Revista de la Facultad de Agronomía de la Universidad del Zulia

Yield and chemical composition of foliage and branches of tropical tree legumes with different trunk diameters

Jorge Oliva-Hernández — 2025-01-09

Erythrina americana Miller and Gliricidia sepium (Jacq.) Walp., are tree legumes presents on livestock farms in the tropical region, mainly on living fences. The goal of the study was to determine the influence of tree legume species (TLS), and of the trunk diameter at base tree (TDB), on production and chemical composition of foliage and branches at a similar regrowth age. The study was conducted in Tabasco, Mexico. Seventy-nine trees were used in a completely randomised design with a 2 X 5 factorial arrangement. The factors were TLS (E. americana y G. sepium), and TDB at 0.20 m height above ground level (D-5: 0.050-0.059 m; D-6: 0.060-0.069 m; D-7: 0.070-0.079 m; D-8: 0.080-0.089 m y D-9: 0.090-0.099 m). The production per tree of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and ash, of foliage and branches were the response variables. The STL x DBT interaction did not affect (P>0.05) the response variables studied in the foliage and branches. In foliage, the TLS and TDB affected the production per tree of DM, CP, ADF, and ash (P<0.01). G. sepium produced a greater amount of DM and the different components assessed than E. americana. An increase in TDB resulted in higher DM production and the components studied in foliage and branches. G. sepium produces foliage with higher CP and lower structural carbohydrate content than E. americana foliage.

Methane production and nutritional content from the diet consumed by grazing cattle

Elizabeth García

It is a high priority to account for methane emissions from cattle grazing grasslands in order to evaluate the strategies for mitigating GHG emissions in livestock. The aim of this study was to evaluate in vitro ruminal methane production and nutritional content of the consumed diet by bovines grazing an open medium grassland in atypical dry and rainy periods in the semi-arid region of the state of Durango, Mexico. Four rumen fistulated bovines were subjected of an ad libitum graze under a repeated measure design. Chemical analysis showed that DM, OM, NDF and ADF increased in rainy period (p<0.05). Otherwise, CP, EE, phosphorus contains and IVDMD increased in dry period (p<0.05). Ruminal fermentation parameters as pH and volatile fatty acids as acetic, propionic and butyric, showed no changes among periods (p>0.05). However, ammonia increased in rainy period (p<0.05). Moreover, gas production kinetics only showed differences in lag phase (p<0.05); whereas, maximum gas production and production constant rate showed no changes among periods (p>0.05). Likewise, methane production showed no changes among both periods (p<0.05). As conclusion, it is observed that nutritional quality of the consumed diet by bovines grazing and open medium grasslands in dry and rainy periods presents acceptable protein values (8-10 %). In addition, phosphorus contents are higher than the minimum requirements for growing bovines. Furthermore, methane production was not affected by dry and rainy periods.

Allelic frequencies of genes associated with productive traits in western Mexican boars

Miguel Ayala-Valdovinos — 2025-01-09

The ESR1, PRLR, and RYR1 genes have previously been associated with traits of productive interest. The objective of this study was to determine the allelic frequencies of genes associated with productive traits in boars from pig farms in western Mexico. A total of 140 boars of six breeds, Duroc, Hampshire, Landrace, Piétrain, and Yorkshire, and Yorkshire/Landrace crosses were sampled. The pigs were genotyped via polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. The two alleles of the ESR1 gene were identified in the six breeds, but only BB homozygotes were recognized in Yorkshire pigs (0.2) and their crosses (0.05). The A and B alleles of the PRLR gene were distinguished in all the breeds studied, recognizing a considerable variability in the allele frequencies. Due to the allelic diversity and its effects evidenced in previous publications, it is suggested to evaluate the association of each genotype with the reproductive parameters to be improved in order to determine which genotype is more relevant in each population. In the RYR1 gene, the mutant allele causing PSS was found in all the breeds studied, which can generate pigs with PSE meat. It is recommended that the selection of boars of any breed to be used as breeders includes a genotyping test. Knowing the genotypes in boars can be used as a way to select better breeders.

Antioxidant activity and physicochemical properties of mango nectar with pitahaya

Jorge Vera — 2025-01-09

Currently, mixed fruit nectars are generating greater consumer interest due to their potential contribution of nutrients and exotic flavors. The objective of the study was to evaluate the antioxidant activity and physicochemical properties of mango nectar (Mangifera indica L.) made with various levels of pitahaya (Hylocereus undatus). A completely randomized experimental design was used. The test consisted of the formulation of three treatments (10, 20, and 30 % pitahaya flesh (pf) and a control). Physicochemical, functional, microbiological, and sensory parameters were evaluated. Analysis of variance and Dunnett and Kruskal Wallis mean comparison test were applied at 5 % significance. The results showed that the levels of pitahaya flesh significantly influenced the response variables of pH, viscosity, soluble solids, density, turbidity, antioxidant activity, and total phenols, on the contrary, the colorimetry parameters (L, a, b) presented a p> 0.05. Regarding sensorial acceptability, a p < 0.05 was determined in the attributes of texture, consistency, and flavor, while color and smell were not significant (p>0.05). The treatments under study met the physicochemical and microbiological requirements established in the NTE INEN 2337 standard. It was shown that the addition of 30 % of pf improved the content of total phenols in mango nectar up to 0.537 ± 0.00 mg Gallic Acid Equivalent.mL^-1. The nectars had a yellow color with a greenish hue and bright luminosity. The treatment T3 was considered the best at the organoleptic level in texture, consistency, and flavor.

Production of a distilled mango drink: volatile compounds and heavy metal

Bruno Giménez-López — 2025-01-09

The optimization of processes for the production of fruit distillates is essential to ensure high product quality, comply with current regulations, and promote the development of the agro-industrial sector. The objective of this study was to evaluate the physicochemical properties of a mango distillate (Mangifera indica L.), varieties Kent and Alphonso, in order to optimize its production process, the fruits underwent controlled fermentation and subsequent distillation, during which volatile compounds and heavy metals were analyzed. The results showed significant differences between both varieties in terms of the concentration of ethyl acetate and furfural, which influence the sensory profile of the distillate. Methanol concentrations and other harmful compounds remained within regulatory limits. However, the copper concentration exceeded the limit allowed by the Peruvian Technical Standard (5 mg.L^-1), while zinc levels remained within safe parameters according to the WHO. This study demonstrates that, with adjustments in process control, mango distillate has the potential to be a high sensory quality product suitable for commercialization.

Physical properties of french fries made with quinoa and opuntia-peel flours

Roenfi Guerra — 2025-01-09

A large part of the world population consumes fast food on a regular basis. Most of these menus are accompanied by french fries. Their consumption does not represent a major nutritional contribution, and the frying process incorporates a considerable amount of oil into the french fries, increasing the risks of diseases such as obesity. The objective of the present work was to evaluate the physical and textural properties of a potato chip substitute made by extrusion technology with the incorporation of flours of a nutritious cereal such as quinoa and prickly pear peel in its formulation. Color and porosity were evaluated by image analysis. Texture by mechanical compression tests with an Instron universal testing machine and oil absorption rate by a modified compression method. Sticks of a potato substitute were obtained and fried by immersion in oil at 180 °C in the same way as a commercial pre-fried product. The firmness of the sticks (4.5 N) is 30 % higher than the commercial product, while the oil absorption rate (6.25 %) of the products obtained is three times lower. This phenomenon could be due to the fiber content present in the prickly pear peel flour and protein content in the quinoa flour. It is concluded that is possible to elaborate products similar to traditional and commercial potato chips, so that, without altering the consumption habits of the population, it can allow the intake of healthier foods.

Chemical study of the macrophyte duckweed (Lemna minor L.)

José Vera — 2024-12-19

Duckweed (Lemna minor L.) has attracted considerable attention in the scientific field due to its nutritional contribution and capacity to phytoremediate waters. Therefore, the objective of the study was to analyze the chemical composition of the macrophyte (Lemna minor) from natural environments. Chemical compounds and Weende composition were determined from the plant, and the fresh weight gain was observed in different types of water (deep well and bovine slurry), waters that were subjected to physical-chemical analysis. The chemical analysis of the macrophyte resulted in the presence of 1.42 mg.g^-1 of total chlorophyll; 2.35 mg.kg^-1 of ascorbic acid; tannin content less than 2.50 mg.kg^-1; 45.34 mg.kg^-1 of phenols; also the presence of alkaloids, phenols and reducing sugars in the chemical screening. The Weende analysis indicates a composition of: 89 % of dry matter, 30 % of crude protein, 4 % of gross energy, 3.2 % of ether extract, 15 % of ashes, 32 % of nitrogen-free extract and 10 % of fiber. The fresh weight gain of Lemna minor obtained in water contaminated with bovine slurry increased significantly 13 g.day.m³ and 5 g.day.m³ in deep well water. The physical-chemical properties of the water improve their quality 16 days after treatment with this aquatic plant with respect to the initial analysis. This macrophyte exhibits remarkable phytoremediation properties to absorb, metabolize and stabilize various pollutants effective in the purification of contaminated waters.

Review of microclimate mapping methods in forestry

Manuel Sánchez-Chero — 2024-12-25

The study of microclimates provides a several benefits that imply their importance to reduce the effects of climate change, so the mapping of microclimates emerges as an alternative for their identification and conservation. The objective of this review is to identify the techniques used in microclimate mapping. The methodology used was an exploratory review in databases such as Science Direct, Springer and IEEXplore, which determined that there is a shortage of works related to microclimate mapping, since only 19 works met the inclusion requirements of the review. It was determined that the main objective of the microclimate mapping focused on the tree canopy, the height and density of the forest structures and their effects on the climatic factors that comprise them. On the other hand, the microclimate mapping methods identified were divided into photogrammetric methods and laser scanning methods, where most of the studies were based on obtaining aerial data, either by drones (UAV, UAS, RPA, RPAS) or airplanes as in the case of airborne LiDAR technologies. It was concluded that there is little research on microclimate mapping, so the forestry scientific community is exhorted to employ the different methodologies for objectives of great impact on the environment such as the prediction of forest fires and the monitoring of forest restoration after these fires.

Use of plant extracts for the protection of the plantain bunch (Musa AAB) against insects, Sucre municipality, Zulia State

Juan Nava — 2024-12-18

Plantain producers from the Sucre municipality of Zulia state, Venezuela, have expressed concerns about improving or maintaining the quality of the bunch, seeking to protect it from damage caused by insects, thus harming its appearance for marketing. It was proposed to evaluate the effect of aqueous plant extracts from the 100 % water-plant organ mixture for the protection of the plantain bunch. A completely randomized experimental design was used with 5 treatments and 20 repetitions. The treatments were: T1: cluster without product application; T2: cluster sprinkled with garlic bulb extract (Allium sativum); T3: cluster sprinkled with hot pepper fruit extract (Capsicum spp.); T4: bunch sprayed with lemongrass (Swinglea glutinosa) leaf extract and T5: bunch sprayed with eucalyptus (Eucalyptus spp.) leaf extract. The variable that was studied was: bunch fruits without damage from insect attack. T2 and T3 presented a higher percentage of fruits without insect damage (94 and 96 % respectively), with better quality in the bunch for commercialization.