Pre-harvest monitoring of apple fruits development with the use of biospeckle method

In this study, the biospeckle method was evaluated for pre-harvest apple monitoring. This non-destructive optical method is based on the analysis of laser light variations scattered from a sample. Apples of the cultivars ‘Ligol’ and ‘Szampion’ were tested at four stages of development and maturity. Biospeckle activity and firmness were measured on individual apples. Moreover, standard quality attributes, including acidity, starch and soluble solids content, were also determined for each development stage.The results revealed that biospeckle activity reflects the biochemical changes during apple development and maturation. An increase in biospeckle activity in pre-harvest stages was observed where increases in soluble solids and a slight decrease in starch and acid content occurred. Strong correlation was obtained between biospeckle activity and soluble solids content, starch content and firmness, showing that this method has the potential to be used for non-destructive evaluation of these properties in the pre-harvest period. This study also showed that this method could possibly also be used for prediction of the harvest date.

► The biospeckle activity was studied in pre-harvest apple monitoring.
► The biospeckle activity was set with quality attributes of apples.
► An increase of biospeckle activity in pre-harvest stages was observed.
► The biospeckle reflects biochemical changes during apple development.