Inactivation Of Antinutritional Factors Research Articles

Mitigation of antinutritional factors and protease inhibitors of defatted winged bean-seed proteins using thermal and hydrothermal treatments: Denaturation/unfolding coupled hydrolysis mechanism

The inactivation of antinutritional factors, protease inhibitors within winged bean protein was induced by two respective method treatments. The physical method based on steam vapor that was conducted using an autoclave and chemical method consisting on pH-gradients of buffer solutions prepared at respective acidic pH, neutral pH and alkaline pH ranges. The activity of remaining protease inhibitors of bowman birk inhibitor (BBI), and kunitz-trypsin inhibitor (KTI) after and before treatments was enzymatically confirmed using relevant antagonistic trypsin and combined trypsin-α-chymotrypsin digests. The resulting molecular assembly indicating an interval molecular relaxation range of °0.16 < °DA < °0.2 corresponding to reconformation in protein units with volume-mass changes of −2.17 < ∂v' < +2.17 and with denaturation/unfolding efficiency based on heat capacity ΔCp of 36.36 < DE/UF% < 54.67. These structural changes had a great benefit in determining and producing functional protein hydrolysates.

Microwave processing: A way to reduce the anti-nutritional factors (ANFs) in food grains

Traditional and novel food processing methods has been employed to reduce the anti-nutritional factors (ANFs) such as phytic acid, trypsin inhibitors, tannins, saponins and oxalate to enhance the safety and quality of edible grains. Among these, microwave processing has advantage of being fast, consistent, safe, efficient, and green technology for the reduction of the ANFs. Microwave processing power and duration has significant effect on the inactivation of ANFs and needs to be critically evaluated for effective application on food grains. The reduction of heat labile ANFs by microwave heating is due to degradation by heat along with formation of insoluble complex. Pre-treatment such as soaking enhance their reduction through leaching and hydrolysis. The present review illustrates the mechanism, scope, application and future prospects of microwave processing to reduce the different ANFs present in food grains.

Inactivation of antinutritional factors that compose the grain and soybean and losses in the extrusion process

&amp;nbsp; &lt;p class="Default" style="text-align: justify; line-height: 200%;"&gt;Extrusion is a process in which the soybean is plasticized and baked through a process combination&amp;nbsp; that involves high temperature, reduced time, pressure and friction, to inactivate the antinutritional factors present in soybeans, among them factor antitrypsin, chymotrypsin and others. Thus, the study aimed to evaluate losses during extrusion processing of soybean after the reactor output. A total of 10 samples were collected from the final product and then classified into six groups: total sample grain; normal whole; spoiled whole; burnt whole; normal broken, and burnt broken. The analyses were performed based on the quality controls such as moisture; crude protein; soluble protein, and urease. However, the physical-chemical analyses results found for normal whole grain were mostly different (P&amp;nbsp;&amp;lt;&amp;nbsp;0.05) from those found for the other samples evaluated. The burnt broken grains presented lower (P&amp;nbsp;&amp;lt; 0.05) values of humidity, crude protein, soluble protein and urease in relation to those obtained for normal whole grain. It was concluded that after the extrusion process the samples of grains whole normal and broken represent up the largest yield of the final portion (90%) and urease, soluble protein within values parameters required by the National Association of Feed Manufacturers. However 10% of the samples final fraction showed low nutritional value and should be used for other purposes.&lt;/p&gt;&lt;p class="Default" style="text-align: justify; line-height: 200%;"&gt;&amp;nbsp;&lt;/p&gt;&lt;p class="Default" style="text-align: justify; line-height: 200%;"&gt;&amp;nbsp;&lt;/p&gt;&lt;p class="Default" style="text-align: justify; line-height: 200%;"&gt;DOI: http://dx.doi.org/10.14685/rebrapa.v2i1.32&lt;/p&gt;

Effect of Water Content on Thermal Behavior of Freeze-Dried Soy Whey and Their Isolated Proteins

Thermal behavior of lyophilized soy whey (LSW) and whey soy proteins (WSP) at different water contents (WC) was studied by DSC. In anhydrous condition, Kunitz trypsin inhibitor (KTI) and lectin (L) were more heat stable for WSP with respect to LSW sample. The increase of WC destabilized both proteins but differently depending on the sample analyzed. Thermal stability inversion of KTI and L was observed for WSP and LSW at 50.0% and 17.0% WC, respectively, which correspond to the same water-protein content mass ratio (W/P ≈ 1.9). At W/P < 1.9, KTI was more heat stable than L. Before the inversion point, WC strongly modified the peak temperatures (T(p)) of KTI and L for WSP, whereas this behavior was not observed for LSW. The high sugar content was responsible for the thermal behavior of KTI and L in LSW under anhydrous condition and low WC. These results have important implications for the soy whey processing and inactivation of antinutritional factors.

Nutritional and antinutritional aspects of an Argentinian soy flour assessed on weanling rats

Inactivation of antinutritional factors on an Argentinian deffated soy flour was evaluated in relation to its corresponding original soybeans. Residual urease and trypsin inhibitors activities, protein solubility, available lysine and phytic acid showed acceptable levels. The nutritional value of a diet based on the same soy flour was compared with that of a casein-based diet by allowing them to each one of two groups of weanling IIMBeta rats during 28 days. Non-significant differences were obtained between groups comparing both body weight gain per gram of protein intake as well as the results of histometric studies performed on the small intestine. Thus, this soy flour contained appropriately inactivated antinutritional factors and its protein content and quality were nutritionally suitable. Large intestine hypertrophy was revealed within the soy-fed group suggesting increased microbial proliferation attributable to non-digestible oligosaccharides and fiber-like compounds. These compounds, employed by gut microflora as fermentation substrates, would be also responsible for an increased nitrogen excretion in the soy-fed group in relation to controls. This increment of nitrogen excretion significantly lowered the value of apparent nitrogen digestibility in the soy-fed group in relation to the casein-fed control one. Nevertheless, nitrogen apparent digestibility in the soy-fed group was equal or higher than other values reported from distinct treated soy meal-based diets.

Destabilization of pea lectin by substitution of a single amino acid in a surface loop.

Legume lectins are considered to be antinutritional factors (ANF) in the animal feeding industry. Inactivation of ANF is an important element in processing of food. In our study on the stability of Pisum sativum L. lectin (PSL), a conserved hydrophobic amino acid (Val103) in a surface loop was replaced with alanine. The mutant lectin, PSL V103A, showed a decrease in unfolding temperature (Tm) by some 10 degrees C in comparison with wild-type (wt) PSL, and the denaturation energy (delta H) is only about 55% of that of wt PSL. Replacement of an adjacent amino acid (Phe104) with alanine did not result in a significant difference in stability in comparison with wt PSL. Both mutations did not change the sugar-binding properties of the lectin, as compared with wt PSL and with PSL from pea seeds, at ambient temperatures. The double mutant, PSL V103A/F104A, was produced in Escherichia coli, but could not be isolated in an active (i.e. sugar-binding) form. Interestingly, the mutation in PSL V103A reversibly affected sugar-binding at 37 degrees C, as judged from haemagglutination assays. These results open the possibility of production of lectins that are active in planta at ambient temperatures, but are inactive and possibly non-toxic at 37 degrees C in the intestines of mammals.

Destabilisation of pea lectin by substitution of a single amino acid in a surface loop

Legume lectins are considered to be antinutritional factors (ANF) in the animal feeding industry. Inactivation of ANF is an important element in processing of food. In our study on the stability ofPisum sativum L. lectin (PSL), a conserved hydrophobic amino acid (Val103) in a surface loop was replaced with alanine. The mutant lectin, PSL V103A, showed a decrease in unfolding temperature (T m ) by some 10 °C in comparison with wild-type (wt) PSL, and the denaturation energy (ΔH) is only about 55% of that of wt PSL. Replacement of an adjacent amino acid (Phe104) with alanine did not result in a significant difference in stability in comparison with wt PSL. Both mutations did not change the sugarbinding properties of the lectin, as compared with wt PSL and with PSL from pea seeds, at ambient temperatures. The double mutant, PSL V103A/F104A, was produced inEscherichia coli, but could not be isolated in an active (i.e. sugar-binding) form. Interestingly, the mutation in PSL V103A reversibly affected sugar-binding at 37 °C, as judged from haemagglutination assays. These results open the possibility of production of lectins that are activein planta at ambient temperatures, but are inactive and possibly non-toxic at 37 °C in the intestines of mammals.