Azucena, Alexis G.
An Official Entry to 2010 Regional Science Fair
Physical Science- Individual
Negros Occidental National Science High School
January 13, 2011
Ma. Melanie P. Romero
Research IIB Adviser
The research paper attached hereto, entitled, “Methanolic Extract of Eggplant (Solanum melogena) Peel as a Dye Pigment in Differential Stains”, prepared and submitted by Alexis G. Azucena in partial fulfillment of the requirement in Research II-B is hereby accepted.
___________________________________________________________ Mrs. Ma. Melanie P. Romero Mr. Philip E. Villanueva Jr. Research II-B Adviser Panelist
___________________________________________________________ Ms. Madonna B. Decena Eng’r. Rafael N. Diamante Jr. Panelist Panelist
Accepted in partial completion of the requirements for graduation in Negros Occidental National Science High School, Victorias City, year 2010-2011.
___________________________________________________________ Mrs. Maritess B. Rivera Mr. Michell L. Acoyong Principal-in-Charge ES-1 Science
NONSHS Division of Negros Occidental
Anthocyanin is a pigment that changes color in different pH level. In this property, anthocyanin becomes a pH indicator. Recent study shows that anthocyanin can be used as a microbiological stain.
This study aims to determine the potential of methanolic extract of eggplant (Solanum melogena) peels as a dye pigment in differential stain. Eggplant contains anthocyanin in the peels.
Eggplants were peeled and then weighed. Fifty (50) grams of peels were homogenized with acidified methanol and then macerated for one hour. The extract was then filtered and then concentrated overnight. The pure crude extract was then added to 10 mL of distilled water. To test the extract, Gram stain was used. Two methods were used, one will be used as a primary stain and one will be used as a substitute in Gram iodine. Bacillus cereus stained into pink when methanolic extract was used as a primary stain and violet when methanolic extract was applied as a substitute in Gram iodine. Other bacteria like Escherechia coli and Pseudomonas aeroginusa stained into pink in the two staining methods. Staphylococcus aureus stained into violet in two staining methods.
Result shows that methanolic extract of eggplant can be used as a substitute in Gram iodine but not as primary stain. Methanolic extract from eggplant peels had a potential as a dye pigment.
Preparation of Materials
Extraction and Purification of Eggplant Peels
Methanolic Extract as a Substitute in Gram Iodine
Methanolic Extract as Primary Stain
Microscopic View of Slides
Preparation and Extraction of Eggplant Peel Extract
Eggplants were taken at the Burgos Public Market, Bacolod City. Eggplants were peeled by using a knife. The peels were then weighed. Fifty (50) grams of eggplant peels were needed.
In preparation of acidified methanol, 0.01% of HCl in methanol was needed. One hundred (100) mL of concentrated methanol was prepared. Ten (10) μL of concentrated HCl was obtained by using a pippetor and then added in the methanol. The acidified methanol was then put in the 100 mL Erlenmeyer flask.
In preparation of Gram staining, the bacteria were prepared. Sixteen (16) glass slides were washed and then dried. The inoculating loop was heated in the flame. The loop was then smeared in the bacteria. The loop was then spread in the glass slide, with the dimension of 1 sq. inch. Then the glass slide was labeled according to what...