Table 2.
Hormetic effects of UV treatment in food

Food (Cultivar) Experimental conditions Hormetic effects
Apple (Red Delicious)

Penicillium expansum inoculation

UV dose: 7.5 kJ/m2

 		•Disease resistance (de Capdeville et al., 2002)
Cactus Pear (Gialla) •UV dose: 0.75 kJ/m2

No effect on rate of decay (Piga et al., 1997)

Observed damage on skin
Cherry (several un-named cultivars)

Botrytis cinerea and Moniliniafructigena inoculation

UV dose: 0.5~15 kJ/m2

 		•No effect on fungal development (Marquenie et al., 2002)
Grape (Italia)

Botrytis cinerea inoculation

UV dose: 0.125~4 kJ/m2

Optimal UV dose: 0.125~0.5 kJ/m2

Disease resistance (Nigro et al., 1998)

Doses above 1.0 kJ/m2 resulted in skin discoloration
Grapefruit (Star Ruby)

Penicillium digitatum inoculation

UV dose: 0.5~3 kJ/m2

Optimal UV dose: 0.5 kJ/m2

Disease resistance (D'hallewin et al., 2000)

Increased levels of scoparone and scopoletin

Rind browning andtissue necrosis occurred at doses of 1.5 kJ/m2
Kumquat (Nagami)

Penicillium digitatum inoculation

UV dose: 0.2~15 kJ/m2

Optimal UV dose: 1.5 kJ/m2

 		•Increased levels of scoparone (Rodov et al., 1992)
Lemon (Eureka)

Penicillium digitatum inoculation

UV dose: 0~15 kJ/m2

Optimal UV dose: 5 kJ/m2

 		•Increased levels of scoparone (Ben-Yehoshua et al., 1992)
Mango (Tommy Atkins)

UV dose: 4.9, 9.9 kJ/m2

Optimal UV dose: 4.9 kJ/m2

Improved appearance and texture (Gonzalez-Aguilar et al., 2001)

Disease resistance

Induced spermidine and putrescence

The higher dose induced senescence
Orange (Biondo Comune, Washington Navel, Tarocco, Valencia Late) •UV dose: 0.5~3 kJ/m2

Disease resistance (D'hallewin et al., 1999)

Reduced decay at doses of 0.5 kJ/m2

Increased levels of scoparone and scopoletin
Orange (Shamouti, Valencia)

Penicillium digitatum inoculation

UV dose: 0.2~15 kJ/m2

Optimal UV dose: 9 kJ/m2

 		•Increased levels ofscoparone (Rodov et al., 1992)
Peach (Elberta)

Monilinia fructicola inoculation

UV dose: 0.84~40 kJ/m2

Optimal UV dose: 7.5 kJ/m2

Delayed ripening (Stevens et al., 1998)

Suppressed ethylene production

Increased phenylalanineammonia-lyase activity

Increased brown rot at doses of 40 kJ/m2
Pepper (Bell Boy, Delphin)

Natural infection and Botrytis cinerea inoculation

UV dose: 0.22~2.2 kJ/m2

Optimal UV dose: 0.88 kJ/m2 (Botrytis cinerea)

 		•Natural infection resistance (Mercier et al., 2001)
Strawberry (Elsanta)

Botrytis cinerea and Moniliniafructicola inoculation

UV dose: 0.5~15 kJ/m2

Optimal UV dose: 0.5 kJ/m2

Reduced fungal development (Marquenie et al., 2002)

Maintained firmness than control groups but browning and drying of the calyx was observed at higher doses
Strawberry (Kent)

Botrytis cinerea inoculation

UV dose: 0.25~1 kJ/m2

Optimal UV dose: 0.25 kJ/m2

Extended shelf life (Baka et al., 1999)

Reduced rate of senescence
Tomato (Capello)

UV dose: 3.7~24.4 kJ/m2

Optimal UV dose: 3.7 kJ/m2

 		•Delayed ripening and increased putrescence at doses of 3.7 kJ/m2 (Maharaj et al., 1999)
Tomato (Floradade, Better Boy)

Alternariaalternata, Botrytis cinerea and Rhizopus stolonifer inoculation

UV dose: 1.3~40 kJ/m2

Optimal UV dose: 3.6~7.5 kJ/m2

Delayed ripening at doses of 3.6 and 4.8 kJ/m2 (Liu et al., 1993)

Skin discoloration occurred at doses of 40 kJ/m2