Lemongrass essential oil to preserve fresh-cut pineapple quality

Malaysian scientists at University Putra Malaysia have studied the effect of lemongrass (Cymbopogon citratus) essential oil (EO) incorporated into alginate-based edible coating [sodium alginate 1.29% (w/v); glycerol 1.16% (w/v), sunflower oil 0.025% (w/v)] on respiration rate, physico-chemical properties, and microbial and sensorial quality of fresh-cut pineapple stored for 16 days at 10±1°C and 65±10% RH.

For the study, different concentrations of lemongrass EO were tested: 0.1%, 0.3%, and 0.5% (w/v), the treatments were:

Samples coated with alginate-based edible coating with lemongrass EO;
Samples coated with alginate-based edible coating without lemongrass EO;
Samples uncoated as control.

Results showed that yeast and mould counts and total plate counts of coated samples containing 0.3% and 0.5% of lemongrass EO were significantly lower than other samples. However, in samples coated with 0.5% lemongrass EO, the pulp firmness and sensory quality decreased significantly during storage.

Fig - Effects of different concentrations of lemongrass essential oil incorporated into alginate-based edible coating on (A) total plate counts and (B) yeast and mould counts of fresh-cut pineapple during 16 days of storage at 10±1°C and 65±10% RH. Means with the same letters (lowercase: amongst different treatments for the same case; uppercase: for the same treatment during different storage times) are not significantly different according to Turkey's test (p>0,05). EC = alginate-based edible coating; Lg = lemongrass.

The scientists conclude that the alginate-based edible coating with 0.3% of lemongrass EO should be the optimal formulation to prolong the shelf-life and preserve quality of fresh-cut pineapple.

Fonte: Azarakhsh N., Osman A., Ghazali H.M., Tan C.P., Adzahan N.M., "Lemongrass essential oil incorporated into alginate-based edible coating for shelf-life extension and quality retention of fresh-cut pineapple", Febbraio 2014, Postharvest Biology and Technology, Vol. 88, pagg. 1-7. Per maggiori info: www.sciencedirect.com/science/article/pii/S0925521413002792