Aloe vera gel: An update on its use as a functional edible coating to preserve fruits and vegetables
Aloe vera L. is a common succulent plant that has been used for centuries regarding their healing properties and health benefits. Nowadays, scientific investigations on its gel have gained more attention because of its interesting antioxidant and antimicrobial properties. Also, the food industry encounters the need to preserve safety and quality of fresh produce; fruits and vegetables are in high demand due to their reported health benefits, and fresh-cut products are a new trend that meets the restless needs of the society. Edible coatings are an effective way to maintain freshness of these products, extend their shelf life, and even act as an alternative to modified atmosphere packaging to be used in conventional packaging. Aloe vera gel is a natural hydrocolloid, composed mainly by polysaccharides, that has been applied in the last years on fruits and vegetables. It can act as a semipermeable barrier for gases and water vapor, decreasing the respiration and ripening processes of the fruit, thus maintaining weight, firmness and valuable compounds. Its antioxidant and antimicrobial properties make it also an interesting material for increasing the shelf-life of fruits and vegetables. This review aims to describe the preparation and preservation of Aloe vera gel as well as the properties and compounds that are effective against oxidation and microbial growth. Moreover, the recent findings of its use - with or without additives - as an edible coating on fruits and vegetables have been widely detailed, showing that Aloe vera gel is a promising preservative method in this industry.