Propiedades antioxidantes y antiinflamatorias de huauzontle (Chenopodium berlandieri subsp. nuttalliae, Chenopodiaceae) fermentado por Lactiplantibacillus plantarum Lp22

Background and Aims: Huauzontle (Chenopodium berlandieri subsp. nuttalliae) is a pseudocereal native to Mexico and is part of its culinary tradition. This pseudocereal is recognized for its high nutritional value and components that are associated with beneficial health effects. However, there is currently no literature on the impact that the fermentation process would have on its bioactive properties. Therefore, the aim of this research was to evaluate the effect of fermentation by Lactiplantibacillus plantarum Lp22 in huauzontle seeds suspended in water on their antioxidant and anti-inflammatory properties in vitro. Methods: Huauzontle seeds were suspended in water (0.3%, w/v), inoculated with L. plantarum Lp22 (1%, v/v) at 108 CFU/ml, and allowed to ferment for 24 h at 37 °C. Then, seeds were recovered by filtration, grounded and aqueous extract was obtained. The antioxidant activity of the extracts was determined by the ABTS and ORAC methods. Moreover, the inhibition of the enzymes lipoxygenase (LOX) and trypsin was evaluated and the total phenolic compounds in methanolic extract (Folin-Ciocalteu method) were also determined. Key results: The antioxidant activity represented as mM of Trolox equivalents was 812.50 and 927.50 by ABTS and 1384.32 and 3391.11 for ORAC, for unfermented and fermented huauzontle, respectively (p<0.05). The inhibition of LOX activity was 40.06% and 37.24% for unfermented and fermented huauzontle, respectively, while for trypsin it was 12.53% and 14.38% (p>0.05). Besides, total phenol content was 7.49 and 20.24 mg/ml (p<0.05), respectively. Conclusions: Our findings evidence that fermentation of huauzontle improves the antioxidant and anti-inflammatory properties, which may be associated with increased phenol content. Therefore, its consumption could enhance the antioxidant and immune system of the human organism.Antecedentes y Objetivos: El huauzontle (Chenopodium berlandieri subsp. nuttalliae) es un pseudocereal nativo de México y forma parte de su tradición culinaria. Este pseudocereal es reconocido por su alto valor nutricional y componentes que se asocian a efectos benéficos a la salud. Sin embargo, al momento no se cuenta con literatura sobre el impacto que tendría el proceso de fermentación sobre sus propiedades bioactivas. Por ello, el objetivo de la presente investigación fue evaluar el efecto de la fermentación por Lactiplantibacillus plantarum Lp22, en semillas de huauzontle suspendidas en agua, sobre sus propiedades antioxidantes y antiinflamatorias in vitro. Métodos: Semillas de huauzontle se suspendieron en agua (0.3% p/v), se inocularon con L. plantarum Lp22 (1% v/v) a una concentración de 108 UFC/ml y se fermentaron por 24 h a 37 °C. Finalmente, las semillas fueron recuperadas por filtración, se molieron y del extracto acuoso se determinó la actividad antioxidante por los métodos de ABTS y ORAC. Además, se evaluó la inhibición de las enzimas lipooxigenasa (LOX) y tripsina y se determinó la concentración de fenoles totales (método de Folin-Ciocalteu) en extractos metanólicos. Resultados clave: La actividad antioxidante representada como mM de equivalentes Trolox fue de 812.50 y 927.50 por ABTS, y 1384.32 y 3391.11, para ORAC, para huauzontle no fermentado y fermentado, respectivamente (p<0.05). La inhibición de la actividad de LOX fue de 40.06% y 37.24%, y para tripsina fue de 12.53% y 14.38% (p>0.05), para no fermentado y fermentado, respectivamente, mientras que el contenido de fenoles totales fue de 7.49 y 20.24 mg/ml (p<0.05), respectivamente. Conclusiones: Estos hallazgos indican que la fermentación del huauzontle mejora las propiedades antioxidantes y antiinflamatorias, y que pueden estar asociados con el incremento en el contenido de fenoles, por lo que su consumo podría fortalecer el mecanismo antioxidante y sistema inmune del organismo humano

In Vitro Antioxidant and Antihypertensive Activity of Edible Insects Flours (Mealworm and Grasshopper) Fermented with Lactococcus lactis Strains

The objective of the present study was to evaluate the potential antioxidant and angiotensin converting enzyme inhibition (ACEI) activity of edible insect flours fermented with Lactococcus lactis strains. For the fermentation, mealworm and grasshoppers flours were dissolved (0.5% w/v) in buffer solution (pH 7.0) and individually inoculated (3%) with Lactococcus lactis strains (NRRL B-50571, NRRL B-50572). The samples were incubated for 72 h at 30 ◦C, and the pH was recorded. The degree of hydrolysis (DH) and protein content were determined. The total polyphenol compounds, antioxidant activity (ABTS, DPPH, ORAC, and FRAP), and ACEI of the \u3c3 kDa fractions were ana- lyzed. The pH of the fermented samples decreased to 3.5–3.9 (p \u3c 0.05). The fermented grasshopper flour showed an increased DH (0.42%) and overall higher total polyphenol content (8.23 mg Gallic Acid Equivalent/mL). In general, the highest antioxidant activity was for the grasshopper fractions fermented for 24 h by Lactococcus lactis NRRL B-50572, which also showed 23.47% ACEI inhibition with an IC50 of 0.97 mg/mL. The peptide profile obtained increased after fermentation, being higher for the mealworm flour fermented sample. This study presents, for the first time, the use of specific strains of Lactococus lactis for fermenting edible insect-derived products in the production of bioactive compounds with potential antioxidant and antihypertensive activity

Invited review: Artisanal Mexican cheeses

AbstractThe objective of this review is to present an overview of some of the most commonly consumed artisanal Mexican cheeses, as well as those cheeses that show potential for a protected designation of origin. A description is given for each of these cheeses, including information on their distinguishing characteristics that makes some of them potential candidates for achieving a protected designation of origin status. This distinction could help to expand their frontiers and allow them to become better known and appreciated in other parts of the world. Due to the scarcity of scientific studies concerning artisanal Mexican cheeses, which would ultimately aid in the standardization of manufacturing processes and in the establishment of regulations related to their production, more than 40 varieties of artisanal cheese are in danger of disappearing. To preserve these cheeses, it is necessary to address this challenge by working jointly with government, artisanal cheesemaking organizations, industry, academics, and commercial partners on the implementation of strategies to protect and preserve their artisanal means of production. With sufficient information, official Mexican regulations could be established that would encompass and regulate the manufacture of Mexican artisanal cheeses. Finally, as many Mexican artisanal cheeses are produced from raw milk, more scientific studies are required to show the role of the lactic acid bacteria and their antagonistic effect on pathogenic microorganisms during aging following cheese making

Shelf-life prediction and flavour quality assessment of pasteurized milk by multivariate analysis of dynamic headspace gas chromatographic data

An objective analytical system for shelf-life prediction and flavour quality monitoring of pasteurized milk was established. Dynamic headspace capillary gas chromatography (DH-GC) was optimized to achieve adequate resolution and maximum recovery of volatiles isolated from milk. The simultaneous factor optimization approach used for establishing purge and trap conditions during milk volatile isolation resulted in a method of high sensitivity and reproducibility. Volatiles, psychrotrophic bacterial counts and sensory evaluation were monitored during refrigerated storage of pasteurized milk and multivariate statistics were applied to accumulated data. Multivariate statistical analysis, including principal components regression and linear discriminant analysis was applied to 46 peak areas from 134 chromatograms. Principal components regression of gas chromatographic data and flavour related shelf-life was successful in developing a model for milk shelf-life prediction. The resulting standard error of the estimate of less than two days in shelf-life was an excellent approximation for shelf-life prediction purposes. Linear discriminant analysis was able to classify milk into good, marginal and poor quality or into fruity, rancid and normal flavour groups at a greater than 80% success rate (p<.001) In addition, the zone of “good” or “normal” flavour groups could be visualized in two dimensional canonical plots. Thus any sample deviating from this zone could be considered a defective product. Since any test for keeping quality of milk must emphasize those organisms (initially present in low numbers) that can spoil the product under refrigeration, preliminary incubation before volatile detection was included. Using DH-GC for shelf-life prediction and flavour quality assessment of pasteurized milk, results were available in 20 h (18h preliminary incubation + 2h detection and data processing). Although other rapid instrumental techniques have been proposed for milk shelf-life prediction, dynamic headspace gas chromatography coupled to mass spectrometry (DH-GC-MS) as reported in this thesis is the only method that allows the chemical identification of milk volatiles, which are ultimately the cause of off-flavours and termination of shelf-life. Linear discriminant analysis of gas chromatographic data allowed the identification of milk volatiles that contributed most significantly (p<0.01) to the discrimination among flavour quality groups. The analytical system established in this thesis may prove to be a useful quality control tool for the dairy industry.Land and Food Systems, Faculty ofGraduat

Two potential applications of bacterial cellulose produced by A. xylinum

The focal point of this research project was the development of two applications of cellulose produced from bacterial cultures of Acetobacter xylinum. The first part of this study relates to the culture method. Selection of influential factors for maximum cellulose production in defined medium was carried out by using Taguchis' L₂₇ (3¹³) Fractional Factorial Design. Sucrose and peptone concentrations and pH were found to be significant sources of variation on cellulose yields. Stability of three strains of A. xylinum were assessed over serial transfers of static and swirled cultures. It was concluded that all the strains tested were unstable under swirled conditions, ATCC 14851 being the most stable of the three when grown under static conditions. Growth curves of the three strains were studied and cellulose yields, pH values, sugar utilization, sugar conversion and nitrogen content in dry cellulose were determined over a 4-0 day incubation period. Comparison of the growth curves of A. xylinum strains showed that this organism varied widely in its efficiency of converting sugar to cellulose. The degree of polymerization (D.P.) values of the cellulose synthesized by two of the strains were followed over an incubation period of 32 days. The D.P. values of both strains appeared to decrease with incubation time. The second aspect of this study was to develop a process that integrates cellulose fibrils into a cotton-like fibre. Since A. xylinum naturally produces cellulose in the form of highly fibrillar ribbons, a process was devised to mechanically direct bacterial cells to spin these ribbons into oriented parallel filaments by cultivating the organisms in a straight-line flow path. Aeration rates in the system appeared to influence growth and cellulose yields. Flow mode (intermittent and continuous) and A. xylinum strain were shown to be highly significant sources of variation on the tensile strength of fibres. Optimum conditions for the mercerization treatment of fibres for achieving maximum tensile strength were determined by using a mapping super simplex optimization technique. Tensile properties of mercerized and unmercerized fibres were studied by conducting load-elongation tests to specimen failure. Light and electron microscopy were employed to observe the fine fibre structure. Finally, the third aspect of this study consisted of the development of a process for the purification and hydrolysis of A. xylinum cellulose for the manufacture of microcrystalline cellulose (MCC). Chemical composition and physical properties of the spray dried MCC were determined. The flow behaviour of A. xylinum MCC dispersions was examined and compared to commercial Avicel PH-101 MCC. Rheograms of both MCC dispersions displayed non-Newtonian pseudoplastic behaviour. A. xylinum MCC dispersions were found to have rheological behaviour of the thixotropic type, that is, there was a reversible change in viscosity with time at a constant rate of shear. Results of this study indicated that it is technically feasible to produce synthetic cotton-like fibres by stimulating A. xylinum cells to extrude their cellulose ribbons in a parallel fashion A. xylinum cellulose appeared to be a good source of raw material in the manufacture of microcrystalline cellulose because it is a highly purified form of cellulose which can be made available all year around at any location.Land and Food Systems, Faculty ofGraduat

Péptidos bioactivos derivados de las proteínas de la leche

Las proteínas lácteas son conocidas por tener propiedades nutricionales, funcionales y biológicas que hacen de ellas ingredientes importantes en alimentos funcionales promotores de la salud. Estas propiedades son parcialmente atribuidas a los péptidos bioactivos codificados en las diferentes proteínas de la leche. Los péptidos bioactivos, son inactivos dentro de la secuencia de la proteína intacta y pueden ser liberados por acción de enzimas proteolíticas nativas de la leche, enzimas de bacterias ácido lácticas o de fuentes exógenas, durante la digestión gastrointestinal o durante el proceso del alimento. Los péptidos derivados de las proteínas caseicas y séricas han demostrado poseer varias propiedades bioactivas como lo son: opioide, antihipertensiva, antimicrobial, inmunomodulatoria, transporte de minerales y antitrombótica. Esta revisión presenta una perspectiva de la importancia de las proteínas lácteas en la producción de péptidos bioactivos y sus actividades biológicas, así como de las principales técnicas utilizadas para el aislamiento e identificación de estos péptidos.Milk proteins are known for having a wide range of nutritional, functional and biological properties that make them important ingredients in functional or health promoting foods. These properties are partly attributed to bioactive peptides coded in the different milk proteins. Bioactive peptides are inactive within the protein sequence but may be released by the action of native proteolitic enzymes from milk, enzymes from lactic acid bacteria or from exogenous sources or may be produced during gastrointestinal digestion or processing of foods. Peptides derived from caseins and whey proteins were shown to present several bioactive properties such as opioid, antihypertensive, antimicrobial, immunodulatory, mineral carrier and antithrombotic. This overview presents a perspective of the importance of dairy proteins in the production of bioactive peptides and their biological activities, as well as the main analytical tecniques that have been used for the isolation and identification of these peptides

Péptidos bioactivos derivados de las proteínas de la leche

Las proteínas lácteas son conocidas por tener propiedades nutricionales, funcionales y biológicas que hacen de ellas ingredientes importantes en alimentos funcionales promotores de la salud. Estas propiedades son parcialmente atribuidas a los péptidos bioactivos codificados en las diferentes proteínas de la leche. Los péptidos bioactivos, son inactivos dentro de la secuencia de la proteína intacta y pueden ser liberados por acción de enzimas proteolíticas nativas de la leche, enzimas de bacterias ácido lácticas o de fuentes exógenas, durante la digestión gastrointestinal o durante el proceso del alimento. Los péptidos derivados de las proteínas caseicas y séricas han demostrado poseer varias propiedades bioactivas como lo son: opioide, antihipertensiva, antimicrobial, inmunomodulatoria, transporte de minerales y antitrombótica. Esta revisión presenta una perspectiva de la importancia de las proteínas lácteas en la producción de péptidos bioactivos y sus actividades biológicas, así como de las principales técnicas utilizadas para el aislamiento e identificación de estos péptidos