Trypsin Inhibitor Content Research Articles

Comparative evaluation of standardized ileal amino acid digestibility in protein supplements for piglets1,2

Standardized ileal digestibility (SID) of AA was determined in 6 protein ingredients for piglets. A basal diet based on corn (Zea mays) starch and casein was supplemented with fluid-bed-dried porcine intestinal mucosa hydrolysate, spray-dried porcine intestinal mucosa hydrolysate, soy (Glycine max) protein concentrate, 2 batches of soy protein, or full-fat soybeans. The SID of AA did not differ between the 4 soybean products (P > 0.05). Compared to most SID values in the 4 soybean products, SID of AA were lower in the 2 porcine intestinal mucosa hydrolysates (P ≤ 0.05). In conclusion, although the initial trypsin inhibitor contents in the raw soybeans have not been determined, high SID values in the 4 soybean products indicate that the different processing procedures used to manufacture these products were efficient to inactivate trypsin inhibitors. For most AA in the 2 porcine intestinal mucosa hydrolysates, drying procedure did not affect SID of AA, but SID values were generally lower compared to the 4 soybean products.

Effect of processing on antinutrients and in vitro protein digestibility of the underutilized legume, Vigna unguiculata (L.) Walp subsp. unguiculata

The effects of hydration, cooking, autoclaving, germination and their combination on the reduction/elimination of antinutrients and the improvement of in vitro protein digestibility of the tribal pulse, Vigna unguiculata subsp. unguiculata were investigated. Hydration and germination processes were less effective in reducing l-Dopa and trypsin inhibitor activity. Cooking and autoclaving of presoaked seeds drastically reduced the content of total free phenolics, tannins, phytic acid, hydrogen cyanide, trypsin inhibitors and oligosaccharides. Germination (96 h) process reduced the total free phenolics, tannins, hydrogen cyanide and phytic acid. The combination of germination followed by autoclaving completely eliminated the total free phenolics, tannins, hydrogen cyanide, phytic acid, trypsin inhibitor, oligosaccharides and phytoheamagglutinating activity. The combination process (germination 96 h + autoclaving) improved the in vitro protein digestibility. We concluded that, a prolonged period of germination followed by autoclaving completely destroyed some of the antinutritional factors.

Thermal Inactivation of Soybean Bioactive Proteins

Abstract Inactivation of trypsin inhibitor, lipoxygenase 1, and urease during the processes of dry extrusion, wet extrusion, micronisation, microwave roasting and autoclaving were studied. Cultivars Bosa, ZPS 015, Goyou Kurakake and L93-7290 were used in the experiment. Depending on a technological procedure of processing, kernels were exposed to temperatures from 57 to 150 oC for different time: from 25-30 sec in the process of dry and wet extrusion, to 30 min in autoclaving. The process of dry extrusion had the greatest influence on reduction of the trypsin inhibitor content and inactivation of urease and lipoxygenase 1. During the dry extrusion at 100 oC trypsin inhibitor declined by 74.2 % and the residual activity of a lipoxygenase 1 and urease was only 0.76 i.e. 0.55 %, respectively. Lipoxygenase 1 was the most heat labile enzyme, followed by urease and than trypsin inhibitor.

The effects of fermented soybean meal on immunophysiological and stress-related parameters in Holstein calves after weaning

The present experiment was conducted to investigate the effects of partial substitution of soybean meal (SBM) with fermented SBM (FSBM) on immunophysiological and stress-related parameters in Holstein calves after weaning. Eighteen Holstein calves were randomly assigned to receive either SBM or FSBM (5% of SBM was replaced with FSBM) calf starter and calves were weaned at 42d of age. It was noted that FSBM contained a lower content of trypsin inhibitor but higher crude protein, amino acids, and small-sized peptides than those of SBM. The group fed FSBM calf starter significantly increased body weight gain and intakes of both feed and milk, when compared with those fed SBM calf starter at 4wk of age. Calves fed the FSBM calf starter had significantly lower fecal scores than those fed the SBM calf starter during both pre- and postweaning periods. Calves also had better health scores when fed the FSBM calf starter than those fed SBM during the preweaning period. Weaning challenge significantly increased proinflammatory cytokines, tumor necrosis factor α, IL-1β, and IL-6 levels at 1d postweaning (DPW). The TNF-α and IL-6 levels of the SBM group were significantly higher compared with those of the FSBM group at 3 DPW. Acute phase proteins (serum amyloid A and haptoglobin) in the serum were increased after weaning. Concentrations of serum amyloid A and haptoglobin in calves fed FSBM calf starter were significantly lower than those fed the SBM calf starter at 3 and 5 DPW, respectively. The concentration of cortisol was significantly lower in the FSBM group than that of the SBM group at 3 DPW. Weaning stress did not cause drastic changes in the total serum immunoglobulin levels and composition of peripheral lymphocytes. Our results indicate that FSBM may not only improve growth performance, feed intake, and health conditions during the preweaning period, but also alleviate stress responses, which was indicated by reduced induction of stress hormone, proinflammatory cytokines, and acute phase proteins in Holstein calves after weaning.

Chemical composition of tempeh from soybean cultivars specially developed for human consumption

Tempeh is a food obtained by fermentation of soybean grains by the fungus Rizophus oligosporus. It is a traditional Indonesian food that presents benefits for human health protecting against diarrhea and chronic diseases. Tempeh processing includes dehulling, cooking, inoculation, and fermentation. In this study, chemical characteristics of tempeh prepared with soybean cultivars specially developed for human consumption (BRS 216, BRS 232, BRS 257, and BRS 267) were investigated. Soybean grains and tempeh obtained from these cultivars were analyzed for oil, protein, antinutrional factors, and isoflavone content. Cultivar BRS 216 presented the highest protein content in the grains (36.81%) and in tempeh (51.99%). On average, the protein content in tempeh increased 16% in relation to that of soybean grains. Isoflavone content was higher in the grains than in tempeh with significant differences among the cultivars. However, the aglycones content increased about 50% in tempeh (49.00 mg.100 g-1 on average) compared to that of raw material (soybean grains - 21.49 mg.100 g-1, on average). The content of Kunitz trypsin inhibitor (KSTI) reduced 83% in tempeh, on average, as compared to the value found in the grains. Phytic acid content was similar in both tempeh and the grains.

Standardised ileal digestibility of crude protein and amino acids of UK-grown peas and faba beans by broilers

In view of the increasing interest in home-grown legumes as components of diets for non-ruminant livestock and in an attempt to reduce the reliance on imported soya bean meal (SBM), two experiments were conducted to evaluate samples of peas and faba beans for their standardised ileal digestibility (SID) of amino acids determined with young broiler chicks. Experiment 1 evaluated six faba bean and seven pea cultivars and Experiment 2 evaluated two faba bean and three pea cultivars as well as a sample of soya bean meal provided as a reference material. Peas and beans were added at 750g/kg as the only source of protein/amino acids in a semi-synthetic diet containing the inert marker titanium dioxide; SBM was added, in a control diet, at 500g/kg. Each diet was fed to six replicates of a cage containing two Ross-type broilers for 96h at which point birds were culled allowing removal of ileal digesta. Chemical analyses allowed the calculation of the coefficient of SID of amino acids. There were no differences between samples of the same pulse species (P>0.05) but peas had higher values (P<0.05), similar to SBM, than beans. Trypsin inhibitor content (expressed as g trypsin inhibitor units/mg sample) of all pea samples was low and in the range 0.83–1.77mg/kg. There was relatively little variation in bean tannin content and composition amongst the coloured-flowered varieties; however, the white-flowered cultivar had no tannins. There was no correlation between tannin content and coefficient of SID. The content of SID of amino acids (g/kg legume) was higher in SBM when compared with peas and beans by virtue of having higher total concentrations.

Purificação parcial de inibidores de tripsina de sementes de Caesalpinia ferrea e Swartzia polyphylla e o efeito dos extratos protéicos sobre fungos fitopatogênicos

Sementes de leguminosas apresentam alta concentração de inibidores de tripsina; estas proteínas estão envolvidas no metabolismo celular e também em mecanismos de defesa vegetal. A fim de confirmar ou não, a possível ação fungicida destas proteínas a partir de extratos de sementes de leguminosas arbóreas, o objetivo deste estudo foi detectar inibidores de tripsina em sementes de Caesalpinia ferrea (CfTI) e Swartzia polyphylla (SpTI) e testar os extratos contra os fungos fitopatogênicos Colletotrichum guaranicola, Corynespora cassiicola, Fusarium oxysporum e Sclerotium rolfsii, avaliando o crescimento micelial e a esporulação. Para tanto, amostras do material biológico vegetal, sementes finamente pulverizadas, foram submetidas à extração em NaCl 150 mM. Os extratos protéicos foram parcialmente purificados em coluna Sephadex G-100, submetidos à detecção dos inibidores e SDS-PAGE (12,5%) e, utilizados nos bioensaios contra os fungos. O perfil eletroforético revelou uma única banda em CfTI e oito bandas em SpTI. Os extratos de C. ferrea e S. polyphylla exibiram efeito na diminuição da esporulação dos fungos testados, mas S. rolfsii foi inibido apenas por C. ferrea. Quanto ao crescimento micelial, os dois extratos tiveram efeito sobre F. oxysporum e S. rolfsii, ao passo que C. guaranicola foi inibido apenas por S. polyphylla, e C. cassiicola por C. ferrea. Concluiu-se que sementes de C. ferrea e S. polyphylla apresentam inibidores de tripsina. Além disso, os resultados sugerem que estas espécies de leguminosas arbóreas são promissoras no que concerne à prospecção de fungicidas naturais, uma vez que os extratos diminuíram o crescimento micelial e a esporulação de C. guaranicola, C. cassiicola, F. oxysporum e S. rolfsii.

Nutritional quality and safety of wheat‐soy composite flour chapattis

PurposeUnleavened bread (chapatti and roti) is the staple diet of people in the Indo‐Pak region, utilizing almost 90 percent of the wheat produced in the region. To improve the nutrition of chapattis, normally legume flour is used in the region. The purpose of the current study is to assess the nutritional quality and safety of chapattis supplemented with soy flour.Design/methodology/approachWheat and soybean were procured and soy flour was prepared. Trypsin inhibitor contents and mineral contents of different flour and chapattis prepared were determined. Chapattis were prepared from different flour blends and whole wheat flour. To assess the quality and acceptability, the chapattis were presented to a panel of judges and the sensory evaluation was carried out for color, taste, aroma, chew ability, folding ability and overall acceptability characteristics. The data obtained for each parameter were subjected to statistical analysis to determine the level of significance.FindingsThe phytic acid and trypsin content were higher in un‐autoclaved soy flour supplement composite flour. The defattening of soy flour also increases the level of these anti‐nutrients in chapattis. The phytate and trypsin content of composite flour decreased as a result of baking. The protein, fiber and ash contents of composite flour increased while moisture content and nitrogen free extracts (NFE) decreased by the addition of soy flour. Mineral contents of chapattis except Mn increased by the incorporation of soy flour. The chapattis were found acceptable by the panel of judges at 10 percent replacement level of whole wheat flour by soy flour.Practical implicationsThe results of the study indicate that 10 percent supplementation of soy flour in wheat flour was found acceptable by consumers as it did not affect the sensory attribute. For improved nutrition and to combat protein energy malnutrition, chapattis flour can be supplemented with soy flour.Originality/valueThe soy supplementation of wheat flour will improve the nutritional quality of the chapatti flour as soy flour is rich in high‐quality protein and mineral. The anti‐nutritional can be minimized or inactivated by autoclaving the soybean.

Effects of Cooking Conditions on the Protein Quality of Chub Mackerel Scomber japonicus

The effects of cooking method (grilling, frying, steaming, and microwaving) on the proximate composition and protein quality of chub mackerel Scomber japonicus treated with 2, 6, and 10% sodium chloride (NaCl) brine were investigated. Moisture content decreased in all cooked samples from 60.22% in the raw sample to 48.7% in the fried samples. Brine (10% NaCl) treatment recorded the highest moisture loss. All cooked samples showed a decrease in fat content, except fried samples. Protein content increased in all cooked samples, from 47.21% in the raw sample to 63.87% in the grilled sample. Brine treatment resulted in the highest degree of fat oxidation (thiobarbituric acid-reactive substances), which was highest in the fried samples and lowest in the microwaved samples. The trypsin inhibitor (TI) concentration was highest in the microwaved samples and lowest in the fried samples. In all samples, 6% salt treatment caused the lowest TI level and the highest in vitro protein digestibility. In vitro digestibility increased from 79.4% in the raw sample to 86.43% in the fried samples. The total essential amino acids of all cooked samples increased. Results suggested that grilling and steaming had beneficial effects on the protein quality of chub mackerel.

Rheological characterization of raw and roasted green gram pastes

Rheological properties of raw and roasted green gram pastes have been determined at different moisture contents (52–56 g/100 g) and temperatures (10–40 °C). These pastes exhibit shear-thinning behavior and possess yield stress. Cross model is suitable (0.986 ≤ r ≤ 0.999, p ≤ 0.01) to explain the flow characteristics of the pastes. The Cross model parameters such as zero-shear viscosity and relaxation time are sensitive to concentration of solids in the paste as well as temperature of measurement, and vary widely between raw and roasted samples. The effect of temperature on the apparent viscosity follows the Arrhenius type relationship (r ≥ 0.961, p ≤ 0.01). The viscoamylographic indices and trypsin inhibitor content are also different for raw and roasted samples. The roasted pastes show a smooth and cohesive microstructure. The optimized sample of roasted flour having a moisture content of 55 g/100 g is suitable as bread spread with appropriate stickiness and spreadability.

Bio-modification of soybean meal with Bacillus subtilis or Aspergillus oryzae

Abstract The nutritional quality of soybean meal (SBM) was improved via solid-state fermentation using the Aspergillus oryzae or Bacillus subtilis microbes in conical flasks. Compared to the control, the protein content in fermented soybean meal (FSBM) was increased by 8.37% and 0.34% with B. subtilis and A. oryzae , respectively, and their trypsin inhibitor contents were reduced by 96% and 82%, respectively. Furthermore, the concentrations of small-size proteins in FSBM were increased from 5% to 63% and from 5% to 35% by B. subtilis and A. oryzae , respectively, while the concentrations of large-size proteins were reduced from 40% to 2% and from 40% to 8%, respectively. Significantly lower levels of antigenic proteins were observed in FSBM compared to SBM. Also, FSBM exhibited a higher level of DPPH free radical-scavenging activity than did the control. The in vitro digestibility of crude protein by pepsin (IVDI) was increased strongly by fermentation. Fermentation with B. subtilis mediated a higher IVDI than did fermentation with A. oryzae . However, the in vitro digestibility of crude protein by pepsin and trypsin (IVDII) derived from B. subtilis and A. oryzae showed no significant difference from that of the control. In general, the protein content and anti-oxidation activity were increased and trypsin inhibitors and antigenic proteins were reduced in FSBM culture, indicating that it could be used as a new protein source in animal diets.

Effects of radiation therapy on tissue and serum concentrations of tumour associated trypsin inhibitor and their prognostic significance in rectal cancer patients

BackgroundWe have previously demonstrated that elevated concentrations of tumour-associated trypsin inhibitor (TATI) in both tumour tissue (t-TATI) and in serum (s-TATI) are associated with a poor prognosis in colorectal cancer patients. It was also found that s-TATI concentrations were lower in patients with rectal cancer compared to patients with colon cancer. In this study, we investigated the effects of neoadjuvant radiotherapy (RT) on concentrations of t-TATI and s-TATI in patients with rectal cancer.MethodsTATI was analysed in serum, normal mucosa and tumour tissue collected at various time points in 53 rectal cancer patients enrolled in a case-control study where 12 patients received surgery alone, 20 patients 5 × 5 Gy (short-term) preoperative RT and 21 patients 25 × 2 Gy (long-term) preoperative RT. T-TATI was analysed by immunohistochemistry and s-TATI was determined by an immunofluorometric assay. Mann-Whitney U test and Wilcoxon Z (Z) test were used to assess t-TATI and s-TATI concentrations in relation to RT. Spearman's correlation (R) test was used to explore the associations between t-TATI, s-TATI and clinicopathological parameters. Overall survival (OS) according to high and low t-TATI and s-TATI concentrations was estimated by classification and regression tree analysis, Kaplan-Meier analysis and the log rank test.ResultsRT did not affect concentrations of t-TATI or s-TATI. In patients receiving short-term but not long-term RT, s-TATI concentrations were significantly higher 4 weeks post surgery than in serum drawn prior to surgery (Z = -3.366, P < 0.001). T-TATI expression correlated with male gender (R = 0.406, P = 0.008). High t-TATI expression in surgical specimens was associated with a significantly shorter OS (P = 0.045). S-TATI concentrations in serum drawn at all time points were associated with an impaired OS (P = 0.035 before RT, P = 0.001 prior to surgery, P = 0.043 post surgery). At all time points, s-TATI correlated with higher age (P < 0.001-0.021) and with increased s-creatinine concentrations assessed prior to surgery (P = 0.041).ConclusionsThe results presented here further validate the utility of t-TATI and s-TATI as prognostic biomarkers in patients with rectal cancer, independent of neoadjuvant RT.

Amino acid digestibility in heated soybean meal fed to growing pigs1

Heat treatment of soybean meal (SBM) is necessary to reduce the concentration of trypsin inhibitors, but excessive heat treatment may reduce AA concentration and digestibility because AA can be destroyed by the Maillard reaction. The objective of this experiment was to determine the effects of heat treatment of SBM on apparent ileal digestibility and standardized ileal digestibility (SID) of AA by growing pigs. A source of conventional dehulled SBM (48.5% CP) was divided into 4 batches. One batch was not additionally heated, 1 batch was autoclaved at 125°C for 15 min, 1 batch was autoclaved at 125°C for 30 min, and 1 batch was oven-dried at 125°C for 30 min. Four SBM-cornstarch diets were formulated, and each of the 4 batches of SBM was used as the sole source of dietary AA in 1 diet. A N-free diet was used to estimate basal endogenous losses of AA. Ten growing barrows with an initial BW of 25.3 ± 2.0 kg were individually fitted with a T-cannula in the distal ileum. Pigs were allotted to treatments in a replicated 5 × 5 balanced Latin square design with 5 diets and 5 periods. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. Results of the experiment indicated that the apparent ileal digestibility and SID of CP and all AA decreased linearly (P < 0.01) as the time of autoclaving increased from 0 to 30 min. The concentration of furosine and the color of samples of SBM indicated that autoclaving resulted in a Maillard reaction in the SBM. However, oven drying at 125°C for 30 min did not change (P > 0.10) the SID of CP and AA in the SBM or the furosine concentration, and the color in the oven-dried sample indicated that this sample was not heat damaged. In conclusion, the digestibility of all AA in autoclaved SBM is linearly reduced as the autoclaving time increases from 0 to 30 min. The reason for these changes is most likely that autoclaving at 125°C results in Maillard reactions in SBM.

Study on One-Step Solid-State Fermentation of Soybean Meal

one-step solid state fermentation process was studied. The orthogonal experiment was carried out to study the effect of the inoculation ratio, the inoculum size, the fermentation water ratio, the fermentation temperature and the fermentation period in this experiment. Optimum conditions were as follows: Bacillus licheniformis: yeast: Lactobacillus plantarum = 2:1:1, the inoculation was 6.0g/100g, the water ratio was 1:0.8, the anaerobic fermentation temperature was 36°C, the fermentation period was 96h. The content of trypsin inhibitor was measured and analyzed before and after the fermentation of soybean under the conditions.

Substitution of fish meal with raw or treated cowpea (Vigna unguiculata L Walp, IT86-D719) meal in diets for Nile tilapia (Oreochromis niloticus L.) fry

Two feeding experiments were carried out to evaluate the effect of partial substitution of fish meal (FM) with raw or heat-treated cowpea Vigna unguiculata L. Walp var. IT86-D719 seeds on growth performance, digestibility and pancreas tissue in Nile tilapia (Oreochromis niloticus L.) fry. Experiment 1 involved six isonitrogenous and isocaloric diets: four containing different concentrations of raw, whole cowpea meal (protein basis), a positive control with FM as sole protein source and a negative with cowpea meal as sole protein source. Substitution at up to 200 g kg−1 had no significant effect on production parameters, although growth was negatively affected in the negative control because of seed antinutritional factor content. Experiment 2 evaluated the effect of heat treatment (oven drying at 48 °C; hot air drying at 70 °C; or autoclaving at 119 °C) and/or seed dehulling using diets containing 200 g kg−1 cowpea meal presoaked in water. Only autoclaving eliminated trypsin inhibitor and lectin contents, independent of dehulling. Histological analysis indicated no histological changes in pancreas tissue. Raw or treated cowpea meal can replace FM in tilapia fingerling diets at up to 200 g kg−1 protein content without significantly affecting productive parameters or pancreas tissue.

Ileal Digestibility of Amino Acids in Conventional and Low-Kunitz Soybean Products Fed to Weanling Pigs

An experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in four sources of full-fat soybeans (FFSB) and in one source of soybean meal (SBM). The FFSB had different concentrations of trypsin inhibitor units (TIU) and included two sources of conventional FFSB, and two sources of a soybean variety that was selected for a reduced concentration of the Kunitz trypsin inhibitor. The conventional FFSB was either low temperature-processed (LT-FFSB-CV; 37.7% CP, 35.4 TIU/mg) or high temperature-processed (HT-FFSB-CV; 40.5% CP, 4.4 TIU/mg). The low-Kunitz FFSB was also either low temperature-processed (LT-FFSB-LK; 36.2% CP, 23.5 TIU/mg) or high temperature-processed HT-FFSB-LK; (38.2% CP, 4.0 TIU/mg). The SBM contained 47.5% CP and 3.20 TIU/mg. Twelve weanling barrows (initial BW: ) were fitted with a T-cannula in the distal ileum. Pigs were allotted to a replicated Latin square design with six diets and six periods per square. Five diets were prepared using each of the soybean sources as the only source of AA in the diet. An N-free diet was also included in the experiment to measure basal endogenous losses of AA. The two low temperature-processed FFSB had lower (p

Effects of citric acid, alpha-galactosidase and protease inclusion on in vitro nutrient release from soybean meal and trypsin inhibitor content in raw whole soybeans

An experiment was conducted to evaluate the effects of citric acid (CA) and commercial preparations of α-galactosidase (α-GAL) and protease on in vitro nutrient release from soybean meal (SBM) and trypsin inhibitor (TI) content in raw defatted whole soybeans. An in vitro model was used to simulate the chicken's digestive process in the crop, the stomach (proventriculus and gizzard) and the small intestine. Soybean meal and ground whole soybeans were used as substrates. Graded levels of either α-GAL (0–13,792 units/kg) or protease (0–888 units/kg) and 0 or 20 g CA per kg were added to the substrates in a factorial arrangement. Reducing sugars (RS) and α-amino N were measured at the end of the crop phase, the stomach phase, and the whole phase (crop through small intestine). Trypsin inhibitor content was measured at the end of the stomach phase. Increasing α-GAL levels linearly (P<0.01) increased the release of RS in both the crop and the whole phases. Addition of CA with α-GAL further increased enzyme activity, resulting in a significant interaction (P<0.01). Linear increases (P<0.05) in α-amino N occurred with increasing doses of protease at the crop, the stomach and the whole phases. Inclusion of CA in the incubation mixture also increased (P<0.05) α-amino N at all three phases. An interactive effect (P<0.01) between protease and CA was observed only in the crop phase. Neither protease nor CA had an effect on TI activity in raw soybeans. The results suggest that α-GAL and protease may be useful in hydrolyzing the carbohydrates and proteins, respectively, in SBM and the effects of these two enzymes may be enhanced by acidifying the diet.

Environmental effect on yield, composition and technological seed traits of some Italian ecotypes of grass pea (Lathyrus sativus L.)

Grass pea seeds are a good source of vegetable proteins, but the presence of toxic and antinutritional compounds represents a barrier to their large-scale use as food or animal feed. How much growing location and/or seasonal climate might affect the storage of these factors has been little investigated. Fourteen Italian ecotypes of grass pea were cultivated in two locations in southern Italy characterised by different climatic conditions. The seven ecotypes with the best yields and/or seed quality were investigated for a further two growing seasons. From a statistical point of view the physicochemical and nutritional traits among ecotypes were not the same from one year to the next. Moreover, a significant positive correlation was found between β-oxalyl-diamino-propionic acid and trypsin inhibitor contents. The lowest levels of both these compounds were associated with the highest amount of rainfall during the plant vegetative cycle. Principal component analysis of the data showed that the overall seed composition was affected by the growing location. Consequently, each grass pea genotype should also be carefully investigated in relation to different environments before being considered for release as safe for widespread human or animal consumption.

Characterization of proteins from kernel of different soybean varieties

Total soybean proteins, storage proteins, glycinin (11S) and β-conglycinin (7S) fractions and their respective subunits in seven soybean varieties were analyzed. In this work we also present the correlation between concentration and activity of bioactive proteins, lipoxygenase and proteinase inhibitors. Glycinin and β-conglycinin comprise about 750 g kg(-1) of the bean storage protein and as such account for both quantity and quality of the kernel protein. The 11S concentration of the varieties studied ranged from 503.4 to 602.9 g kg(-1) and those of 7S varied from 178.2 to 230.6 g kg(-1) of total extractable proteins. The ratio of 11S/7S proteins varied from 2.43 to 3.29 among the varieties. A very strong positive correlation was found between the concentration of Kunitz trypsin inhibitor and activity of total trypsin inhibitor (r = 0.96). However, lipoxygenase concentration did not show a strong correlation with lipoxygenase activity. It appears that among the seven ZP soybean genotypes there are genotypes with different amounts of subunits that should be bred in the future for a desired level of protein components.

Influência do processamento na qualidade proteica de novos cultivares de soja destinados à alimentação humana

OBJETIVO: Avaliar o efeito do processamento na qualidade proteica de cultivares de soja destinados à alimentação humana. MÉTODOS: As dietas foram preparadas a partir dos grãos dos cultivares Embrapa 48, BRS 213, BRS 155 e UFVTN 105, que receberam tratamento térmico em estufa a 130 e 150°C, com posterior retirada ou não da casca para a produção das farinhas. Realizou-se ensaio biológico para avaliação de quociente de eficiência proteica, quociente de eficiência proteica líquida e digestibilidade verdadeira. RESULTADOS: Os valores de razão proteica líquida e digestibilidade das farinhas foram inferiores aos da caseína. As farinhas de soja com casca tratadas a 150ºC apresentaram melhores índices de qualidade proteica que as farinhas sem casca tratadas a 130ºC. O quociente de eficiência proteica e o quociente de eficiência proteica líquida dos cultivares Embrapa 48 e BRS 155 foram maiores (p&lt;0,05) que os demais. O cultivar UFVTN 105 apresentou maior (p&lt;0,05) digestibilidade quando processado a 130ºC. No tratamento a 150ºC, a digestibilidade foi inferior (p&lt;0,05) para os cultivares BRS 213 e BRS 155. Não foi observada melhoria na digestibilidade da proteína de soja quando utilizado o cultivar com baixo teor de inibidor de tripsina (BRS 155) em comparação com o cultivar convencional (Embrapa-48). CONCLUSÃO: O tratamento térmico e a retirada ou não da casca interferiram na qualidade proteica de novos cultivares de soja destinados à alimentação humana, com melhores resultados para as farinhas com casca produzidas a partir de grãos tratados a 150ºC por 30 minutos. O tratamento térmico favoreceu a qualidade proteica das farinhas de soja convencionais, que obtiveram valores semelhantes aos dos cultivares sem inibidor de tripsina e superiores aos dos cultivares sem lipoxigenase.