Examinando por Autor "Oliva, Manuel"

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Análisis proximal y rendimiento de cinco especies nativas con valor forrajero
(Universidad del Zulia, 2022-01-13) Oliva, Manuel; Meléndez Mori, Jegnes Benjamín; Maicelo Quintana, Jorge Luis; Milla Pino, Manuel Emilio; Leiva, Santos
El objetivo del presente estudio fue evaluar el establecimiento, crecimiento, rendimiento y valor nutritivo de cinco especies nativas con valor forrajero (Cenchrus clandestinus, Philoglossa mimuloides, Philoglossa sp., Trifolium dubium y Trifolium repens). El experimento se realizó en el distrito de Molinopampa (Perú), donde se instalaron parcelas de 30 m2. La altura de planta se midió mensualmente hasta los 90 días. El material se cortó a nivel del suelo, se pesó, se secó y se determinaron los rendimientos de forraje verde y materia seca. El valor nutricional de las muestras se realizó siguiendo el procesamiento de la AOAC. Los resultados muestran que el porcentaje de establecimiento más alto fue alcanzado por T. repens (89,51%). La altura de planta mostró que P. mimuloides y Philoglossa sp. registraron su mayor crecimiento entre los días 30 y 60 después del establecimiento; y además fueron las especies con mayores niveles forraje verde (7,46 y 8,04 kg/m2) y materia seca (8,58 y 8,90 t/ha). En términos de valor nutricional, T. dubium y C. clandestinus registraron los niveles más altos de proteína y fibra, respectivamente; mientras que las especies del género Philoglossa tienen mayor digestibilidad.
Forest structure and fragmentation dynamics in cacao-producing landscapes of Amazonas, Peru, revealed by multi-temporal land-use change and spaceborne LiDAR
(Springer Science+Business Media, LLC, part of Springer Nature, 2026-05-27) Cotrina Sanchez, Alexander; Barboza, Elgar; Veneros, Jaris; Huaman Pilco, Angel Fernando; García, Ligia; Guzman Valqui, Betty Karina; Oliva, Manuel; Rojas Briceño, Nilton B.; Torresani, Michele
The ongoing loss and degradation of tropical forests poses a significant threat to biodiversity, carbon storage, and ecosystem services throughout the Amazon Basin. Agroforestry systems such as cacao cultivation can help balance production and conservation, yet integrated analyses combining spatial and structural forest data remain limited. This study integrates multi-temporal land-use/land-cover (LULC) data, fragmentation metrics, and canopy indicators from the Global Ecosystem Dynamics Investigation (GEDI) mission to assess forest transformation across two contrasting cacao-producing landscapes in the Amazonas region of Peru. LULC dynamics (1985–2020) were derived from the 30m Global Land Cover Change Dataset (GLC_FCS30D), with 2020 used as a baseline consistent with the European Union Deforestation Regulation (EUDR). The 2020 forest/non-forest map was compared with the 10m Global Forest Cover 2020 product to quantify fragmentation across multiple grid sizes. GEDI L2A and L2B data provided structural metrics, including relative height (RH25–RH98), plant area index (PAI), foliage height diversity (FHD), and canopy cover, which were linked to fragmentation indicators. In the indigenous territories of Condorcanqui, cacao landscapes maintained stable forest cover, while rural areas in Bagua and Utcubamba showed greater forest loss and landscape modification. Fine-scale (10m) data revealed localised zones of conservation and degradation, particularly in lowland cacao areas. Taller, more structurally complex canopies were associated with less fragmented forests, whereas shorter and more heterogeneous structures reflected long-term disturbance. Integrating spaceborne LiDAR with multi-scale fragmentation metrics provides robust indicators of forest integrity, supporting sustainable cacao agroforestry management and conservation plannin.
Fresh cheese production using freeze-dried papain as a vegetable coagulant
(Instituto de Tecnologia de Alimentos (ITAL), 2024-10-25) Villacréz Chavez, Grégor; Grimaldo Chávez, Segundo; Rivera Botonares, Ralph; Vilca Valqui, Nuri Carito; Zzuta Puscan, Marileydi; Oliva, Manuel; Tineo, Daniel
The study examined the efficacy of freeze-dried papain enzyme obtained from three Vasconcellea species (V. pubescens, V. chachapoyensis, V. heilbornii) as a natural coagulant in cheese making. Notably, the enzyme V. pubescens demonstrated the most promising results when concentrations of 2 g/L, 4 g/L, and 6 g/L were used to produce fresh cheese, while other enzyme species exhibited lower efficacy. The optimal yield of fresh cheese with minimal residual enzyme was achieved when a 2 g/L dose of papain enzyme was employed at a coagulation temperature of 30 °C, resulting in physicochemical and organoleptic characteristics comparable to those produced with commercial Hansen's rennet. Nevertheless, an increase in the coagulation temperature (42 °C) and a higher dose of papain enzyme (4 g/L) resulted in a reduction in the yield of fresh cheese and; consequently, the residual enzyme increased. Further studies are required to determine the purity of freeze-dried papain and the most effective dosage to increase profitability for producers and consumers. Such findings could facilitate the ecological application of this alternative in producing of fresh cheese.
Genetic structure of traditional cacao reveals four new genetic lineages in indigenous Amazonian sites in Peru
(Public Library of Science (PLOS), 2026-07-06) Motilal, Lambert A.; Calderon, Martha S.; Bustamante, Danilo E.; Gopaulchan, David; Tineo Flores, Daniel; Márquez Romero, Fanny R,; Lastra Paucar, Sphyros Roomel; Díaz Valderrama, Jorge R.; Guerrero Abad, Juan Carlos; Oliva, Manuel; Umaharan, Pathmanathan
Cacao genetic resources in Peru are largely uncharacterized. Knowledge of their genetic structure is needed for their conservation and use. Indigenous on-farm cacao trees (n = 390) from the Departments of Amazonas (n = 130), Ayacucho (n = 76), Cajamarca (n = 1), Cusco (n = 110), Madre de Dios (n = 10), Piura (n = 59), San Martín (n = 3) and Ucayali (n = 1) in Peru were fingerprinted with 192 single nucleotide polymorphic markers. Identity, group differentiation, phylogenetic, multivariate and ancestry analyses were conducted. Four new populations were identified guided by phylogenetic, accepted ancestral backgrounds of reference samples and least admixture among samples. The cacao from these eight Departments were variably mixed containing both pure members of new populations and admixed samples with these new populations and Amelonado, Contamana, Criollo, Curaray, Guiana, Iquitos, Marañon, Nacional, Nanay and Púrus. The findings of this study suggest that while the cacao germplasm is genetically related across different departments, each region harbors its own distinct genetic composition. The Clade IV (Chuncho 2) population was associated with the Contamana cluster and Clade I (Chuncho 1) was associated with Purus cluster. Clades II (Awajun) and III (Porcelana) were associated with the Nacional cluster. The ancestry of the economically desired CCN 51 cultivar was revealed to be better assigned as 15% Amelonado, 13% Criollo, 25% Iquitos and 45% Awajun. The results of this study will improve the understanding of the genetic landscape in Peru, enhance genebank collections in Peru and enable the differentiation of the fine flavour industry in Peru. The new groups of cacao identified in this study will help understand the genetic structuring of cacao and represent a valuable new resource to search for valuable traits for breeding and commercialization programmes in the fine flavour cacao industry in Peru.
Integrating agroecological suitability of cacao (Theobroma cacao L.) with biodiversity and land-use constraints in Peru
(Elsevier Ltd., 2026-01-29) Cotrina Sanchez, Alexander; Guzman Valque, Betty Karina; Barboza, Elgar; Oliva, Manuel; Huaman Pilco, Angel Fernando; Rojas Briceño, Nilton B.
CONTEXT: Cacao cultivation is vital for rural economies in Peru, but its expansion often overlaps with sensitive ecosystems, raising concerns for biodiversity conservation. Despite international commitments to deforestation-free supply chains, integrated analyses combining agroecological suitability with land-use constraints remain scarce in Peru. OBJECTIVES: This study aims to identify suitable areas for cacao cultivation under multiple exclusion scenarios, evaluate conflicts with biodiversity and conservation areas, and quantify degraded lands that could provide opportunities for agroforestry-based restoration. METHODS: Cacao suitability was modelled with an ensemble of nine machine-learning algorithms using bioclimatic, edaphic, and topographic predictors. Outputs were filtered to exclude biophysical barriers and overlaid with national-scale layers of species richness, protected areas, forest cover, and degraded lands through GIS-based spatial analysis to evaluate exclusion scenarios and trade-offs. RESULTS AND CONCLUSIONS: The ensemble achieved high predictive power, with Random Forest (AUC = 0.997) and XGBoost (AUC = 0.972) performing best. Highly suitable areas were concentrated in the Andean-Amazon transition, especially in San Martín, Cusco, Huánuco, and Junín departments, where they overlapped with biodiversity hotspots and legally protected areas. Degraded yet suitable lands highlighted opportunities to expand cacao through agroforestry systems, reducing forest pressure and enhancing ecological restoration. SIGNIFICANCE: By integrating suitability modelling with national-scale geospatial layers, this study delivers a framework linking crop suitability with land-use constraints. The findings support national-scale planning while remaining adaptable to local contexts. They also align with international policy frameworks such as the European Deforestation Regulation (EUDR), promoting sustainable cacao production, biodiversity conservation, and long-term rural development in Peru.