# Applications of Pulsed Light Decontamination Technology in Food Processing: An Overview
## 6 Effect on Food Quality Characteristics
### Effects on Organoleptic Properties (Color, Texture and Flavor) of Food Products  
Fruits and vegetables contain several phytochemicals and pigments which impart color and other sensory characteristics to them. It is very important to have a knowledge of the effects of PL on these product characteristics. In earlier studies conducted by [PERSON] et al. [30], PL was claimed to maintain sensory attributes without any significant changes. Many studies have emerged thereafter which have shown both similar and opposite results of effect of PL on the sensory properties of products like fruits and vegetables. [PERSON] and [PERSON] [28; 82] treated blueberries, raspberries and strawberries using pulsed UV light and observed insignificant color parameter and sensory changes, as well as no damages on the treated samples as compared to untreated ones. However, [PERSON] and [PERSON] [28] reported high inactivation at a high fluence level of 32.4 J/cm\({}^{2}\) at 3 cm sample distance from lamp but carried out color and sensory analyses at lower levels of 22.6 and 11.3 J/cm\({}^{2}\) at 8 cm distance. In another study, the color and firmness of strawberries remained acceptable after PL treatments [67]. [PERSON] [99]treated blueberry wine by PL and did not observe any significant effects on hue and lightness values of blueberry wine. However, many studies have shown significant undesirable changes by PL treatment. [PERSON] and [PERSON] [34] observed that undesirable color changes occurred on PL treatment of black pepper and wheat flour, which was apparent well before achieving the required microbial inactivation. [PERSON] et al. [80] reported discoloration in PL-treated iceberg lettuce and plastic like off-odor in shredded white cabbage immediately after treatment at 2700 pulses of 7 J intensity at 12.8 cm distance. This indicates a severe PL treatment might lead to significant changes to food quality. Slight color changes were also observed on PL treated apple juice [92]. Similarly, [PERSON] et al. [43, 54, 94] showed that the UV-C component of PL significantly hampered the firmness and color in fresh cut avocado, watermelons and mushrooms as UV-C wavelengths corresponding to higher energy have tendency to bring about undesirable sensory changes. There was a significant change in lightness value of the fresh-cut avocado and post-storage browning [43] after PL treatment with the main role of the UV-C region. There was a significant decrease in the color parameters and firmness of water-melons by PL application contributed significantly by UV-C. Color changes were attributed to decrease in carotenoid concentration [94] which might be due to the slight heating of samples and exposure to UV-C. A similar decrease in the lightness and firmness values of mushrooms was observed [54] after PL application. [PERSON] et al. [15] also reported such effects of PL treatment on mushroom texture due to thermal damage by photo-thermal effect. [PERSON] et al. [93] affirmed that PL treatment affected the tactile properties of fruit and vegetables like texture and firmness, which was shown by [PERSON] et al. [43, 54, 94]. A slight decrease in the firmness of PL treated tomatoes was observed [115]. In PL treated mango pulp, there was 40% decrease in fruit firmness post-storage [129]. There was also significant improvement in color in PL treated mango peel and pulp after storage for seven days. Chroma values increased up to 140% in the peel and 130% in the pulp post-storage which was attributed to increments in their carotenoid concentration due to chlorophyll degradation, however, contradicting the study by [PERSON] et al. [94]. This might depend on the product matrix, e.g., in watermelon the PL decreases carotenoids, whereas in mango it leads to the conversion of chlorophyll into carotenoids.