Citrus fruits are among the most important global crops, with annual production exceeding 160 million tons. Processing produces significant waste, mainly peels, seeds, and pulp, which can make up to fifty percent of the fruit’s mass. This review critically examines innovative ways to valorize these byproducts. Recent research shows that peels, seeds, and pulp can be converted into high-value materials, including biocomposites and biomaterials, marking a shift from traditional uses like animal feed and biogas production. Notable innovations include smart packaging, pectin-based wound dressings, and biodegradable polymers for sustainable electronics. Advanced green extraction methods, such as deep eutectic solvents, have achieved extraction yields over 85% for flavonoids. Additionally, multifunctional biorefineries processing citrus and olive residues have increased biogas yields by 38–42%. The review explores emerging applications in nanotechnology, nutraceuticals, biodegradable polymers, and functional coatings, all aligned with principles of circular economy and green chemistry. These advances suggest that citrus waste can play a significant role in sustainability efforts and new market development. The review also discusses barriers to adoption, including scalability challenges, regulatory limits, and consumer acceptance, from both global and regional viewpoints.

Numerous fruits are produced in Ecuador, of which about 40% are never eaten. In addition, fresh goat cheeses are in high demand. However, goat cheese generates goat milk whey with high contamination loads, and, therefore, it must be adequately treated before being discharged into ecosystems. This research aims to use a mixture of tree tomato, common strawberry juices, and goat’s milk whey, to be statically fermented by milk and water kefir grains (WKG) for 48 h. For this, a dual mixture design of L-optimal response surface methodology was carried out to find the conditions that maximized all the responses evaluated (lactic-acid bacteria and yeasts concentrations and the overall acceptability assessed on a 7-point scale). Experiments were carried out in San Gabriel, Ecuador. Temperatures during the day and night were 20.2 ± 0.3 °C and 18.7 ± 0.3 °C, respectively. Three conditions were selected, where the highest response values were reached. Complementary experiments demonstrated the validity of the models. When comparing the results of the present study with similar ones carried out previously, higher values were observed in the concentration of yeasts, which seems related to the presence of the WKG. It is concluded that they could be suitable functional beverage candidates.

Este documento describe la historia de la tecnología de atmósferas controladas, sus avances tecnológicos y sus aplicaciones, proporcionando perspectivas de investigaciones en distintos campos de estudio. Para ello se ha desarrollado una revisión de información, sobre los distintos campos donde la tecnología ha sido aplicada y su eficiencia como alternativa de tratamiento. Los estudios relacionados con este campo generados hasta la fecha, están asociados con el efecto que produce la tecnología en las características organolépticas y funcionales de determinadas frutas (aroma, calidad, potencial antioxidante, polifenoles, etc.) y en la automatización de la tecnología (adaptaciones, monitoreo computarizado), así como el efecto en el campo de la electrónica. En la mayoría de los casos la tecnología ha mostrado una mayor eficiencia que en los métodos tradicionales. Se puede concluir que debido a la amplia alternativa de aplicación y la eficiencia de la de la tecnología de atmósferas controladas, se pueden generar estudios adicionales para complementar su desarrollo futuro.

Citrus fruits are among the world's most important crops, with annual production exceeding 160 tons. However, their industrial processing generates substantial amounts of waste (mainly peels, seeds, and pulp), which can represent up to 50% of their total weight. This review examines innovative strategies to valorize these byproducts. Research shows that citrus residues (CR) have great potential for extracting high-value bio composites or converting them into biomaterials, going beyond traditional uses such as animal feed and biogas production. Special attention is paid to emerging applications in nanotechnology, nutraceuticals, biodegradable materials, and functional coatings. In line with the principles of the circular economy and green chemistry, this study highlights the potential of citrus residues to address major sustainability challenges while fostering the development of new market opportunities. The review also critically assesses current limitations related to scalability, regulatory frameworks, and consumer acceptance, with global and regional implications.

Large volumes of orange residues generated by domestic and industrial consumption in Ecuador are commonly discarded, contributing to environmental burdens despite their high content of bioactive antioxidant compounds. This study evaluated the impact of osmotic dehydration (OD) on the physicochemical properties and functional attributes of Ecuadorian Valencia orange (Citrus sinensis) peels. A 2³ factorial design was applied, evaluating blanching time (BT: 5–10 min), sucrose concentration (SC: 50–70 °Brix), and immersion time (IT: 12–24 h). Results revealed highly significant (p < 0.01) non-linear effects of processing variables on mass transfer kinetics. Notably, milder intermediate conditions (50 °Brix, 12 h, 5 min BT) yielded significantly lower water activity (0.70 ± 0.005) and moisture content (11.83% ± 0.12%) compared to severe processing (70 °Brix, 24 h, 5 min BT), which trapped internal water (aw = 0.81 ± 0.009, moisture = 13.77% ± 0.20%), which suggested the occurrence of solute-induced surface case hardening, minimizing subsequent moisture diffusion. Processing induced an extraordinary reduction in total phenolic content (TPC) by 86% to 93% (p < 0.01) from the fresh baseline down to a range of 1.40–2.70 mg GAE/g dw, alongside a critical drop in antioxidant capacity, with post-dehydration ABTS retained at <65% and FRAP at <30% of fresh values due to cellular membrane disruption and subsequent hydrophilic leaching. Conversely, lipophilic total carotenoid content was maximized under severe configurations (10 min BT, 70 °Brix SC, 24 h IT) at 52.92 ± 2.19 µg/g dw (p < 0.01) due to protective sugar matrix encapsulation. Ultimately, these findings demonstrate that while osmotic processing involves an inherent trade-off in soluble antioxidant depletion, it establishes a precise technological process window to stabilize highly perishable citrus by-products into microstructurally stable, value-added dietary fiber matrices, providing a predictable and scalable upcycling strategy for functional ingredient development within the regional circular bioeconomy.