Preparation and antibacterial activity of chitosan-silver nanoparticles for application in preservation of minced meat

Bulletin of the National Research Centre

Table 3 In vivo antibacterial activity against E. coli (10⁴ cfu/g) in minced beef meat products treated with chitosan (Ch) and chitosan-silver nanoparticles (Ch-AgNPs) after storage for 10 days at 4 °C

Treatment	Concentration (μg/g)	Antimicrobial activity against E. coli (10⁴ cfu/g) ± SE at time (day)			Average ± SE
Treatment	Concentration (μg/g)	3	7	10	Average ± SE
Control+	0.00	295.00 ± 2.89	˃ 300	˃ 300	˃ 300
Control−	0.00	137.50 ± 1.44	295.00 ± 2.89	298.5 ± 0.87	243.67^ed ± 53.09
Ch	1000	75.00 ± 2.89	132.50 ± 1.44	172.50 ± 1.44	126.67^d ± 28.30
Ch	2500	62.50 ± 1.44	85.00 ± 2.89	105.00 ± 2.89	84.17^c ± 12.28
Ch-AgNP1	1000	8.50 ± 0.29	14.50 ± 0.29	21.00 ± 0.58	14.67^c ± 3.61
Ch-AgNP1	2500	1.50 ± 0.29	11.00 ± 0.58	14.50 ± 0.29	9.00^b ± 3.88
Ch-AgNP2	1000	5.50 ± 0.29	12.50 ± 0.87	16.50 ± 0.87	11.50^b ± 3.21
Ch-AgNP2	2500	2.00 ± 0.00	4.50 ± 0.29	11.00 ± 1.73	5.83^a ± 2.68
Ch-AgNP3	1000	1.50 ± 0.29	9.50 ± 0.29	13.50 ± 0.87	8.17^a ± 3.53
Ch-AgNP3	2500	1.50 ± 0.29	2.50 ± 0.29	7.00 ± 0.58	3.67^a ± 1.69
Mean		85.25^a	121.4^b	129.75^c	Between treatment for 1000 = 2.38
LSD_0.05		Between time = 1.23			Between treatment for 2500 = 2.60

Values are mean of three replicates ± standard error (SE). Different letters in the same column indicate significant differences according to Duncan's multiple range test (P ≤ 0.05)
Before treatment, 130 × 10⁴ cfu/g
Control (+) minced meat treated with E. coli, Control (−) minced meat without E. coli, Ch chitosan, NP nanoparticle, Ch-AgNP1 (0.1% Ag), Ch-AgNP2 (0.2% Ag), Ch-AgNP3 (0.3% Ag)