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dissertação
Secagem em camada de espuma de manga: otimização do processo e da qualidade nutricional do pó
(Universidade Federal de Lavras, 2026-07-03) Correa, Jefferson Luiz Gomes; Silveira, Paula Giarolla; Petri Junior, Irineu; Macedo, Leandro Levate; Jesus, Josane Cardim de
Tommy Atkins mango (Mangifera indica L.) is a tropical fruit of high nutritional and economic importance, distinguished by its content of β-carotene, vitamin C, and phenolic compounds. However, its high perishability results in significant postharvest losses, making it necessary to adopt technologies that enable its preservation and value addition.In this context, the present study aimed to produce stable mango powder through foam-mat drying (FMD), evaluating the effects of different foaming agents and ethanol addition on drying kinetics and the physicochemical properties of the final product. Initially, the formulations were optimized using a Central Composite Rotational Design (CCRD), employing albumin and whey protein as foaming agents and xanthan gum as a stabilizer. The optimal conditions obtained were 8.02% whey protein without xanthan gum addition and 7.13% albumin associated with 0.54% xanthan gum, resulting in foams with low density and high stability. Drying was carried out in a convective tunnel dryer at temperatures of 50 °C and 70 °C, with and without ethanol application. The results demonstrated that increasing temperature and adding ethanol significantly accelerated water removal, reducing drying time by up to 43% for the whey protein containing formulation at 70 °C. The powders obtained were characterized in terms of moisture content, water activity, solubility, hygroscopicity, and color parameters. The ethanol-treated samples exhibited lower residual moisture content and improved drying performance, contributing to the production of powders with characteristics suitable for storage and industrial applications. The formulation containing whey protein combined with ethanol showed the most promising results in terms of process efficiency. It was concluded that the combination of foam-mat drying and ethanol application constitutes an efficient strategy for producing mango powder with suitable physical properties, contributing to the agro-industrial valorization of the fruit and to the reduction of postharvest losses.
Video
Mapeamentos de processos e fluxogramas da Biblioteca Universitária
(2026-09-28) Ribeiro, Nivaldo Calixto; Cunha, Simone Assis Medeiros
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tese
Eficiência de mercado e conectividade dinâmica em commodities agrícolas: uma análise comparativa entre os mercados internacional e brasileiro em contexto de choques exógenos
(Universidade Federal de Lavras, 2026-06-24) Moraes, Alexandra Kelly de; Calegario, Cristina Lelis Leal; Castro Júnior, Luiz Gonzaga de; Safadi, Thelma; Costa, Jaqueline Severino da; Avila, Ednilson Sebastião de; Ceretta, Paulo Sergio
The COVID-19 pandemic intensified instability in global markets and expanded discussions regarding informational efficiency, dynamic connectivity, and interdependence among agricultural commodities, particularly in environments characterized by high volatility and strong international integration. In this context, understanding how exogenous shocks affect the functioning of these markets has become relevant to both the financial literature and agribusiness risk management. This thesis aimed to analyze the operational dynamics of agricultural commodity markets (soybeans, corn, and Arabica coffee)— specifically focusing on informational efficiency, dynamic connectivity, and interdependence across international futures markets (CME, ICE) and the Brazilian market (B3 and CEPEA)—while considering the impacts of COVID-19. To this end, the research was structured into three complementary articles. The first article conducted a bibliometric analysis of scientific literature on market efficiency and dynamic connectivity in agricultural commodities from 1979 to 2024, aiming to map emerging trends and literature gaps while identifying new research opportunities. The results revealed that the field is still consolidating, characterized by methodological heterogeneity and the increasing adoption of dynamic and non-linear approaches. The second article evaluated the informational efficiency of agricultural commodity markets by analyzing the impacts of the COVID-19 pandemic using the Adjusted Magnitude of Market Inefficiency (AMIM) metric. The findings demonstrated that informational efficiency exhibits dynamic, heterogeneous behavior that is highly sensitive to exogenous shocks. A hierarchical efficiency structure was observed: international futures markets demonstrated the greatest capacity to absorb shocks and maintain relative efficiency; the Brazilian futures market occupied an intermediate position; and the spot market exhibited the highest persistence of inefficiencies. The third article analyzed the dynamic connectivity and interdependence of returns and volatility in agricultural commodities (soybeans, corn, and coffee) from 2015 to 2025, applying the Time-Varying Parameter Vector Autoregression (TVP-VAR) model. The research revealed that the pandemic drove a temporary intensification of market connectivity and an increase in the transmission of returns and volatility, with soybeans emerging as the primary source of uncertainty. Corn exhibited relatively more autonomous behavior, while coffee displayed an intermediate pattern that varied depending on the specific market segment analyzed. In the post-pandemic period, a reduction in connectivity and shock transmission intensity was observed, indicating a rebalancing process rather than a permanent structural change in market functioning. Synthesizing these findings reveals that informational efficiency, dynamic connectivity, and interdependence constitute complementary dimensions of agricultural commodity market dynamics. Consequently, there is a need to advance analyses by adopting a relational and systemic perspective on agricultural markets, thereby understanding how they reorganize in the face of exogenous shocks and regimes of high uncertainty. The results demonstrated that informational efficiency is not static but responds dynamically to exogenous shocks, while changes in connectivity and shock transmission occur simultaneously during periods of high uncertainty. Thus, the thesis's main contribution is providing evidence that informational efficiency and shock transmission do not operate in isolation but respond in an integrated manner to conditions of systemic uncertainty. Furthermore, these findings highlight the limitations of the Efficient Market Hypothesis in crisis contexts and support the Adaptive Market Hypothesis as a suitable theoretical framework for understanding agricultural commodity market dynamics in the face of exogenous shocks.
tese
Anatomical and physiological traits of Cattleya lundii (Rchb.f. & Warm.) under prolonged water stress
(Universidade Federal de Lavras, 2026-06-30) Antunes, Joseline de Fátima; Oliveira, Denis Coelho de; Lira, Marines Ferreira Pires; Arriola, Igor Abba; Gonçalves, Letícia de Almeida; Magalhães, Thiago Alves
Water deficit is one of the most limiting factors for plant growth and development, even for the Orchidaceae family, which is known for colonizing diverse environments with fluctuations in temperature, light, and water availability. During the study, Cattleya lundii (Rchb.f. & Warm.) Van den Berg was subjected to prolonged stress for 60 days, during which its anatomical aspects and the occurrence of cell wall components, photosynthetic activity, chloroplast pigments, and structural parameters of the bulbs and leaves were evaluated and compared to the control treatment. After the structural analyses, it was observed that the stressed plants showed a decrease in leaf area, accumulation of reserve substances in the pseudobulbs, and epidermal folding. The cell wall of the control treatment presented homogalacturonans (HGs) with high methylesterification, as well as extensins, which favor cell wall elasticity and volume increase. Plants under water deficit presented HGs with low methylesterification and (1→4)-β-d-galactans, which are associated with greater reinforcement of these structures, preventing their collapse and preparing for future rehydration. Regarding physiological aspects, statistical analyses indicated that plants under water deprivation presented low values in the analyzed photosynthetic parameters than the control treatment, indicating damage to the photosynthetic apparatus, mainly in photosystem II. Despite this, the pigments presented high values, indicating a possible compensation for this damage in order to balance the photosynthetic capacity. The results indicate that Cattleya lundii showed high tolerance to water deficit, and the anatomical and physiological modifications helped in adjusting to fluctuations in the water regime.
dissertação
Mitigação de estresse hídrico em mudas de Eucalyptus urophylla × E. grandis pela aplicação de regulador de crescimento
(Universidade Federal de Lavras, 2026-07-24) Alberto, Flávio Juízo; Brondani, Gilvano Ebling; Leite, Douglas Machado; Faria, Júlio Cézar Tannure; Leite, Douglas Machado
Eucalyptus is one of the most important forest species in Brazil due to its high productivity and economic and environmental importance. However, water deficit is one of the main factors limiting seedling growth and survival. In this context, growth regulators such as paclobutrazol (PBZ) have been investigated due to their ability to induce morphological, physiological, and biochemical adjustments associated with stress tolerance. This study aimed to evaluate the effects of PBZ application on morphological, physiological, biochemical, nutritional, and survival responses of clonal seedlings of Eucalyptus urophylla × Eucalyptus grandis under different water availability conditions. The experiment was conducted in a greenhouse using a randomized block design with a factorial arrangement consisting of six soil water levels (0, 10, 20, 40, 60, and 80% of field capacity) and two PBZ treatments (with and without application). Growth parameters, stress intensity, photosynthetic pigments, osmoprotective compounds, leaf nutrient concentrations, and seedling survival were evaluated. PBZ application increased seedling survival under moderate water deficit conditions, particularly at 20 and 40% of field capacity, and delayed the progression of stress symptoms after irrigation suspension. The regulator reduced shoot height and leaf expansion, altered leaf number, and increased the Dickson Quality Index. Root dry biomass was enhanced mainly under moderate water deficit conditions. Regarding photosynthetic pigments, PBZ contributed to the maintenance of total chlorophyll under severe water stress, while chlorophyll a content was reduced regardless of water availability; carotenoid levels were not affected by PBZ application. Biochemical analyses showed that PBZ promoted the accumulation of proline, sucrose, and total soluble sugars under severe water restriction, whereas soluble protein content was reduced by PBZ. Leaf nutritional status was modulated by PBZ, with specific changes in macro- and micronutrient concentrations, including increased calcium, magnesium, and some micronutrients, as well as reduced sodium accumulation under certain water conditions. Overall, PBZ promoted physiological and biochemical adjustments that contributed to the acclimation responses of Eucalyptus seedlings to water deficit.