A B S T R A C TThe present study was carried out to evaluate the effect of chitosan-based edible coatings with Aloe vera extract on the postharvest blueberry fruit quality during storage at 5 C. Firstly, A. vera fractions (pulp and liquid) were extracted from leaves and evaluated in terms of antifungal and antioxidant capacities. The choice of the most adequate chitosan and A. vera fraction concentrations to be incorporated in coating formulation was made based on the wettability of the corresponding coating solutions. Coatings with 0.5% (w/v) chitosan + 0.5% (w/v) glycerol + 0.1% (w/v) Tween 80 + 0.5% (v/v) A. vera liquid fraction presented the best characteristics to uniformly coat blueberry surface. Physico-chemical (i.e., titratable acidity, pH, weight loss) and microbiological analyses of coated blueberries (non-inoculated or artificially inoculated with Botrytis cinerea) were performed during 25 d. Microbiological growth and water loss levels were approximately reduced by 50% and 42%, respectively, in coated blueberries after 25 d compared to uncoated blueberries. After 15 d, weight loss values were 6.2% and 3.7% for uncoated and chitosan-A. vera coated blueberries, respectively. Uncoated fruits presented mold contamination after 2 d of storage (2.0 AE 0.32 log CFU g À1 ), whilst fruits with chitosan-based coatings with A. vera presented mold contamination only after 9 d of storage (1.3 AE 0.35 log CFU g À1 ). Overall, coatings developed in this study extend blueberries' shelf-life for about 5 d, demonstrating for the first time that the combination of chitosan and A. vera liquid fraction as edible coating materials has great potential in expanding the shelflife of fruits.

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.

Nanotechnology has been referred to as one of the most interesting topics in food technology due to the potentialities of its use by food industry. This calls for studying the behavior of nanosystems as carriers of biological and functional compounds aiming at their utilization for delivery, controlled release and protection of such compounds during food processing and oral ingestion. This review highlights the principles of design and production of bio-nanosystems for oral delivery and their behavior within the human gastrointestinal (GI) tract, while providing an insight into the application of reverse engineering approach to the design of those bio-nanosystems. Nanocapsules, nanohydrogels, lipid-based and multilayer nanosystems are discussed (in terms of their main ingredients, production techniques, predominant forces and properties) and some examples of possible food applications are given. Phenomena occurring in in vitro digestion models are presented, mainly using examples related to the utilization of lipid-based nanosystems and their physicochemical behavior throughout the GI tract. Furthermore, it is shown how a reverse engineering approach, through two main steps, can be used to design bio-nanosystems for food applications, and finally a last section is presented to discuss future trends and consumer perception on food nanotechnology.

Fruit waste and by-products are economical materials for the development of biodegradable and active packaging. The aims of this study were to develop, characterize and evaluate biodegradable coatings and films by using mango peel and antioxidant extracts of seed kernel. The proximate composition of peel was also determined. Structural, barrier, optical and antioxidant properties were analyzed in the films. Gas transfer rates and the ethylene production in peach were evaluated. Edible films formulated with mango peel showed good barrier properties, with the water vapor permeability varying from 0.88 × 10 −10-1.00 × 10 −10 g m −1 s −1 Pa −1. The addition of antioxidant extract does not show a significant effect (p > 0.05) on optical properties. Furthermore, antioxidant activity and polyphenol content increased by 18% and 60% respectively. Peach coated with a solution of mango peel (1.09%), antioxidant extract of mango seed kernel (0.078 g L −1) and glycerol (0.33%) showed 64% and 29% less ethylene and CO 2 production, respectively, and 39% less O 2 consumption when compared with peaches without coating. The reduction in gas transfer ensures the greater extension of the shelf life of fruit treated. By-products of mango may thus be suitable for the production of low-cost biodegradable and active packaging.