Browsing by Author "Ranaweera, K. K. D. S."

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Development of a pomegranate based jelly
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) Senanayake, P. U. A.; Ranaweera, K. K. D. S.
Jelly is a semi solid preserved mixture of fruit juice and sugar. Chemical and artificial ingredients were used for preparation of jelly products and it has a major health related concern. Hence, this study was aimed to develop a value added product using pomegranate which is a popular functional fruit. A pomegranate based jelly was prepared using different concentration of pomegranate juice and Gracilaria seaweeds and constant concentration of Hibiscus, sugar and citric acid as a health promoting product. Four samples of jelly were prepared, and 1st part of the sensory evaluation was done using a non-trained panel of thirty members, and the best sample was selected based on the sensory evaluation. The second part of the sensory evaluation was done comparing the selected sample with a control sample Proximate and physicochemical properties were analysed by using AOAC methods. Data were analysed with MINITAB-19 version at 0.01 significance levels. The proximate analysis of jelly sample was done to determine moisture content, protein content, fat content, ash content, total sugar content, pH value and titratable acidity. The proximate analysis of sample PJ002 revealed 43.66% moisture content, 8.36% protein content, 0% fat content, 0.38% ash content, 90.33% total sugar content, 3.07 pH value and 3.03 titratable acidity. Hence, the sample number PJ002 has the overall best acceptance. The comparison of all microbial parameters (coliform, yeast, mould and total plate count) with the SLS standards for four weeks were below the SLS standards. Hence pomegranate based jelly product has a prolonged shelf life of four weeks under refrigerator conditions below 40c. Finally, based on the sensory, Proximate and microbial analysis, it can be concluded that pomegranate based jelly can be proposed as a product having consumer acceptability.
The effect of incorporation of natural chelators to the diet on the iron bioavailability through in vitro analysis
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Liyanapathirana, N.; Ranaweera, K. K. D. S.; Gunathilake, K. D. P. P.
There are many natural iron chelators found in food sources. The use of these natural chelators could increase the bio availability of iron and benefit conditions such as iron deficient anemia or decrease the bio availability and benefit iron overload conditions such as beta thalassemia. The present study was carried out to assess the potential of incorporating food sources rich in natural iron chelators into the diets to control the complications of elevated iron in genetic conditions such as beta thalassemia. Fifteen diet plans were formulated based on four ingredients namely, red rice, fresh milk, turmeric and black tea that are rich in natural iron chelators against a control diet (no iron chelator source). The designed diets were in vitro digested using the stimulated gastro-intestinal conditions and their effect on bio-availability of iron in the obtained digesta was tested using the Atomic Absorption Spectrometric method. The results showed that the bioavailability of the iron had comparatively reduced in all the diet plans except in the diet plan comprising of all the four food sources (diet plan 15). The diet plans containing red rice and black tea showed a significant (p <0.05) decrease in the iron bioavailability compared to the control indicating that fibers in red rice and tannin in black tea negatively affected the iron bioavailability and their actions surpassed the action of other natural iron chelators. The diet plan 15 showed a 37.22% increase in the bioavailability of iron compared to the control but is not significant (p > 0.05). This indicates the combination of natural chelators in the four food sources have increased the mobility of iron in the digesta without increasing the dietary iron contribution to the iron overload. Therefore, it can be concluded that under in vitro conditions there is a potential to incorporate the food sources rich in natural iron chelators to the diet for control of iron overload conditions and their combinations have synergistic effects compared to those of individual chelators. It is recommended to analyse and quantify the chelation action of the digested natural iron chelators.
Enzyme-assisted extraction of cinnamon (Cinnamomum zeylanicum) bark oil and its effect on extraction yield and quality
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Sethunga, S. M. M. C.; Ranaweera, K. K. D. S.; Munaweera, I.; Gunathilake, K. D. P. P.
Cinnamon (Cinnamomumzeylanicum) is a highly significant spice, native to Sri Lanka and its bark oil is used as a fragrance, flavor in many applications and in the pharmaceutical industry. The volatiles are mainly extracted using traditional distillation methods such as hydro-distillation and steam distillation. In this study, the novel extraction method, Enzyme-assisted Distillation (EAD) is studied to extract the volatile compounds from plant matrices. Aqueous Enzyme solution of Viscozyme and α-amylase were prepared in different concentrations of 0.25%, 0.5%, 1% ((w/w) of raw materials). In the method, the crushed plant materials were soaked in a prepared enzyme solution (pH 4-5) and incubated at 45+2 °C for 90 min followed by hydro-distillation for 6 hours. The same procedure was followed for the control sample without enzyme pretreatment. Cinnamon Bark Oil (CBO) yield was determined for all the samples and GC-MS analysis was carried out to analyze Trans-Cinnamaldehyde Content (TCC) in the prepared samples. The CBO yield and the TCC of the pre-treated samples with enzymes were significantly higher (P < 0.05at 95% confidence level) compared to the control (1.4487±0.0033% CBO yield, 57.095±0.593 % TCC). Amidst various treatments, which were done using different types of enzymes and different concentrations, viscozyme treated sample showed significantly higher CBO yields of 1.6369±0.0019% and 1.6362±0.0022% at 0.5% and at 1% concentrations respectively. TCC was significantly higher in same concentrations of viscozyme; 67.577±0.288% at 0.5% and 67.623±0.080 at 1%. The mixture of viscozyme and α-amylase concentrations showed high CBO yields and trans-cinnamaldehyde content than α-amylase in all concentrations. Therefore, the overall study reveals that viscozyme enzyme is performing better compared to α-amylase enzyme as a pretreatment for cinnamon bark oil distillation. This happens due to the disruption of the cell wall structure in cinnamon after treating with vicozyme, which is composed of cellulase and pectinase than the treatment with α-amylase. Further, the study demonstrated that the 0.5% Viscozyme concentration is the optimum concentration for treating cinnamon bark. The application of Enzyme-assisted extraction substantially improved the oil yield compared to traditional methods. The overall results of this study reveal that EAD could be effectively used in the spice industry to enhance the extraction yield as well as the quality of cinnamon bark oil in an economical way.
Incorporation of natural antioxidants from plant extracts in to virgin coconut oil for extension of shelf life
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Rangani, S. C.; Ranaweera, K. K. D. S.
Lipid oxidation renders a tremendous impact on the quality deterioration of edible oils. In oils the oxidation leads to loss of flavour, aroma, and overall nutritional value, along with texture degradation. High levels of oxidation products act as cyto-toxic substances that lead to health problems. Synthetic antioxidants are often used to preserve edible oils. Fruits, vegetables and seasoning spices contain high amount of phytochemicals which can be used as natural antioxidants. Objective of this study is to develop natural antioxidants over synthetic antioxidants due to reported health issues. In this study, soxhlet extractions of ten plant varieties were evaluated for their antioxidant properties using DPPH assay and noted Fragaria ananassa (Strawberry) whole fruit, Beta vulgaris (Beet Root) whole fruit with peel, Cinnamom verum (Cinnamon) barks, and Zingiber officinale (Ginger) rhizome with peel contains highest antioxidant activity. The dry crude ethanolic extracts of these four varieties were further evaluated for total phenolics content, total flavonoids content, total antioxidant activities and for their oxidative stability. The oxidative stability was evaluated in comparison with synthetic antioxidant BHT and natural antioxidant vitamin E under accelerated oxidation conditions of 65 ºC for 72 hours, using virgin coconut oil (VCO) as the oxidation substrate. Each and every VCO sample fortified with individual antioxidants and their every possible combination were monitored at each 24 hour intervals. The total phenolics contents evaluated using Folin- Ciocalteu reagent were 0.612, 0.437, 0.429, and 0.068 mg gallic acid /g dry weight in Fragaria ananassa, Zingiber officinale, Cinnamom verum and Beta vulgaris respectively, while total antioxidant activities evaluated using ammonium molibdate assay were 0.828, 0.892, 0.302, and 0.058 mg Trolox /g equivalent (DW) respectively. Highest flavonoids value was reported in Zingiber officinale against 2% AlCl3 solution used. The oil samples fortified with antioxidants subjected to accelerated oxidation was observed with inverse relationships between peroxide value and oxidative stabilities and secondary oxidation products and stability at termination of stage. On the basis of the obtained results, the combination of strawberry, beet root and cinnamon barks and ginger rhizome extracts of 1:1:1:1 ratio and ginger and beet root extract of 1:1 ratio at 1500 ppm could be used as natural antioxidants and might be explored to prevent oxidation of vegetable oils. Therefore, they could be used as preservative ingredients in the oil based food industries.
Utilization of Cinnamon (Cinnamomum verum) and Turmeric (Curcuma longa) to develop novel low glycemic index bread products
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Wijewardhana, U. S.; Jayasinghe, M. A.; Wijesekara, I.; Ranaweera, K. K. D. S.
Type II diabetes is a major healthcare problem in the world affecting almost all households and economies. Diet is a crucial factor in the etiology of Type II diabetes and therefore, dietary interventions can be used effectively to prevent and manage the disease. Bread is a staple among all communities which is high in carbohydrates and glycaemic index. Regular consumption of high-glycaemic foods can lead to the onset and development of Type II diabetes. Hence, innovating low-glycaemic indexed bread products is a timely intervention. The study aimed to develop novel low-glycaemic bread products incorporating minuscule amounts of Cinnamon (Cinnamomum verum) and Turmeric (Curcuma longa) powder without affecting palatability and sensory properties. Initially, breads were formulated with different percentages of Cinnamon and Turmeric powder and separate sensory evaluations were carried out to select the best ones according to sensory perceptions. A semi-trained sensory panel consisting of 30 panellists was used for sensory evaluations and products were evaluated for their Appearance, Aroma, Texture, Taste, and Overall acceptability. Statistically selected best bread products proceeded to human study to calculate the glycaemic index along with a control. Twelve healthy adults were selected for the study on a voluntary basis and finger prick blood samples were drawn in a 2-hour time window, upon ingestion of test foods. Glycaemic index values were calculated using D-glucose as a standard. Calculated glycaemic index values were 57.1±14.94, 45.06±12.34, and 42.98±13.9 for control bread, Cinnamon bread, and Turmeric bread respectively. Thus, it could be concluded that the incorporation of Cinnamon powder and Turmeric powder in minuscule amounts has hindered the glycaemic impact of wheat bread reducing the glycaemic index from the ‘medium GI (56-69)’ to low GI (≤55) category. The study provides future insights into reducing the glycaemic impact of a diet incorporating functional ingredients. Future research is needed to explore whether the addition of antidiabetic plant ingredients could reduce the glycaemic impact of other high glycaemic foods. These novel products will be greatly beneficial to the diabetic community and the general public and will be highly marketable.