https://repositorio.ufu.br/handle/123456789/21377 Fri, 28 Aug 2026 03:34:38 GMT 2026-08-28T03:34:38Z https://repositorio.ufu.br/handle/123456789/49390 Title: Impactos de processos de secagem na qualidade do café Arábica (Coffea arabica L.) Abstract: In the coffee drying process, the use of mechanical dryers has grown in order to reduce quality losses, save time, and increase production efficiency. Fixed-bed dryers offer the lowest acquisition and maintenance costs, allowing for the processing of large volumes. This type of equipment requires strict control of drying parameters such as fruit mass temperature, layer height, airflow, and hot air temperature. In addition to equipment conditions, fruit characteristics also influence drying quality. Thus, after harvesting, the fruits need to be washed and separated into different stages of maturation: cherry coffee fractions (denser and more moisture) and overripe fractions (less dense and less moisture). In this sense, the present work aimed to evaluate the impacts of drying processes on the quality of Arabica coffee (Coffea arabica L.) in fixed-bed dryers with different useful operating volumes (12, 15 and 18 m³) at the cherry and overripe stages of maturation. It identifies potential impacts caused by differences in dryer size and initial moisture content, identifies which parameters directly impact moisture removal behavior, and predicts mathematical models for drying under each condition, assisting producers in deciding on the best drying parameters. This study is divided into three chapters. The first presents a theoretical study based on data obtained from scientific literature, with emphasis on publications indexed in the Elsevier (ScienceDirect), SpringerLink, Web of Science, Wiley Online Library, MDPI, and SciELO databases. It covers the main fundamentals related to the drying of agricultural products, coffee quality and processing, fermentation processes, kinetic modeling, and drying technologies, providing a scientific basis for the research. The second chapter comprises a study that relates different drying volumes and maturation stages to the final beverage quality, through physicochemical and sensory analyses, and evaluates the relationship between quality and the possible occurrence of natural fermentations in drying process. The third chapter presents a mathematical modeling study of the fixed-bed drying process under these same conditions, emphasizing the influence of equipment dimensions on moisture behavior and the prediction of kinetic models that best describe the drying of each volume and maturation stage. This study offers novel contributions to the understanding of mechanical drying behavior at different volumes and maturation stages, suggesting the presence of fermentations in the process and highlighting that the smaller volumes are recommended for obtaining coffees with higher sensory quality, as the height of the fruit layer significantly impacts the moisture removal rate. The Midilli mathematical model best describes the fixed-bed drying data and aids in the reproducibility and predictability of processes. This led to the creation of a decision flowchart to assist producers in determining the ideal drying volume for each stage of maturation and final objective. Wed, 25 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49390 2026-02-25T00:00:00Z https://repositorio.ufu.br/handle/123456789/49257 Title: Obtenção e caracterização do pó do aquoso da folha de Ora-pro-nóbis (Pereskia aculeata) seco por spray drying Abstract: Ora-pro-nóbis (*Pereskia aculeata*) is an Unconventional Food Plant (UFP) belonging to the Cactaceae family, recognized for its high protein content as well as its fiber, vitamins, and bioactive compounds. Traditionally used in cooking, its leaves can be consumed raw or sautéed. The presence of mucilage, proteins, and bioactive compounds attracts interest from both the food and pharmaceutical industries: the former for the enrichment of functional products, and the latter due to studies on antioxidant activity and nutraceutical potential. Because it is highly perishable, its consumption is largely restricted to family farming, which hinders large-scale commercialization. Drying aids in the preservation of perishable foods and facilitates the storage, transport, and application of the resulting powders in food products. Therefore, this study aimed to obtain and characterize a powder derived from the aqueous extract of ora-pro-nóbis leaves produced via spray drying. To this end, the study evaluated the effect of heat treatment prior to drying, as well as drying with and without the use of maltodextrin as a carrier agent, and the effect of temperature (100°C and 140°C) on the physicochemical properties (moisture, water activity, hygroscopicity, antioxidant activity, total chlorophylls, protein content, morphology, and particle size) of the resulting powder. The results showed that the powder obtained with heat treatment and the use of maltodextrin generally exhibited lower moisture content compared to the powder obtained without heat treatment or the carrier agent. Powder hygroscopicity ranged from 13.81% to 26.60%, influenced primarily by the addition of maltodextrin. Regarding color, the powders with higher lightness (L*)—that is, the lighter-colored ones—were those obtained using maltodextrin, likely due to the white color of the carrier agent. The powders exhibited a tendency toward green (a* parameter) and yellow (b* parameter) coloration. Antioxidant capacity was also evaluated, with the highest values observed in experiment 4, which involved heat treatment at 140°C without the use of maltodextrin. Partial degradation of the chlorophyll present in the leaves occurred due to the heat treatment, influencing the chlorophyll content results for the resulting powders. The treatments performed had no impact on protein analysis results. SEM images show that the particles generally exhibit irregular morphology, rough surfaces, and a tendency to agglomerate. The largest particle sizes were found in experiments 3 (100°C, with heat treatment, without maltodextrin) and 4 (140°C, with heat treatment, without maltodextrin). Tue, 30 Jun 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49257 2026-06-30T00:00:00Z https://repositorio.ufu.br/handle/123456789/48812 Title: Desenvolvimento e caracterização de geleias de morango contendo edulcorantes e fruto-oligossacarídeo (FOS) Abstract: This work addresses the development of diet strawberry-flavored jams that utilize fructooligosaccharide (FOS), a sweetened dietary fiber, as a substitute for sucrose or other sweeteners. The literature review article, including studies from 2014 to 2025, aimed to capture studies with different sweetener alternatives and describe the findings regarding the consequences of consuming these substances on human health and industrial applications. As a result, the included articles found an association between the consumption of artificial sweeteners and health alterations, mainly in animals, such as a higher risk of cancer incidence and alterations in the intestinal microbiota. Further studies are needed to confirm these negative consequences in humans. In the consumer market, a large portion of foods (66.7%) contained added sugars or non-nutritive sweeteners, notably acesulfame-k. Sweeteners are used in greater quantities in non-alcoholic beverages (37.2%) and foods with high energy value (25%). The most common natural sweeteners, such as Stevia and polyols, have shown successful applications in foods like chocolate, especially when used in combination, but their physicochemical attributes in bakery products were further from the control. Short-chain fruit sweeteners, such as fructooligosaccharide (FOS) and oligofructose (OF), are soluble fibers with a sweetness of 35 to 55% compared to sucrose and, according to studies, need to be used in conjunction with other sweeteners to achieve good sensory acceptance and adequate technological properties (pH, TSS, moisture) in foods, including jams. The experimental article aimed to develop two strawberry jam formulations (GSA and GFOS) containing FOS as a sweetening agent and to analyze their physicochemical (Brix degrees, water activity, moisture, pH, acidity, texture, viscosity, soluble solids content, determination of reducing, non-reducing and total sugars, total monomeric anthocyanins, phenolic compounds, antioxidant activity), sensory (descriptive and acceptance tests and purchase intention) and microbiological (molds and yeasts and total and thermotolerant coliforms) characteristics when compared to a control jam (GT). The results showed that the jams with FOS had higher instrumental color parameters a*, b*, C and h than GT. The values for moisture, water activity (Aw), and soluble solids (SST) were similar between the GSA (33.24% ± 1.04; 0.748 ± 0.01; 66°Brix ± 1.17) and control sample GT (33.26% ± 0.86; 0.763 ± 0.01; 66°Brix ± 0.98). GFOS was less hard, adhesive, and gummy than the others and had an intermediate viscosity (22,044 cP ± 102). Light jams made with FOS had a higher quantity of phenolic compounds (GSA: 329.08 ± 9.50 mg of EAG/100g; GFOS: 365.64 ± 12.00 mg of EAG/100g), antioxidants (GSA: 2,344.38 ± 165.73 µmol of ET/100g; GFOS: 2,365.20 ± 89.31 µmol of ET/100g) and anthocyanins (GSA: 1.04 mg/100g ± 0.08; GFOS: 2.31 mg/100g ± 0.14) than the commercial GT jam (69.39 mg of EAG/100g ± 7.04; 388.64 µmol of ET/100 g ± 39.06; 0.52 mg/100 g ± 0.02). Regarding sugars, the jams with FOS had more sucrose than the commercial one because the cooking process converted part of the fiber into its carbohydrates (fructose and sucrose), but with a 25% reduction in total sugars when compared to the GT. The research concluded that the production of light jam with the addition of FOS, xylitol and Stevia (GSA) presented adequate physicochemical characteristics, similar to other studies, and with good sensory acceptance in the tests performed. Furthermore, all samples showed no microbial growth of fungi, yeasts, and coliforms, thus proving safe for consumption. Thu, 26 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48812 2026-02-26T00:00:00Z https://repositorio.ufu.br/handle/123456789/48523 Title: Extração de proteínas das folhas de ora-pronóbis (Pereskia aculeata) para desenvolvimento de novos produtos alimentícios Abstract: Ora-pro-nóbis (Pereskia aculeata) is a non-conventional food plant (PANC) widely distributed in Brazil and recognized for its high nutritional value, especially for the high protein content present in its leaves. Given the growing demand for alternative sources of plant-based proteins and the interest in developing new food ingredients, this work aimed to evaluate and optimize the extraction of proteins from ora-pro-nóbis leaves, aiming to obtain a protein concentrate with potential application in the food industry. Initially, the physicochemical characterization of the fresh leaves was carried out, revealing a high moisture content and significant protein concentration on a dry basis. Subsequently, the leaves were subjected to freeze-drying, grinding, and mucilage removal. Protein extraction was performed by alkaline extraction followed by isoelectric precipitation, and the effects of pH, temperature, and extraction time were evaluated using a central composite rotatable design (CCRD). The results demonstrated that the recovery of proteins from ora-pro-nóbis was efficient, allowing the production of concentrates with protein content between 18.85% and 30.51%. Optimization of the extraction process using DCCR allowed the identification of favorable operating conditions to maximize the percentage of protein in the extract, yield, and protein recovery. Determining the isoelectric point was fundamental for the proper conduct of the precipitation step, contributing to increased process efficiency. The obtained protein concentrate was subjected to freeze-drying and characterized in terms of its physicochemical and functional properties. Thus, the results obtained indicated that ora-pro-nóbis has high potential as an alternative source of vegetable proteins, contributing to the valorization of unconventional food plants (PANCs) and the development of new food products with greater nutritional value and sustainable appeal. Thu, 05 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48523 2026-02-05T00:00:00Z