African mesquite elicits neuroprotective activity against quaternary metal mixture -induced olfactory bulb-hippocampal oxido-inflammatory stress via nrf2-hmox-1pathway.

African mesquite AM is widely used as an anti-inflammatory agent in sub-Sahara Africa especially Nigeria. Given its strong anti-inflammatory potency, this study has evaluated the neuroprotective properties of AM in the hippocampus HIP and olfactory bulb OB of rats exposed to Cd, As, Hg, and Pb. Twenty-five albino Sprague Dawley rats were randomly divided into five groups in this experiment. Group 1, the control received only water. Group 2 received heavy metal mixture HMM (PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg), for 60 days. Groups 3, 4, and 5 were treated with HMM along with AM at doses of 500, 1000, and 1500 mg/kg, respectively. AM decreased the Cd, As, Hg, and Pb levels in OB and HIP, restored the activities of antioxidants, Hmox-1, reduced the activities of AChE, NRF2 and NFkB and improved histopathology.

Application of the SeDeM system for the preparation of antiparasitic tablets from mesquite flour for use in sheep.

The use of herbal medicine to treat various diseases is becoming increasingly important as an alternative therapy. Numerous plants have been traditionally used for different purposes, including antiparasitic in humans and animals. Diseases caused by gastrointestinal parasites in ruminants, especially by the nematode Haemonchus contortus, cause large economic losses to the producers, whether by complications of the diseases or the cost of treatment. The main way of handling nematodiasis is by administering anthelmintic drugs, but their excessive use has the disadvantage of causing drug resistance; therefore, an alternative is the use of herbal medicine for this purpose. Mesquite (Prosopis spp.) has been used in Mexico to treat gastrointestinal diseases attributed to helminths. The present study aimed to characterize the rheological properties of mesquite flour using the SeDeM Expert System to determine its suitability for tablet production by direct compression. Direct compression technology facilitates the tableting process by reducing manufacturing costs. The results of the present study indicate that mesquite flour can be processed by direct compression. The latter could allow the manufacturing of economic tablets to treat infections by H. contortus in ruminants.

Muffin-Type Bakery Product Based on Mexican Mesquite (Prosopis spp.) Flour: Texture Profile, Acceptability, and Physicochemical Properties.

In this research, muffin-type bakery products were developed based on wheat flour (WF) and mesquite flour (MF) in the following proportions: WFMF 90:10, WFMF 75:25, and WFMF 50:50. The products were characterized based on various properties in which it was possible to observe that the water activity (aw) did not show a significant change with the increase in the concentration of MF. In addition, the increase in the concentration of MF modified the sensory properties (color, odor, flavor, texture, and acceptance), further decreasing the luminosity and increasing the values of the a* and b* coordinates. Moreover, in the texture profile analysis, it was found that the increase in the MF concentration increased hardness, fracturability, and gumminess and decreased adhesiveness and cohesiveness. All the previously mentioned changes were more evident in the WFMF50:50 and, to a lesser degree, in WFMF75:25. In general, in most evaluations realized, the WFMF90:10 treatment was the most similar to the control (without MF). However, WFMMF75:25 provided a higher protein and fiber content and a lower fat content. Finally, it is possible to use the flour obtained from the mesquite fruit to make bakery products since it is an important source of food due to the wide distribution of mesquite in the country.

Green Synthesis of Mesquite-Gum-Stabilized Gold Nanoparticles for Biomedical Applications: Physicochemical Properties and Biocompatibility Assessment.

Using cytotoxic reducing and stabilizing agents in the synthesis of gold nanoparticles (AuNPs) limits their use in biomedical applications. One strategy to overcome this problem is using "green" synthesis methodologies using polysaccharides. In the present study, we propose a green methodology for synthetizing AuNPs with mesquite gum (MG) as a reducing agent and steric stabilizer in Gold(III) chloride trihydrate aqueous solutions to obtain biocompatible nanoparticles that can be used for biomedical applications. Through this method, AuNPs can be produced without using elevated temperatures or pressures. For synthetizing gold nanoparticles coated with mesquite gum (AuNPs@MG), Gold(III) chloride trihydrate was used as a precursor, and mesquite gum was used as a stabilizing and reducing agent. The AuNPs obtained were characterized using UV-Vis spectroscopy, dynamic light scattering, transmission electron microscopy, scanning transmission electron microscopy, and FT-IR spectroscopy. The stability in biological media (phosphate buffer solution), cytotoxicity (MTT assay, hematoxylin, and eosin staining), and hemocompatibility (Hemolysis assay) were measured at different concentrations and exposure times. The results showed the successful synthesis of AuNPs@MG with sizes ranging from 3 to 30 nm and a zeta potential of -31 mV. The AuNPs@MG showed good colloidal stability in PBS (pH 7.4) for up to 24 h. Finally, cytotoxicity assays showed no changes in cell metabolism or cell morphology. These results suggest that these gold nanoparticles have potential biomedical applications because of their low cytotoxicity and hemotoxicity and improved stability at a physiological pH.

A Thorough Examination of the Solution Conditions and the Use of Carbon Nanoparticles Made from Commercial Mesquite Charcoal as a Successful Sorbent for Water Remediation.

Water pollution has invaded seas, rivers, and tap water worldwide. This work employed commercial Mesquite charcoal as a low-cost precursor for fabricating Mesquite carbon nanoparticles (MUCNPs) using a ball-milling process. The scanning electron energy-dispersive microscopy results for MUCNPs revealed a particle size range of 52.4-75.0 nm. The particles were composed mainly of carbon with trace amounts of aluminum, potassium, calcium, titanium, and zinc. The X-ray diffraction peaks at 26.76 and 43.28 2θ° ascribed to the (002) and (100) planes indicated a crystalized graphite phase. Furthermore, the lack of FT-IR vibrations above 3000 cm-1 showed that the MUCNPs were not functionalized. The MUCNPs' pore diameter, volume, and surface area were 114.5 Ǻ, 0.363 cm3 g-1, and 113.45 m2 g-1. The batch technique was utilized to investigate MUCNPs' effectiveness in removing chlorohexidine gluconate (CHDNG) from water, which took 90 min to achieve equilibrium and had an adsorption capacity of 65.8 mg g-1. The adsorption of CHDNG followed pseudo-second-order kinetics, with the rate-limiting step being diffusion in the liquid film. The Langmuir isotherm dominated the CHDNG adsorption on the MUCNPs with a correlation coefficient of 0.99. The thermodynamic studies revealed that CHDNG adsorption onto the MUCNPs was exothermic and favorable, and its spontaneity increased inversely with CHDNG concentration. The ball-milling-made MUCNPs demonstrated consistent efficiency through regeneration-reuse cycles.

Antifungal In Vitro Activity of Phoradendron sp. Extracts on Fungal Isolates from Tomato Crop.

Synthetic chemicals are mainly used for the control of fungal diseases in tomato, causing the phytopathogens to generate resistance to the chemical active ingredient, with a consequent risk to human health and the environment. The use of plant extracts is an option for the control of these diseases, which is why the main objective of this research was to study an alternative biocontrol strategy for the management of plant diseases caused by fungi through obtaining polyphenol extracts from mistletoe plants growing on three different tree species-mesquite (Prosopis glandulosa), cedar (Cedrus), and oak (Quercus), which contain flavones, anthocyanins, and luteolin. The overall chemical structure of the obtained plant extracts was investigated by RP-HPLC-ESI-MS liquid chromatography. The antifungal effect of these extracts was examined. The target phytopathogenic fungi were isolated from tomato plantations located in Altamira, Tamaulipas, Mexico. The microorganisms were characterized by classical and molecular methods and identified as Alternaria alternata, Fusarium oxysporum, Fusarium sp., and Rhizoctonia solani.

The Use of Removed Mesquite Brush as a Fiber Replacement in Silage Production.

Mesquite (Prosopis L.) is considered an invasive browse species in most of the American Southwest. Mechanical intervention removes yields an excess of organic debris. Anecdotal evidence in the past has supported using such browse as feed for livestock. Thus, our objectives were to (1) determine the nutritive value and fermentation characteristics of silage produced with mesquite biomass, and (2) evaluate solvent treatment of mesquite biomass prior to ensiling. In Experiment 1, we evaluated mesquite inclusion rate (0, 250, 500, 750, or 1000 g kg−1 DM), length of fermentation (28, 56, or 84 d), and silage inoculant. In Experiment 2, we evaluated the effects of mesquite pre-treatment with acid (H2SO4) or alkali (NaOH) solutions. Concentrations of NDF, ADF, and ADL, as well as IVTD, decreased (p < 0.05) with increasing mesquite inclusion. However, 250 g mesquite kg−1 DM did not differ from grass silage. There was no effect (p > 0.05) of inoculation, though increasing length of incubation did increase (p < 0.05) VFA production and decrease (p < 0.05) silage pH. Solvent treatment did not improve ensiling properties. Results are interpreted to mean that mesquite biomass may be effectively incorporated into silage at levels up to 250 g kg−1.

Identification of Allergenic Proteins in Velvet Mesquite (Prosopis velutina) Pollen: An Immunoproteomics Approach.

Velvet mesquite (Prosopis velutina) is a native legume of the southwestern United States and northwestern Mexico, contributing significantly to the desert ecosystem and playing key ecological roles. It is also an important cause of allergic respiratory disease widely distributed in the Sonoran, Chihuahuan, and Mojave Deserts. However, no allergens from velvet mesquite pollen have been identified to date. Pollen proteins were extracted and analyzed by one- and two-dimensional electrophoresis and immunoblotting using a pool of 11 sera from mesquite-sensitive patients as the primary antibody. IgE-recognized protein spots were identified by mass spectrometry and bioinformatics analysis. Twenty-four unique proteins, including proteins well known as pollen, food, airway, or contact allergens and four proteins not previously reported as pollen allergens, were identified. This is the first report on allergenic proteins in velvet mesquite pollen. These findings will contribute to the development of specific diagnosis and treatment of mesquite pollen allergy.

Reproductive disruption in adult female and male rats prenatally exposed to mesquite pod extract or daidzein.

Phytoestrogens are considered to be endocrine disruptors, since they can alter the endocrine system, thus disturbing many reproductive events. The intake of diets containing a high content of phytoestrogens has increased worldwide in human populations and in domestic animals. Phytoestrogens in maternal blood can pass through the placenta to the fetus in high amounts and can have long-term organizational effects. Mesquite (Prosopis sp) is a leguminous plant widely used to feed several livestock species, and is also used in the human diet. In this study we assessed the effects of exposure to mesquite pod extract during the periconception and pregnancy periods on the reproduction of male and female descendants. The females of three experimental groups received one of the following treatments: 1) vehicle injection; 2) mesquite pod extract or 3) the isoflavone daidzein during the periconception and pregnancy periods. Estrous cyclicity, sexual behavior and hormones, as well as uterine and vaginal epithelia were evaluated in the female descendants. In the males, sexual behavior and hormones, apoptosis in testicular cells and sperm quality were evaluated. In females the following was observed: alterations in estrous cycles, decreased sexual behavior, estradiol and progesterone levels, increased uterine and vaginal epithelia. In males, we observed a decrease in sexual behavior, testosterone and sperm quality, and apoptosis increased in testicular cells. All these effects were similar to those caused by daidzein. These results indicate that prenatal exposure to mesquite pod extract or daidzein, administered to females before and during pregnancy, can disrupt normal organizational-activational programming of reproductive physiology in female and male descendants.

Prosopis juliflora piperidine alkaloid extract levels in diet for sheep change energy and nitrogen metabolism and affect enteric methane yield.

BACKGROUND: Ionophore antibiotics improve the efficiency of energy metabolism, which has driven their use as a feed additive in ruminants for decades. Currently, they have not been approved in many countries, generating a challenge for the immediate search for plant extracts with a similar mode of action on rumen metabolism. This study evaluated the effects of enriched Prosopis juliflora (mesquite) piperidine alkaloid extract (MPA) levels as an alternative phytoadditive to sodium monensin (MON) in sheep. RESULTS: The MPA diet did not differ from MON with regard to nutrient intake. A quadratic effect (P < 0.05) was observed for organic matter and neutral detergent fibre digestibility, with respective maximum point at 25.40 and minimum point at 0.95 mg kg-1 MPA. The MPA levels linearly decreased (P < 0.05) faecal nitrogen loss. MPA did not differ from MON with regard to nutrient digestibility, and MPA levels increased (P < 0.05) the proportion of digestible energy and metabolizability from dietary gross energy. The MPA levels linearly decreased (P < 0.05) enteric CH4 production, the yield showing lower (P < 0.05) energy loss as CH4 than MON. CONCLUSION: The results show that MPA levels of 17.3 and 27.8 mg kg-1 are enteric CH4 inhibitors and enhance energy and protein utilization, indicating a promising alternative to MON for ruminants. © 2022 Society of Chemical Industry.

Woody-plant encroachment: Precipitation, herbivory, and grass-competition interact to affect shrub recruitment.

Woody-plant encroachment is a global phenomenon that has been affecting the southwestern United States since the late 1800s. Drought, overgrazing, herbivory, and competition between grasses and shrub seedlings have been hypothesized as the main drivers of shrub establishment. However, there is limited knowledge about the interactions among these drivers. Using a rainfall manipulation system and various herbivore exclosures, we tested hypotheses about how precipitation (PPT), competition between grasses and shrub seedlings, and predation affect the germination and first-year survival of mesquite (Prosopis glandulosa), a shrub that has encroached in Southern Great Plains and Chihuahuan Desert grasslands. We found that mesquite germination and survival (1) increased with increasing PPT, then saturated at about the mean growing season PPT level, (2) that competition between grasses and shrub seedlings had no effect on either germination or survival, and (3) that herbivory by small mammals decreased seedling establishment and survival, while ant granivory showed no effect. In addition to its direct positive effect on survival, PPT had an indirect negative effect via increasing small mammal activity. Current models predict a decrease in PPT in the southwestern United States with increased frequency of extreme events. The non-linear nature of PPT effects on Mesquite recruitment suggests asymmetric responses, wherein drought has a relatively greater negative effect than the positive effect of wet years. Indirect effects of PPT, through its effects on small mammal abundance, highlight the importance of accounting for interactions between biotic and abiotic drivers of shrub encroachment. This study provides quantitative basis for developing tools that can inform effective shrub management strategies in grasslands and savannas.

Prosopis glandulosa persistence is facilitated by differential protection of buds during low- and high-energy fires.

Rangelands worldwide have experienced significant shifts from grass-dominated to woody-plant dominated states over the past century. In North America, these shifts are largely driven by overgrazing and landscape-scale fire suppression. Such shifts reduce productivity for livestock, can have broad-scale impacts to biodiversity, and are often difficult to reverse. Restoring grass dominance often involves restoring fire as an ecological process. However, many resprouting woody plants persist following disturbance, including fire, by resprouting from protected buds, rendering fire ineffective for reducing resprouting woody plant density. Recent research has shown that extreme fire (high-energy fires during periods of water stress) may reduce resprouting capacity. This previous research did not examine whether high-energy fires alone would be sufficient to cause mortality. We created an experimental framework for assessing the "buds-protection-resources" hypothesis of resprouting persistence under different fire energies. In July-August 2018 we exposed 48 individuals of a dominant resprouting woody plant in the region, honey mesquite (Prosopis glandulosa), to two levels of fire energy (high and low) and root crown exposure (exposed vs unexposed) and evaluated resprouting capacity. We censused basal and epicormic resprouts for two years following treatment. Water stress was moderate for several months leading up to fires but low in subsequent years. Epicormic and basal buds were somewhat protected from low- and high-energy fire. However, epicormic buds were protected in very few mesquites subjected to high-energy fires. High-energy fires decreased survival, caused loss of apical dominance, and left residual dead stems, which may increase chances of mortality from future fires. Basal resprout numbers were reduced by high-energy fires, which may have additional implications for long-term mesquite survival. While the buds, protection, and resources components of resprouter persistence all played a role in resprouting, high-energy fire decreased mesquite survival and reduced resprouting. This suggests that high-energy fires affect persistence mechanisms to different extents than low-energy fires. In addition, high-energy fires during normal rainfall can have negative impacts on resprouting capacity; water stress is not a necessary precursor to honey mesquite mortality from high-energy fire.

Mesquite pod (Prosopis juliflora) meal on meat quality of pasture-finishing lambs.

This study was carried out to validate the inclusion of up to 750 g/kg of mesquite pod (Prosopis juliflora) meal in the diet and evaluate the effects on carcass characteristics and meat quality for lambs finished in pasture. Forty male, non-castrated, crossbred Santa Inês lambs, with an initial body weight (24.2 ± 3.1 kg), and approximately 120 days old were used. The animals were kept in a total area of 4 ha, divided in four paddocks of 0.62 ha each (10 animals/paddocks), on pastures of Massai (Panicum maximum cv. Massai) with drinkers and feeders during the finishing phase. Dietary treatments based on mesquite pod meal inclusion levels (g/kg of dry matter): CON, without mesquite pod meal; MPM25, 250 g/kg of mesquite pod meal; MPM50, 500 g/kg of mesquite pod meal; and MPM75, 750 g/kg of mesquite pod meal. No treatment effect were detected (P > 0.05) for carcass measures, carcass characteristics, chemical composition of longissimus thoracis muscle, tissue composition, and lipid oxidation. Lamb meat color values, such as lightness (L*) and yellowness (b*), were not affected (P > 0.05) by mesquite pod meal inclusion on the diets, whereas for redness (a*), HUE-angle, and chroma were influenced (P < 0.05). Palmitic acid had a quadratic effect, while oleic acid, eicosatrienoic acid, saturated fatty acids, monounsaturated fatty acids, and PUFA:SFA had a linear course (P < 0.05). In conclusion, the mesquite pod meal can be used as an energy feed source up to 750 g/kg of dry matter in the diet, without changing the carcass characteristics and meat quality of lambs finished in pasture.

Green Bean, Pea and Mesquite Whole Pod Flours Nutritional and Functional Properties and Their Effect on Sourdough Bread.

In this study, proximal composition, mineral analysis, polyphenolic compounds identification, and antioxidant and functional activities were determined in green bean (GBF), mesquite (MF), and pea (PF) flours. Different mixtures of legume flour and wheat flour for bread elaboration were determined by a simplex-centroid design. After that, the proximal composition, color, specific volume, polyphenol content, antioxidant activities, and functional properties of the different breads were evaluated. While GBF and PF have a higher protein content (41-47%), MF has a significant fiber content (19.9%) as well as a higher polyphenol content (474.77 mg GAE/g) and antioxidant capacities. It was possible to identify Ca, K, and Mg and caffeic and enolic acids in the flours. The legume-wheat mixtures affected the fiber, protein content, and the physical properties of bread. Bread with MF contained more fiber; meanwhile, PF and GBF benefit the protein content. With MF, the specific bread volume only decreased by 7%. These legume flours have the potential to increase the nutritional value of bakery goods.

Modification of Branched Polyethyleneimine Using Mesquite Gum for Its Improved Hemocompatibility.

In the present study, the modification of branched polyethyleneimine (b-PEI) was carried out using mesquite gum (MG) to improve its hemocompatibility to be used in biomedical applications. In the copolymer synthesis process (carboxymethylated mesquite gum grafted polyethyleneimine copolymer (CBX-MG-PEI), an MG carboxymethylation reaction was initially carried out (carboxymethylated mesquite gum (CBX-MG). Subsequently, the functionalization between CBX-MG and b-PEI was carried out using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as crosslinking agents. The synthesis products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Thermogravimetric analysis showed that CBX-MG and CBX-MG-PEI presented a lower decomposition temperature than MG. The CBX-MG-PEI has a high buffer capacity in the pH range of 4 to 7, similar to the b-PEI. In addition, the CBX-MG-PEI showed an improvement in hemocompatibility in comparison with the b-PEI. The results showed a non-hemolytic property at doses lower than 0.1 µg/mL (CBX-MG-PEI). These results allow us to propose that this copolymer be used in transfection, polymeric nanoparticles, and biomaterials due to its physicochemical and hemocompatibility properties.

Genetic insights into the globally invasive and taxonomically problematic tree genus Prosopis.

Accurate taxonomic identification of alien species is crucial to detect new incursions, prevent or reduce the arrival of new invaders and implement management options such as biological control. Globally, the taxonomy of non-native Prosopis species is problematic due to misidentification and extensive hybridization. We performed a genetic analysis on several Prosopis species, and their putative hybrids, including both native and non-native populations, with a special focus on Prosopis invasions in Eastern Africa (Ethiopia, Kenya and Tanzania). We aimed to clarify the taxonomic placement of non-native populations and to infer the introduction histories of Prosopis in Eastern Africa. DNA sequencing data from nuclear and chloroplast markers showed high homology (almost 100 %) between most species analysed. Analyses based on seven nuclear microsatellites confirmed weak population genetic structure among Prosopis species. Hybrids and polyploid individuals were recorded in both native and non-native populations. Invasive genotypes of Prosopis juliflora in Kenya and Ethiopia could have a similar native Mexican origin, while Tanzanian genotypes likely are from a different source. Native Peruvian Prosopis pallida genotypes showed high similarity with non-invasive genotypes from Kenya. Levels of introduced genetic diversity, relative to native populations, suggest that multiple introductions of P. juliflora and P. pallida occurred in Eastern Africa. Polyploidy may explain the successful invasion of P. juliflora in Eastern Africa. The polyploid P. juliflora was highly differentiated from the rest of the (diploid) species within the genus. The lack of genetic differentiation between most diploid species in their native ranges supports the notion that hybridization between allopatric species may occur frequently when they are co-introduced into non-native areas. For regulatory purposes, we propose to treat diploid Prosopis taxa from the Americas as a single taxonomic unit in non-native ranges.

Antifungal Activity In Vitro and In Vivo of Mesquite Extract (Prosopis glandulosa) Against Phytopathogenic Fungi.

Fungi are the primary infectious agents in plant crops and many post-harvest fungal diseases of fruit and vegetables causing significant economic losses worldwide. Here, the antifungal effect of Prosopis glandulosa extract (PgE) against phytopathogenic fungi was evaluated. The effect with PgE (5, 4, 2, 1, 0%) as AI (%) and radial growth rate reduction (Kr %) were determined in vitro in Colletotrichum gloeosporoides, Fusarium oxysporum, Rhizopus oryzae and R. stolonifer (1 × 105 spores/mL). The phytopathogenicity of fungal strains was performed under in vivo conditions (room temperature, 25-30 °C and refrigeration, ~ 4 °C) by fruit surface inoculation method on strawberries, tomatoes and carrots by recording the development of mycelial growth, necrosis, soft rot and dehydration symptoms showed on each fruit at 14 days. The extract (5%) showed the highest AI against C. gloesporioides (~ 96%), and F. oxysporum (~ 79%) and growth rate reduction of 74.92% and 64.82% respectively. Likewise, the extract controls the development of phytopathogenicity symptoms against C. gloesporioides and F. oxysporum in vivo conditions, nevertheless, was less efficiency against both Rhizopus species. The P. glandulosa extract represents an efficient, economical, and eco-friendly alternative to preserve the quality of the agricultural products and to increase their shelf life.

Role of the thermal environment in scaled quail (Callipepla squamata) nest site selection and survival.

Temperature is increasingly recognized as an important component of wildlife habitat. Temperature is particularly important for avian nest sites, where extreme temperatures can influence adult behavior, embryonic development, and survival. For species inhabiting arid and semiarid climates, such as the scaled quail (Callipepla squamata), frequent exposure to extreme temperatures may increase the importance of the nest microclimate. Limited data suggest that scaled quail respond to temperature when selecting nest sites, and they are also known to respond to the presence of surface water and shrub cover on the landscape, two resources which may mitigate thermal stress. To better understand the role of temperature in nest site selection and survival, and to evaluate how other landscape resources may benefit nesting quail, we investigated nest site characteristics of scaled quail in southeastern New Mexico, USA. During the breeding seasons of 2018 and 2019 we located nests, monitored nest fate, and recorded thermal and vegetation characteristics at three spatial scales: the nest bowl, the nest microsite (area within 10 m of the nest bowl), and the landscape. We found that nest bowls moderated temperature relative to both the surrounding microsite and the broader landscape, remaining almost 5 °C cooler on average than the surrounding microsite at mid-day. Nest bowls also had taller, greater cover of vegetation compared to both the surrounding microsites and the landscape. Despite apparent selection for cooler temperatures and taller vegetation, these characteristics demonstrated a weak relationship with nest survival. Rather, nest survival was positively influenced by proximity to surface water and honey mesquite (Prosopis glandulosa), with survival decreasing with increasing distance from these features. Although the mechanism for this relationship is unclear, our results support the importance of temperature for nest site selection of ground-nesting birds in semiarid landscapes, and suggest further exploration of landscape-level sources of thermal mitigation.

Effects of intense pulsed light and gamma irradiation on Bacillus cereus spores in mesquite pod flour.

This study was conducted to evaluate the inactivation of Bacillus cereus spore in mesquite flour with intense pulsed light (IPL) and gamma radiation. The physical, chemical, and toxicity of treated mesquite flour were also investigated. The results showed that up to 3.51 log10CFU/g B. cereus spore inactivation was achieved with 8 kGy of gamma radiation, and up to 1.69 log10CFU/g reductions could be achieved after 28s of catalytic IPL exposure. Although chemometric analysis showed 9-hydroxy-10,12-octadecadienoic acid was slightly increased after a 28s-catalytic IPL treatment, the concentration is within the acceptable range. No significant increase in acetic or propionic acids (typical off-flavor volatile compounds) was observed after either treatment. For cytotoxicity, the Caco-2 cell viability analysis revealed that these two technologies did not induce significant cytotoxicity to the treated mesquite flour. Overall, these two technologies exhibit strong potential for the decontamination of B. cereus in mesquite flour.

Thermal Reduction of Bacillus spp. in Naturally Contaminated Mesquite Flour with Two Different Water Activities.

ABSTRACT: Mesquite flour with endogenous high sugar content is often contaminated with Bacillus cereus. The purpose of the present study was to evaluate the thermal resistance of Bacillus spp. in naturally contaminated mesquite flour. Flours with and without adjusted water activity (aw) were treated at various temperatures (100 to 140°C) and times (up to 2 h). Total mesophilic bacteria and Bacillus spp. were enumerated using tryptic soy agar and Brilliance Bacillus cereus Agar, respectively. Results revealed that naturally contaminated Bacillus spp. and other mesophilic bacteria in mesquite flour (aw = 0.34) were highly resistant to heat. To reduce the initial populations (4.75 log CFU/g) of Bacillus spp. to nondetectable levels (<1.18 log CFU/g), thermal treatments of 120°C for 2 h were required. D100°C-values for total mesophilic bacteria were 5.6-fold higher than those of Bacillus spp. With increasing treatment temperature, the difference in D-value between total mesophilic bacteria and Bacillus spp. became smaller. When the aw of flour was adjusted from 0.34 to 0.71, the D-values for Bacillus decreased significantly. Treatment at 100°C for 1 h reduced Bacillus spp. populations to nondetectable levels. Our results demonstrate that naturally present Bacillus spp. in flour are highly resistant to heat, whereas increasing the aw increased their heat sensitivity. The high thermal resistance of microbes in mesquite flour warrants further investigations.