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Degree: search.filters.degree.Bachelor of Science in ChemistrySDG: search.filters.sdg.SDG 2 - Zero hunger

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    Antimicrobial, antioxidant and phytochemical properties of ethanolic and water extracts of selected local spices from Miagao, Iloilo
    Besinga, Yvonne Grace M. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)
    Spices such as garlic, pepper and turmeric are indispensable in the daily food preparation and are reported to have compounds which prevent the microbial spoilage of food. This study evaluates the antimicrobial and antioxidant activities as well as the phytochemical properties of the ethanol and aqueous spice extracts of garlic, pepper and turmeric. The antioxidant activity was performed using l,l-diphenyl-2-picryl- hydrazyl (DPPH) Radical Scavenging Method and the antimicrobial activity was evaluated by Disk Diffusion Assay. Phytochemical compounds tested were alkaloids, flavonoids, terpenoids, phenol and saponins. In decreasing order, the potency of the antioxidant activities showed Ascorbic acid > turmeric ethanol extract >pepper water extract> pepper ethanol extract> turmeric water extract> garlic ethanol extract> garlic water extract. The antimicrobial activity was highest in turmeric aqueous extract in terms of mean inhibition zone (7.5±2.10) against E. coli. The most effective treatment against B. subtilis was turmeric ethanol with highest mean inhibition zone (6.87±1.13). And for S. aureus, garlic ethanol extract has the highest mean inhibition zone (7.80±1.32). Phytochemical screening tests showed that in all treatments, the most abundant phytochemical were alkaloids and terpenoids. This study indicates that the spices like garlic, pepper and turmeric have antimicrobial and antioxidant activity.
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    Isolation and partial characterization of globulin from Cassava (Manihot esculenta Crantz) tubers
    Barbosa, May R. (Division of Physical Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)
    Soluble globulin was isolated using an extraction buffer (0.4 M NaCl in 35 mM potassium phosphate buffer, pH 7.6 with 0.02% Na azide). The isolated globulin was subjected to solubility tests with different NaCl concentrations. It has the highest solubility in 1.25M NaCl (1.09%), but no significant differences existed among the NaCl concentrations by analysis using one-way ANOVA at a = 0.05. Three major bands existed at LOOM NaCl dissolved globulin with molecular weight ranges of 28-33kDa, 38- 43kDa, and 65-70kDa relative to BSA. Two of these bands (38-43kDa and 65-70kDa) were observed in 0.50M and 0.75M NaCl soluble globulin. The 1.25M and 1.50M NaCl concentrations gave a single band (28-33kDa) each, while no clear bands were observed in other NaCl concentrations. Amino acid analysis revealed glutamic acid (12.09%) as the most abundant amino acid component of cassava globulin. Nine (9) essential amino acids were present. Of these nine, lysine (10.50%) is the most predominant. Cystine (0.39%) has the lowest percentage, followed by methionine (1.76%).
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    Antioxidative properties of the fruits of selected tomato (Lycopersicon esculentum Mill.) varieties
    Baltazar, Gleza Wae D. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-05)
    This study was conducted to compare the antioxidative properties of greenstage fruits of selected Lycopersicon esculentum Miller varieties (Diamante, Diamante Max, and Pidada) from Barangay Durog, Miagao, Iloilo. The fresh fruit samples were extracted with 95% ethanol. The crude extracts were concentrated using rotary evaporator. The antioxidant activity of the ethanolic fruit extracts was assayed for DPPH radical scavenging activity and the IC50 values were determined. The determination of the phenolic and flavonoid contents was done employing Folin- Ciocalteu method and aluminum chloride spectrophotometric method, respectively. The results show that the fruits of the studied L. esculentum varieties exhibit DPPH radical scavenging activity. The IC50 values, however, differ significantly among the varieties. The IC50 values for Diamante (24.22 ± 1.41 g/L) and Diamante Max (25.08 ± 0.45 g/L) are comparable but are significantly lower than Pidada (29.47 ± 1.33 g/L). These findings imply that Diamante and Diamante Max varieties have stronger antioxidative capacity than the Pidada variety. Moreover, the results indicate that the antioxidative property of L. esculentum is variety-dependent. The results of the determination of the total phenolic content, expressed in mg gallic acid equivalent (GAE) per g fresh sample, are in the order of 0.16 ± 0.02 mg GAE/g for Diamante > 0.15 ± 0.02 mg GAE/g for Diamante Max and Pidada. On the other hand, the results of the determination of the flavonoid content, expressed in μg quercetin equivalent (QE) per g fresh sample, are in the order of 6.31 ± 1.27 μg QE/g for Diamante >6.21 ± 0.88 μg QE/g for Diamante Max > 5.63 ± 0.94 pg QE/g for Pidada. No significant difference in the total phenolic and flavonoid contents was found among varieties. Nonetheless, the detection of phenolics and flavonoids, known antioxidants, supports the present results on the antioxidative property of the fruits of the L. esculentum varieties studied.
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    Antioxidant property of anthocyanin from malatinta (Phyllanthus reticulatus Poir.) fruits obtained by static and microwave-assisted extraction
    Baldonasa, RB Hera Angelica R. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)
    Fresh fruits of Phyllanthus reticulatus Poir. were analyzed for anthocyanin by spectrophotometric method. The antioxidant activity using 1,1 -diphenyl-2-picrylhydrazyl (DPPH ) free radical scavenging activity (FRSA) and reducing power (RP) through FeCl3 assay were determined. The use of two extraction processes, namely, the static method and microwave-assisted extraction, using two extraction solvents, acidified methanol and aqueous ethanol (1:1) were compared. The total anthocyanin content (TAC) of P. reticulatus fruit was highest in extract using static method of extraction in acidified methanol solvent (279.94 ±17.31 mg/lOOg), comparable to levels found in plants rich in anthocyanins, (e.g., berries genotypes, grapes and red cabbages). In microwave-assisted extraction, TAC using acidified methanol was higher (278.01 ± 18.76 mg/lOOg) compared to using aqueous ethanol (210.96 ± 2.02 mg/100g). P. reticulatus fruits exhibited high antioxidant activity as revealed by its RP and DPPH FRSA results when compared to ascorbic acid. These findings highlight the usefulness of P. reticulatus as a source of anthocyanins with good antioxidant properties, which, in turn, gives importance to the undervalued and underutilized plant.
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    A novel water-in-oil-in-water emulsion to encapsulate antibacterial agents
    Balcarcel, Angelica V. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)
    Encapsulating bioactive compounds can protect them from adverse conditions. This study aimed to encapsulate bioactive agents in a stable multiple emulsion system using a material that can be recovered easily from a product abundant here in the country. Results of the study revealed that the method of encapsulation used is effective in encapsulating and releasing the bioactive compound encapsulated. The antibacterial activity determination showed that encapsulated chlorhexidine is effective against both S. aureus and E. coli bacteria. Further investigation was made by encapsulating aqueous guava (Psidium guajava) extract in the same emulsion system (water-in-oil- in-water) using recovered coconut milk protein (CMP) as a gelling agent. The evaluation of the stability of the emulsions revealed that the treatment with 40% guava extract in the aqueous phase of its primary emulsion (Emulsion 3) is the most stable among the other treatments. This treatment showed the smallest droplet size range and most uniformed droplet sizes. The creaming index of this treatment also showed the lowest values after three (3) weeks of storage. On the other hand, the treatment with 60% guava extract in the aqueous phase of its primary emulsion (Emulsion 4) appeared to be the most stable against heating. However, no antibacterial activity was observed for any of the emulsion systems both S. aureus and E. coli bacteria. Additional test revealed that the bioactive compound present in the plant extract was disrupted by the sonication process
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    Determination of the concentration of essential minerals (Ca, Fe, K, Mg, Na, Zn) in honey samples from Negros Occidental
    Arellano, Lory Mae F. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)
    Honey is a natural, sweet and highly nutritional substance produced by bees through a series of nectar collection and chemical processes. Due to the popularity of the product, certain regions in the Philippines has been producing honey and recently, different apiaries from Negros Occidental has been producing its own share of popular product in the market. The products are well received by the consumers, but the problem is the lack of characterization which gives the product doubtful and unconfirmed nutritional value. This study focuses on the quantification of essential minerals (Ca, Fe, K, Mg, Na, Zn) present in local honey samples from Negros Occidental. Eight honey samples were obtained from the different apiaries including an external sample from Mindoro. Samples were acid digested using HNO3/H2O2 solution at 130 °C. The concentration of each minerals in the honey samples were analyzed using AAS. The data reported high concentration (5.71 to 93.20 ppm) of K on most of the samples. The second most abundant mineral in the local honey is Ca ranging from 13.67 to 45.88 ppm. The Mg concentration ranges from 1.19 to 4.09 ppm while Na is in between 0.82 to 3.14 ppm. The mineral Zn and Fe contained the lowest concentration in most of the samples with Zn at 0.46 to 0.86 ppm and Fe at 0.04 to 0.30 ppm.