Publication Details
Abstract
Poultry meat is considered as one of the important foods due to its high nutritional value and the preservation of frozen poultry meat from microbial spoilage is a great challenge, due to the ability of many species of bacteria to adapt and grow at low temperatures. There is a global drive to reduce chemical additives due to the long-term health damage they cause, with safe natural alternatives from agricultural waste. The objective of this study was to assess the in vitro inhibitory activity of hydrolysable tannin extracts from pomegranate peels (Punica granatum) and condensed tannin extracts from grapefruit peels (Citrus paradisi) at different concentrations (12.5, 25, 50, 75, 100 mg/mL) against four species of pathogenic and psychrophilic bacteria from chicken meat (Campylobacter jejuni, Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli). The three-factor factorial experiment (2×4×5) was designed based on Completely Randomised Design (CRD) and Three-Way Analysis of Variance (Three Way ANOVA) was performed and Duncan’s Multiple Range Test was applied at a significance level of ( p < 0.05 ). The results showed a significant superiority of the grapefruit peel tannin extract with an average of 14.85 mm inhibition compared to the pomegranate peel extract (9.91 mm) ( p < 0.05 ). In contrast, the extract of grapefruit peel at 100 mg/mL concentration showed the highest inhibition diameters against P. mirabilis with a mean of 21.83 mm, followed by C. jejuni with a mean of 21.00 mm. The inhibitory activity was also found to be directly proportional to the concentration (Dose-Dependent Manner). C. jejuni was also sensitive to grapefruit peel extract even at the low concentration of 12.5 mg/mL (15.27 mm), however it was resistant to pomegranate peel extract at the concentration of 25 mg/mL (0.00 mm). In contrast, both extracts showed complete resistance against E. coli at a concentration of 12.5 mg/mL. The study proves the high efficiency of grapefruit and pomegranate peel tannins as natural bio-additives for meat preservation. The concentration of 75 mg/mL of grapefruit peels can be used in active packaging technologies and microencapsulation to extend the shelf life of poultry meat.