Agronomía Mesoamericana

Strategies in developing tropical maize hybrids.

2024-06-17T08:12:58-06:00

The strategies in a hybrid development program should be so oriented to achieve short, medium and long term objectives. The germplasm source utilized is quite important and should possess desirable agronomic traits with good plant and ear height characteristics along with good stalk quality to allow development of good progenitors. To achieve these objectives, it is imperative to introduce new strategies and modifications in the conventional systems to obtain higher efficiency. In this presentation various aspects are discussed relating to germplasm source oriented towards hybrids, integration and introduction of new schemes of population improvement parallel to hybrid development, production of vigorous and productive lines using diversified and efficient strategies, precise characterization of lines in inbred-line evaluation trials, combining ability in crosses with testers, identification of new hybrids during various stages of hybrid development, prediction of new hybrids with less number of single crosses, use of inbred lines in forming new populations as well as heterotic groups and synthetics. Options for developing single cross hybrids to add efficiency in the future are discussed.

Some considerations for the organic production of vegetables.

2024-06-17T07:54:46-06:00

This article is based on a Bibliographical Compilation where the ecosystemic problems, generated by the scientific and technological advances in modern agriculture, are analyzed. The basic principles ruling the organic, bilological, alternative or ecological agriculture are defined, emphasizing the importance of maintaining and improving the soil as the basic component of organic production, adducing that a well nourished plant is most resistant to any plague. Diseases, insects, weeds and nematodes are also mentioned, giving emphasis to practices of integrated plague management.

The phytogenetic resources: an option for the agricultural development in the American Tropics.

2024-06-17T07:49:32-06:00

The Central American agriculture shows a low productivity in most of the cultivated crops, apparently due to a lack of improved varieties and a reduced used of cultural practices. The Central American region has climatic, topographic, edaphic and social characteristics that could allow a more integral development and exploitation of the autochthonous phytogenetic resources. Nonetheless, in spite of the significance that it has to the farmer and the industry, there is little research and information on the use and of cultural practices of some potential species of American origin. A better knowledge of the genetic diversity, seasonal production, quality, supply and demand of the products, will allow for the preparation of a list of the phytogenetic potential which is still preserved. The most important incentive of any crop is its economic profitability. On this way, the economic factor promotes the basis for developing an increased production, improve quality and open new alternatives to the farmer and the industry. If a new crop is not profitable, it is rejected inmediately; but on the other hand, if a crop is highly profitable, it is almost imposible to restrain its diffusion. The recognition and conscience drawn by the reasonable use of the "genetic resources" on the national, regional and world level, as an essential base for a dynamic and rational agriculture, by far justifies the programs of the countries in the American Tropics to join their efforts in the preservation and promotion of the genetic diversity.

Aerobiology: a new research area.

2024-06-17T07:38:28-06:00

A workshop to address the science of aerobiology was held at Michigan State University‘s Kellog Biological Station on October 10-13, 1992. The purpose of the workshop was to bring together scientistis and to our-reach specialists from diverse disciplines to advance the understanding of aerobiology and improve the capability to predict the atmospheric movement of biota. Biota important to agriculture, forestry, human health and the envirommental move in predictable atmospheric transport events. The workshop participants discussed the principles of long-distance atmospheric transport of biota, formulated strategies to share diagnostic technologies and information systems, and concluded that science is positioned to make major advances in forecasting the movement of arthropods, plant viruses, fungi, and bacteria; birds and human allergens. A North American alliance for aerobiology research is being accelerate research advances in the important area of science. Approximately 70 nationally and internationally recognized scientists from agriculture, medicine, engineering, physics, eviromental science, and systems science participated in the workshop. The workshop generated (1) a set of generic foci and scientific hypotheses that will serve as guidelines to conceptualize and direct research in aerobiology, (2) recommendations for networking biological, atmospheric, and other environmental monitoring networks for in forecasting aerobiological transport events, (3) recommendations for utilizing existing electronic networks to link scientistis with agencies and institutions with and tools, (4) recommendations for developing an information database on an electronic comunications network to facilitate access to aerobioogical information, and (5) the establishment of an organizational, structure for the Alliance for Aerobiological Research (AFAR)with a governing board to serve the membership.

Biotechnology and the agricultural field.

2024-06-17T07:24:41-06:00

This article summarizes how the modern biotechnology techniques can be used as a tool to make the traditional animal and plant breeding methodologies more efficient. The advantages and disadvantages of using these techniques were analyzed at each stage of the selection process of the breeding program. We compared the ease of handling and time saving obtained when the biotechnology component is integrated in the process used by the breeder. The new techniques analyzed were: a- Tissue and organ culture; b- Genetic transformation; c- Molecular genetic markers. Likewise, the current interest of multinational corporations on the potential of the agriculture modified by the biotechnology and the further concentration of knowledge and intellectual rights was analyzed. The importance for the Latin American countries to rule as a group and to share a common criteria in order to legislate in favor of the intellectual rights and biosafty was also emphasized. This legislation would allow a harmonic development of biotechnology among our countries.

Effect of ozone on the postharvest quality of blackberry (Rubus adenotrichos) during storage

2024-06-12T11:47:03-06:00

Introduction. Blackberries are highly perishable fruits due to their soft skin and susceptibility to fungal diseases, such as gray mold caused by Botrytis cinerea. Ozone is a gas that can extend the shelf life and protect the fruit from the growth of B. cinerea. Objective. To evaluate the effect of gaseous ozone application on the physicochemical characteristics and postharvest quality parameters of fresh blackberries during storage. Materials and methods. This study was carried out at the National Center for Food Science and Technology of the Universidad de Costa Rica in 216. Blackberries (Rubus adenotrichos) of the “Vino con espinas rojas” variety were used. The fruits were inoculated with B. cinerea and treated with gaseous ozone at a range of 50-200 μg L^-1for 150 min once a day over 0, 2, 4, 7, and 10 days of storage at 2 °C. Additionally, a control treatment (without ozone) was applied. Various physicochemical characteristics (color, total soluble solids, titratable acidity, and hardness) and postharvest quality parameters (percentage of damaged fruit and fruit infected with B. cinerea) were evaluated. Results. Storage time significantly affected (p < 0.05) all the parameters analyzed, regardless of ozone application. No effect of ozone on the physicochemical parameters was observed. However, ozone treatment influenced the percentage of damaged fruit (p = 0.0067) and fruit affected by B. cinerea (p < 0.0001). After 10 days, ozone-treated fruits showed a lower percentage of fruit affected by B. cinerea (78.95 ± 1.08 %) compared to untreated samples (96.07 ± 2.19 %). Conclusion. Ozone application could be an effective method for maintaining blackberry quality, extending storage time, and improving resistance to fungal deterioration.

Insects as protein supplements in the livestock production animals: A sustainable and efficient alternative

2024-06-21T07:45:49-06:00

Introduction. The agricultural sector faces the challenge of finding sustainable alternatives for animal feed, given the growing demand for food and environmental problems. Objective. Document the outstanding nutritional characteristics of insects and their potential as a food alternative livestock production. Methodology. A bibliographic search was conducted in the Science Direct databases, based on the terms related to the consumption and production of animal feed and its environmental impact. Development. The nutritional profile of insects is outstanding due to the content of proteins (from 32 to 74 %), essential amino acids (from 8 to 39 %), healthy fats (from 6 to 21 %), vitamins, and minerals (up to 278.3 mg per 100 g dry matter). The high digestibility of nutrients makes them an important option to complement the animal diet. However, its use carries risks such as allergies, contamination, and nutritional imbalances, which can be minimized with proper management of appropriate hygiene practices, guaranteeing the quality of the insects used and complying with relevant regulations. Conclusions. The insects are an important source of proteins, amino acids, fats and minerals, all these elements of comparable quality to other traditional sources such as soybeans, wheat, improved grasses and other legumes. The use of insect represents an innovative and sustainable alternative for animal feeding, becoming a balanced and nutritious food source and benefits for both animals and the environment. Its successful adoption requires a balance between nutritional and environmental benefits and the costs associated with its production and regulation.

Survival or traditional statistics? Purple corn (Zea mays L.) premix shelf life estimation

2024-07-08T14:55:05-06:00

Introduction. Because the development process of a food product is not complete until its useful life is known, the development of a novel product food product such as the purple flour corn pancake premix raises the need of determining it. Objective. Estimate the shelf life of a pancake premix based on pujagua corn flour (Zea mays L.), through a storage study, using linear regression and Weibull distribution data analysis to compare both methodologies. Materials and methods. The study was carried out at the National Center for Food Science and Technology (CITA) of the University of Costa Rica, between 2018 and 2023. The storage study of the pancake premix was carried out with three repetitions, in a chamber at 25 °C and control samples at -18 °C for 7,5 months, considering nine sampling times and 26 days sampling frequency. For the pancakes, the critical sensory variables chewiness and atypical flavor were analyzed; the atypical odor variable was selected for the premix. A liking test was carried out with consumers (n=100).With these and the obtained from trained panel, two useful life values were calculated, one with the cut-off point method using linear regressions and another using the Weibull distribution. Results. The sensory variable determinant of the premix shelf-life was chewiness. With the first methodology, a useful life value of 124 days was estimated and with the second, a value of 265 days at 25 °C was obtained. Conclusions. The cut-off point method is more conservative and sensitive to the selected critical variables. The method using Weibull distribution was more practical, but care must be taken when evaluating products that are little familiar or about which consumers have little information.

25 years of operation of the Program of Interlaboratory Rounds for Food Analysis (PRIDAA): Contributions to the evaluation of the performance of chemical food analysis laboratories in Latin America

2024-05-20T21:13:49-06:00

The Food Analysis Interlaboratory Rounds Program (PRIDAA) was designed and developed between 1998 and 2023 by the National Center for Food Science and Technology (CITA) at the University of Costa Rica to provide an accessible proficiency testing program in food chemistry for Latin American laboratories. The program operated regularly during this period, with four to five rounds per year covering five food groups: cereals and derivatives, fruits and derivatives, dairy, meat or fish products, and roasted coffee, aimed at evaluating analyses of nutritional components or quality parameters. The program's design was based on ISO/IEC Guide 43:1 and the “International Harmonized Protocol for Proficiency Testing of (Chemical) Analytical Laboratories” developed by IUPAC/ISO/AOAC, later adopting INTE/ISO/IEC 17043:2013 as the reference standard for program accreditation by the Costa Rican Accreditation Entity, obtained in 2020. Over its 25 years of operation, PRIDAA completed 108 rounds with the participation of 91 laboratories across 16 Latin American countries. The participant profile consisted of 54 % institutional laboratories, 24 % private service laboratories, and 22 % quality control laboratories from food industries. The countries with the highest participation were Costa Rica, Guatemala, and Ecuador, accounting for 56 % of the laboratories involved. The results obtained over these years primarily provided feedback to participants for performance improvement, but they also allowed identification of the analyses in which laboratories demonstrated stronger overall performance and the more complex tests to achieve satisfactory results. The preparation process for accreditation led to enhancements in the calculation methodologies used, facilitating statistical analysis and decision-making, and ensuring reliable results for participating laboratories.

Pesticide imports in El Salvador from 2013 to 2021

2024-05-31T09:24:11-06:00

Introduction. Limited information exists on the import volumes, usage, environmental fate, and human health effects of pesticides in El Salvador. Objective. To identify import trends and the relative contribution of each active ingredient to the global volume of pesticide imports during the period 2013-2021. Materials and methods. Import records of pesticides provided by the Import Registration and Supervision Unit of the Ministry of Agriculture and Livestock of El Salvador (MAG) for the period from January 1, 2013, to December 31, 2021, were classified by active ingredient (a.i.). For each import event, the net quantity of each a.i. was calculated based on the technical data sheet of the commercial product. Each a.i. was categorized based on its properties into one of the following categories: herbicides, fumigants and soil disinfectants, insecticides-nematicides, fungicides-bactericides, molluscicides, and rodenticides. Results. Herbicides were imported in the largest volumes, followed by fumigants and soil disinfectants, insecticides-nematicides, fungicides-bactericides, molluscicides, and rodenticides. The most imported herbicides, in descending order, were 2,4-D, paraquat, glyphosate, and atrazine; for fumigants and soil disinfectants, methyl bromide, aluminum phosphide, and metam sodium; for fungicides-bactericides, mancozeb, chlorothalonil, carbendazim, and propineb; for insecticides-nematicides, chlorpyrifos, cypermethrin, terbufos, and malathion; for molluscicides, metaldehyde; and for rodenticides, coumatetralyl and diphacinone, respectively. Conclusions. From 2013 to 2021, among the most imported a.i. by volume, there was a notable increase in glyphosate, chlorpyrifos, chlorothalonil, and mancozeb, while imports of terbufos declined. Other a.i. showed minimal variation, were imported in smaller volumes, or are no longer imported due to international regulations on the trade and use of chemical substances, and market demand.

National Center for Food Science and Technology linkage with the agri-food sector

2024-05-17T10:05:38-06:00

The academia-socio-productive sector linkage model of the National Center for Food Science and Technology (CITA) is presented through examples of technology transfer in the agri-food field. This model is organized under three figures, technical assistance, technology transfer and licensing, and the CITA Co-Lab program. CITA has promoted the development of the agri-food sector by improving existing formulations, transferring new technologies and by bringing new products to the market. The CITA Technological Support Program for Industry (PATI) was created in 1984, while the CITA Co-Lab Program began its activities aimed at supporting entrepreneurs in 2020. Through the examples developed in this manuscript, it is possible to understand the processes and identify some factors that influence products’ successful entrance into the market.

Effectiveness of chlorine and peracetic acid in the disinfection of minimally processed cabbage (Brassica oleracea) and green plantain (Musa AAB)

2024-05-22T14:48:51-06:00

Introduction. The consumption of minimally processed vegetables may pose health risks, making it imperative to understand the effectiveness of their disinfection. Objective. To evaluate the effect of peeling, cutting, and shredding on the effectiveness of sodium hypoclorite or chlorine (HClO) and peracetic acid (C₂H₄O₃) in disinfecting cabbage (Brassica oleracea) and green plantain (Musa AAB). Materials and methods. The research was conducted at Centro Nacional de Ciencia y Tecnología de Alimentos, Costa Rica, in 2012. Cabbage and green plantain (unpeeled, peeled, cut, or shredded) were disinfected by immersion in chlorine solutions (200 mg l^-1) and peracetic acid (80 mg l^-1) to evaluate desinfectant concentration over time, the reduction of Escherichia coli in shredded samples, and their sensory characteristics. Results. Both disinfectants were stable in time except when the shredded vegetables were treated with the concentration decreasing faster for chlorine and shredded green plantain. In shredded cabbage, a greater reduction of E. coli (6,767 log10 UCF/g) was observed when peracetic acid was used compared to chlorine (4 log10 UCF/g), although both equal to the control (4 log10 UCF/g). In shredded plantain, reductions with chlorine (6 ± 1 log10 UCF/g) and peracetic acid (5,7 ± 0,7 log10 UCF/g) were different from those with water (3,17 ± 0,06 log10 UCF/g), but there were no significant differences between the two disinfectants. Sensory differences were detected for shredded cabbage disinfected with chlorine or peracetic acid, however, consumer acceptance must be assessed. Conclusions. The level of vegetable subdivision affected the effeciveness of chlorine and peracetic acid when disinfecting cabbage and green plantain. Peracetic acid provides greater reductions of E. coli than chlorine in the case of shredded cabbage and equivalent reductions in shredded green plantain.

Radical biostimulation and solar irradiation in Coffea arabica L. nursery plants

2024-05-20T13:49:30-06:00

Introduction. In the nursery stage, quality Coffea arabica plants can be formed, which reduces the stressful effects after transplanting, increases photosynthetic efficiency and maintains a constant growth rate. Objective. To evaluate the effect of biostimulants and solar irradiation on the growth and physiology of C. arabica plants during the nursery stage. Materials and methods. The experiments were carried out in a greenhouse at the Benemérita Universidad Autónoma de Puebla, Mexico. Each lasted 270 days and were carried out in 2018 and 2022. In a factorial design in blocks; factor 1 (biostimulants: control, mycorrhizal fungi, seaweed, and organic polymers). Factor 2 (irradiation: 81, 168, 278 and 440 µmol m^-2 s^-1). Factor 3 (varieties: Costa Rica 95, Marsellesa, Caturra Roja and Garnica). Mycorrhizal colonization (MC), root system proportion (RSP), growth rate (GR), aerial proportion (AP), chlorophylls, and nutritional content were all determined. An ANOVA was performed on the data to detect differences between treatments. Results. At 270 days after sowing, the Marsellesa variety biostimulated with mycorrhizal fungi and exposed to an irradiation of 168±36 µmol m^-2 s^-1, reached higher values in MC with 36.51 %, and GR with 0.175 g g^-1 day. In Costa Rica 95 and Marsellesa, biostimulation with polymers and an irradiation of 440±59 µmol m^-2 s^-1was significantly related (p≤0.05) to increases of 3.08 mg g^-1 FMW in total chlorophyll. In Marsellesa, high nutritional contents in N, P, K, Ca, and Mg were obtained by biostimulation with polymers and exposure to 168±36 μmol m^-2 s^-1of irradiation. Conclusions. Radical biostimulation with mycorrhizal fungi and irradiation levels of 168 to 278 μmol m^-2 s^-1led to better development in coffee plants.

Use of organic acids for reduction of microorganisms in shredded cabbage (Brassica oleracea) and carrot (Daucus carota)

2024-05-13T11:51:29-06:00

Introduction. Alternative disinfection processes for fresh and minimally processed vegetables have been studied recently. Methods such as the use of organic acids can reduce microbial loads in foods. Objective. To evaluate the use of citric and lactic acids at different concentrations in reducing Escherichia coli and Listeria monocytogenes in shredded cabbage and carrot. Materials and methods. The study was conducted in San José, Costa Rica, between September and November 2023. Carrots and cabbages were shredded, inoculated with E. coli and L. monocytogenes, and then disinfected using lactic or citric acid at concentrations of 5, 10 y 20 g l^-1for 5 min. After disinfection, logarithmic reductions were determined, and orthogonal contrast and Bonferroni test were applied to evaluate the effect of the acids in comparison to the water control, the differences in the reduction between acids, and effect of the acid concentration. Results. In both carrot and cabbage, logarithmic reductions of E. coli between 2 and 5 log CFU/g were determined. Greater reductions were generally found at 20 g l^-1 compared to 5 g l^-1, and for lactic acid compared to citric acid. For L. monocytogenes in carrots, no reduction could be determined, however, in cabbage, reductions between 1,2 and 2,4 log CFU/g were determined, with higher reductions at 20 g l^-1compared to 5 g l^-1and for lactic acid compared to citric acid. Conclusions. Under studied concentration and time conditions, lactic and citric acids can be used in disinfection processes for shredded cabbage and carrot, achieving reductions of at least 2 log CFU/g.

Soil organic carbon storage in different agroforestry systems associated with Coffee in Nariño, Colombia

2024-05-02T15:07:25-06:00

Introduction. Anthropogenic activities are one of the causes of the increase in global temperature, which affects agro-environmental, ecological and socioeconomic processes. The contributions of agricultural production systems in the capture and storage of greenhouse gases have been little studied. Still, the literature indicates that the inclusion of trees on farms is an option to capture and store some greenhouse gases. Objective. To evaluate the relationship between floristic and structural diversity of coffee production systems and soil organic carbon storage (SOC). Materials and methods. The study was carried out during the period 2019-2020, in three localities Sandoná, San Pablo and Buesaco, Nariño-Colombia. Twelve agroecosystems with coffee were visited, where Shannon-Weiner and Simpson indices, tree density and complete soil analysis with samples at 30 cm depth were evaluated. An analysis of variance and principal components was sufficient for the analysis of the information. Results. The SOC was not presented statistical differences (p>0.05), which ranged between 38.55 Mg ha^-1 in the full sun coffee arrangement in Buesaco and 96.63 Mg ha^-1 in the coffee arrangement with miscellaneous in the same municipality, which presented the highest species diversity. Conclusions. It was proved that the coffee harvest associated with agroforestal systems (T3 and T4) with higher diversity and abundance of species, is higher than carbon accumulated in the soil compared to the monoculture arrangement (80,43 Mg ha^-1 vs 58,32 Mg ha^-1, severally), this diversification give to the family and enviroment some services and goods, contributing to the mitigation of climate change.

Effect of hot red pepper supplementation and different storage time on hens egg quality

2024-05-13T07:40:18-06:00

Introduction. Eggs are a food source of protein that easily deteriorates during storage. Supplementation of hot red chilli pepper powder rich in bioactive compounds in diets for laying hens can improve egg quality and prevent egg deterioration during storage. Objective. To determine the effect of hot red pepper powder supplementation and different storage times on the physical egg quality of laying hens. Materials and methods. This study was conducted from January to March 2024 at the Research Barn of PT. Agromix Lestari Group, Kulon Progo, Yogyakarta, Indonesia. Eighty 56-week-old Novogen laying hens (1681 ± 64 g) were assigned into four dietary treatments (4 replications, 5 hens per replication): basal diet as control (P0); basal diet + 0.25 % hot red pepper powder (P1); basal diet + 0.5 % hot red pepper powder (P2); and basal diet + 0.75 % hot red pepperpowder (P3). At the end of week 6, one egg per replicate group was collected and analyzed for physical quality in three storage treatments: fresh condition (S0), one week storage (S1), and two weeks storage (S3). Egg quality data were analyzed with a factorial experimental design (4 x 3) using SPSS 26 software. Results. Supplementation of 0.5 % hot red pepper powder significantly increased egg weight. Hot red pepper addition and treatment duration significantly affected egg yolk colour. The hot red pepper treatment group showed significantly lower pH of albumen and yolk. Conclusions. The supplementation of hot red pepper powder in laying hens diets has been shown to improve the egg yolk color. The inclusion of 0.5 % in the ration was able to keep the pH of yolk and albumen low.

Biological potential of Beauveria spp. for the control of Anthonomus eugenii in sweet pepper

2024-05-15T09:43:53-06:00

Introduction. Anthonomus eugenii causes considerable economic losses in sweet pepper (Capsicum annuum). Chemical control is ineffective; therefore, it is essential to explore other management alternatives. Objective. Determine the potential of Beauveria spp. strains for the biological control of Anthonomus eugenii in sweet pepper under greenhouse conditions. Materials and methods. The research was conducted between May and august 2023 at the Fabio Baudrit Moreno Experimental Station in Alajuela, Costa Rica, in a 96 m² multispan greenhouse. The evaluated treatments were INTA H-140, INTA H-149, INTA H-168, and INTA H-181, along with an absolute control, using a completely randomized design (CRD) with three replications. The number of live adults and infested peppers were quantified weekly. Pearson correlation analysis and repeated measures ANOVA were performed for the evaluated variables. Results. There was interaction between treatments and evaluation date for the number of adults (p < 0,05). INTA H-168 strain significantly reduced the Anthonomus eugenii population in 60 ddt and 64 ddt evaluations, with differences of 22,96 and 47,15 adults, respectively. For the variable of the number of infested peppers, there was only an individual effect by ddt (p < 0,05). Additionally, a positive correlation was found between the average number of infested peppers and the number of live adults for the 64 ddt and 73 ddt (p < 0,05). Conclusion. The significant reduction in live adults in the first two evaluations of INTA H-168 strain and its parasitism evidence biological potential for the control of Anthonomus eugenii.

Valorization of Algerian food by-products in animal feed

2024-05-02T09:18:10-06:00

Introduction. The valorization of food by-products in animal feed has emerged as a pivotal strategy. This innovative approach not only addresses the challenge of food waste management but also contributes to the optimization of resources in animal nutrition. Objective. To characterize food waste (carob molasses residue, carob seeds, bitter orange peels, and brown chicken eggshells) with a view to its use as a value-added feed supplement for animals based on its biologically active compounds. Materials and methods. In this study, several food by-products were utilized, including carob molasses residue, orange peels, and eggshells. The biological material was collected in Boumerdes, Algeria, during 2021, according to the ripening period of the plant material (August for carob and December for oranges). For the characterization of the different components of the biological material, phytochemical tests based on coloring reactions, HPLC, atomic absorption spectrophotometry, and solubility in solvents were employed. Results. The by-products were found to be low in fat and protein and moderately high in sugar. Orange peel constitutes a reservoir of vitamin C, carotenoids, and phenolic compounds. The mineralogical study showed a predominance of calcium, magnesium, and phosphorus in the eggshells. The comparison of by-products shows that carob seeds are the least rich in crude fiber and therefore supply more available carbohydrates, providing more assimilable energy compared to other by-products. Conclusion. These food byproducts provide bioactive compounds, including vitamin C, carotenoids, phenolic compounds, as well as some minerals, and offer more available energy. The combination of these by-products constitutes a value-added food supplement for livestock feed.

Determination of an instrumental method for measuring hardness in whole cooked beans (Phaseolus vulgaris L.)

2024-05-08T10:06:47-06:00

Introduction. Hardness measurement of cooked beans in Costa Rica is conducted using a sensory method and without a standardized instrumental method. Objective. To determine a potential instrumental method for the measuring hardness in whole cooked beans, based on a hardness analysis of two brands of canned beans marketed in Costa Rica. Materials and methods. The study was conducted at the Chemistry Laboratory of Food Technology Department at the Universidad de Costa Rica, San José, Costa Rica, from November 2019 to April 2020. Measuring of hardness were performed by placing five beans in an adjustable cell texture analyzer with a cylindrical probe (50 mm) at a compression speed of 1 mm/s, until reaching 75 % bean compression. The results of these measurements were analyzed using a 2x2 factorial treatment design, where the experimental factors were brand and container size. The levels in each factor were considered as brand: A and B, and container size: 420 g and 823 g. The required number of repetitions was then estimated to ensure a test power of 90 %. Results. Significant differences were found in the brand factor, but not in the container size factor. Power analysis results indicated that, with a 90 % power, 16 repetitions of the texture analysis are necessary. Conclusion. The specific processing of each company influences the final texture of the cooked bean. The developed methodology enables instrumental analysis of bean hardness with a 90 % test power and a number of 16 replicates.

Soil loss due to water erosion in the Estibaná River sub-basin, Panama

2024-05-06T07:24:42-06:00

Introduction. Soil degradation develops naturally on a small scale, however, human intervention has accelerated and maximized it. Erosion is one of the main processes linked to degradation; this, combined with exploitation systems not adapted to the environment, is the basis for the reduction of productivity and pollution of water bodies. In Panama, soil degradation affects 20,787 km², an area that covers areas where much of the country's agricultural production is concentrated. Objective. To determine soil loss due to water erosion in the Estibaná River sub-basin through the implementation of erosion plots. Materials and methods. The research was carried out in the Estibaná River sub-basin, province of Los Santos, Azuero Peninsula, Panama (Arco Seco), during the rainy season (May – December) of the years 2020 and 2021. The methodology of erosion plots was used, using a Random Complete Block (BCA) design, in three locations, evaluating three treatments, with three repetitions, where total runoff, mass of transported sediments (suspended and precipitated), a Multifactorial ANOVA was performed. Results. Erosion was influenced by factors such as slope, soil cover and precipitation. It was determined that erosion amounted to 62.98 Mg/ha/year in bare soil on 10 % slopes, introducing living barriers and soil cover mitigated erosion damage, the behavior on other slopes presented a similar behavior. Conclusions. The variation of precipitation in frequency, intensity, duration; as well as anthropogenic interventions in the natural environment, are the main causes of the increase in soil loss within the Estibaná River sub-basin. The implementation of low-cost conservation efforts can mitigate the erosive effect of surface runoff.

Fine and flavor cocoa: Key aroma compounds and their behavior during processing

2024-07-11T09:32:28-06:00

Introduction. The cocoa varieties (Theobroma cacao L.) that are classified in the global market as fine and flavor, represent 6 % and are marketed at a differentiated price. These varieties have unique characteristics determined by their genotype, and their aroma complexity is a fundamental factor that distinguishes them. Objective. To integrate updated information that provides scientific evidence about fine and flavor cocoa, identify the key compounds that confer this denomination, and describe their behavior during the stages of fermentation, drying, and roasting. Development. Fine and flavor cocoa is highly valued in the market for its unique flavor and aromas, and is especially sought after for the production of gourmet and nutraceutical products. This type of cocoa is cultivated by small producers in the Mesoamerican region, who employ family-based, organic, and sustainable production systems. This region, the main producer of fine and flavor cocoa, faces the risks of losing its valuable biodiversity. It is crucial to conserve cocoa´s genetic diversity and understand its physicochemical components, especially the volatiles responsible for its sensory attributes. Conclusion. The primary processing of cacao, particularly the stages of fermentation and drying, significantly influences its aromatic profile. Controlling and standardizing these processes is essential for producers to obtain their cocoa beans with a differentiated quality, thereby enhancing their value in the market due to their unique sensory characteristics. Future studies should focus on developing standardized methods for fermentation and drying, as well as on conserving the genetic diversity of fine and aromatic cocoa.

Effect of Bacillus megaterium on strawberry crop

2024-05-08T10:48:30-06:00

Introduction. In Ecuador, strawberry cultivation holds significant economic and social importance, having witnessed substantial growth in recent years. However, this sector faces challenges from various pests and diseases. Objective. To evaluate the effect of Bacillus megaterium on strawberry crop variables related to plant health and agronomic yield. Materials and methods. Field trial was conducted on the Albion variety of strawberries, four months after the first harvest, in Pichincha province, Ecuador. Using IB6 and AB4 strains of Bacillus megaterium at concentrations of 1x109 y 5 x108 cfu/L. These were compared with a chemical control using captan (3 g/L) and chlorothalonil (2 mL/L) as fungicides, and abamectin (0.75 mL/L) and lambdacyhalothrin (0.3 mL/L) as insecticides in rotation. A split-plot design with evaluations conducted at two intervals between April and June 2023. Variables measured included Botrytis cinerea incidence and severity index, fresh weight, yield, diameters, and Brix degrees of fruits. Results. There was no interaction between the factor showed no statistical difference for variables of health and agronomic interest, the incidence of B. cinereal in the biological treatments was the lowest with 13 % on average, the control of mites was 72.71 % higher with strain IB6 high concentration this same treatment, showed significant increases in the fresh weight of fruits (13.2 %), diameters (14 %), and soluble solids concentration (23 %) higher than the control. Conclusion. The use of Bacillus megaterium reduced the incidence of Botrytis cinereal, effective control against mites and thrips, improved fresh weight, diameters and Brix degrees of fruits.

An overview on extenders used in ram sperm cryopreservation

2024-06-17T11:09:09-06:00

Introduction. One of the most critical methods for improving domestic animal reproduction is sperm cryopreservation. To achieve the best results, this complex process requires the meticulous balance of numerous variables. Sperm cryopreservation is an essential technique in programs that improve breeding and conservation for many species, especially small ruminants. In this case, genetic material from a limited number of exceptional sires can be used to breed a huge number of female sheep. Objective. To analyze the current advances in extenders used in ram sperm cryopreservation. Development. In rams, spermatozoa have a lower intramembrane cholesterol-to-phospholipid ratio than other species, making them more susceptible to cryopreservation damage than other livestock species. Adequate freezing and thawing would prevent metabolic and structural damage to ram sperm cells, something that has not been possible until the present time. The success of the sperm freezing process depends on several factors such as freezing/thawing rate, equilibration time, spermatozoa, or the composition of medium surrounding spermatozoa among others. In this sense, sperm extender is one of the most critical factors in the cryopreservation process. Conclusion. The vulnerabilities of ram sperm to cryogenic stress poses challenges to maintaining viability after thawing and achieving consistently high fertility rates. Further research to refine supplementation strategies, optimize freezing protocols, and explore novel cryoprotectants is essential to overcome these challenges and enhance the efficacy of ram semen cryopreservation to improve reproductive outcomes in ovine breeding programs.

Obtaining wild sunflower (Helianthus annuus L.) plants for bioassays with herbicides

2024-04-25T07:10:15-06:00

Introduction. The wild sunflower or polocote (Helianthus annuus L.) is the main annual weed in the cultivation of sorghum and corn in northern Tamaulipas, Mexico. To date, there is little information about this species to carry out bioassays with herbicides. Objetive. Establish a methodology for obtaining polocote seedlings for bioassays with herbicides from seed to multiplication in the nursery. Materials and methods. The polocote seed was collected in January 2023, within the INIFAP Experimental Field, in Río Bravo, Tamaulipas. Afterwards, the initial germination test was carried out on filter paper and viability with Tetrazolium, latency was confirmed due to low germination (12 %) and high viability (86 %). Twelve treatments were used to break it using ethanol (70 %) and water (75, 25), as a control only water, at 5 ^oC and 20 ºC on paper, filter, cotton and Peat moss in Petri dishes for seven days and then at (± 25 ºC). With the previous results, the nursery phase was established with four schemes with pre-germinated seed transplantation and two with direct sowing. Results. The best treatment to break dormancy was immersion in water at 5 ºC for seven days on cotton with 73 %. The best methods to obtain plants were trays with seedlings and transplanting into black open-air pots with 75 and 50% survival, respectively. The shade inhibited the growth of the plants. Direct sowing, with or without seed prehydration, was unfavorable for germination and emergence. Conclusion. Obtaining wild sunflower seedlings was higher when the seed was subjected to water pre-treatment and subsequent transplanting into trays or open-air bags.

Effect of industrial processing of crackers on the recovery and quantitation of allergens with ELISA kits

2024-08-20T14:05:32-06:00

Introduction. Processing foods may generate limitations on the recovery and quantitation of allergens. Factors such as geometry or thermal treatment can influence the veracity of the assay results. Objective. To determine the effect of processing on the recovery and quantification of allergens. Materials and methods. Study conducted in Costa Rica between 2020 and 2021 in the Compañía de galletas Pozuelo DCR. S.A. The geometry was evaluated with two cracker molds (traditional and XL). The effect of baking was evaluated with the traditional cracker type. For both experiments, samples were taken from four batches, and they were analyzed with three different kits for milk and egg analysis in an independent way. Results. The effect of geometry was observed for recovery and quantitation of egg residues was significantly affected by cracker geometry (P= 0.0228) compared to milk (P= 0.4335), regardless of the analytical kit used. The post baking decrease of quantitation effect was presented equally regardless of the kit used (P=0.4245) on egg. Very poor recovery of egg residues (4-5 %) was observed after cracker baking. For milk allergens, there was not a significant difference on the quantitation and recovery after baking among kits (P=0.1682), which is due to the variability of the data among kits. Conclusions. Processing reduces the efficacy of kits to detect the real quantity of allergens in foods. The analytical kit must be evaluated with the matrix to be analyzed, to determine how much impact the processing can have on the quantitation of allergens.

Prevalence of ahpnd in shrimp farms of the Nicoya Gulf and Central Pacific, Costa Rica

2024-04-01T08:55:15-06:00

Introduction. The Acute hepatopancreas necrosis disease (AHPND) is caused by bacteria Vibrio parahaemolyticus containing a plasmid encoding the toxin genes pirA and pirB. The disease is characterized by massive sloughing of epithelial cells in hepatopáncreas, also showing atrophy and discoloration of that organ. Diseased shrimp display anorexia with empty gut, weakness, body discoloration and high mortalities. Objective. To determine the prevalence of Vibrio parahaemolyticus causing AHPND in farms that grow shrimp in the Pacific zone of Costa Rica. Material and methods. During the years 2019 and 2020, water and shrimp (P. vannamei) samples were obtained from 32 farms located in the western coast of the Gulf of Nicoya (Northwest of Costa Rica) and the Central Pacific coast (Puntarenas- Parrita) The samples were analyzed by the endpoint Polymerase Chain Reaction (PCR) using different protocols and primers to detect the toxins pirA and pirB. Further, a linear correlation between the presence of AHPND and water quality was done using the R statistical program. Results. The presence of Vibrio parahaemolyticus causing AHPND occurred in 93.75 % (30/32) of sampled ponds in both farming areas. Conclusion. This work confirms the presence and wide distribution of AHPND in water and shrimp from thirty shrimp farms in the Costa Rican Pacific.