Bacterial inactivation mechanism of SC-CD and TEO combinations in watermelon and melon juices

ERKMEN, Osman

doi:10.1590/fst.62520

Osman ERKMEN ^**Corresponding author: erkmen@gantep.edu.tr

Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Gaziantep, Turkey

http://orcid.org/0000-0001-9113-9638

*Corresponding author: erkmen@gantep.edu.tr

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Figure 1
Schematic diagram of high-pressure CO₂ treatment. (1) = CO₂ cylinder; (2) = pressure regulator; (3) = needle valve for CO₂ inlet; (4) = thermostatic water bath; (5) = pressure vessel; (6) = line filter; (7) = needle valve for CO₂ outlet; (8) = thermocouple; (9) = temperature data logger; (10) = pressure transducer; (11) = pressure data logger; (12) controller; (13) water circulation pump; (14) Heater; (15) Immersion heater.

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Figure 2
Antibacterial activity of SC-CO₂ and SC-CO₂+TEO on S. Typhimurium at 35 °C. Treatments are: 7.6 MPa (○) in TSB, 10.13 MPa (•) in TSB, 7.6 MPa+TEO (□) in TSB, 10.13 MPa+TEO (■) in TSB, 10.13 MPa +TEO (Δ) in watermelon and 10.13 MPa+TEO (▲) in melon.

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Figure 3
Antibacterial activity of SC-CO₂ and SC-CO₂+TEO on E. coli at 25 °C. Treatments are: 7.6 MPa (○) in TSB, 10.13 MPa (•) in TSB, 7.6 MPa+TEO (□) in TSB, 10.13 MPa+TEO (■) in TSB, 10.13 MPa +TEO (Δ) in watermelon and 10.13 MPa+TEO (▲) in melon.

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Figure 4
Antibacterial activity of SC-CO₂ and SC-CO₂+TEO on K. pneumoniae at 35 °C. Treatments are: 7.6 MPa (○) in TSB, 10.13 MPa (•) in TSB, 7.6 MPa+TEO (□) in TSB, 10.13 MPa+TEO (■) in TSB, 10.13 MPa +TEO (Δ) in watermelon and 10.13 MPa+TEO (▲) in melon.

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Figure 5
Mechanism of SC-CO₂ and TEO actions on cell structures and cytoplasm.

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Table 1
Effect of SC-CO₂ and SC-CO₂+TEO on the inactivation rates (k) and decimal reduction times (D) of S. Typhimurium in TSB, watermelon and melon juice^a a ×¯ = means and sx = standard deviations of three determinations, r2 = regression coefficient; .

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Table 2
Effect of SC-CO₂ and SC-CO₂+TEO on the inactivation rates (k) and decimal reduction times (D) of E. coli in TSB, watermelon and melon juice^a a ×¯ = means and sx = standard deviations of three determinations, r2 = regression coefficient; .

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Table 3
Effect of SC-CO₂ and SC-CO₂+TEO on the inactivation rates (k) and decimal reduction times (D) of K. pneumonia in TSB, watermelon and melon juice^a a ×¯ = means and sx = standard deviations of three determinations, r2 = regression coefficient; .

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Table 4
Effect of SC-CO+EO treatment on total soluble solids and pH of watermelon and melon juices.

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Table 5
Effect of SC-CO+EO treatment on BD of watermelon and melon juices.

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Table 6
Effects of SC-CO+EO treatment on watermelon juice L*, a* and b* values after treatment (0) and during storage (7 days).

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Table 7
Effects of SC-CO+EO treatment on melon juice L*, a* and b* values after treatment (0) and during storage (7 days).

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(1)

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(2)

Medium	Pressure (MPa)	k (min^-1)		D (min)		r²
Medium	Pressure (MPa)	$\bar{\times}$ ^b b There are significant differences (P < 0.01) between different treatments.	s_x	$\bar{\times}$ ^b	s_x	r²
TSB	7.6	0.0962	0.0019	10.40	0.21	0.98
TSB	10.1	0.1536	0.0053	6,5124	0.2259	0.97
ThymMIC-TSB	7.6	0.1211	0.0042	8,2587	0.2895	0.97
ThymMIC-TSB	10.1	0.1669	0.0055	5,9907	0.1964	0.98
ThymMIC+ Watermelon	10.1	0.1856	0.0115	5,3889	0.3349	0.95
ThymMIC+Melon	10.1	0.1409	0.0030	7,0995	0.1514	0.99

Medium	Pressure (MPa)	k (min^-1)		D (min)		r²
Medium	Pressure (MPa)	$\bar{\times}$ ^b b There are significant differences (P < 0.01) between different treatments.	s_x	$\bar{\times}$ ^b	s_x	r²
TSB	7.6	0.0885	0.0014	11.31	0.18	0.99
TSB	10.1	0.1186	0.0018	8,4282	0.1272	0.99
ThymMIC-TSB	7.6	0.1021	0.0022	9,7948	0.2087	0.98
ThymMIC-TSB	10.1	0.1442	0.0031	6,9354	0.1506	0.99
ThymMIC+ Watermelon	10.1	0,1401	0.0039	7,1372	0.1975	0.98
ThymMIC+Melon	10.1	0.1255	0.0026	7,9650	0.1626	0.99

Medium	Pressure (MPa)	k (min^-1)		D (min)		r²
Medium	Pressure (MPa)	$\bar{\times}$ ^b b There are significant differences (P < 0.01) between different treatments.	s_x	$\bar{\times}$ ^b	s_x	r²
TSB	7.6	0.0785	0.0018	12,7310	0.2837	0.98
TSB	10.1	0.0940	0.0018	10,6337	0.2056	0.98
ThymMIC-TSB	7.6	0.1046	0.0018	9,5593	0.1649	0.99
ThymMIC-TSB	10.1	0.1383	0.0035	7,2324	0.1809	0.98
ThymMIC+ Watermelon	10.1	0.1263	0.0031	7,9150	0.1946	0.98
ThymMIC+Melon	10.1	0.1107	0.0027	9,0293	0.2206	0.98

	Watermelone juice				Melon juice
Day	Total soluble solid		pH		Total soluble solid		pH
Day	Untreated	SC-CO₂+TEO	Untreated	SC-CO₂+TEO	Untreated	SC-CO₂+TEO	Untreated	SC-CO₂+TEO
0	11.29 ± 0.02^* * Mean of three values ± Std Error.	11.32 ± 0.01	5.38 ± 0.01	5.32 ± 0.01	9.47 ± 0.21	9.47 ± 0.21	6.80 ± 0.15	6.69 ± 0.15
1	11.33 ± 0.03	11.36 ± 0.03	5.37 ± 0.02	5.30 ± 0.02	9.54 ± 0.18	9.58 ± 0.18	6.64 ± 0.20	6.62 ± 0.14
3	11.28 ± 0.03	11.30 ± 0.01	5.35 ± 0.01	5.28 ± 0.01	9.48 ± 0.19	9.55 ± 0.25	6.72 ± 0.13	6.58 ± 0.13
5	11.19 ± 0.02	11.28 ± 0.03	5.34 ± 0.02	5.27 ± 0.02	9.53 ± 0.13	9.51 ± 0.12	6.63 ± 0.09	6.59 ± 0.08
7	11.17 ± 0.03	11.30 ± 0.02	5.32 ± 0.03	5.27 ± 0.03	9.50 ± 0.09	9.54 ± 0.19	6.69 ± 0.12	6.62 ± 0.15

	Watermelon juice		Melon juice
Day	Untreated¹	SC-CO₂+TEO¹	Untreated¹	SC-CO₂+TEO¹
0	1.12 ± 0.01	1.12 ± 0.02	1.09 ± 0.01	1.13 ± 0.01
1	1.12 ± 0.01	1.12 ± 0.01	1.08 ± 0.02	1.40 ± 0.01
3	1.11 ± 0.02	1.11 ± 0.02	1.08 ± 0.03	1.13 ± 0.02
5	1.09 ± 0.03	1.1 ± 0.03	1.07 ± 0.01	1.14 ± 0.03
7	1.07 ± 0.03	1.09 ± 0.03	1.08 ± 0.02	1.09 ± 0.01

Day	Untreated¹ 1 Control, Without application of SC-CO2+EO.			SC-CO₂+TEO¹
Day	L*	a*	b*	L*	a*	b*
0	28.31 ± 1.23	19.34 ± 1.23	8.38 ± 0.23	30.87 ± 1.23	19.43 ± 1.23	8.58 ± 0.23
1	29.29 ± 1.10	17.56 ± 1.06	9.12 ± 0.12	31.23 ± 1.20	19.65 ± 1.14	8.78 ± 0.19
3	30.12 ± 2.05	16.61 ± 1.09	9.54 ± 0.08	31.17 ± 2.06	20.43 ± 2.12	8.82 ± 0.22
5	30.46 ± 2.14	17.36 ± 1.11	9.58 ± 0.11	31.02 ± 2.23	21.76 ± 2.08	8.54 ± 0.15
7	30.22 ± 2.07	17.44 ± 1.16	9.56 ± 0.12	31.68 ± 2.07	21.49 ± 1.12	8.23 ± 0.10

Day	Untreated1			SC-CO₂+TEO¹
Day	L*	a*	b*	L*	a*	b*
0	24.25 ± 1.12	10.89 ± 0.12	19.75 ± 1.12	25.12 ± 1.12	10.45 ± 0.12	19.70 ± 1.14
1	26 ± 1.18	11.67 ± 0.15	19.65 ± 1.08	26.10 ± 2.18	10.10 ± 0.15	19.66 ± 2.08
3	25 ± 1.10	11.34 ± 0.16	18.98 ± 1.06	25.79 ± 1.10	9.62 ± 0.16	19.43 ± 1.06
5	26 ± 1.09	11.45 ± 0.09	19.45 ± 1.18	26.76 ± 1.09	9.30 ± 0.09	19.45 ± 1.18
7	25 ± 1.12	11.26 ± 0.013	19.24 ± 1.20	27.97 ± 2.12	9.08 ± 0.25	19.69 ± 2.20

[1] *Corresponding author: erkmen@gantep.edu.tr

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Brasil

Bacterial inactivation mechanism of SC-CD and TEO combinations in watermelon and melon juices

Abstract