Browsing by Author "Rajakaruna, R.A.M.A.T."

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    Effect of Hinembilla (Antidesma alexiteria) Extract on Oxidative Stability of Selected Edible Oils
    (Uva Wellassa University of Sri Lanka, 2019) Nanayakkara, S.U.G.; Wedamulla, N.E.; Wijesinghe, W.A.J.P.; Rajakaruna, R.A.M.A.T.; Wijerama, H.J.K.S.S.
    Oxidation of oil is a major challenge in food processing sector which leads to deterioration of quality. Though, synthetic antioxidants are effective in preventing rancidity of oils, these substances show adverse health effects. Thus, the present study aimed to utilize natural antioxidant extracted from Hinembilla (Antidesma alexiteria) to retard the rancidity of selected edible oils. Extract was prepared with 70% ethanol using ultrasoundassisted extraction. The antioxidant efficacy of extract was measured using 2,2-diphenyl1-picrylhydrazyl (DPPH) radical scavenging capacity and Folin-Ciocalteu method was used to measure total phenolic content (TPC). Free fatty acid (FFA) content and peroxide value (PV) of sunflower oil (SO) and virgin coconut oil (VCO) were measured at 3-day intervals after addition of extract at three different concentration levels viz 500, 1,000, and 2,000 ppm, and α-tocopherol (500 ppm) was used as the positive control and the experiment was continued for 21days at 65±1°C. Antioxidant activity (IC50) and TPC of the extract were 135.33±4.49 µg mL-1 and 6.77±0.03 mg GAE per gram extract, respectively. FFA content and PV of both oils were increased with the time. FFA content and PV of SO (FFA:0.14%; PV:12.23 meq kg-1) and VCO (FFA:0.22%; PV:1.19 meq kg1) added with extract at 2,000 ppm were significantly lower (p<0.05) than those of positive control; SO with α-tocopherol (FFA:0.22%, PV:17.94 meq kg-1) and VCO with αtocopherol (FFA:0.29%, PV:1.39 meq kg-1) after 21 days. In conclusion, Hinembilla extract had a positive impact on oxidative stability of selected oils at 1,000 and 2,000 ppm levels. Hence, A. alexiteria fruit is an excellent antioxidant source which can be effectively used to stabilize the oxidation of edible oils.
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    Extraction of Anthocyanin from Hinembilla (Antidesma alexiteria) Fruit as a Natural Food Colorant
    (Uva Wellassa University of Sri Lanka, 2019) Narayana, S.D.T.U.; Wedamulla, N.E.; Wijesinghe, W.A.J.P.; Rajakaruna, R.A.M.A.T.; Wijerama, H.J.K.S.S.
    Artificial food colorants impart health hazards thus, present study attempts to extract anthocyanin from Hinembilla (Antidesma alexiteria) fruit as a natural food colorant with promising antioxidant properties. Anthocyanin was extracted with ultrasound-assisted extraction (UAE) and maceration by using four different solvents (70% ethanol, acidified 70% ethanol, absolute ethanol and acidified absolute ethanol) at 40°C. Total monomeric anthocyanin (TMA) pigment content and total phenolic content (TPC) were determined by pH differential method and Folin-Ciocalteu method, respectively. Antioxidant efficacy of extracts were determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assays. TMA content ranged from 67.80 to 129.92 mg L-1. DPPH radical scavenging activity as measured by IC50 ranged between 135.33 and 194.90 mg L-1. FRAP ranged from 0.44 to 0.92 µmol Fe2+ per gram extract. TPC ranged from 3.33 to 6.77 mg gallic acid equivalents (GAE) per gram extract. Significantly (p<0.05) higher TMA (129.92 mg L-1), FRAP (0.92 µmol Fe2+ per gram extract), TPC (6.77 mg GAE per gram extract) and lower IC50 (135.33 mg L-1) values were recorded in UAE with 70% ethanol. Hence, anthocyanin can be extracted effectively with UAE than maceration with comparatively high antioxidant properties. Moreover 70% ethanol served as the best solvent to extract anthocyanin. The correlation of TPC with DPPH assay (IC50) (R2=0.7) and FRAP values (R2=0.8) was strong, suggesting the phenolic compounds are the major contributor towards the exhibited properties. In conclusion, A. alexiteria serves as an excellent source of anthocyanin with high antioxidant properties thus suggesting the potential applications as a natural food colorant.
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    Utilization of Jackfruit Seed Flour (Artocarpus heterophyllus L.) as a Thickening Agent in Tomato Sauce Production
    (Uva Wellassa University of Sri Lanka, 2019) Maduwage, C.S.D.S.; Rajakaruna, R.A.M.A.T.; Wijesinghe, W.A.J.P.; Jeewanthi, P.W.
    Even though Jackfruit seeds are a good source of starch, they are still underutilized. This study investigated the potential of using of Jackfruit Seed Flour (JSF) as a thickening agent in tomato sauce production. Lye peeled mature jackfruit seeds were used to obtain flour. Proximate analysis and functional behavior of the JSF were compared with corn flour. Tomato sauce samples were prepared according to the Sri Lankan Standard specification for tomato sauce (SLS 260:1989). Three batches of tomato sauce were prepared by adding JSF, corn flour and without any thickening agent separately. Thickening agents were added at 3.75g/100g of tomato pulp. Sensory evaluation and microbial analysis were conducted to determine the acceptability of the sauce samples. Sauce samples were analyzed for physicochemical properties during 8 weeks of storage at ambient temperature. JSF contained 69.96±0.31% carbohydrate, 13.40±0.09% crude protein, 8.53±0.19% moisture, 2.93±0.15% crude fiber, 2.77±0.05% fat and 2.39±0.37% total ash. JSF had 0.80 g cm-3 bulk density, 2.5 ml g-1 oil absorption capacity, 1.4 ml g-1 water absorption capacity, 3.5 ml g-1 emulsifying capacity and 5% gelation capacity. Swelling power was increased with the temperature. JSF incorporated tomato sauce received the highest scores in the sensory assessment. Microbial counts were less than standard maximum limits. Total soluble solids, titratable acidity were not significantly changed (p > 0.05) while pH, water activity significantly increased (p < 0.05) during storage period in JSF added tomato sauce. JSF showed the role of a thickening agent in tomato sauce with lowest serum separation and highest viscosity. This study concludes that JSF can be successfully used as a thickening agent in the tomato sauce industry.