Stefan-Boltzmann constant (5.669 x 10 в€’8 W m в€’2 K в€’4) Radiation intensity, which depends on position and direction, W m в€’2 Hence, delivering the optimal dosage with uniform dose distribution is important to successfully implement UV-C treatment of fruits. Thirdly, the inactivation effect of UV-C on fruits is found to increase with UV-C dose initially but then begins to diminish after exceeding a certain threshold ( Nigro et al., 2000 Stevens et al., 1996). Potential damage to strawberries under high UV-C dose includes browning of the calyx ( Lammertyn et al., 2003). Thus, the range of dose intensity should be as narrow as possible to avoid applying too much radiation. Secondly, overexposure to UV-C could degrade the quality of the fruits. Firstly, uniform dose distribution is needed to achieve an even level of inactivation. There are many reasons a uniform irradiation dose is desired for UV-C treatment. Nevertheless, one obstacle which has been slowing down the practical implementation of UV-C is the difficulty in achieving a uniform irradiation dose on complicated surfaces. The inactivation effect of UV-C radiation has been investigated in many agricultural products such as fresh-cut apples ( Manzocco et al., 2011), baby spinach ( Escalona et al., 2010), peppers ( Vicente et al., 2005) and strawberries ( Marquenie et al., 2003). It is cheap, easy to operate and can be readily incorporated in the processing line. The use of UV-C radiation as a non-chemical surface decontamination treatment of fresh fruits has several merits. UV-C radiation has a wavelength ranging from 100 to 280 nm and is known to be highly germicidal. Due to a growing concern over the effect of chemical residues on human health, alternative physical techniques such as UV-C irradiation have received attention in recent years. There are many types of surface decontamination techniques available however, most methods involve the use of chemicals ( Beuchat, 1998). To reduce the loss due to fungal decay, various postharvest treatments such as surface decontamination should be implemented. A considerable amount of fruits and vegetables are lost during postharvest, processing and distribution processes ( FAO, 2011).

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