Extraction and characterization of proteins present in concentrates from quality protein maize (QPM)

Quality protein maize (QPM) represents an alternative protein source for food. This work aims to characterize fractions, molecular weights, and thermal stability of the proteins present in QPM protein concentrates obtained by isoelectric precipitation. Flours from two treatments, non-nixtamalized and nixtamalized, as well as three types of maize varieties: Sac Beh (QPM white), Chichén Itzá (QPM yellow), and Blanco Uxmal (control), were obtained. The experiment was conducted using a bifactorial 2x3 design. Four isoelectric precipitation pHs were evaluated, having the highest yield and maximum protein precipitation at pH 2,5 at 4 °C. The relative protein fractions in the maize varieties in both treatments showed more elevated amounts of prolamins (PR) and glutelins (GT) compared to the control. All QPM showed higher GT and lower PR. The denaturing electrophoretic profile (SDS-PAGE) showed molecular weights for the concentrates ranging from 17,6 to 225 kDa (non-nixtamalized), from 12,9 to 132,2 kDa (nixtamalized), and from the fractions with weights from 10,2 to 220,7 kDa. The thermograms showed a change in thermal stability in the concentrates from non-nixtamalized flour; there were no thermal transitions in the nixtamalized ones due to the denaturation of the proteins when obtaining the samples during nixtamalization of all the varieties studied

Propiedades, beneficios y efectos de la guanábana (Annona muricata L.) sobre la glucemia y el cáncer.

Soursop (Annona muricata L.) is a fruit that has presented various benefits to human health. Different parts of the plant have been used in traditional medicine to reduce inflammation, fever, cough, and asthma. The fruit promotes some antihyperglycemic and weight loss activity in the body; additionally, it has been used as an anticancer remedy. Due to all of the above, this work aimed to review and analyze different results of experimental research conducted with different parts of the soursop, considering its glycemic activity and its antitumor effect, for a possible future application. Several articles, journals, and books from virtual servers which contained the characteristics requested for the topic in question were reviewed to prepare this paper. The results showed the presence of certain components such as tannins, flavonoids, catechins, quercetins, and polyphenols. Among the active principles most present in soursop are the annonaceous acetogenins; these natural phytochemicals produced in the tree’s roots, bark, stems, and leaves, as well as in the fruit’s seeds, have demonstrated diverse beneficial effects. Leaves, fruits, roots, and seeds have been regarded as components with anti-diabetic effects; some research showed that the daily administration of leaf extract in rats decreased blood levels of glucose, triglycerides, and cholesterol; other studies administered an extract of soursop with ginger for thirty days, showing a decrease in liver damage caused by diabetes mellitus. The acetogenins present in soursop have been studied for their antitumor activity since these compounds can selectively inhibit the growth of cancer cells. The fruit's polyphenols have demonstrated antioxidant effects, which could have co-adjuvants effects in cancer treatments. Despite the benefits, caution should be exercised if ingested in large quantities and for prolonged periods due to potentially adverse effects.La guanábana (Annona muricata L) es un fruto que ha presentado diferentes beneficios a la salud humana. Se han empleado diversas porciones de la planta en medicina tradicional para disminución de inflamación, fiebre, tos y asma. El fruto promueve cierta actividad antihiperglucemiante y adelgazante en el organismo; adicionalmente se ha empleado como remedio anticancerígeno. Debido a lo anterior, el objetivo de este trabajo fue revisar y analizar diversos resultados de investigaciones experimentales realizadas con diferentes partes de la guanábana, para considerar su actividad glucémica y su efecto antitumoral para una posible aplicación a futuro. Para desarrollar el presente trabajo, se revisaron diversos artículos, revistas y libros de servidores virtuales que contenían las características solicitadas para el tema tratado. Los resultados demostraron la presencia de ciertos componentes como taninos, flavonoides, catequinas, quercetinas y polifenoles. Entre los principios activos mayormente presentes en la guanábana están las acetogeninas anonáceas; estos fitoquímicos naturales producidos en las raíces, corteza, tallos y hojas del árbol, así como en las semillas de los frutos, se ha demostrado diversos efectos benéficos. Hojas, frutos, raíces y semillas, han sido considerados componentes con efectos antidiabéticos; ciertas investigaciones demostraron que la administración diaria de extracto de hojas en ratas disminuyó los niveles sanguíneos de glucosa, triglicéridos y colesterol; otros estudios suministraron por treinta días un extracto de guanábana con jengibre, con una disminución en el daño hepático causado por diabetes mellitus. Las acetogeninas presentes en la guanábana, han sido estudiadas por su actividad antitumoral ya que estos compuestos pueden inhibir selectivamente el crecimiento de las células cancerígenas. Los polifenoles del fruto demostraron efecto antioxidante, los cuales pudieran presentar efectos coadyuvantes con los tratamientos contra el cáncer. A pesar de los beneficios, se debe tener precaución en caso de ingerirse en grandes cantidades y por períodos prolongados debido a potenciales efectos adversos

Effects of sequential enzymatic hydrolysis on structural, bioactive and functional properties of Phaseolus lunatus protein isolate

Significant initiatives exist within the global food market to search for new, alternative protein sources with better technological, functional, and nutritional properties. Lima bean (Phaseolus lunatus L.) protein isolate was hydrolyzed using a sequential pepsin-pancreatin enzymatic system. Hydrolysis was performed to produce limited (LH) and extensive hydrolysate (EH), each with different degrees of hydrolysis (DH). The effects of hydrolysis were evaluated in vitro in both hydrolysates based on structural, functional and bioactive properties. Structural properties analyzed by electrophoretic profile indicated that LH showed residual structures very similar to protein isolate (PI), although composed of mixtures of polypeptides that increased hydrophobic surface and denaturation temperature. Functionality of LH was associated with amino acid composition and hydrophobic/hydrophilic balance, which increased solubility at values close to the isoelectric point. Foaming and emulsifying activity index values were also higher than those of PI. EH showed a structure composed of mixtures of polypeptides and peptides of low molecular weight, whose intrinsic hydrophobicity and amino acid profile values were associated with antioxidant capacity, as well as inhibiting angiotensin-converting enzyme. The results obtained indicated the potential of Phaseolus lunatus hydrolysates to be incorporated into foods to improve techno-functional properties and impart bioactive properties

Protein and energy evaluation of detoxified Canavalia seeds as a feedstuff for poultry in the tropics

El Algoritmo de Recocido Simulado, cristalización simulada o enfriamiento simulado, es un algoritmo de búsqueda metaheurística para problemas de optimización; el objetivo general de este tipo de algoritmos es encontrar una buena aproximación al valor óptimo de una función en un espacio de búsqueda grande. A este valor se lo denomina "óptimo local u óptimo global". El nombre e inspiración viene del proceso de recocido del acero y cerámicas, una técnica que consiste en calentar y luego enfriar lentamente el material para variar sus propiedades físicas. El calor causa que los átomos aumenten su energía y que puedan así desplazarse de sus posiciones iniciales (un mínimo local de energía); el enfriamiento lento les da mayores probabilidades de recristalizar en configuraciones con menor energía que la inicial (mínimo global). El método fue descrito independientemente por Scott Kirkpatrick, C. Daniel Gelatt y Mario P. Vecchi en 1983