Antimicrobial efficacy of pummelo (Citrus maxima (Burm.) Merr.) extracts on spoilage and pathogenic microorganisms in raw chicken meat / Aimee Sheree Adato Barrion; Reynaldo C. Mabesa, chair, advisory committee.

Date

4-2011

Abstract

The antimucrobial activty of crude ethanolic extracts of pericarp, mesocarp and segment membrane of CItrus maxima (Burm.) Merr. fruit was evaluated against four selected pathogenic bacteria, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes after a preliminary phytochemical and antioxidant activity test were carried out of the sample extracts. The inhibitory effect was measured by means of total plate count (CFU/g) and by in-vitro antibacterial assay using the cup cylinder method. Preliminary pytochemical test revealed the presence of phenols (CE/100ml), tannins (CE/100ml), flavonoid (GAE/100ml) and saponin (CE/100ml) in which the order was as follows pericarp extract (29.64%LP). The differences in the measured amount of phytochemicals and antioxidant activity among the three sample extracts were found to be significant. The inhibition test showed that treating the raw chicken neck with pericarp, mesocarp and segment membrane extracts using 100% concentration and 1:1 w/v ratio, significantly achieved 1.63, 1.77 and 1.36 log CFU/g reductions, respectively, after 3 days of storage at 4°C. The log CFU/g reduction of the control was measured at 0.48. The in vitro microbial activity showed that Salmonella typhimurium was inhibited significantly by increasing concentrationns of extracts as compared to other test organisms. The growth of Staphylococcus aureus and Listeria monocytogenes were moderately suppressed by the extracts significantly at increasing concentrations while Escherichia coli to resist the inhibitory effect of the phytochemicals in the extracts may be morphological in nature that is to say its rough corrugated cell wall and thick periplasmic space as opposed to the smooth curved cell wall and very thin periplasmic space of Salmonella typhimurium. The zone of inhibition produced by the standard antibiotic Kanamycin sulfate (1000ppm), was 30-60% greater than the sample extracts. The pericarp extract displayed the highest significant antimicrobial effect with mean zone of inhibition of 17.10 mm, 9.90 mm and 15.25 mm for Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes, respectively. The phytochemical content and antioxidant activity were found to be significantly correlated to the in vitro antimicrobial activity against all the test organism except for Salmonella typhimurium. Although results showed fair inhibitory effect, these data provide evidence that Citrus maxima (Burm.) Merr. can be a potential source of natural antimicrobial and antioxidant agents.

Document Type

Dissertation

Degree

Doctor of Philosophy in Food Science

Adviser/Committee Chair

Reynaldo C. Mabesa

Committee Member

Erlina I. Dizon, Francisco B. Elegado, Wilma A. Hurtada, Reynaldo C. Mabesa

Language

English

LC Subject

Pummelo, Chickens, Food science. Institute of Food Science and Technology

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 996 2011 F61 B37

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