Improvement of Andean Blueberries Postharvest Preservation Using Carvacrol/Alginate-Edible Coatings

Abstract

Edible coatings are attractive strategies for blueberries postharvest preservation. In this work, carvacrol/alginate coatings were developed for application on Andean blueberries. Coating formulations were prepared based on blends of sodium alginate (2% w/v), carvacrol (0%, 0.03%, 0.06% or 0.09%), glycerol, and water and applied to the fruits by dip-coating. Then, the fruits were immersed in a calcium batch to induce a crosslink reaction. Changes in the physicochemical and microbiological characteristics of the blueberries were monitored during 21 days of storage at 4 °C. Coated blueberries were better preserved throughout the 21 days of storage because of their lower respiration rate and water loss, in comparison with the uncoated ones. Besides, the coatings enhanced the appearance and the gloss of the fruits. Control fruits showed a significant decrease in the firmness, while, in the coated fruits, this critical postharvest quality was preserved during the entire storage. Coating formulations with 0.09% of carvacrol was the most effective in preventing mesophilic aerobic bacteria and molds/yeasts growth on the fruits during the storage. Edible carvacrol/alginate coatings can be considered as a useful alternative to complement the benefits of refrigerated storage by delaying post-harvest spoilage of Andean blueberries.

Preparation and Characterization of Carboxymethyl Cellulose-Based Bioactive Composite Films Modified with Fungal Melanin and Carvacrol

“…For better packaging films, low WVTR is required [ 23 ]. Although CV is reported to be hydrophobic [ 35 , 36 , 41 ], no significant WVTR differences of neat CMC (1098.68 ± 6.74 (g/(m 2 × Day)) and CMC + CV (1092.38 ± 11.73 g/(m 2 × Day)) were observed ( p > 0.05), presumably linked with small amount of carvacrol used. Similarly, Medina-Jaramillo et al reported that the low concentrations of CV added (0.03%, 0.06%, and 0.09%) did not cause changes in the water vapour barrier properties of the alginate coatings [ 41 ].…”

“…Although CV is reported to be hydrophobic [ 35 , 36 , 41 ], no significant WVTR differences of neat CMC (1098.68 ± 6.74 (g/(m 2 × Day)) and CMC + CV (1092.38 ± 11.73 g/(m 2 × Day)) were observed ( p > 0.05), presumably linked with small amount of carvacrol used. Similarly, Medina-Jaramillo et al reported that the low concentrations of CV added (0.03%, 0.06%, and 0.09%) did not cause changes in the water vapour barrier properties of the alginate coatings [ 41 ]. In contrast, Du et al found that the addition of carvacrol (0.5%, 1.0%, and 1.5%) to tomato puree films increased WVTR compared to the control [ 39 ], similarly for chitosan-based films modified with 0.5% and 1.0% of CV as reported by Flores et al [ 5 ].…”

“…This bioactive compound possesses antimicrobial properties, antioxidant, and a particular aroma which makes an attractive ingredient for certain types of foods [37,38]. Moreover, CV has been also reported to be used for modification of biopolymer [5,30,31,36,[39][40][41][42][43][44], and synthethic films [45,46].…”

“…Considering the potential of melanins and carvacrol as functional materials, some synergies can be expected when these materials are used together. Moreover, the application of bioactive and biodegradable films seem to be an excellent alternative to reduce food loss and waste and to improve food security [5,41].…”

Feasibility of Using Carvacrol/Starch Edible Coatings to Improve the Quality of Paipa Cheese

“…After cooling, carvacrol (0.1 g/100 g of blend) and Polysorbate 80 (0.01 g/100 g of blend) were added to the starch suspension and the mixture was homogenized at 1000 rpm for 10 min using a vertical agitator IKA C- MAG HS4 (IKA ® WERKE, Strufen, Germany) and then degassed using a vacuum pump. The coating formulation was chosen based on the results of previous work and preliminary experiments [ 8 , 15 , 16 ]. In particular, the carvacrol concentration was selected considering the results of preliminary sensory assays and the study reported by Kuorwel [ 13 ] about the antifungal activity of starch-based coatings carrying linalool, carvacrol and thymol on the Cheddar cheese.…”