Design and development of dragon fruit (Hylocereus polyrhizus) peel extract-based freshness indicators for avocado (Persea americana Mill.) smart packaging

Avocado (Persea americana Mill.) is classified as a climacteric fruit, which experience a surge in respiration rate after harvest. Therefore, consumers usually need to be cautious when selecting avocados to ensure they obtain fruits with an acceptable level of freshness. However, the actions taken by consumers further exacerbate the damage to avocados, such as bruising caused by pressing the fruit to assess its ripeness. One approach to minimize such damage is the use Persea americana of indicator labels to assess the fruit quality. Freshness indicators can be made from various natural and synthetic materials. One natural dye that can be used is dragon fruit peel, which contains high levels of anthocyanin compounds that serve as natural colorants. This study aims to determine the optimal treatment for indicator labels production and color changes of indicator labels during avocado storage. The research was conducted in two stages: stage I to determine the optimal pH of dragon fruit extract and stage II to assess the quality changes of avocado and the color changes of the indicator label. The best treatment for producing smart packaging indicator labels was at pH 7 with a soaking time of 5 hours. These labels can indicate changes in avocado quality during storage through color variation. A purplish-red color indicates that the fruit is still unripe, which then changes to pink when the fruit ripens. The indicator label turns to shades of pink and yellow as the ripening progresses, and eventually develops black spots, indicating that the fruit has deteriorated.