Preparation and Application of Starch/Polyvinyl Alcohol/Citric Acid Ternary Blend Antimicrobial Functional Food Packaging Films

Ternary blend films were prepared with different ratios of starch/polyvinyl alcohol (PVA)/citric acid. The films were characterized by field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis, as well as Fourier transform infrared (FTIR) analysis. The influence of different ratios of starch/polyvinyl alcohol (PVA)/citric acid and different drying times on the performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water solubility (WS), color difference (ΔE), and antimicrobial activity of the ternary blends films were investigated. The starch/polyvinyl alcohol/citric acid (S/P/C1:1:0, S/P/C3:1:0.08, and S/P/C3:3:0.08) films were all highly transparent. The S/P/C3:3:0.08 had a 54.31 times water-holding capacity of its own weight and its mechanical tensile strength was 46.45 MPa. In addition, its surface had good uniformity and compactness. The S/P/C3:1:0.08 and S/P/C3:3:0.08 showed strong antimicrobial activity to Listeria monocytogenes and Escherichia coli, which were the food-borne pathogenic bacteria used. The freshness test results of fresh figs showed that all of the blends prevented the formation of condensed water on the surface of the film, and the S/P/C3:1:0.08 and S/P/C3:3:0.08 prevented the deterioration of figs during storage. The films can be used as an active food packaging system due to their strong antibacterial effect

Aloe barbadensis: how a miraculous plant becomes reality

Aloe barbadensis Miller is a plant that is native to North and East Africa and has accompanied man for over 5,000 years. The aloe vera plant has been endowed with digestive, dermatological, culinary and cosmetic virtues. On this basis, aloe provides a range of possibilities for fascinating studies from several points of view, including the analysis of chemical composition, the biochemistry involved in various activities and its application in pharmacology, as well as from horticultural and economic standpoints. The use of aloe vera as a medicinal plant is mentioned in numerous ancient texts such as the Bible. This multitude of medicinal uses has been described and discussed for centuries, thus transforming this miracle plant into reality. A summary of the historical uses, chemical composition and biological activities of this species is presented in this review. The latest clinical studies involved in vivo and in vitro assays conducted with aloe vera gel or its metabolites and the results of these studies are reviewed

Enhancement of storage life and quality maintenance of papaya fruits using <i style="">Aloe vera</i> based antimicrobial coating

83-89Papaya is one of the main tropical fruits of India. The desiccation of fruits and perishable nature of papaya is a major drawback during transportation to distant markets and storage during glut in the market. Aloe vera gel, mainly composed of polysaccharides, has been recently explored as an edible coating owing to its antifungal activity. To improve the performance of edible coatings, various substances/chemical additives have been incorporated. Papaya leaf is a potential antifungal agent that could be used as a bio-based additive, especially, by papaya growing farmers. The present study was carried out to evaluate the ability of Aloe gel based antimicrobial coatings to reduce/control the loss of post harvest fruit quality in papaya and to compare the effects with a natural polysaccharide-chitosan, an established coating material with antifungal activity. Freshly harvested papaya fruits were coated with Aloe gel/AG (50%), papaya leaf extract/PLE incorporated Aloe gel (1:1) and 2.5% chitosan. The coated and uncoated (control) fruits were stored at 30±3°C and 42-55% RH for 15 d. Physical (PLW, fruit size), chemical (pH, titrable acidity and TSS), and sensory characteristics (colour, taste & firmness); fruit disease index (FDI), and marketability were analyzed at regular intervals during the storage period. The coated fruits survived the storage period of 15 d, whereas, all the uncoated controls decayed within 10 d. The uncoated/control fruits exhibited significantly greater changes in all the parameters tested. Among the coated fruits, PLEAG treated fruits exhibited least changes followed by AG and chitosan coated fruits. The coatings controlled the PLW, ripening process (chemical changes, colour development and softening of fruit tissue) and decay to a great extent and thereby extended the shelf life quality of the fruits. Marketability was also found to be better for PLEAG coated fruits among the 3 coatings, followed by AG and chitosan coated fruits. The effectiveness of AG coating was found to improve on incorporation of PLE. Shelf life could be further extended in low temperature storage. This is probably the first study on utilizing a natural alternative such as Aloe-gel and PLE to extend shelf life quality in papaya. On the basis of the over all physiological changes, Aloe gel based antimicrobial coating has been identified as a suitable method to extend the shelf life of papaya fruits