Table 3.

Summary of effects of non-thermal methods to inactivation of T. gondii and its infectious forms.

Type of methods	Experimental Conditions	Main finding	Ref.
High Pressure Processing	400 or 300 MPa to 30, 60, or 90 sec	No mice inoculated with tissue cysts exposed to 400 or 300 MPa became infected.	[104]
	340 MPa to 1 min	Use of HPP at 340 MPa for 60 sec required to render oocysts spot inoculated on raspberries non-infectious for mice.	[104]
	550 MPa, 480 MPa, 400 MPa, or 340 MPa to 1 min	T. gondii oocysts in HBSS (without calcium or magnesium) or distilled water treated with HPP at 550, 480, 400 or 340 MPa for 60 sec were rendered noninfectious for mice.	[105]
Ionizing Irradiation	Gamma (70 krad)	Use of 70 krad gamma radiation was minimum effective dose for fresh pork.	[93]
	Gamma (40 krad)	T. gondii in tissue cysts killed by exposure to 40 krad of gamma irradiation.	[93]
	Gamma (50 krad or more)	Tissue cysts irradiated with 40 krad were infectious when inoculated in mice, but when irradiated with 50 krad or more, tissue cysts were not detected.	[107]
	Gamma (70 krad or 100 krad)	Tissue cysts in murine brains and edible pig flesh irradiated with 30 and 50 krad doses were not effective, whereas irradiation with 70 or 100 krad did not infect cats or mice in bioassay.	[108]
	Gamma (20 krad)	Irradiation treatments at doses as low as 20 krad effectively inactivated T. gondii oocysts on blueberry surfaces with minimal impact on texture, color, or anthocyanin content of treated berries.	[109]
	Gamma (60 krad and 45 krad)	The minimal effective dose for Chinese NT strain and the American ME-49 and TS-2 strains of T. gondii cysts in mouse and pig tissues was 60 krad. The infectivity for mice of NT strain bradyzoites irradiated at 45 krad decreased 10,000-fold.	[95]
	Ultraviolet (>20 mJ/cm2)	A 4-log inactivation of the oocyst/sporozoite infectivity was obtained for UV fluence.	[110]
	Ultraviolet (4 mJ/cm2 and 10 mJ/cm2)	The results from the animal bioassay show that 1- and 3-log10 inactivation was achieved with 4 mJ/cm2 UV and 10 mJ/cm2 low-pressure UV, respectively.	[94]
	Ultraviolet (40 mJ/cm2)	A 2-log10 reduction of T. gondii oocyst infectivity was achieved at 40 mJ/cm2.	[111,112]
	Ultraviolet (>500 mJ/cm2)	Inactivation of T. gondii oocysts occurred with exposure to pulsed and continuous UV radiation, as evidenced by mouse bioassay. Even at >500 mJ/cm2, some oocysts retained their viability.	[113]
	Ultraviolet (1 min UV exposure)	Using 1 min UV light at 3689.04 µJ/cm2/sec powers for a total energy exposure, tachyzoites were unable to replicate in vitro or produce parasite cysts in vivo.	[96]
Curing	3.9% NaCl, 25 mg/kg nitrate, and 3 mg/kg nitrite; 14 months	The last curing salt concentration of 3.9% NaCl, 25 mg/kg nitrate and 3 mg/kg nitrite for a duration of curing of 14 months inactivated T. gondii.	[114]
	2.5% of sodium nitrite; 14 days	About 2.5% of initial amount of sodium nitrite was effective for killing T. gondii cysts in 14 days.	[115]
	7% nitrates, 4% nitrites, sodium ascorbate, and sodium chloride; 9–12 months	The viability of T. gondii was higher in hams cured for 9 months compared to those cured for 12 months.	[116]
	2.0% NaCl or 1.4% or higher lactate-based salt solutions; 8 h	The injection of 2.0% NaCl or 1.4% or higher lactate-based salt solutions into pork loins containing infective tissue cysts within 8 h prevented transmission of T. gondii.	[103]
	salt and sugar for 64 h at 4°C; smoking at 50°C to 24–28 h	Curing of lamb meat with salt and sugar for 64 h at 4°C or smoking salt-injected meat at temperatures not exceeding 50°C for 24 to 28 h was effective for killing T. gondii.	[110]
	6% NaCl; 4–20°C; 3–56 days	In various time intervals and all temperatures examined, tissue cysts were killed in 6% NaCl solution.	[101]
	2.0 and 2.5% of salt; 48 hours	Pig sausage experimentally inoculated with T. gondii showed that salt in concentrations of 2.0 and 2.5% inactivated the parasite within 48 h of onset of curing.	[117]
	3% table salt; 3–7 days	About 3% table salt after 3–7 days killed T. gondii tissue cysts.	[118]
	2.5 and 3.0%, NaCl and 0.5% nitrite; 1–8 day	The cysts lost their infectivity in concentrations of 2.5 and 3.0% NaCl after 1 day. NaCl plus 0.5% nitrite had a stronger effect on T. gondii cysts than common table salt.	[119]