Host-driven subspeciation in the hedgehog fungus, Trichophyton erinacei, an emerging cause of human dermatophytosis.

Trichophyton erinacei is a main cause of dermatophytosis in hedgehogs and is increasingly reported from human infections worldwide. This pathogen was originally described in the European hedgehog (Erinaceus europaeus) but is also frequently found in the African four-toed hedgehog (Atelerix albiventris), a popular pet animal worldwide. Little is known about the taxonomy and population genetics of this pathogen despite its increasing importance in clinical practice. Notably, whether there are different populations or even cryptic species associated with different hosts or geographic regions is not known. To answer these questions, we collected 161 isolates, performed phylogenetic and population-genetic analyses, determined mating-type, and characterised morphology and physiology. Multigene phylogeny and microsatellite analysis supported T. erinacei as a monophyletic species, in contrast to highly incongruent single-gene phylogenies. Two main subpopulations, one specific mainly to Atelerix and second to Erinaceus hosts, were identified inside T. erinacei, and slight differences in the size of microconidia and antifungal susceptibilities were observed among them. Although the process of speciation into two lineages is ongoing in T. erinacei, there is still gene flow between these populations. Thus, we present T. erinacei as a single species, with notable intraspecies variability in genotype and phenotype. The data from wild hedgehogs indicated that sexual reproduction in T. erinacei and de novo infection of hedgehogs from soil are probably rare events and that clonal horizontal spread strongly dominates. The molecular typing approach used in this study represents a suitable tool for further epidemiological surveillance of this emerging pathogen in both animals and humans. The results of this study also highlighted the need to use a multigene phylogeny ideally in combination with other independent molecular markers to understand the species boundaries of dermatophytes. Citation: Cmoková A, Kolarík M, Guillot J, et al. 2022. Host-driven subspeciation in the hedgehog fungus, Trichophyton erinacei, an emerging cause of human dermatophytosis. Persoonia 48: 203-218. https://doi.org/10.3767/persoonia.2022.48.06.

Scale-up of a packed bed column for wastewater treatment.

After checking the success of the biosorption process to remove heavy metals from wastewater using olive tree pruning as a cheap biosorbent in the laboratory scale, the scale-up is necessary to progress towards industrial applications chance. The aim of this work was the study of the effect of scale-up in the process of biosorption of Pb(II) with olive tree pruning in a packed bed column. Experiments were performed using two different scale-up criteria and results obtained in both scales were compared. Similar parameters were obtained for each pair of equivalent tests, with a slightly advanced of the obtained breakthrough curves in the pilot plant. The experimental results were fitted by the Thomas model and the obtained mean values were KTh = 0.187 mL/min·mg and q0 = 20.59 mg/g for criterion 1 and KTh = 0.217 mL/min·mg and q0 = 20.27 mg/g for criterion 2. Finally, the mathematical model was applied to simulate industrial applications and it was obtained that under optimal operative conditions, a column according to the criterion 1 was able to operate 2.3 h, and a column according to the criterion 2 was able to operate for 3.6 h.

[Translated article] Postsurgical analgesic efficacy by the intra-articular administration of ropivacaine with dexmedetomidine versus simple ropivacaine in patients undergoing knee arthroscopy.

The effective relief of postsurgical pain in patients undergoing knee arthroscopy is important to allow the initiation of activities of daily living. The objective of this study is to demonstrate the analgesic efficacy of dexmedetomidine as an adjuvant added to ropivacaine by the intra-articular route. METHOD: Seventy patients underwent knee arthroscopy which were randomly assigned into two groups (n=35). The RD group received ropivacaine 1.5mg/kg plus dexmedetomidine 1µg/kg intra-articularly. Group R received ropivacaine 1.5mg/kg intra-articularly. The analgesic effect was evaluated by measuring the intensity of pain (VAS score) and the duration of analgesia. RESULTS: A longer duration of the analgesic effect was observed in the RD group (655min) compared to the R group (318min) being statistically significant (p=0.03). CONCLUSION: Dexmedetomidine as an adjuvant to intra-articular ropivacaine improves the quality and duration of postoperative analgesia in patients undergoing knee arthroscopy.

Initial assessment of natural diversity in Mexican fig landraces.

The common fig (Ficus carica L.) was introduced into Mexico by Spanish Franciscan missionaries in the 16th century. It is widely assumed that Mexican figs are the Spanish cultivar Black Mission. We collected and propagated 12 fig plants from six landraces from different states in Central Mexico that represent different climate. All of them were grown in a greenhouse at Universidad Autónoma Chapingo, in the State of Mexico. During the experimental period, the greenhouse had an average temperature and relative humidity of 29.2° ± 5.4°C (SEM) and 78.1 ± 6.7% (SEM), respectively. Morphological characterization was done following a selected set of quantitative and qualitative descriptors established by the IPGRI. DNA analysis was based on a combination of ISSR and RFLP markers. We observed great diversity mainly in fruit weight (28.1-96.2 g), fruit shape (ovoid, pyriform), and neck length (0.97-3.80 cm), which could not be explained by environmental conditions such as temperature and relative humidity. The Nei and Li/Dice similarity coefficient between landraces was determined by cluster analysis using the UPGMA method. Based on the morphological characterization and DNA fingerprinting data presented in this study, our results showed that after hundreds of years, black figs have adapted to local environmental condition in Central Mexico, yielding at least six clearly distinct landraces that represent valuable and previously undescribed genetic diversity. We also suggested names for those landraces according to their location and established a basis for further agronomic and molecular characterization of fig landraces.

Postsurgical analgesic efficacy by the intra-articular administration of ropivacaine with dexmedetomidine versus simple ropivacaine in patients undergoing knee arthroscopy. / Eficacia analgésica posquirúrgica en la administración intraarticular de ropivacaína con dexmedetomidina en comparación con ropivacaína simple en pacientes intervenidos de artroscopia de rodilla.

The effective relief of postsurgical pain in patients undergoing knee arthroscopy is important to allow the initiation of activities of daily living. The objective of this study is to demonstrate the analgesic efficacy of dexmedetomidine as an adjuvant added to ropivacaine by the intra-articular route. METHOD: Seventy patients underwent knee arthroscopy which were randomly assigned into two groups (n=35). The RD group received ropivacaine 1.5mg/kg plus dexmedetomidine 1µg/kg intra-articularly. Group R received ropivacaine 1.5mg/kg intra-articularly. The analgesic effect was evaluated by measuring the intensity of pain (VAS score) and the duration of analgesia. RESULTS: A longer duration of the analgesic effect was observed in the RD group (655min) compared to the R group (318min) being statistically significant (p=0.03). CONCLUSION: Dexmedetomidine as an adjuvant to intra-articular ropivacaine improves the quality and duration of postoperative analgesia in patients undergoing knee arthroscopy.

Identification of a gene cluster for cell-surface genes of the SRS superfamily in Neospora caninum and characterization of the novel SRS9 gene.

Here we present the detection of a gene cluster for Neospora caninum surface genes, similar to the Toxoplasma gondii SRS9 locus, and the cloning and characterization of the NcSRS9 gene. PCR genome walking, using NcBSR4 gene as a framework, allows the identification, upstream NcBSR4, of 2 sequences homologous to the SRS5 and the Ubiquinol-cytochrome C reductase genes and, downstream NcBSR4, of an ORF of 1191 bp coding for a 396-amino acid polypeptide with 59% similarity to the TgSRS9 antigen. A putative 39-residue signal peptide was found at the NH2-terminus followed by a hydrophilic region, and a potential site for a glycosylphosphatidylinositol anchor at the COOH-terminus. A recombinant NcSRS9 protein was produced and was recognized on a Western blot by a low proportion of sera from a panel of naturally infected cows and calves. In addition, Western blot analysis using polyclonal anti-rNcSRS9 revealed stage-specific expression of NcSRS9 in bradyzoites but not in tachyzoites, and immunohistochemistry on brain from a congenitally infected calf showed NcSRS9 recognition in bradyzoites contained in tissue cysts. However, bradyzoite-specific expression of NcSRS9 could not be proven by immunofluorescence on bradyzoites obtained in vitro and RT-PCR analysis showed no significant variations of NcSRS9 transcripts during in vitro tachyzoite-bradyzoite switch, probably due to incomplete maturity of in vitro bradyzoites. Initial characterization of NcSRS9 in this study may lead to further studies for a better understanding of N. caninum persistence.

[Epidemiologial profile of invasive candidiasis in intensive care units at a university hospital]. / Perfil epidemiológico de la candidiasis invasora en unidades de pacientes críticos en un hospital universitario.

UNLABELLED: Invasive candidiasis (IC) epidemiology has changed in critically ill patients and limited data are available in Chile. OBJECTIVE: To describe the epidemiological and microbiological profile of IC in critically ill patients. METHODS: Observational prospective study conducted from October 2001 to August 2003 in critically ill adults with suspected or confirmed IC. RESULTS: 53 patients met criteria for IC, finding 18 (33.9%) candidemias, 22 (41.5%) disseminated IC, and 13 (24.5%) local IC. We identified 8 (44.4%) C. albicans and 10 (55.6%) non-albicans Candida in candidemias. C. tropicalis was the predominant non-albicans species (27.7%). An 88.8 % of Candidas sp recovered in candidemias were fluconazole susceptible. Overall hospital mortality was 24.5%. Mortality in candidemia was significantly lower than in disseminated IC (16.6 vs 31.8%, p = 0.02). CONCLUSIONS: A higher proportion of non-albicans Candida was observed in candidemias from critically ill patients. However, most of these strains were fluconazole susceptible. A lower overall mortality was observed in candidemias.

Fenofibrate treatment for severe hypertriglyceridemia in dogs.

Lipid disorders are relatively common in dogs. Hyperlipidemia can be primary or secondary to other diseases. In humans, fenofibrate is used to control hypertriglyceridemia. In dogs, there are no studies evaluating fenofibrate in hypertriglyceridemia. The aim of the study was to evaluate the safety and efficacy of fenofibrate to control severe hypertriglyceridemia in dogs. A total of 124 dogs (n = 124) with severe hypertriglyceridemia (>300 mg/dL, 3.39 mmol/L) were randomly distributed in the fenofibrate group (n = 64) and the diet group (n = 60). Dogs of the fenofibrate group were treated with fenofibrate (10 mg/Kg) once daily. Dogs of the diet group were treated with low-fat diet (10%). Serum triglycerides (TGs), total cholesterol (TC), liver enzymes, and creatine kinase concentrations were evaluated, before and after 1 mo of medical or dietary treatment. Triglyceride concentrations were reduced with fenofibrate (P < 0.001), and 85.93% of the dogs normalized their levels. Triglyceride concentrations also decreased with low-fat diet (P < 0.001), but only 26.6% of the dogs normalized their levels. Triglyceride concentrations were reduced with fenofibrate (P < 0.01) and with low-fat diet (P < 0.01). Of the cases with hypercholesterolemia, 53.7% and 50% of the dogs normalized their TC concentrations, with fenofibrate and diet, respectively. No significant adverse effects were observed (3% showed diarrhea). Fenofibrate was safe and effective in reducing and normalizing TG concentrations in dogs with severe hypertriglyceridemia, regardless of the cause of hyperlipidemia. The low-fat diet was effective in reducing, but not normalizing, TG concentrations. Fenofibrate and low-fat diet were effective in reducing TC concentrations. This is the first study evaluating fibrates in dogs with severe hypertriglyceridemia and comparing results with a low-fat diet.

Urinary vanillylmandelic acid:creatinine ratio in dogs with pheochromocytoma.

Pheochromocytoma diagnosis in dogs is challenging because biochemical tests are not always available. In humans, urinary vanillylmandelic acid (VMA) is part of a pheochromocytoma biochemical diagnostic profile, whereas its diagnostic accuracy is currently unknown in dogs with pheochromocytoma. Prospectively, VMA was determined by HPLC and expressed as the ratio with respect to urinary creatinine (VMA:C). The diagnostic accuracy of the VMA:C ratio was evaluated by analyzing the receiver operating characteristic (ROC) curve in 10 healthy dogs, 8 dogs with pituitary-dependent hypercortisolism, 8 dogs with adrenal-dependent hypercortisolism, and 7 dogs with pheochromocytoma. The pheochromocytoma diagnosis was confirmed by histology and immunohistochemistry in all tumors. The VMA:C ratio was significantly higher in dogs with pheochromocytoma (158 [53.4 to 230.8] × 10-3) than in dogs with adrenal-dependent hypercortisolism (48.1 [24.3 to 144.9] × 10-3; P < 0.05), dogs with pituitary-dependent hypercortisolism (37.5 [32 to 47.1] × 10-3; P < 0.001), and healthy dogs (33.8 [13.3 to 87.9] × 10-3; P < 0.001). When using a VMA:C ratio >58.2 × 10-3 for pheochromocytoma diagnosis, a sensitivity of 85.7% and a specificity of 88.4% were obtained. Nevertheless, when using a cut-off ratio of 4 times the median VMA:C ratio determined in healthy dogs, there was no overlap (100% specificity). The area under the ROC curve indicated that the VMA:C ratio test could be used to discriminate between dogs with and without pheochromocytoma, what leads to the conclusion that it is useful for pheochromocytoma diagnosis in dogs.

[Feeding behavior, dietary sufficiency and nutritional status in children between 6 and 18 months]. / Comportamiento alimentario, suficiencia dietaria y estado nutricional en niños entre 6 a 18 meses.

INTRODUCTION: Infant feeding has specific qualitative and quantitative characteristics. The influence of parents on food intake is crucial in the development of habits and an adequate nutritional state. OBJECTIVE: To evaluate eating behavior, dietary characteristics, and nutritional status of children between 6 to 18 months. SUBJECTS AND METHOD: Cross-sectional descriptive study in 199 children. Using convenience sampling, demographic and anthropometric data were recorded for nutritional status, and dietary history, through a 24-hour reminder for dietary behavior and food sufficiency. The Student's t-test and one-way ANOVA were applied for continuous variables and the chi-square test for the categori cal ones. RESULTS: 54.8% were women. Regarding nutritional status, 21.1% were overweight and 7.6% obese. 56.8% of the children had meal numbers according to their age. The average energy intake was 652.9 ± 224.2 calories per day. The intake of energy and macronutrients was significantly higher in children not consuming breast milk and aged 12 to 18 months. The energy, lipids, and carbohydrates adequacy in girls was significantly higher than in boys. 83.1% of food consumption was habitual for this age group. CONCLUSION: In eating behavior, we observed that 4 out of 10 children have meal numbers higher than suggested for their ages. Regarding dietary sufficiency, there is a higher intake in children with normal nutritional status, without breastfeeding, and between 12 and 18 months. Despite the high prevalence of obesity, it was lower than that observed at the national level.

[The importance of bone scintigraphy in the diagnosis of SAPHO syndrome]. / Importancia del estudio gammagráfico óseo en el diagnóstico del síndrome de SAPHO.

The SAPHO acronym corresponds to a group of benign conditions that combine osteoarticular and skin involvement whose diagnosis is mainly clinical and is supported by imaging findings. The bone scintigraphy has a relevant role due to its sensitivity and early detection ability. We present 8 patients with SAPHO syndrome whose clinical involvement began with skin manifestations. All of them had palmoplantar pustulosis, either of recent onset or outbreak evolution. Some had associated osteoarticular pain in shoulders, sternum, lumbar area or limbs. Bone scintigraphy with Tc-99m-diphosphonate showed pathological findings in all the patients, detecting sternoclavicular joint damage, this being the most frequent involvement in 7 of them, and also in other less usual localizations.

Modulation of Toll-like receptor-mediated innate immunity in bovine intestinal epithelial cells by lactic acid bacteria isolated from feedlot cattle.

The ability of lactobacilli isolated from feedlot cattle environment to differentially modulate the innate immune response triggered by Toll-like receptors (TLRs) activation in bovine intestinal epithelial (BIE) cells was evaluated. BIE cells were stimulated with Lactobacillus mucosae CRL2069, Lactobacillus acidophilus CRL2074, Lactobacillus fermentum CRL2085 or Lactobacillus rhamnosus CRL2084 and challenged with heat-stable pathogen associated molecular patterns (PAMPs) from enterotoxigenic Escherichia coli (ETEC) to induce the activation of TLR4 or with polyinosinic:polycytidylic acid (poly(I:C)) to activate TLR3. Type I interferons, cytokines, chemokines and negative regulators of TLR signalling were studied by RT-PCR. L. mucosae CRL2069 significantly reduced the expression of interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1 in BIE cells in the context of TLR3 activation. L. mucosae CRL2069 also reduced the expression of tumour necrosis factor-α, IL-ß, MCP-1, and IL-8 in heat-stable ETEC PAMPs-challenged BIE cells. In addition, reduced expressions of IL-6, MCP-1, and IL-8 were found in BIE cells stimulated with L. rhamnosus CRL2084, although its effect was significantly lower than that observed for the CRL2069 strain. The reduced levels of pro-inflammatory factors in BIE cells induced by the CRL2069 and CRL2085 strains was related to their ability of increasing the expression of TLR negative regulators. L. mucosae CRL2069 significantly improved the expression of A20-binding inhibitor of NFκ-B activation 3 (ABIN-3), interleukin-1 receptor-associated kinase M (IRAK-M) and mitogen-activated protein kinase 1 (MKP-1) while L. rhamnosus CRL2084 augmented ABIN-3 expression in BIE cells. The results of this work suggest that among the studied strains, L. mucosae CRL2069 was able to regulate TLR3-mediated innate immune response and showed a remarkable capacity to modulate TLR4-mediated inflammation in BIE cells. The CRL2069 strain induce the up-regulation of three TLR negative regulators that would influence nuclear factor kB and mitogen-activated protein kinases signalling pathways while reducing the expression of pro-inflammatory cytokines and chemokines. Therefore, L. mucosae CRL2069 is an interesting immunobiotic candidate for the protection of the bovine host against TLR-mediated intestinal inflammatory damage.

Antifungal susceptibility testing practices in mycology laboratories in France, 2018.

A survey of mycology laboratories for antifungal susceptibility testing (AFST) was undertaken in France in 2018, to better understand the difference in practices between the participating centers and to identify the difficulties they may encounter as well as eventual gaps with published standards and guidelines. The survey captured information from 45 mycology laboratories in France on how they perform AFST (number of strains tested, preferred method, technical and quality aspects, interpretation of the MIC values, reading and interpretation difficulties). Results indicated that 86% of respondents used Etest as AFST method, with a combination of one to seven antifungal agents tested. Most of the participating laboratories used similar technical parameters to perform their AFST method and a large majority used, as recommended, internal and external quality assessments. Almost all the participating mycology laboratories (98%) reported difficulties to interpret the MIC values, especially when no clinical breakpoints are available. The survey highlighted that the current AFST practices in France need homogenization, particularly for MIC reading and interpretation.

Stage-specific expression of Nc SAG4 as a marker of chronic Neospora caninum infection in a mouse model.

Neospora caninum infection persists throughout the life of its intermediate host due to the conversion of tachyzoites to slowly dividing bradyzoites that encyst in the brain. This event results in persistent N. caninum infection in bovine herds and partially explains the poor efficacy of many chemotherapeutic agents and vaccine formulations. Thus, there is a need for greater understanding of the tachyzoite-to-bradyzoite conversion mechanisms. Here we studied for the first time the transcription kinetics of the N. caninum bradyzoite-specific gene NcSAG4 in brain samples from chronically infected mice by means of real-time RT-PCR. NcSAG4-messenger RNA (mRNA) levels increased significantly during the chronic phase but followed 2 different expression patterns depending on the isolate used for murine inoculation. NcSAG4-mRNA levels in brains from Nc-1-inoculated mice peaked during late chronic infection (on day 64 post-infection, p.i.), whereas those from Nc-Liv-inoculated mice peaked earlier during the chronic infection (on day 32 p.i.). This difference could be a reflection of the different abilities of these isolates to replicate and form cysts in parasitized brains. These results are consistent with our observations of anti-rNcSAG4 antibody production; low levels were present at seroconversion and slowly increased during the chronic phase. In contrast, NcSAG1 transcription levels, which mark the tachyzoite stage, were maintained without variation in both groups of mice. This suggests the presence of a significant amount of tachyzoites or intermediate zoites expressing NcSAG1 in the brain, even during the late chronic infection.

First isolation of Besnoitia besnoiti from a chronically infected cow in Spain.

Besnoitia besnoiti was isolated from a skin biopsy of a chronically infected cow from central Spain. Zoites released from macroscopic cysts were adapted to its culture in vitro on a MARC-145 cell monolayer. Tachyzoites produced in vitro were either cryopreserved or used for genomic DNA isolation. A 2206 nt sequence containing 18S ribosomal RNA gene, internal transcribed spacer 1 (ITS 1), and a partial sequence of 5.8S ribosomal RNA gene was amplified by PCR and sequenced. This sequence showed a 99-100% identity to 18S, ITS1, and 5.8S sequences of B. besnoiti published in databases. After analysis by transmission and scanning electron microscopy of isolated bradyzoites and tachyzoites, it was observed that their ultrastructural morphology coincided with B. besnoiti. The isolate characterized in this study was identified as B. besnoiti on the basis of the disease produced, molecular characteristics, and morphology. The B. besnoiti isolate was denoted as BbSpain-1; it is the first isolate obtained and characterized in Spain and one of the first European isolates adapted to grow in vitro. The isolation and in vitro production of this B. besnoiti isolate offers a good opportunity to study general aspects of bovine besnoitiosis, including epidemiology, pathogenesis, and diagnosis of this re-emergent disease.

Long- and short-term effects of omitting two weekend milkings on the lactational performance and mammary tight junction permeability of dairy ewes.

The long- and the short-term effects of omitting 2 milkings weekly in early (wk 8 to 14) and mid lactation (wk 15 to 22) were investigated in an experiment conducted with a total of 58 dairy ewes (40 Manchega and 18 Lacaune). Ewes submitted to 2 milking omissions were milked twice daily from Monday to Friday (0800 and 1800 h), and once daily on Saturday and Sunday (1600 and 1400 h, respectively). Individual data were collected for milk yield (weekly), milk composition (biweekly), and somatic cell count (SCC; monthly). Omitting 2 milkings per week in early lactation tended to decrease milk yield in Manchega ewes (-15%), whereas no effects were observed in Lacaune ewes. Averaged milk composition was not modified by milking omissions in either breed. Milking omissions in late lactation did not affect milk yield and milk composition in either breed. The SCC were unaffected by milking omissions in both breeds and in both stages of lactation. A sample of 22 Manchega and 11 Lacaune ewes were used to evaluate the short-term (daily) effects of the 2 milking omissions per week on milk yield and composition, udder health, and tight junction permeability, both in early lactation (wk 12) and in mid lactation (wk 20). Milking omission decreased milk yield, milk fat, and milk lactose contents on the first omission day in both breeds, with losses being more noticeable in early lactation than in mid lactation. Milk protein content and SCC did not vary by effect of the weekend milking omissions. After restoring the twice-daily milking routine on Monday, milk yield showed a compensatory increase that was greater in the large-cisterned than in the small-cisterned ewes, which allowed milk yield to return to Friday values in both breeds. Milk fat content increased during Sunday and Monday, reestablishing Friday values thereafter in both breeds. Weekend milking omissions in early lactation caused tight junction leakiness in both breeds, but mammary epithelia adapted to extended milking intervals when applied successively, recovering their tight state after milking. In mid lactation, the mammary tight junction showed leakiness only in Manchega ewes. In conclusion, 2 milkings per week could be omitted with no negative effects on milk yield, milk composition, and milk SCC values in large-cisterned dairy ewes, as observed in Lacaune and large-cisterned Manchega ewes. Losses in milk yield could be reduced if milking omissions were done from mid lactation in small-cisterned ewes.

Diurnal ACTH and plasma cortisol variations in healthy dogs and in those with pituitary-dependent Cushing's syndrome before and after treatment with retinoic acid.

Daytime variations in ACTH and plasma cortisol were studied in healthy dogs and in dogs with pituitary-dependent hypercortisolism (PDH), before and after treatment with retinoic acid. In control dogs ACTH showed a higher concentration at 8.00 AM and between 2.00 and 6.00 PM, with the lowest concentration registered at 10.00 AM (p<0.05 vs. 8.00 AM and 2.00 PM and p<0.01 vs. 4.00 PM). Cortisol did not show significant differences. In dogs with PDH, ACTH was lower at 8.00 AM (ACTH: p<0.01 vs. 2.00 and 4.00 PM; and p<0.05 vs. 6.00 PM). The lowest cortisol concentration was registered at 8.00 AM and 8.00 PM and the highest at 4.00 PM (p<0.05 vs. 8.00 AM and p<0.01 vs. 8.00 PM). After treatment, the lowest ACTH concentration was registered at 10.00 AM (p<0.01 vs. 2.00 and 4.00 PM). To conclude, the adrenal is desensitized in PDH possibly showing negative in diagnostic tests.

[Effect of calcium hydroxide concentration and cooking time of corn grain (Zea mays L.) nixtamalized, over physicochemical and rheological nixtamal characteristics]. / Efecto de la concentración de hidr6xido de calcio y tiempo de cocción del grano de maíz (Zea mays L.) nixtamalizado, sobre las caracteristicas fisicoquímicas y reológicas del nixtamal.

The effect of calcium hydroxide (Ca(OH)2) concentration and cooking time on physicochemical and pasting properties of maize, during traditional nixtamalization was evaluated. It was observed that the higher the Ca(OH)2 concentration and cooking time the higher the gelatinization temperature. Grain samples treated with 2 g/100 g of Ca(OH)2 and 60 min of cooking time presented higher calcium absorption (0.152 g/100 g) showing a significant increment (approximately 500 g/100 g). Results of X-ray diffraction showed that all the samples had X-ray diffraction pattern of starch type A, showing differences in the intensity of the diffraction as indicated by the percentage of cristallinity. The apparent viscosity of the nixtamal considerably decreased when the processes conditions were higher. Water retention capacity increased with temperature.