New technological advances in antimicrobial edible coatings for food may hold promise in extending shelf life, reducing packaging layers, meeting food safety and quality requirements. Emerging research shows polysaccharides, bacteriocins, essential oils, enzymes, proteins and lipids are all natural coatings that have unrealized potential in food preservation. Recently, interest has increased in using Aloe vera gel-based edible coating material for fruits and vegetables. Aloe vera gel has been proven one of the best edible and biologically safe preservative coatings for different types of foods because of its film-forming properties, antimicrobial actions, biodegradability and biochemical properties. It is composed mainly of polysaccharides and acts as a natural barrier to moisture and oxygen, which are the main agents of deterioration of fruits and vegetables. Aloe vera gel has the ability to prolong shelf life of the fruits and vegetables by minimizing the rate of respiration and maintaining quality attributes (color, flavor etc.). It has antifungal and antibacterial property which provides a defensive barrier against microbial contamination of fruits and vegetables. The present review describes the preparation, properties and potential application of Aloe vera gel coatings for enhancing the postharvest life and quality of different types of fruits.

In this experiment the effect on post-harvest preservation of papaya (Carica papaya L.) fruit coated with either Aloe gel (AG; 100%) or papaya leaf extract with Aloe gel (PLEAG; 1:1) was studied. To evaluate the role of coating on ripening behavior and quality of papaya the uncoated and coated fruits were stored and ripened at room temperature (25 ºC-29 ºC) and 82-84% relative humidity. Physicochemical properties were analyzed at 4 day intervals during the storage period. The incidence of disease attack was also visually observed. The overall results showed the superiority of AG and PLEAG coating in lengthening the shelf-life of papaya fruit compared to controls which showed significant decay from 6 th day onward and complete decay within 12 days of storage. The AG and PLEAG coated fruits maintained their shelf life for 12 days and decayed at 16 th day. The coated fruits also maintained their color, flavor and firmness up to 12 days of storage. An increase in ascorbic acid content (120.2 mg/100 g) was also found in coated fruits in contrast to the control (59 mg/100 g). Only 27% disease incidence was observed in AG and 13% in PLEAG coated fruits as compared to control (100%) during the storage period. The results of this study show that both AG and PLEAG coatings have excellent potential to be used on fresh produce to maintain quality and extend shelf-life.

In this experiment the effect on post-harvest preservation of papaya (Carica papaya L.) fruit coated with either Aloe gel (AG; 100%) or papaya leaf extract with Aloe gel (PLEAG; 1:1) was studied. To evaluate the role of coating on ripening behavior and quality of papaya the uncoated and coated fruits were stored and ripened at room temperature (25 °C-29 °C) and 82-84% relative humidity. Physico-chemical properties were analyzed at 4 day intervals during the storage period. The incidence of disease attack was also visually observed. The overall results showed the superiority of AG and PLEAG coating in lengthening the shelf-life of papaya fruit compared to controls which showed significant decay from 6th day onward and complete decay within 12 days of storage. The AG and PLEAG coated fruits maintained their shelf life for 12 days and decayed at 16th day. The coated fruits also maintained their color, flavor and firmness up to 12 days of storage. An increase in ascorbic acid content (120.2 mg/100 g) was also found in coated fruits in contrast to the control (59 mg/100 g). Only 27% disease incidence was observed in AG and 13% in PLEAG coated fruits as compared to control (100%) during the storage period. The results of this study show that both AG and PLEAG coatings have excellent potential to be used on fresh produce to maintain quality and extend shelf-life.

Nano-encapsulation is a platform which offers a promising application for control release and the delivery of drugs in pharmaceuticals and antioxidant/antimicrobial in food systems. Poly (lactic-co-glycolide acid) (PLGA) is a biodegradable and biocompatible co-polymer of lactic acid and glycolic acid which is used for synthesizing food based polymeric nanoparticles (NP). The aim of this study was to evaluate the morphological and physicochemical properties and the controlled release of bioactive components derived from Aloe vera gel loaded PLGA NP. The results shows the mean hydrodynamic diameter of the unloaded NP is 103 nm which is significantly (p < 0.01) smaller than the loaded freeze dried powered gel (FDG) (147 nm) and liquid gel (LG) (221 nm) and the particle size distribution given by the Poly-dispersity Index were 0.2, 0.2 and 0.3, respectively. The zeta potential for unloaded, FDG and LG NP were ±60, ±28 and ±22 mV, respectively, hence were electrokinetically stable NP. No significant (p > 0.05) inhibition of the antioxidant potential was observed with loaded NP. The entrapment efficiency for the FDG synthesized was 87%, and the burst effect was observed after 4 h as a result of the encapsulation effect. The release kinetics of bioactive is govern by the combination of mass diffusion and capillary action.

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