Characterization and effect of edible coatings on minimally processed garlic quality

The main benefits of edible active coatings are their edible characteristics, biodegradability and increase in food safety. In this study the physical properties of the agar-agar based (1%) coatings incorporated with 0.2% chitosan and 0.2% acetic acid, as well as their effects on coating of minimally processed garlic cloves were evaluated. Moisture loss of coated garlic cloves was, on average, three times lower when compared to the control samples (no coated garlic cloves). There was a marked increase in color difference values (ΔE∗) for control cloves compared to the other treatments. Filamentous fungis and aerobic mesophilic were inhibited on garlic cloves coating incorporated with acetic acid + chitosan antimicrobial compounds. During 6 days-storage, at 25 °C, the filamentous fungis and yeasts count was maintained between in 102 and 103 CFU g−1 for the coated garlic cloves and around 106 CFU g−1 for the control. The coatings provided significant reduction (p < .05) in clove respiration. Coated garlic cloves, had a respiration rate (≈30 mg CO2 h−1 kg−1) halved compared to the non-coated garlic cloves. Water vapor transmission was lower for the films added with chitosan. These films showed no visible color difference, possibly because of the reduced thickness, since chitosan films tend to have a more intense shade.