Chlorophyll Fluorescence Imaging Allows Early Detection and Localization of Lemon Rind Injury following Hot Water Treatment

Abstract

<jats:p>Green lemons (<jats:italic>Citrus limon</jats:italic> (L.) Burm.) were imaged for chlorophyll fluorescence (CF) 30 minutes after immersion of the fruit into 55 °C water for 5 minutes to determine if CF could be used to identify areas of hot water-induced rind injury before the appearance of visible symptoms. Fluorescence was variable in intensity over the surface of the rind with defined areas of enhanced fluorescence being present that corresponded in shape and location with visible injury that later developed during 24 hours of storage. Images showing minimum fluorescence (F<jats:sub>0</jats:sub>) and maximal fluorescence (F<jats:sub>m</jats:sub>) provided the best image contrast between injured and noninjured areas of the rind. Total F<jats:sub>0</jats:sub> present in the image was closely correlated (<jats:italic>r</jats:italic><jats:sup>2</jats:sup> = 0.87) with the area of rind injury present following storage. Holding the fruit under conditions of low humidity for 24 h before hot water treatment prevented both the formation of areas of enhanced fluorescence and the corresponding rind injury. Imaging of CF has potential as a means to identify areas of incipient rind injury in citrus to facilitate study of the causal mechanisms of postharvest rind disorders.</jats:p>

Applications of chlorophyll fluorescence imaging technique in horticultural research: A review

“…CFI has also been used in lemons for the early detection of areas of hot water-induced rind injury before the appearance of visible symptoms during storage (Obenland and Neipp, 2005). Nonpathological rind disorders, which can be initiated in pre-and/or postharvest, are common occurrences that reduce the marketability value of the fruit (Grierson, 1981).…”

“…F 0 and F m provided the best image contrast between injured and non-injured areas of the rind. The increase of F 0 observed in injured areas indicated photoinhibition damage (Obenland and Neipp, 2005). Nedbal et al (2000b) showed that CFI can be used in lemon to discriminate between damaged areas that, although visually similar, have different underlying causes.…”

Mapping Grape Berry Photosynthesis by Chlorophyll Fluorescence Imaging: The Effect of Saturating Pulse Intensity in Different Tissues

“…[10][11][12][13][14], and in phototrophic aquatic systems (e.g. [15][16][17], but this technique has been seldom used for photosynthetic measurements in fruits (18)(19)(20)(21)(22). Moreover, the few studies with imaging-PAM techniques have been directed to assess the ripening stage (23), fruit quality (18) or early injury detection (19) in intact fruits.…”

Advances in Machine Vision Applications for Automatic Inspection and Quality Evaluation of Fruits and Vegetables

“…These induce visible fluorescence (550-500 nm) on molecules of essential oils present in the skin after cell breakage. Chlorophyll fluorescence was employed by Obenland and Neipp (2005) to locate incipient peel injury caused by hot water treatment in lemons. Visible-and UV-induced fluorescence (UVFL) was also used by Ariana et al (2006a) to detect different types of defects in three varieties of apples.…”