This study addressed the effects of chitosan-based nanoparticles on microbiological quality, colour, polyphenol oxidase (PPO) and peroxidase (POD) and firmness of fresh-cut ‘Gala’ apple slices during storage at 5 °C for 10 days. The treatments carried out were as follows: (i) slices pulverised with 110-nm chitosan nanoparticles, (ii) slices pulverised with 300-nm chitosan nanoparticles, (iii) 2 g L−1 chitosan dissolved in 2% citric acid and (iv) noncoated samples. There was an increase in chroma and a proportional decrease in hue angle and lightness. Browning of the slices coated with conventional chitosan and control was slightly intense than those coated with chitosan nanoparticles of 110 and 300 nm. The PPO and PDO activities increased with time for all samples, with irrelevant difference among the treatments. Flesh firmness did not change for any treatment and period. Coatings with chitosan nanoparticles of 110 nm showed higher antimicrobial activity against moulds and yeasts, and mesophilic and psychrotrophic bacteria than the other treatments. No Salmonella, and total and faecal coliforms were detected. This investigation supports the potential use of chitosan nanoparticles as edible coatings in controlling microbial activity in fresh-cut apples.

Edible coatings to extend the shelf life and preserve the quality of fruit and vegetables are highly demanded nowadays. Recently, plant-based edible coatings have gained importance in the context of sustainability, which in combination with suitable top-down process can render “greener” nanoemulsions with optimized properties. Herein we developed a carnauba wax nanoemulsion (CWN) by using a high-pressure processing to be applied as an edible coating for fruit and vegetables. The as-developed nanoemulsion properties were compared to conventional carnauba wax emulsion (CWM), where CWN showed particle size diameter of 44 nm and narrow distribution, while CWM displayed larger particles and wider size distribution (from 200 to 1700 nm). For assessment of the postharvest quality, cv. ‘Debora’ tomatoes, employed here as a model, were coated with CWN or CWM, at concentrations of 9 and 18%, and then compared to uncoated fruit during storage at 23 °C for 15 days. Evaluation of fruit quality, including sugar, acids, pH, water vapor loss, firmness, gloss, color, ethylene and respiratory activity, were assessed at every 3 days, while sensory test were carried out at the end of storage. Uncoated tomatoes presented the highest water loss values, meanwhile, firmness, ethylene, and respiratory activity were not largely modified by the coatings during storage. Tomatoes coated with the CWN exhibited the highest instrumental gloss and were preferred by consumers in sensory evaluations, indicating the potential of the as-developed carnauba wax green nanoemulsion for postharvest applications.

Challenges in global food supply chains include preserving postharvest quality and extending the shelf life of fruits and vegetables. The utilization of edible coatings (ECs) combined with biocontrol agents (BCAs) represents a promising strategy to enhance the postharvest quality and shelf life of these commodities. This review analyzes the most recent developments in EC technologies and their combination with BCAs, highlighting their synergistic effects on postharvest pathogen control and quality maintenance. Various types of ECs, including polysaccharides, proteins, and lipids, are discussed alongside coating fundamentals and the mechanisms through which BCAs contribute to pathogen suppression. The review also highlights the efficacy of these combined approaches in maintaining the physicochemical properties, sensory attributes, and nutritional value of fruits. Key challenges such as regulatory requirements, consumer acceptance, and the scalability of these technologies are addressed. Future research directions are proposed to optimize formulations, improve application techniques, and enhance the overall efficacy of these biocomposite coatings and multifunctional coatings. By synthesizing current knowledge and identifying gaps, this review provides a comprehensive understanding of the potential and limitations of using ECs and BCAs for sustainable postharvest management.

A considerable genetic diversity of this species is observed in Brazil, originated by segregation and as a consequence of the introduction of plants from different places. This variability is also evident for the flesh colors, ranging from white, light yellow, yellow, orange, to purple (^{Ritschel & Huamán, 2002}; ^{Silva et al., 2012}; ^{Carmona et al., 2015}; ^{Vargas et al., 2018}). Purple-fleshed roots are rich in anthocyanins, a phenolic compound associated to reduction of the risk for a variety of degenerative diseases, due to its antioxidant activity (^{Reyes et al., 2005}). In addition, sweetpotatoes are more affordable, easy to access and produced in large quantities per area when compared to other antioxidant foods (^{Mu et al., 2017}). The diversity of foods with high levels of bioactive compounds available in the Brazilian market is high, but their affordability may be restricted to a portion of the population due to economic reasons. Fruits like blueberries, black plums or cherries are grown mainly in the subtropical region of the country, but mainly imported, which leads to high retail prices. Some vegetables and fruits, such as red onion, cabbage and table beet, açaí and black grapes can be considered exceptions, as they are widely distributed in the country. Thus purple-fleshed sweetpotatoes can become a year-round/feasible alternative to those species.

Sweetpotato (Ipomoea batatas) is a root crop grown in many countries. This tuberous root is a source of energy, nutrients, and phytochemicals. In this study, bioactive compounds and physical and physicochemical qualities of sweetpotato genotypes were evaluated. Eight new genotypes of sweetpotato produced by Embrapa Hortaliças (orange-fleshed: MD09026-OF and MD09024-OF; cream-fleshed: MD09011-CF, MD09004-CF, MD10039-CF, and MD10004-CF; yellow-fleshed: MD09017-YF and MD12002-YF) and two cultivars used as controls (Beauregard and Brazlândia Roxa) were evaluated for color, soluble solids, dry matter, phenolic compounds, total carotenoids and β-carotene. Hue angles differed even between those sweetpotatoes with the same flesh color. The orange-fleshed genotypes MD09024-OF, MD09026-OF, and Beauregard, had the lowest L*, showing to be darker than the others. These sweetpotatoes also had the brightest flesh colors with higher C*. The orange-fleshed genotypes MD09026-OF and MD09024-OF were sweeter (10.55oBrix and 9.23oBrix) than Beauregard (5.12oBrix). Brazlândia Roxa had the highest dry matter content (38.05%), followed by the genotypes MD10004-CF, MD09017-YF, MD09026-OF MD10039-CF, and MD09011-CF, which showed similarity, ranging from 32.33% to 29.12%. The highest contents of total carotenoids were found for the orange-fleshed genotypes MD09026-OF (80.06 mg g-1) and MD09024-OF (70.56 mg g-1) and Beauregard (73.12 mg g-1). These same genotypes showed the highest total phenolic compounds (0.815 mg g-1 and 0.686 mg g-1, respectively). MD09026-OF showed the highest content of β-carotene (46.47 mg g-1). MD09026-OF was the most prominent genotype among those evaluated, as it showed the highest total carotenoid, β-carotene, phenolic compounds, and soluble solids content, in addition to a high dry matter content.

Scarlet eggplant (Solanum aethiopicum var. gilo) is a Solanaceae with an appreciated peculiar bitter taste, which plays a significant role in family farming in Brazil. Fruit anthracnose is the main pre- and postharvest disease that affects scarlet eggplant in Brazil. This study aimed to evaluate the effect of chitosan-based coating on in vitro inhibition of Colletotrichum tamarilloi and anthracnose control of scarlet eggplant fruits. Chitosan was dissolved in a 2% citric acid solution at 40°C and then homogenized with potato dextrose agar (PDA), and poured into Petri dishes, as follows: 1) PDA + 0.1% chitosan, 2) PDA + 0.2% chitosan, 3) PDA + 0.3% chitosan, 4) PDA + 0.4% chitosan, and 5) pure PDA as control. Discs of 5 mm diameter of pure fungus culture were placed on the center of the culture medium in the plates. The plates were then maintained in BOD at 25°C and 12-h photoperiod for 10 days. Colony characteristics, mycelial growth rate, and mycelial growth inhibition were evaluated. Afterward, the effect of chitosan coating was evaluated in fruit inoculated or not with C. tamarilloi. The treatments were: T1) uncoated and injured uninoculated fruits, T2) uncoated and inoculated fruit, T3) fruits coated with 0.1% chitosan and inoculated, T4) fruits coated with 0.2% chitosan and inoculated, and T5) fruits coated with chitosan at 0.3% and inoculated. For inoculation, 15 μL of a conidial suspension (2 x 10⁵ conidia/mL) were deposited on an injury caused by a needle, and the fruits were coated by immersion into the different concentrations of chitosan gel. Fruits were placed on expanded polystyrene trays. Fresh weight loss, the mean incidence of disease, and lesion diameter were measured. All concentrations of chitosan reduced the in vitro growth of C. tamarilloi. The treatment T4 reduced the severity of anthracnose but did not prevent its incidence in scarlet eggplant fruits.