Degradative enzymatic activities in fresh‐cut blood‐orange slices during chilled‐storage

Abstract

Blood-orange fruits are suitable to fresh-cut fruit production because of their chemical compositions. Nevertheless, the main limitation of using freshly cut oranges is their susceptibility to juiciness loss and ascorbic acid degradation because of enzymatic alterations. The aim of this work is: to identify some of the enzymes causing the qualitative decay in blood-orange slices during 15 days of chilled storage (at 4 ± 0.5°C and 85% RH); to investigate the susceptibility to the previous alterations of five blood-orange clones (Moro nucellare, Sanguinello nucellare, Tarocco arcimusa, Tarocco gallo and Tarocco meli) to select the most suitable one for fresh-cut production. The enzymes studied were: pectinmethylesterase (PME) as index of juiciness loss, ascorbate oxidase (AAO) as index of ascorbic acid's degradation and polyphenol oxidase (PPO) as browning index. As far as we know, the changes of AAO activity during chilled storage of blood-orange freshcut slices has not previously reported and studied. Different clones showed different enzymatic activities and quality changes during chilled-storage. In particular a low juiciness loss in orange slices was correlated with a lower PME activity, as described in T. meli clone, while a high degradation of ascorbic acid was correlated with an higher AAO activity, as described in T. gallo clone; PPO activity seemed to have no significant action in quality degradation. Tarocco meli was the most suitable clone to the fresh-cut blood-orange production because it has the lowest enzymatic activity (PME, PPO and AAO) and the highest sensorial quality.

Passive Modified Atmosphere Packaging Extends Shelf Life of Enzymatically and Vacuum‐Peeled Ready‐to‐Eat Valencia Orange Segments

“…Catalano et al . () and Rocha et al . () explained this observation as a low polyphenol oxidase activity in cut oranges.…”

“…() and Catalano et al . (), but they could not relate it to changes in anthocyanin content. Catalano et al .…”

“…Karacay and Ayhan (2010) and Rapisarda et al (2006) also found no significant changes in lightness and b*, evidencing absence of browning. Catalano et al (2009) and Rocha et al (1995) explained this observation as a low polyphenol oxidase activity in cut oranges. Slight changes in a* values were reported by Caggia et al (2004) and Catalano et al (2009), but they could not relate it to changes in anthocyanin content.…”

“…In the particular case of minimally processed oranges ( Citrus sinensis ), MAP has been reported to reduce weight loss, inhibit bacterial and mold growth, and delay sensory changes (Catalano et al . ; Karacay and Ayhan ). When stored at 4C, shelf lives of as long as 12 days have been reported (Rapisarda et al .…”

“…Application of modified atmosphere packaging (MAP) in combination with low temperature storage for shelf life extension has been widely studied for a vast variety of fruit and vegetable products in the last years, yet much research is still to be done in order to develop safe fresh-cut fruit products with high sensory quality and nutritional value (Oms-Oliu et al 2010;Sandhya 2010). In the particular case of minimally processed oranges (Citrus sinensis), MAP has been reported to reduce weight loss, inhibit bacterial and mold growth, and delay sensory changes (Catalano et al 2009;Karacay and Ayhan 2010). When stored at 4C, shelf lives of as long as 12 days have been reported (Rapisarda et al 2006).…”