The system, consisting of a label infused with cinnamon essential oils, was attached to plastic packaging and used to lengthen the shelf life of late maturing ‘Calanda’ peaches, said Spanish scientists. The tag was placed inside a macro-perforated PET tray, which included 20 macro-perforations.
Shelf life and quality
The study by Christina Nerin et al concluded that use of the cinnamon active packaging slashed the amount of fruit spoiled after being stored for almost two weeks.
“After 12 days of storage at room temperature, the percentage of infected fruit in the active label packaging was 13 per cent versus 86 per cent in the non-active packaging”, said the group from the University of Zaragoza. The fruit normally has a shelf life of 3-5 days at room temperature.
The paper, published in the journal Postharvest Biology and Technology, said use of the packaging cut weight loss in the fruit and helped it maintain firmness.
The technology also reduced the production of enzymes leading to oxidation in the fruit over the course of the storage period. The scientists said they reached this conclusion after examining the influence of the active packaging on the in vivo activity of lipoxygenase (LOX), polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and of malondialdehyde (MDA) content as an indicator of lipid oxidation.
It added that in carrying out sensory analysis, “most positive descriptors were not significantly different from the optimum quality level (day 0) for peaches stored in the active package after 12 days at room temperature”.
The researchers said it has been more usual to incorporate the active packaging agent directly into the plastic polymers - while use of active labels less common.
“Labels are very versatile and also easily adapted to an industrial scale and can be added just before packaging the food, thereby maximizing their functionality,” said Nerin.
Conclusions
She concluded that the self-adhesive active label developed by the team placed inside the packaging offered an “efficient option” for extending shelf life of the fruit at room temperature.
Nerin added: “This type of active packaging is more efficient than the use of an active macro-perforated tray of PET, probably due to the higher concentration of active compounds released by the packaging.”
The system also demonstrated an improvement in physico-chemical properties such as weight loss and firmness.
The cinnamon essential oil also inhibited the activity of lipoxygenase. The use of the active packaging “somehow influences the activity of some selected enzymes”, said the research.
The global sensory qualities of the fruit were also enhanced so that after 12 days of storage at room temperature they were “similar to that at the optimum quality level”.
The panel of 11 assessors detected no cinnamon or off-flavours.
Active label-based packaging to extend the shelf-life of “Calanda” peach fruit: Changes in fruit quality and enzymatic activity by Pablo Montero-Pradoa, Angel Rodriguez-Lafuente and Cristina Nerin; published in Postharcest Biology and Technology
doi:10.1016/j.postharvbio.2011.01.008