Application of Edible Coatings to Improve Shelf-Life of Mexican Guava

Abstract

One method of extending postharvest shelf-life is the use of edible coatings. Such coatings are made of edible materials that are used to enrobe fresh produce, providing a semipermeable barrier to gases and water vapour. Guavas cultivated at Aguascalientes, Mexico were coated with a solution of one of the following polymers: Potato starch, sodium alginate, carragenan, and pectin. The fruit was covered by immersion in the solution at 50°C, then dried at 50°C during 30 minutes. After coating, the maturation process was compared to uncoated fruit. The evaluation of the functional properties of the edible coatings was done by measurement of the barrier properties of edible films to water vapour (gravimetric method) and to aroma compounds (dynamic method). The results showed an increase of the fruit's shelf-life with at least three days compared to the uncoated fruit, at 25°C and 50-70% R.H. The highest efficiency preserving the fruit was obtained with potato starch and pectin based coatings, increasing the preservation of the sensorial characteristics of the fruit (size, yellow colour and aroma) with 15 days.

Influence of Osmotic Dehydration on Mass Transfer Kinetics and Quality Retention of Ripe Papaya (Carica papaya L) during Drying

“…According to Rekha et al [6] 30-40% of initial ascorbic acid in some fruits can be lost on dehydration. To preserve the functional components and improve the product quality of foods, some pretreatment could be applied prior to drying [7]. Among various pretreatment methods, osmotic dehydration (OD) is traditionally applied to food dewatering which leads to attractive products.…”

Edible Coatings Influence Fruit Ripening, Quality, and Aroma Biosynthesis in Mango Fruit

“…Application of various types of biopolymers as edible coatings on guava and apricot fruits showed that dextran and carboxymethylcellulose were more effective than polyethylene in retaining water and aroma compound (2-pentanone) of the fruit (17). Similarly, starch-and pectin-based coatings were also reported to improve the shelf life and aroma of Mexican guava (18). 'Valencia' oranges coated with commercial polysaccharidebased or shellac-based coatings exhibited higher concentrations of several aroma volatiles such as ethanol, ethyl butanoate, ethyl acetate, and R-pinene as compared to the untreated fruit (19).…”

Edible Coatings: Innovation to Improve the Shelf Life of Guava

“…At 25°C and between 50 and 70 percent of R.H., the coated fruit had a shelf life of at least three days longer than the untreated fruit. Potato starch and pectinbased coatings were shown to be the most effective in preserving the fruit's sensory features (size, yellow colour, and scent) for 15 days [51].…”