ABSTRACT
Las proteínas y polisacáridos con frecuencia son utilizados simultáneamente en la industria de alimentos. Las interacciones entre ambos biopolímeros juegan un papel importante en la estructura y estabilidad de muchos alimentos procesados ya que pueden resultar en un sistema con propiedades bioactivas diferentes como ocurre en el caso de las funcionales. Objetivo. Evaluar los cambios en la capacidad antioxidante de un sistema hidrocoloide mixto formado por un hidrolizado enzimático proteico de frijol endurecido (P. vulgaris) y goma modificada de flamboyán (Delonix regia) (SHM). Materiales y métodos. El estudio se hizo entre febrero-octubre, 2014, en Mérida, México. Se modificó enzimáticamente el concentrado proteico de P. vulgaris con Pepsina-Pancreatina® y la goma extraída del flamboyán mediante carboximetilación, preparando dispersiones al 1% de cada uno de los biopolímeros, determinado la fluorescencia intrínseca de Trp (FIT) como indicador de la interacción entre ambos biopolímeros y la actividad antioxidante y quelante del sistema resultante. Resultados. Se obtuvo un hidrolizado proteico extensivo con 28,8% de grado de hidrólisis y una goma de flamboyán con grado de sustitución de 0,91. La mayor interacción entre ambos biopolímeros, se obtuvo empleando una relación 5:1 del SHM a pH 4 de acuerdo con el valor de FIT. Conclusiones. Los sistemas hidrocoloides mixtos preparados con hidrolizado extensivo de las proteínas Phaseolus vulgaris y goma modificada de flamboyán presentaron un incremento en la actividad antioxidante, respecto del hidrolizado dependiendo del mecanismo de oxidación, así como de las condiciones de pH en que se encuentra el sistema y la interacción entre ambos componentes(AU)
Proteins and polysaccharides are frequently used simultaneously in the food industry. The interactions between both biopolymers play an important role in the structure and stability of many processed foods since they can result in a system with different bioactive properties as in the case of functional ones. Objective. Evaluate the changes in the antioxidant capacity of mixed hydrocolloid system formed by a hard to cook bean (P. vulgaris) protein enzymatic hydrolyzate and modified flamboyant gum (Delonix regia) (SHM). Materials and methods. The study was conducted from February to October 2014 in Merida, Mexico. For this, the protein concentrate of P. vulgaris was treated with Pepsin-Pancreatin® and the gum extracted from the flamboyant were modified enzymatically by carboxymethylation, preparing 1% dispersions of each of the biopolymers, determining the intrinsic Trp fluorescence (FIT) as an indicator of the interaction between both biopolymers and the antioxidant and chelating activity of the resulting system. Results. The main results indicated that an extensive protein hydrolyzate with 28.8% degree of hydrolysis and a flamboyant gum with a substitution degree of 0.91 were obtained. The greatest interaction between both biopolymers was obtained using a 5:1 ratio of SHM to pH 4 according to the FIT value. Conclusions. The mixed hydrocolloid systems prepared with extensive hydrolyzate of the hard to cook P. vulgaris and modified flamboyant gum proteins showed an increase in antioxidant activity, compared to the hydrolyzate depending on the oxidation mechanism, as well as the pH conditions used and interaction between both component(AU)
Subject(s)
Polysaccharides , Protein Stability , Food Handling , Fabaceae , Antioxidants , Biopolymers , Food Industry , ColloidsABSTRACT
To prepare and identify ACE-inhibitory peptides originated from sesame seed protein, peptides with strong ACE-inhibitory activities were obtained via the optimization of protease and hydrolysis conditions, and these peptides were purified and identified by membrane separation, gel filtration, and liquid chromatography-mass spectrometry. Results showed that the dual-enzyme comprised alcalase and trypsin with the enzyme activity ratio of 3:7 was suitable to produce ACE-inhibitory peptides. The highest ACE-inhibitory activity of 98.10 ± 0.26% was obtained at the following parameters, pH 8.35, E/S ratio of 6,145 U/g, and hydrolysis time of 4.4 hr. ISGAQPSLR and VVISAPSK ranked the first and second ACE-inhibitory activity among 15 identified ACE-inhibitory peptides. Both peptides influenced ACE via binding with the S1 pocket, S2 pocket, and Zn2+ ion. ISGAQPSLR even impacted the S1' pocket. ISGAQPSLR and VVISAPSK acted as a competitive and noncompetitive inhibitor, respectively. ACE-inhibitory peptides derivated from sesame seed protein have potential applications in functional food. PRACTICAL APPLICATIONS: Although sesame seed protein is proven as the precursor of ACE-inhibitory peptide, preparing ACE-inhibitory peptide from sesame seed protein is still suffering from insufficient information on hydrolysis condition and the peptide sequence. Therefore, the performance of the typical protease on preparing ACE-inhibitory peptide from sesame seed protein has been evaluated, the effect of the amino acid composition of sesame seed protein and cleavage specificity of protease on the generation of ACE-inhibitory peptide has been investigated, hydrolysis conditions have been optimized, the peptide sequence has been identified to illuminate the effect of sesame seed protein fraction on the formation of ACE-inhibitory peptide and discuss the structural characteristics. ACE-inhibitory peptides originating from sesame seed protein could apply in functional food. It is promising for dual-enzyme hydrolysis to utilize in preparation of high-value bioactive peptides.
Subject(s)
Protein Hydrolysates , Sesamum , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Hydrolysis , Peptides , SeedsABSTRACT
Reducing the manifestations of food allergy by the inclusion of specialized foods in the nutrition of children and adults suffering from this disease is an important problem. The aim was to obtain and characterize in vitro food protein hydrolysates to evaluate their use in specialized foods with reduced potential allergenicity. MATERIAL AND METHODS: Whey protein concentrate (WPC) and chicken egg protein (CEP) and enzymes such as pancreatin and alkalase have been used. Proteolysis of proteins was carried out in an FA-10 fermenter for 3 hours at an enzyme : substrate ratio of 1:50 in dry matter, at optimal pH and temperature for pancreatin and alkalase. Enzymes were inactivated at +75 °C and fermentolizate was ultrafiltered. The solutions were concentrated by reverse osmosis and freeze-dried. The molecular weight distribution of the peptide fractions was evaluated by HPLC. Residual antigenicity was determined by the method of indirect enzyme-linked immunosorbent assay and expressed as the fold of antigenicity reduction relative to the original protein. RESULTS AND DISCUSSION: During WPC proteolysis with pancreatin the hydrolyzate was obtained with a fold reduction of antigenicity of 2.3×103 relative to the initial WPC. A decrease in antigenicity of 4.7×104 times was achieved with proteolysis of WPC by alkalase. The combination of WPC fermentolysis with pancreatin or alkalase followed by ultrafiltration reduced the content of high molecular weight peptides with a mass more than 8.7 kDa. The multiplicity of decrease in antigenicity with respect to the starting protein was 1.64×105 and 1.90×105, respectively. After repeated ultrafiltration the reduction in antigenicity of the obtained WPC alkalase or pancreatin hydrolysate was more than 1.0×106 and more than 5.0×105, respectively. The decrease in antigenicity of the CEP hydrolyzate obtained with proteolysis by alkalase and ultrafiltration compared to the initial CEP was 1.0×105 times, and 5.0×105 times when we used repeated ultrafiltration. CONCLUSION: A significant decrease in the content of high molecular weight peptides and a decrease in the antigenicity of peptide mixtures based on WPC and CEP to the values that permit their use in hypoallergenic products is achieved by combining proteolysis and double ultrafiltration through a UF10 membrane.
Subject(s)
Egg Proteins, Dietary/chemistry , Foods, Specialized , Protein Hydrolysates/chemistry , Whey Proteins/chemistry , Animals , Chickens , PeptidesABSTRACT
Antidiabetic properties of vanadium are known more than 100 years, however the researches of specific therapeutic usage of vanadium were conducted only in the last two decades. Along with, the organic vanadium compounds are more harmless in comparison with inorganic vanadium salts. Thus, the development of method of obtaining the organic source of vanadium with high bioavailability is prospective field. Aim of the work was to obtain and provide the physical-chemical characterization of vanadium complex with enzymatic hydrolysate of soy protein isolate (SPI), obtained by one-stage enzymatic hydrolysis. MATERIAL AND METHODS: The complex was obtained at room temperature: 10% water solution of SPI was mixed with 25% solution of vanadium salt (VOSO4×Ñ H2O) in ratio 10:1 (in dry matter). The reaction was kept during 1 h at constant mixing with pH kept at 7.0- 7.1 with 1.0 M NaOH. The concentration of vanadium was determined in dry product by means of inductively coupled plasma mass-spectrometry. The chromatograms of SPI and V-SPI were obtained by means of size-exclusion high-pressure liquid chromatography, and then were integrated by weight method in the range of free till full column volume. RESULTS AND DISCUSSION: The obtained complex of vanadium with SPI enzymatic hydrolysate (V-SPI) was water-soluble and contained 15.8 mg of vanadium per gram of product dry weight. Analysis of the molecular weight distribution of the peptide fractions of the original SPI enzymatic hydrolysate and the V-SPI complex showed that more than 87% of the vanadium complex was in peptide fractions with molecular weights more than 4.1 kD, including more than 75% of vanadium contained in fractions with molecular weights from 14.6 to 4.1 kD. CONCLUSION: The experimental evaluation in vivo will be the next stage of this research. The complex bioavailability and its effects on carbohydrate and lipid metabolism of Wistar rats with obesity will be evaluated.