of sugarcane leafhas not been previously investigated therefore, little is known regarding its suitability as an antioxidant for the preservation of vegetable oils at ambient temperature. The antioxidant activity of plant based natural antioxidants for the stabilization of vegetable and animal fat has been described by Nadeem et al. (2013); Anwar et al. (2011) and Mohdaly et al. (2011).

Anisidine value. The results of anisidine value of vegetable oils added with SLE are presented in Table 3. Anisidine value of the experimental samples and their controls increased during the storage period of 180 days. Anisidine value of SFO supplemented with SLE and without SLE was highest at 60, 120 and 180 days of determination followed by SBO and CO and vegetable oils supplemented with SLE exhibited the lower concentration of oxidation products over their controls (P<0.05). In this study, the effect of antioxidant on vegetable oils with different fatty acid composition was compared and the oxidizability of vegetable oils was in the order of SFO < SBO < CO. The generation of oxidation products also followed the fashion of oxidizability. The oxidation rate of linoleic acid is 12 times greater than oleic acid (Baer et al., 2001) that could be the justification of higher extents of oxidation products in SFO over SBO and CO. CO contains considerably higher concentration of monounsaturated fatty acids which are relatively more stable than polyunsaturated fatty acids that could be connected to the lower amount of oxidation products in CO. Determination of anisidine value gives information of the amount of oxidation products generated during the course of oxidative breakdown (Erickson, 1995). Addition of Moringa oleifera leaf extract considerably enhanced the storage stability of butter (Nadeem et al., 2013). The long term preservation of SFO and CO through barley and rice bran extracts has been reported earlier (Chatha et al., 2011; Anwar et al., 2010). Conjugated dienes and trienes. The results of conjugated dienes and trienes of oils added with SLE and controls are given in Table 4 and 5. Oxidation products in the form of conjugated dienes and trienes went on increasing throughout the storage period of 180 days at ambient temperature depending upon the addition of natural antioxidant and fatty acid composition of individual oils. The rise of conjugated dienes and trienes at the end of storage period was in the order of SFO > SBO > CO, the determination frequencies of 60 and 120 days revealed the same order. In current investigation vegetable oils were compared with each other and their controls (without antioxidant). SFO, SBO and CO yielded the varying extents of oxidation product, also their extent was considerably lower than their controls (P<0.05) which revealed that the addition of SLE had a pronounced effect on the inhibition of auto-oxidation in these oils during long term storage at ambient temperature. The protective effect of SLE can be seen in all three types of 60, 120 and 180 days stored vegetable oils as compared to their controls. The inhibition of generation of oxidation products by SLE also has health beneficial effects as oxidation products have been implicated with flavour defects and health related disparities. Determination of conjugated dienes and trienes is regarded as one of the useful and convenient methods to quantify the oxidation products.

Changes in peroxide value in accelerated oxidation chamber. Schaal oven test is one of the simplest and widely used method to assess the antioxidant activity of antioxidants in the accelerated oxidation chamber at 63[degrees]C for 5 days, the extent of oxidation was measured in terms of peroxide value. In the accelerated oxidation chamber SLE provided a high degree of protection to the supplemented oils (Fig. 3). Among the supplemented oils, the greatest peroxide value was exhibited by the SFO followed by SBO and CO; similar trend was also seen in the non-supplemented vegetable oils. Enhancement of the oxidative stability of vegetable oils through the supplementation of SLE has not been previously investigated and this is the pioneer study suggesting the suitability of SLE for the long term stabilization of vegetable oils at room temperature. Fatty acid composition had a major effect on the rise of peroxide value in the oxidation chamber, oils rich in monounsaturated fatty acids are usually more stable to auto-oxidation, and therefore, CO yielded the lowest peroxide value as compared to SBO and SFO. Reduction in unsaturated fatty acids of SFO and SBO had a great effect on the enhancement of the oxidative stability of SBO and SFO (Anwar et a!., 2007).

Induction period. Accelerated oxidation techniques are widely used for the assessment of antioxidant activity of antioxidants. Induction period of fats and oils is usually corroborated with keeping quality; higher values are usually connected with better storage stability and vice versa (Anwar et a!., 2011). From the results of Fig. 4 it is obvious that SLE significantly improved the induction period of SFO, SBO and CO over their controls. In the absence of SLE, controls suffered from serious consequences of autoxidation during the long term storage and in the accelerated oxidation conditions (120 [degrees]C; 22 L air/h). The induction period of SLE supplemented vegetable oils were in the order of CO > SBO > SFO. The remarkable resistance of the supplemented vegetable oils in the accelerated oxidation conditions was due to the antioxidant activity of phenolics contained in SLE.

Changes in fatty acid composition. The changes in fatty acid composition of vegetable oils as a function of addition of SLE and ambient storage are presented in Table 6. Major changes were observed in the fatty acid composition of controls, while, the change in fatty acid composition from the original value was not drastic in the SLE supplemented vegetable oils. Addition of SLE and degree of unsaturation were the two major factors responsible for the changes in fatty acid composition. The concentration of unsaturated fatty acids in 6 months stored controls and supplemented samples were less than the initial value due to their breakdown into oxidation products and increase in saturates was on percentage basis. C18:1 and C18:2 in fresh, 6 months stored controls and SLE supplemented SFO were 46.12%, 42.59%, 44.91% and 47.15%, 40.29, 43.13%, respectively. C18:2 and C18:3 in fresh and 180 days stored control and SLE supplemented SBO were 51.19%, 45.61%, 48.97% and 6.19%, 3.37,% 5.67%, respectively. C18:2 and C18:3 in fresh and 6 months stored CO were 25.73%, 22.47%, 24.12% and 10.35%, 7.62%, 9.24%, respectively. The phenolics of SLE provided a high degree of protection to the unsaturated fatty acids towards their breakdown into oxidation products which is evident from the lower generation of concentration of oxidation products in SLE supplemented vegetable oils. The strong correlation between degree of unsaturation and the generation of oxidation products during storage of oils rich in unsaturated fatty acids has been suggested by Gulla and Wagahary (2011). Addition of Moringa oleifera leaf extract in butter oil with higher extent of unsaturated fatty acids significantly inhibited the auto-oxidation phenomenon (Nadeem et al., 2013).

Conclusion

Supplementation of SFO, SBO and CO with sugarcane leaf extract at 600 ppm concentration significantly (<0.05) inhibited the auto-oxidation. Supplemented vegetable oils yield the lower extents of primary and secondary oxidation products with minimum changes in the fatty acid composition during storage period and improved resistance in the accelerated oxidation conditions, with no effect on viscosity and sensory characteristics. Sugarcane leaf extract therefore, can be used to prolong the shelf life of vegetable oils.

References

Abbas, S.R., Ahmad, S.D., Khan, S.A., Aziz, W., Shah, A.H., Rao, A., Abbas, M.R., Khan, R.T., Batool, A. 2013. Comparative antioxidant activity in sugarcane leave's samples against polyethylene glycol. Journal of Biotechnological Sciences, 1: 42-54.

Adedapo, A.A., Jimoh, F.O., Afolayan, A.J., Masika, P.J. 2008. Antibacterial and antioxidant properties of the methanol extracts of the leaves and stems of Calpurnia aurea. BMC Complement Alternative Medicine, DOI: 10.1186/1472-6882-8-53

Al-Farsi, M., Alasalvar, C., Morris, A., Baron, M., Shahidi, F. 2005. Comparison of antioxidant activity, anthocyanins, carotenoids, and phenolics of three native fresh and sun-dried date (Phoenix dactylifera L.) varieties grown in Oman. Journal of Agricultural andFood Chemistry, 53: 7592-7599.

Anwar, F., Rashid, U., Mahmood, Z., Iqbal, T., Sherazi, T.H. 2011. Inter-varietal variation in the composition of okra (Hibiscus esculentus L.) seed oil. Pakistan Journal of Botany, 43: 271-280.

Anwar, F., Qayyum, H.M.A., Hussain, A.I., Iqbal, S. 2010. Antioxidant activity of 100% and 80% methanol extracts from barley seeds (Hordeum vulgare L.): stabilization of sunflower oil. Grasasy Aceites, 61: 237-243.

Anwar, F., Hussain, A.I., Iqbal, S., Bhanger, M.I. 2007. Enhancement of the oxidative stability of some vegetable oils by blending with Moringa oleifera oil. FoodChemistry, 103: 1181-1191.

AOCS, 1995. Official Methods and Recommended Practices of the American Oil Chemists ' Society, 4th edition, AOCS, Champaign, IL, USA.

Baer, R.J., Ryali, J., Schingoethe, D.J., Kasperson, K.M., Donovan, D.C., Hippen, A.R., Franklin, S.T. 2001. Composition and properties of milk and butter from cows fed fish oil. Journal of Dairy Science, 84: 345-353.

Chatha, S.A.S., Hussain, A.I., Bajwa, J.R., Sherazi, S.T.H., Shaukat, A. 2011. Wheat bran extracts: a potent source of natural antioxidants for the stabilization of canola oil. Grasasy Aceites, 62: 190-197.

Choe, E., Min, D.B. 2006. Mechanisms and factors for edible oil oxidation. Comprehensine Reviews in Food Science and Food Safety, 5: 169-186.

Erickson, D.R. 1995. Practical Handbook of Soybean Processingand Utilization. pp.292-299, 1st edition AOCS Press, Champaign, IL, USA.

Fabiana, C.V., Renata, C., Tatiana, O.D., Janete, H.Y. 2008. HPLC microfractionation of flavones and antioxidant (radical scavenging) activity of Saccharum officinarum L. Journal of Brazil Chemist's Society, 5: 903-908.

Fereidoon, S. 2005. Bailey's Industrial Edible Oil and Fat Products. 6th edition, John Wiley and Sons, Pub. Co., NY, USA.

Gulla, S., Waghray, K. 2011. Effect of storage on physicochemical characteristics and fatty acid composition of selected oil blends. Journal of Lipid Science, 3: 35-46.

IUPAC 2006. Standard Methods for the Analysis of Oils, Fats and Derivatives, C. Paquot and A. Hautfenne (eds), 7th revised and enlarged edition, International Union of Pure and Applied chemistry Blackwell Scientific, London, UK).

Kanner, J. 2007. Dietary advanced lipid oxidation endproducts are risk factors to human health. Molecular Nutrition & Food Research, 51: 10941101.

Koge, K., Nagai, Y., Suzuki, M., Araki, S. 2000. Physiological effects of sugurcane extracts. Up to Date FoodProcessing, (In Japanese) 35: 39-41.

Lazarou, D., Grougnet, R., Papadopoulos, A. 2007. Antimutagenic properties of a polyphenol-enriched extract derived from sesame-seed perisperm. Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 634: 163-171.

Li, X., Yao, S., Tu, B., Li, X., Jia, C., Song, H. 2010. Determination and comparison of flavonoids and anthocyanins in Chinese sugarcane tips, stems, roots and leaves. Journal of Separation Science, 33: 1216-1223.

Magdalini, A.P., Andriana, D., Zacharoula, I. L., Paul, C., Dorothy, K., Marigoula, M., FotiniN.L. 2009. Effect of a polyphenol-rich wild blueberry extract on cognitive performance of mice, brain antioxidant markers and acetylcholinesterase activity. Behavioural Brain Research, 198 : 352-358.

Mansouri, A., Embarek, G., Kokkalou, E., Kefalas, P. 2005. Phenolic profile and antioxidant activity of the Algerian ripe date palm fruit (Phoenix dactylifera). Food Chemistry, 89: 411-420.

Metrohm, A.G. 1993. Oxidative stability of oils and fats-Rancimat method. Metrohm Application Bulletin No. 204/le: pp.1-4, Metrohm AG, Herisau, Switzerland.

Mohdaly, A.A., Smetanska, A.I., Ramadan, M.F., Sarhan, M.A., Mahmoud, A. 2011. Antioxidant potential of sesame (Sesamum indicum) cake extract in stabilization of sunflower and soybean oils. Industrial Crops and Products, 34: 952-959.

Nadeem, M., Situ, C., Mahmud, A., Khalique, A., Imran, M., Rahman, F., Khan, S. 2014. The effect of sesame (Sesamum indicum L.) cake extract for oxidative stabilization of olein based butter. Journal of the American Oil Chemist's Society. DOI: 10.1007/s11746-014-2432-3

Nadeem, M., Abdullah, M., Hussain, I., Inayat, S., Javid, A. , Zahoor, Y. 2013. Antioxidant potential of Moringa oleifera leaf extract for the stabilization of butter at refrigeration temperature. Czech Journal of Food Sciences, 4: 332-339.

Pillon, N.J., Soulere, L., Vella, R.E; Croze, M., Care, B. R., Soula, H.A. 2010. Quantitative structureactivity relationship for 4-hydroxy- 2-alkenal induced cytotoxicity in L6 muscle cells. Chemico Biological lnteractions, 188: 171-180.

Pritchard, J.L.R. 1991. Analysis and properties of oilseeds. In: Analysis of Oilseeds, Fats and Fatty Foods, vol. 127, pp. 80-98, Elsevier Applied Sciences, London, NY, USA.

Qian, M., Peterson, D.G., Reineccius, G.A. 2010. Gas chromatography, Ch. 29. In: Food Analysis, 4th edition,. S.S. Nielsen (ed), Springer, New York, USA.

Quiles, J.L., Huertas, J.R., Battino, M., Ramirez-Tortosa, M. C., Cassinello, M., Mataix, J. 2002. The intake of fried virgin olive or sunflower oils differentially induces oxidative stress in rat liver microsomes. British Journal of Nutrition, 88: 57-65.

Sasaki, H., Matsumoto, M., Tanaka, T., Maeda, M., Nakai, M., Hamada, S., Ooshima, T. 2004. Antibacterial activity of polyphenol components in Oolong tea extract against Streptococcus mutans. Caries Research, 38: 2-8.

Shun, M.C., Yu, W., Park, S.K., Sanders, B.G., Kline, K. 2010. Downregulation of epidermal growth factor receptor expression contributes to-Tea's proapoptotic effects in human ovarian cancer cell lines. Journal of Oncology, 824571.

Siddhuraju, P., Becker, K. 2003. Antioxidant properties of various solvent extracts of total phenolic constituents from three different agro climatic origins of drumstick tree (Moringa oleifera Lam). Journal of Agricultural Food Chemistry, 54:2144-2155.

Souza-Sartori, J.A., de Prado, A., Veiga, L.F., Torres, N. , Alencar, S.M., de Aguiar, C.L. de. 2013. Antioxidant capacity of fractions of alcoholic extracts of sugarcane leaves. Sugar Industry/Zuckerindustrie, 138: 165-169.

Steel, R.G.D., Torrie, J.H., Dickey, D.A. 1997. Principles and Procedures of Statistics. A Biometrical Approach, 3rd edition, Mc-Graw Hill Book Co., NY, USA.

Taguri, T., Tanaka, T., Kouno, I. 2006. Antibacterial spectrum of plant polyphenols and extracts depending upon hydroxyphenyl structure. Biological & Pharmaceutical Bulletin, 29: 2226-32235.

Turner, R., McLean, C.H., Silvers, K.M. 2006. Are the health benefits of fish oils limited by products of oxidation. Nutrition Research Reviews, 19: 53-62.

Valantina, S.R., Neelameagam, P., Gayathri, K. 2009. Estimating antioxidant stability in sunflower and rice bran oil on heating using in-vitro analysis, Biomedicine, 29 : 31-35.

Wolf, K., Wu, X., Liu, R.H. 2003. Antioxidant activity of apple peels. Journal of Food Chemistry, 51: 609-614.

Yazdanparast, R., Ardestani, A. 2007. In vitro antioxidant and free radical scavenging activity of Cyperus rotundus. Journal of Medicinal Food, 10: 667-674.

Yen, G.C., Duh, P.D. 1993. Antioxidative properties of methanolic extracts from peanut hulls. Journal of American Oil Chemist's Society, 70: 383-386.

Zamir, R., Khalil, S.A., Shah, S.T., Saima, N.A. 2012. Antioxidant activity influenced by in vivo and in vitro mutagenesis in sugarcane (Saccharum officinarum L.). African Journal of Biotechnology, 11: 11686-11692.

Zarate, J., Goicoechea, E., Pascual, J., Echevarria, E., Guillen, M.D. 2009. A study of the toxic effect of oxidized sunflower oil containing 4- hydroperoxy2-nonenal and 4-hydroxy-2-nonenal on cortical TrkA receptor expression in rats. Nutrition Neurosciences, 12: 249-259.

An Assessment of the Bivalve Perna viridis, as an Indicator of Heavy Metal Contamination in Paradise Point of Karachi, Pakistan

Muhammad Nadeem (a) *, Muhammad Waqar Azeem (b)

(a) Department of Dairy Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan

(b) United Industries Ltd., Kashmir Road, Faisalabad, Pakistan

(received February 19, 2015; revised October 10, 2015; accepted November 13, 2015)

* Author for correspondence;

E-mail: muhammad.nadeem@uvas.edu.pk

Caption: Fig. 1. DPPH free radical scavenging activtiy of SLE. SD= standard deviation, BHT= butylated hydroxyl toluene; BHA= butylated hydroxyl anisole; SLE= sugarcane leaf extract.

Caption: Fig. 2. Antioxidant activty of SLE in linoleic acid system. SD= standard deviation; BHT= butylated hydroxyl toluene; BHA= butylated hydroxyl anisole; SLE= sugarcane leaf extract.

Caption: Fig. 3. Peroxide value (PV) of SLE added vegetable oils in Schaal oven test. SFO= sunflower oil; SLE = sugarcane leaf extract.

Caption: Fig. 4. Induction period (IP) of vegetable oils added with SLE. SFO = sunflower oil; SLE = sugarcane leaf extract.
Table 1. Chemical composition of sunflower (SFO),
soybean (SBO) and canola oils (CO)

Parameter    Unit         SFO

Free fatty   %            0.08 [+ or -] 0.01 (a)
acids
Colour       Lovibond     14 [+ or -] 0.54 (c)
             scale
Rancidity    Kries Test   -ve
USM          %            0.72 [+ or -] 0.03 (a)
Iodine       Unit         122.46 [+ or -] 1.29 (a)
value

Parameter    SBO             CO

Free fatty   0.08 [+ or -] 0.0.09 [+ or -] 0.02 (a)
acids
Colour       18 [+ or -] 0.9221 [+ or -] 0.74 (a)

Rancidity    -ve             -ve
USM          0.66 [+ or -] 0.0.68 [+ or -] 0.07 (a)
Iodine       133.19 [+ or -] 110.54 [+ or -] 1.42 (c)
value

Within a row means denoted by a common letter are not
statistically different; USM = Unsaponifiable matter.

Table 2. Effect of sugarcane leaf extract on peroxide
value (Meq[O.sup.2] /kg) of vegetable oils stored at ambient
temperature

Treatments   0-Day                     60-Days

SFO          0.25 [+ or -] 0.03 (n)    1.25 [+ or -] 0.08 (j)
SFO+SLE      0.25 [+ or -] 0.03 (n)    0.84 [+ or -] 0.05 (k)
SBO          0.22 [+ or -] 0.02 (n)    0.95 [+ or -] 0.09 (k)
SBO+SLE      0.22 [+ or -] 0.02 (n)    0.62 [+ or -] 0.04 (l)
CO           0.19 [+ or -] 0.04 (n)    0.81 [+ or -] 0.05 (k)
CO+SLE       0.19 [+ or -] 0.04 (n)    0.45 [+ or -] 0.03 (m)

Treatments   120-Days                  180-Days

SFO          2.88 [+ or -] 0.11 (d)    4.47 [+ or -] 0.36 (a)
SFO+SLE      1.34 [+ or -] 0.07 (i)    2.18 [+ or -] 0.23 (f)
SBO          2.53 [+ or -] 0.15 (e)    3.95 [+ or -] 0.34 (b)
SBO+SLE      1.74 [+ or -] 0.13 (h)    1.92 [+ or -] 0.35 (g)
CO           1.46 [+ or -] 0.09 (i)    3.19 [+ or -] 0.46 (c)
CO+SLE       1.22 [+ or -] 0.07 (j)    1.57 [+ or -] 0.18

Within rows and columns means denoted by a different letter
are statistically different (P<0.05).

Table 3. Effect of sugarcane leaf extract on anisidine
value of vegetable oils stored at ambient temperature

Treatments   0-Day                     60-Days

SFO          4.11 [+ or -] 0.04 (m)    14.64 [+ or -] 0.62 (j)
SFO+SLE      4.11 [+ or -] 0.04 (m)    9.62 [+ or -] 0.47 (k)
SBO          4.31 [+ or -] 0.02 (m)    12.95 [+ or -] 0.77 (j)
SBO+SLE      4.31 [+ or -] 0.02 (m)    8.29 [+ or -] 0.59
CO           3.86 [+ or -] 0.01 (m)    10.51 [+ or -] 0.92 (k)
CO+SLE       3.86 [+ or -] 0.01 (m)    7.62 [+ or -] 0.38 (l)

Treatments   120-Days                   180-Days

SFO          23.72 [+ or -] 1.13 (h)    47.96 [+ or -] 1.54 (a)
SFO+SLE      17.68 [+ or -] 0.91 (i)    34.67 [+ or -] 1.18 (d)
SBO          32.54 [+ or -] 1.64 (e)    41.18 [+ or -] 1.76 (b)
SBO+SLE      13.67 [+ or -] 2.16 (j)    29.22 [+ or -] 0.86 (f)
CO           25.64 [+ or -] 1.43 (B)    39.89 [+ or -] 1.32 (c)
CO+SLE       12.38 [+ or -] 0.66 (j)    19.35 [+ or -] 0.43

Within rows and columns means denoted by a different letter
are statistically different (P<0.05).

Table 4. Effect of sugarcane leaf extract on conjugated
dienes of vegetable oils stored at ambient temperature

Treatments   0-Day                 60-Days

SFO          0.21 [+ or -] 0.030   3.65 [+ or -] 0.17 (i)
SFO+SLE      0.21 [+ or -] 0.030   1.18 [+ or -] 0.11 (l)
SBO          0.15 [+ or -] 0.020   2.98 [+ or -] 0.21 (j)
SBO+SLE      0.15 [+ or -] 0.020   1.02 [+ or -] 0.14 (l)
CO           0.19 [+ or -] 0.010   0.83 [+ or -] 0.09 (m)
CO+SLE       0.19 [+ or -] 0.010   0.55 [+ or -] 0.07 (n)

Treatments   120-Days                  180-Days

SFO          8.92 [+ or -] 0.31 (d)    19.87 [+ or -] 0.49 (a)
SFO+SLE      3.57 [+ or -] 0.21 (i)    7.84 [+ or -] 0.33 (e)
SBO          7.51 [+ or -] 0.17 (e)    16.84 [+ or -] 0.71 (b)
SBO+SLE      2.94 [+ or -] 0.16 (j)    5.63 [+ or -] 0.25 (g)
CO           6.54 [+ or -] 0.24 (f)    14.35 [+ or -] 0.34 (c)
CO+SLE       2.56 [+ or -] 0.12 (k)    4.29 [+ or -] 0.10 (h)

Within rows and columns means denoted by a different letter
are statistically different (P<0.05).

Table 5. Effect of sugarcane leaf extract on conjugated
trienes of vegetable oils stored at ambient temperature

Treatments   0-Day                 60-Days

SFO          0.08 [+ or -] 0.02l   1.85 [+ or -] 0.08 (h)
SFO+SLE      0.08 [+ or -] 0.02l   1.79 [+ or -] 0.05 (h)
SBO          0.08 [+ or -] 0.02l   1.35 [+ or -] 0.13 (i)
SBO+SLE      0.08 [+ or -] 0.02l   0.59 [+ or -] 0.04 (T)
CO           0.08 [+ or -] 0.02l   1.17 [+ or -] 0.13 (i)
CO+SLE       0.08 [+ or -] 0.02l   0.42 [+ or -] 0.05 (k)

Treatments   120-Days                  180-Days

SFO          4.53 [+ or -] 0.29 (d)    8.76 [+ or -] 0.41 (a)
SFO+SLE      2.19 [+ or -] 0.18 (g)    3.41 [+ or -] 0.10 (e)
SBO          3.43 [+ or -] 0.14 (e)    7.64 [+ or -] 0.22 (b)
SBO+SLE      1.42 [+ or -] 0.08        2.76 [+ or -] 0.16 (f)
CO           3.24 [+ or -] 0.17 (e)    6.19 [+ or -] 0.11 (c)
CO+SLE       1.22 [+ or -] 0.04 (i)    2.14 [+ or -] 0.07 (g)

Within rows and columns means denoted by a different letter
are statistically different (P<0.05).

Table 6. Effect of sugarcane leaf extract on fatty acid composition
of sunflower, soybean and canola oils during storage period of 180/
days at ambient temperature (mg/g)

Fatty                             Sunflower oil
acid    Fresh                     6M-SFO

C16:0   6.54 [+ or -] 0.22 (e)    10.38 [+ or -] 0.39 (c)
C18:0   1.89 [+ or -] 0.05 (e)    3.15 [+ or -] 0.27 (c)
C18:1   46.12 [+ or -] 1.34 (d)   42.59 [+ or -] 0.95 (f)
C18:2   47.15 [+ or -] 0.89 (c)   40.29 [+ or -] 1.38 (f)
C18:3   0.11 [+ or -] 0.01 (f)    0.03 [+ or -] 0.01 (f)

Fatty   Sunflower oil             Soybean oil
acid    6M-SFO+                   Fresh
        SLE

C16:0   7.14 [+ or -] 0.56 (d)    10.41 [+ or -] 0.21 (f)
C18:0   2.45 [+ or -] 0.18 (d)    3.55 [+ or -] 0.95 (b)
C18:1   44.91 [+ or -] 1.47 (e)   22.95 [+ or -] 2.14 (g)
C18:2   43.13 [+ or -] 0.76 (e)   51.19 [+ or -] 0.12 (a)
C18:3   0.07 [+ or -] 0.02 (f)    6.19 [+ or -] 0.64 (d)

Fatty                           Soybean oil
acid    6M-SBO                     6M-SBO+
                                   SLE

C16:0   14.25 [+ or -] 0.12 (a)    12.55 [+ or -] 0.12 (b)
C18:0   3.76 [+ or -] 0.64 (b)     2.38 [+ or -] 0.09 (d)
C18:1   19.35 [+ or -] 1.35 (i)    21.13 [+ or -] 1.31 (h)
C18:2   45.61 [+ or -] 0.26 (d)    48.97 [+ or -] 0.23 (b)
C18:3   3.37 [+ or -] 0.45 (e)     5.67 [+ or -] 0.14

Fatty                             Canola oil
acid    Fresh                     6M-CO

C16:0   4.15 [+ or -] 0.03 (f)    7.32 [+ or -] 0.09 (d)
C18:0   3.17 [+ or -] 0.06 (c)    4.45 [+ or -] 0.08 (a)
C18:1   56.32 [+ or -] 1.79 (a)   53.67 [+ or -] 2.16 (c)
C18:2   25.73 [+ or -] 0.62 (g)   22.47 [+ or -] 1.13 (i)
C18:3   25.73 [+ or -] 0.62 (g)   7.62 [+ or -] 0.49 (c)

Fatty   Canola oil
acid    6M-CO+
        SLE

C16:0   5.74 [+ or -] 0.23 (df)
C18:0   3.69 [+ or -] 0.18 (b)
C18:1   54.91 [+ or -] 1.92 (b)
C18:2   24.12 [+ or -] 0.10 (h)
C18:3   9.24 [+ or -] 0.17 (b)

Within a row means denoted by a different letter are statistically
different (P<0.05); Fresh=freshly deodorized vegetable oils; 6-M=six
months stored oils at ambient temperature; 6M-SFO+SLE=sunflower oil
supplemented with 600 ppm sugarcane leaf extract; 6M-SBO+SLE=Soybean
oil supplemented with 600 ppm sugarcane leaf extract;
6M-CO+SLE=canola oil supplemented with 600 ppm sugarcane leaf extract.
COPYRIGHT 2016 Pakistan Council of Scientific and Industrial Research
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2016 Gale, Cengage Learning. All rights reserved.

 
Article Details
Printer friendly Cite/link Email Feedback
Author:Nadeem, Muhammad; Azeem, Muhammad Waqar
Publication:Pakistan Journal of Scientific and Industrial Research Series B: Biological Sciences
Article Type:Report
Date:Nov 1, 2016
Words:6070
Previous Article:The influence of storage of pawpaw carica papaya fruit on the bioactive components, antioxidative properties and inhibition of [Fe.sup.2+]-induced...
Next Article:An assessment of the bivalve perna viridis, as an indicator of heavy metal contamination in paradise point of Karachi, Pakistan.
Topics:

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters