Effect of Edible Coating on the Quality of Fresh-Cut Garlic in Modified Atmosphere Packaging (MAP)

Garlic is commonly used as a seasoning or condiment in most dishes worldwide and it is recognized for its medicinal health benefit. However, the removal of the peel results in a significant reduction of shelf life due to an increase in weight loss, color discoloration, rooting formation and microbial growth. The objective of this study was to determine the effect of an edible coating in combination with modified atmosphere packaging (MAP) on the quality of fresh-cut garlic cloves. Hydroxypropyl methylcellulose (HPMC) with and without glycerol was used as edible coating in combination with active MAP (1% O-2 and 10% CO2). Uncoated and water dipped garlic cloves were used as control treatments. Garlic cloves were packed in low density polyethylene (LDPE) bags and stored at 25 degrees C for 12 days. Application of the HPMC coating did not show any root formation and lower apparent microbial growth in fresh-cut garlic cloves compared to uncoated and water dipped. The coating did not reduce the weight loss of garlic cloves, probably due to the hydrophilic nature of the HPMC. There were no significant differences in firmness among treatments during storage. Coated fresh-cut garlic cloves presented significant higher gloss than uncoated garlic. Higher concentration of CO2 in the headspace of MAP of coated garlic cloves was found. This might indicate an increase in respiration rate as fresh-cut garlic cloves were coated, however, further research is needed to validate this result. The O-2 concentration in all treatments increased from the initial O-2 value, which might be due to the high oxygen permeability of LDPE. Results show the potential of edible coatings to extend the shelf life of garlic cloves by reducing rooting and improving gloss. Further research is required to improve the composition of coating to reduce weight loss and to determine microbial growth.