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Bacterial, nutritional, and bioactive compositions of fermented sweet potato leaves (SPL) were investigated. Three samples were utilized: control (C), natural fermentation (NF), and probiotic fermentation (PF). Bacterial composition was assessed by high-throughput sequencing. Lactobacillus plantarum and Enterococcus durans were identified in NF. Lactobacillus plantarum was also found in PF, showing a relative abundance of 90.2%. Polyphenol composition determined by HPLC changed considerably during NF decreasing its concentration to a value of 6.69 mg/g dw compared to the value found in C (42.77 mg/g dw). PF maintained the polyphenol concentration (38.64 mg/g dw) but some interconversion between polyphenols seems to occur. ABTS radical scavenging capacity value was similar in C and PF, demonstrating no changes in antioxidant activity. During PF antioxidant activity was maintained, and angiotensin-converting enzyme inhibitory activity was even improved. Fermentation was a good process for SPL. According to the parameters assessed, PF was better than NF. Novelty impact statement: The effect of natural and probiotic fermentations on the bacterial composition, nutritional, and bioactive composition of sweet potato leaves was compared. Results showed that fermentation was a good process for sweet potato leaves. According to the parameters assessed, probiotic fermentation was better than natural fermentation., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The objective of this study was to formulate a beverage based on amaranth proteins, stable and nutritious. The process of obtaining the beverage was based on the existing knowledge about starch separation techniques and techno-functional properties of the amaranth proteins. Gums, gellan and xanthan were added to the protein extract and it was heat-treated at 80 °C during 20 min. A beverage with a composition similar to skim cow’s milk was obtained (3.42 ± 0.08; 0.60 ± 0.06; 1.9 ± 0.4; 0.43 ± 0.01; 3 and 90.58 ± 0.01% for proteins, lipids, fiber, ashes, carbohydrates and water, respectively). Thermal treatment caused the denaturation and aggregation of the proteins, while the addition of gums induced a decrease in the sensitivity to heat treatment of the proteins. Formation of protein aggregates and gum-protein complexes was characterized by electrophoresis, differential scanning calorimetry, and particle size distribution. Heat treatment and addition of gums generated macrocomplexes with enhanced absolute value of ζ-potential, which contributed to the high colloidal stability of amaranth-based beverage. This beverage is suitable for vegans, celiac patients, and lactose intolerants., Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo en Criotecnología de Alimentos

This paper investigated the effects of heat treatment (75 °C × 18 s and 100 °C × 18 s) and wet-mix total solids level (TS: 50 and 60%, w/w) on the physicochemical and techno-functional properties of model infant milk formula (IMF) powders. IMF produced from wet-mixes with 50% TS preheated at 75 °C (50%-75°C) exhibited the longest wettability time (55 ± 2 s) and the poorest flowability, explained by the small particle size (D [4;3]= 16.5 ± 2.29 μm) and low poured bulk density (0.27 ± 0.02 g/cm3). Larger particles were obtained by increasing both pasteurization temperature and TS. Further, powders from 60% TS wet-mixes showed less particle size uniformity, leading to better packing and higher bulk densities. 50%-75°C powders also showed the lowest onset glass transition temperature, which may affect its storage stability. Wettability time was reduced by increasing TS from 50 to 60% or by increasing pre-heating temperature from 75 to 100 °C. However, as observed by low-field nuclear magnetic resonance, the increase in the pasteurization temperature slowed down the global rehydration process. The flowing properties of the powders improved by increasing TS level of the wet-mix. In conclusion, the pre-spray drying wet-mix processing variables, pasteurization temperature and TS level, had a major effect on the physicochemical and functional properties of the IMF powders. It is crucial to understand how variations in the process parameters affect these powder characteristics, due to their functional, technological and economic importance.

This study investigated the effects of total solids (TS) in the wet-mix and pasteurisation temperature on the whey protein (WP) denaturation, rheological behaviour, emulsifying properties and available lysine content of a model infant milk formula (IMF). IMF with 50% or 60% (w/w) TS were produced by wet-mix process and pasteurised at 75 °C or 100 °C for 18 s. Measurements were taken after dispersion, pasteurisation, homogenisation and spray-drying of wet-mix. Pasteurisation at 100 °C caused extensive WP denaturation (above 80%) and increased the viscosity. Available lysine content was 52% higher in powdered IMF obtained from wet-mixes pasteurised at 75 °C compared to 100 °C. A significant reduction in energy consumption could be achieved by producing IMF from 60% TS wet-mixes pasteurised at 75 °C, while obtaining powders with less than 7% WP denaturation, no loss of available lysine during processing and post-reconstitution stability for 2 h.

A number of functional foods containing seaweed-derived peptides are currently commercialized. Some seaweed derived peptide-containing products include Wakame peptide® and Nori peptide S®. To develop functional foods with the addition of Ulva spp. peptides, the isolation and identification of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from hydrolysates of this seaweed was performed. Ulva spp. peptides were fractionated and purified sequentially by anion exchange, ultrafiltration, and reversed phase high performance liquid chromatography. The fractions obtained from each analytical step were collected and the in vitro enzyme inhibitory activity was evaluated. The applied purification process increased the in vitro DPP-IV inhibitory activity. The inhibition mechanism of DPP-IV of the most active fraction was evaluated and it was analyzed by MALDI-TOF. A peptide SLAVSVH was identified. It has 57% of hydrophobic residues in their sequence (including Ala and branched chain amino acids), which could be a common feature among inhibitory peptides of DPP-IV. Molecular docking analysis showed that SLAVSVH/DPP-IV complex was stabilized by CH–π interactions between the side chains of Val6 with the indol of Trp629, and between rings of His7 with Trp563. The energy values obtained for the peptide under study indicate that it is a good candidate to inhibit DPP-IV.

In the present work the effect of the presence of soluble and insoluble protein on the stability of oil-water emulsions prepared with amaranth protein isolates (API) was analyzed. For this purpose, four types of emulsions were prepared: API-pH2 and API-pH6.3 dispersions and solutions. At pH 2.0 the amaranth proteins present higher solubility, are denatured and partially hydrolyzed; while at pH 6.3 its solubility is lower and its structure is more similar to the native protein. The soluble proteins present in API-pH2 and API-pH6.3 reduce with equal intensity the interfacial tension. However, the proteins present in API-pH2 are adsorbed twice as fast as those present in API-pH6.3, with equal rearrangement rate at the oil/water interface. Both, solutions and dispersions of API-pH2 and API-pH6.3 allow the formation of oil-in-water emulsions. Flocculation phenomena are evident, particularly in the case of API-pH6.3 dispersions. The calculated creaming-flocculation constant demonstrates that stability of emulsions increase with protein concentration and with the decrease of pH. The behaviour of API-pH2 and API-pH6.3 solutions was similar to that corresponding to the dispersions discarding a negative effect of the insoluble protein on the emulsifying properties of amaranth proteins., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The objective of this work was to develop a new protocol to predict with greater confidence peptides as potential inhibitors of the renin enzyme. For this, free, friendly and rigorous servers developed specifically for peptides as ligands were used. Six peptides (SFNLPILR; FNLPILR; SFNLPIL; QAFEDGFEWVSFK; AFEDGFEWVSFK and VNVDDPSKA) identified in an amaranth hydrolysate obtained with alcalase (hydrolysis degree 21%±4) were used. Two positive (angiotensinogen and IRLIIVLMPILMA) and one negative (a tridecapeptide of alanine) controls were included in the analysis. A protocol was designed to include two consecutive stages was performed using CABS-dock server (http://biocomp.chem.uw.edu.pl/CABSdock) and FlexPepDock server (http:// flexpepdock.furmanlab.cs.huji.ac.il/). Peptides SFNLPILR, FNLPILR and AFEDGFEWVSFK inhibited the enzyme in vitro. The heptapeptide FNLPILR was the most potent inhibitor, with an IC50 of 0.41 mM., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

Las proteínas del suero son sometidas a calor durante la producción de fórmulas infantiles. Su desnaturalización y agregación puede reducir la solubilidad, lo que tiene connotaciones funcionales, tecnológicas y nutricionales en el producto final. En el presente trabajo se estudió el efecto del tratamiento térmico y la presencia de caseína, lactosa e inulina, en las proporciones utilizadas en fórmulas infantiles, en la solubilidad proteica. Se prepararon dispersiones acuosas de WPI, con o sin caseinato de calcio (CAS), inulina (INUL) y lactosa (LAC). Las dispersiones se analizaron antes (STT) y luego del tratamiento térmico (TT) a 66ºC, 75ºC y 85ºC durante 30 o 60 min. Los sistemas STT con mayor solubilidad fueron WP (89,3±2,0 %) y WP-INUL (89,6±1,8 %). La solubilidad de WP disminuyó paulatinamente con el TT a partir de 75ºC-30 min, alcanzando una solubilidad mínima de 41,7±1,2 % luego de 85ºC-60 min. WP-INUL mostró la misma tendencia. WP-LAC redujo su solubilidad con el TT, aunque la caída en la solubilidad luego del TT 75ºC-60 min fue menor que en el sistema sin lactosa. La presencia de CAS impidió la pérdida de solubilidad proteica, que aumentó con el TT hasta 75ºC-60 min (alcanzando 100 % en el sistema WP-CAS). Whey proteins are heated during production of infant formulae. The denaturation and aggregation of whey proteins can reduce their solubility, with functional, technological and nutritional implications. In the current work, the effect of heat treatment and presence of casein, lactose and inulin, at the proportions used during production of infant formula, on the protein solubility was studied. Aqueous whey protein isolate (WPI) dispersions with or without calcium caseinate (CAS), inulin (INUL) and lactose (LAC) were prepared. Unheated (UH) and heated (HT) dispersions at 66, 75 and 85 ℃ for 30 and 60 min were analyzed. The UH systems with the highest solubility were WP (89.3 ± 2.0% w/w) and WP - INUL (89,6 ± 1,8% w/w). Solubility of WP decreased with HT from 75 ℃ - 30 min, reaching the minimum solubility (41,7 ± 1.2 % w/w) after 85 ℃ - 60 min. WP - INUL showed the same trend. Solubility of WP - LAC decreased with HT, although the solubility loss after HT 75 ℃ - 60 min was lower than in the system without lactose. CAS presence prevented the loss of protein solubility, which increased with HT until 75 ℃ - 60 min (reaching 100% w/w in the WP - CAS system). This study provides relevant information on the role of the main non - fatty ingredients of infant formulae in the loss of solubility of whey proteins. As proteínas do soro de leite são submetidas ao calor durante a produção de fórmulas para bebês. Sua desnaturação e agregação podem reduzir a solubilidade, que possui conotações funcionais, tecnológicas e nutricionais no produto final. Neste trabalho estudamos o efeito do tratamento térmico e a presença de caseína, lactose e inulina, nas proporções utilizadas nas fórmulas infantis, na solubilidade das proteínas. Dispersões aquosas de isolado de proteínas do soro de leite (WPI) foram preparadas, com ou sem caseinato de cálcio (CAS), inulina (INUL) e lactose (LAC). As dispersões foram analisadas antes (STT) e após tratamento térmico (TT) a 66 ℃, 75 ℃ e 85 ℃ por 30 ou 60 min. Os sistemas STT com maior solubilidade foram WP (89,3 ± 2,0% m/m) e WP - INUL (89,6 ± 1,8 % m/m). A solubilidade do WP diminuiu gradualmente com o TT de 75 ℃ - 30 min, atingindo uma solubilidade mínima de 41,7 ± 1,2 % m/m após 85 ℃ - 60 min. WP - INUL mostrou a mesma tendência. O WP - LAC reduziu sua solubilidade com TT, embora a queda na solubilidade após TT 75 ℃ - 60 min foi menor do que no sistema sem lactose. A presença de CAS impediu a perda de solubilidade da proteína, que aumentou com o TT até 75 ℃ - 60 min (atingindo 100% m/m no sistema WP - CAS). Este estudo fornece informações relevantes sobre o papel dos principais ingredientes não gordurosos das fórmulas infantis na perda de solubilidade das proteínas do soro de leite Fil: Rodríguez Arzuaga, M.. Laboratorio Tecnológico del Uruguay; Uruguay Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Abraham, Analia Graciela. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina

The aim of this work was to evaluate the ability of broken rice, an underutilized industrial by-product, as a potential functional and health promoting ingredient. With this purpose, the ability to inhibit the angiotensin converting enzyme and renin of a rice protein hydrolyzate (RPH) obtained from a high-protein variety of broken rice (var. Nutriar FCAyF) was analyzed (IC₅₀ = 0.87 and 2.7 mg/mL, respectively). RPH was separated by gel permeation chromatography and in a second purification step by RP-HPLC. The sequence of antihypertensive peptides presented in two RP-HPLC fractions was analyzed. Peptides capable of interacting with the active sites of both enzymes were identified. In this study, we demonstrate that the hydrolysis treatment improves functional and biological properties of rice proteins. Protein preparations obtained from a by-product of rice industry, such as broken rice, are a promising ingredient with potentially good biological properties., Facultad de Ciencias Agrarias y Forestales, Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo en Criotecnología de Alimentos

A rapid method of screening for lactic acid bacteria with high inhibitory power was developed. The methodology employed was the agar-diffusion assay, which was standardized for the indicator strain, medium composition, and incubation conditions. The assay was performed in nutrient agar at 30°C with 10 8 spores of Bacillus subtilis per plate as indicator strain. The inhibition produced by supernatants of lactic acid bacteria cultures harvested at stationary phase was determined. The inhibitory powers of different strains were compared with a standard curve obtained with racemic lactic acid. Results obtained with lactic acid and supernatants of bacterial cultures demonstrate that the diameter of the inhibition zone (d) was related to the pH by the exponential relation d = a exp (- b pH). Results obtained with strains that produced inhibitory substances other than lactic acid could not be fitted into the standard linear curves obtained in the plot of ln d versus pH of lactic acid.

The aim of this work was to analyse the hypotensive effect of amaranth protein/peptides on spontaneously hypertensive rats (SHR). The mechanism of action of these peptides was studied in vivo and ex vivo. We also tested the effect of protection against gastrointestinal digestion (GID) exerted by an O:W emulsion on the integrity of the antihypertensive peptides. All samples tested produced a decrease in blood pressure (SBP). The animals treated with emulsion (GE) and emulsion + peptide (GE+VIKP) showed the most significant reduction in the SBP (42 ± 2 mmHg and 35 ± 2 mmHg, respectively). The results presented suggest that after GID, a variety of peptides with biological activities were released or were resistant to this process. These peptides play a role in the regulation of the SBP by acting on plasma ACE, plasma renin and the vascular system. These results support the use of amaranth protein/peptides in the elaboration of functional foods for hypertensive individuals., Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Facultad de Ciencias Médicas

We analyze the possibility of using the emulsifying properties of amaranth proteins and the bioactivity shown by peptide sequences encrypted in these proteins to formulate functional emulsions with angiotensin I-converting enzyme (ACE) inhibitory activity. For this we formulate O:W emulsions, 20:80, from a mixture in equal parts (50:50) of amaranth protein isolates (API), and hydrolysates (AH) at 1 and 2% protein w/v. Results obtained showed that these emulsions, API50-AH50-1% and API50-AH50-2%, are highly flocculated (Flocculation index: 8.2 and 5.9) and stable at least for 8 days, without evident creaming or coalescence. The components present in the emulsions were capable of inhibiting ACE, in in vitro assays (IC₅₀ of 0.14 ± 0.02 mg/mL). API and API50-AH50 emulsions were subjected to a simulated gastrointestinal digestion in vitro. The emulsions were susceptible to aggregation and coalescence phenomena during this process, which could be a consequence of the chaotropic action of the bile salt on the interface and the proteolytic and lipolytic action of pancreatin and lipase, respectively (D₄.₃ of original emulsion: 1.22 ± 0.01 μm and D₄.₃ of digested emulsion 79.5 ± 17.1 μm). We also found that amaranth proteins were more resistant to gastric than duodenal digestion. After the process of simulated gastrointestinal digestion, the inhibition of ACE (IC₅₀ of 0.13 ± 0.07 mg/mL) was maintained. This fact evidences the protective effect of the emulsion on the bioavailability of the ACE inhibitory peptides, by either their participation in the formation of the interfacial film and/or their participation in the network of formed flocs., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

In this study, amaranth flour was used as an ingredient to prepare gluten-free cookies. The production process and attributes of amaranth cookies were characterised, and the potential use of amaranth flour as a functional ingredient was analysed. Cookies exhibited a non-uniform reddish brown colour and a cookie factor ratio of 4.5 ± 0.6. Storage studies indicated that after 3 weeks at room temperature cookies presented slight variations in the texture. Simulated gastrointestinal digestion of this product was able to release peptides capable of exerting potential antithrombotic and antihypertensive activities, IC₅₀ values of 0.22 ± 0.04 and 0.23 ± 0.03 mg mL⁻¹ protein, respectively. This work demonstrates for the first time that food made with amaranth flour exerts potential antithrombotic and antihypertensive activity. In conclusion, these amaranth cookies could be an alternative way of incorporating potentially health beneficial products for people who choose a conscious diet, including coeliac or vegan consumers., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The in vivo immunomodulatory effect of a bioactive peptide from Amaranthus hypochondriacus grains in an IgE-mediated food allergy mouse model was examined. The synthetic SSEDIKE peptide was orally administered to prevent food allergy. Upon oral challenge with milk allergens we observed an alleviation of hypersensitivity symptoms with negativization of skin test, a significant inhibition of specific IgE and IgG1 secretion, a substantial reduction in the secretion of IL-5 and IL-13 by antigen-stimulated spleen cells and mucosal reduction of transcripts coding for ccl20, gata-3 and nf-kb. In addition tgf-β and foxp3 mRNA levels were up-regulated in jejunum. The charged SSEDIKE peptide from Amaranth inhibited the allergy reaction in a mouse model of food allergy, with suppression of IgE secretion and control of the intestinal inflammation preventing the activation of NF-κB, which might be attributed to the induction of local tolerance. Fil: Moronta, Julián. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Smaldini, Paola Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina Fil: Fossati, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Docena, Guillermo H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina

The effect of casein (CAS) and inulin (INUL), at ratios commonly found during infant formula processing, on the conformational changes of whey proteins (WP) was investigated. Model systems were prepared as aqueous dispersions of WP isolate alone or with calcium caseinate and/or INUL, and heated for 30 min at66, 70 or 75 C. Heat treatment of WP induced denaturation and aggregation. Solubility of WP system decreased by 25% when heated at 75 C. Upon heating, the presence of CAS did not prevent WP denaturation, but increased protein solubility up to 100% in WPeCAS system and prevented aggregation. INULaffected the secondary structure of WP and increased the denaturation temperature, although it did not prevent aggregation nor solubility loss at 75 C. In conclusion, presence of CAS prevented aggregationand solubility loss of WP during heating while INUL induced WP conformational changes impacting the denaturation stage. Fil: Rodríguez Arzuaga, Mariana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Laboratorio Tecnológico del Uruguay; Uruguay Fil: Bosch, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Abraham, Analia Graciela. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina

The hypocholesterolemic effect of amaranth was studied in male Wistar rats fed a high-fat diet that was supplemented with amaranth flour, AF, or isolated protein, AI. Likewise, an in vitro test was carried out, in which the capacity of the AI, AF, the digested isolate, DAI, and the digested amaranth flour, DAF, to displace the cholesterol of the model micelles was evaluated. The in vivo results showed an increase in the excretion of cholesterol through feces (77% for AF7; 23% and 108% for AI30 and AF30, respect control) and a decrease in the content of hepatic cholesterol (98% for AF7; 96% and 53% for AI30 and AF30 respect control); whereas in vitro it was shown that both AF and DAF have greater power to displace cholesterol than the AI and DAI (IC50 0.1, 0.71, 0.2, and 2.1 for AF, DAF, AI, and DAI, respectively). These evidences show that the proteins and fibers of amaranth have an effect on cholesterol metabolism., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

Amaranth protein isolate was obtained and subjected to simulated gastrointestinal digestion to evaluate its potential antithrombotic activity. The protein isolate did not present fibrin clotting inhibition at the concentrations studied, whereas the hydrolysate (DH% = 51.1 ± 3.8%) exhibited inhibition of fibrin coagulation, showing a dose–response behaviour (IC50 = 0.23 ± 0.02 mg/mL), confirming that the enzymatic treatment was able to release bioactive peptides from amaranth proteins. A fraction with high antithrombotic activity was obtained from this hydrolysate, and resulted to be three times more potent than its original sample (IC50 = 0.07 ± 0.01 mg/mL). The absorption of this active fraction was studied with an in vitro peptides transport assay through intestinal epithelium and it was observed that some peptides are able to cross the Caco2-TC7 cell monolayer. Potentially bioactive peptides were found after sequencing them, and informatics tools allowed us to select and locate in their native molecules those peptides prone to inhibit thrombin activity., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

In the Northeast of Argentina, cowpeas are frequently produced by small- and medium-sized farmers for either personal consumption or trade. The objective of this work was to study, using a principal component analysis (PCA), the effect of thermal and non-thermal treatments on the nutritional and anti-nutritional properties of the four different varieties of Vigna unguiculata . Anti-nutrients contents allowed treatment differentiation for each variety because they contributed mainly in the PC1 axis construction (PCA). In contrast, nutrient (proteins and carbohydrates) contribution to treatment differentiation was not significant. Colorado variety presented the highest mineral in vitro availability, with the exception of iron. Thermal treatment increased the protein digestibility of all flours. The typical thermograms of native flours presented a two overlapping endotherm with denaturing temperatures (Td) of 83–84 °C and 91–93 °C respectively and a total enthalpy (Δ H ) 7–9 J/g. Heat treatments produced a shift of Td (67–73 °C) with increasing treatment time. Cowpea seeds varieties, especially Colorado and Cuarenton, because of their nutritional and antinutritional components under thermal treatments, could be used as an alternative low cost protein source for food formulas.

Los alimentos ejercen una influencia importante en el desarrollo de diversas enfermedades no transmisibles, entre las que es posible incluir el cáncer. Por otra parte, existe información que da cuenta de que algunos alimentos o algún componente alimentario pueden proteger contra el desarrollo de esta enfermedad. El objetivo de este trabajo fue purificar, caracterizar y analizar la potencial actividad antiproliferativa de una lectina proveniente de Amaranthus hypochondriacus (AH). Para ello se purificó parcialmente la lectina a partir de harina desgrasada de AH (LPP). Se encontró una proteína con una masa molecular aproximada de 65-70 kDa, compuesta por dos subunidades de aproximadamente 35 kDa unidas por interacciones no covalentes, con actividad hemaglutinante característica de las lectinas. Se estudió la inhibición de la proliferación celular utilizando la línea celular tumoral CaCo2/TC7 mediante el ensayo del cristal violeta. Además de la lectina parcialmente purificada, se estudió el efecto antiproliferativo de los aislados de Amaranhus hypochondriacus y mantegazzianus, y una lectina comercial de Amaranthus caudatus. Todas las muestras ensayadas mostraron efectos citotóxicos en forma de dosis respuesta., Food exerts an important influence on the development of several chronic diseases, including cancer. On the other hand there is evidence indicating that some food components can protect against the development of this disease. The aim of this work was to purify, characterize and analyze the potential antiproliferative activity of a lectin from Amaranthus hypochondriacus. Lectin was partially purified from defatted Amaranthus hipochondriacus flour. A protein with an approximate molecular mass of 65-70 kDa, composed of two subunits of about 35 kDa held together by noncovalent interactions with hemagglutinating activity characteristic of lectins was found. Inhibition of cell proliferation was studied using the tumor cell line CaCo2/TC7 by the crystal violet assay. In addition to the partially purified lectin, the antiproliferative effect of Amaranhus hypochondriacus and mantegazzianus isolates, and a commercial lectin from Amaranthus caudatus was studied. All samples tested showed cytotoxic effects in a dose dependent way., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

Ingestion of diets with antithrombotic and antioxidant components offer a convenient and effective way to prevent and reduce the incidence of cardiovascular diseases. The aim of the present work was to obtain an amaranth hydrolysate by the activation of an endogenous aspartic protease, to establish adequate experimental conditions, and to evaluate its antithrombotic and antioxidant activity in order to assess its potential application as an ingredient in functional foods. The results obtained not only confirmed the presence of an endogenous protease in the amaranth isolate, but also allowed us to select an adequate incubation conditions (pH 2, 40 °C, 16 h). The hydrolysate obtained (degree of hydrolysis 5.3 ± 0.4 %) showed potential antithrombotic activity (IC₅₀ = 5.9 ± 0.1 mg soluble protein/mL) and had more antioxidant activity than the isolate, indicating that the activation of the protease released bioactive peptides from amaranth proteins. Decreasing the pH is a simple and cheap process and is another way to obtain potential functional ingredients with bioactive compounds., Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The goal of this work was to analyze the effect of different treatments on functional properties (Color parameters, water holding capacity, oil holding capacity, water imbibition capacity, protein solubility and apparent viscosity) and microstructure of three cowpea varieties. Proteins present in flours obtained from heat-treated seeds exhibited a significant increase in water and oil absorption values, water imbibition capacity, and apparent viscosity, whereas solubility decreased. Color determinations on flours showed a reduction in L * and H *, and an increment in C * with treatment intensity. Structural changes in seeds would explain the variations in the functionality of flours. This study shows that cooking and autoclaving affect significantly the functional properties of flours, while soaking had a lower impact. The knowledge about these changes will be very useful for developing and obtaining new preparations based on cowpea flour.

Rate of the retrogradation process of five new argentine genotypes rice starches with different amylose contents and gelatinization temperatures during storage at 4.5 ± 0.5 °C was studied using differential scanning calorimetry (DSC). Significant differences were not found among transition temperatures, i.e., T0 (onset temperature), Tp (peak temperature) and Tc (conclusion temperature), of non-waxy genotypes when studied using DSC. An increased retrogradation enthalpy (ΔH, mJ/mg) with the storage time occurred with all non-waxy samples. The waxy genotype, W4109, did not show a retrogradation peak for the period under study. Genotypes with high total amylose content (TAM) retrograded more than those with lower content. The kinetic parameters “k” and “n” were evaluated using the Avrami model appearing to be related to the water-soluble amylose (SAM) content. Relationship between the retrogradation degree (%R) and the water-insoluble amylose (IAM) content was found. Gelatinization temperature of the starch (TG) seemed to affect the retrogradation rate.

This study investigated, with the aim of obtaining more flexible and hydrophobic proteins, the attachment of a low chain fatty acid, decanoic acid, to alkaline and acid soybean proteins; and the effect on their conformational and functional properties. The extent of esterification was high at acid pH and also increased with heating. Protein solubility decreased, mainly at the highest temperature (60 °C). Increasing levels of fatty acid formed a complex with a slightly more soluble protein with less surface hydrophobicity. Esterified proteins exhibited aggregation/dissociation and were stabilized by different protein subunits belonging to 7S and 11S globulins. Denaturation of these soybean protein fractions (7S and 11S) were also detected in these complexes. The highest level of fatty acids favored formation of a more ordered protein structure., Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Facultad de Ciencias Agrarias y Forestales

8 pages, 6 figures, 3 tables, The structure-function relationship of composite films obtained from soybean-protein isolate (SPI) and cod gelatin was studied. Films with different ratios of SPI:gelatin (0, 25, 50, 75, 100% [w/w]) and plasticized by a mixture of glycerol and sorbitol were prepared by casting. Regardless of the soybean-protein concentration, the thickness and water-vapor permeability of the composite films diminished significantly as compared to pure-gelatin films. The formulation containing 25% SPI: 75% cod-skin gelatin had the maximum force at the breaking point, which was 1.8-fold and 2.8-fold greater than those of 100% gelatin and 100% SPI films, respectively. Moreover, this formulation offered high percent-deformation values lower than those of gelatin but higher than all other films containing SPI-, and the same relatively low water-vapor permeability as the 100% SPI film. While all the films exhibited high water solubility, a slight reduction in film solubility and soluble protein was observed with increasing SPI concentration. Differential-scanning calorimetry analyses revealed that gelatin was completely denatured in all films, while soy proteins largely maintained their native conformation. Analysis by fourier-transform–infrared spectroscopy revealed that the presence of 25% SPI produced gelatin conformational changes, self-aggregation of gelatin chains, and intermolecular associations via CO bonds between gelatin and SPI proteins. All films were translucent in appearance, but the yellowish color increased with increasing proportions of the soybean proteins., This work has been performed within the framework of the project CYTED XI.20 and sponsored by the Spanish Ministry of Education and Science under project AGL2005-02380/ALI and by the National Agency of Scientific and Technological Support (SECyT,) of Argentina under project PICT 35036/05.

The functional properties of proteins from a high-protein–content rice cultivar (Nutriar) were analyzed and compared with those from a usual Latin-American cultivar (El Paso 144). Isolates from brown and milled flours were prepared and their emulsifying, foaming, and hydration properties studied. The four isolates displayed a very low solubility within a wide range of moderate pH, but demonstrate a significantly higher solubility at extreme pHs (either high or low). Nutriar isolates had a significantly higher solubility and greater surface properties than El Paso 144 isolates. The Nutriar isolate from brown flour was more soluble at pH 9 than the other isolates and moreover showed the highest capacity for forming and stabilizing foams and emulsions. In contrast, the Nutriar isolate from milled rice exhibited a higher solubility and greater foaming properties at an acid pH. The surface properties and solubility were significantly correlated among the four samples. All four isolates exhibited good water-imbibition and water-holding capacities.

The amino acid composition and the physicochemical and functional properties of quinoa flour proteins (QFP) were evaluated during storage (at 20, 30 and 40 °C). Quinoa flour showed a protein content of 14.2 ± 0.1 g 100 g-1 and high levels of essential amino acids as lysine. SDS-PAGE of the QFP presented ten major band, and native-PAGE of the QFP showed similar banding; there was a little variation due to time-temperature. TCA-protein solubility variation (%) was small and the values of water activity were low, a non-significant endogenous hydrolysis was observed. Differential scanning calorimetry flour analysis allowed determining two endotherms, starch and protein. Important structural changes of protein soluble fractions were not detected by UV and fluorescence spectroscopy due to temperature and time of storage. It was found during storage time loss of protein solubility and water absorption. These changes could be to influence in the manufacture of quinoa flour based products. For avoid changes in these functional properties (solubility and water holding capacity), quinoa flour can be stored at ambient temperature (between 20 and 30 °C) and packed in double kraft paper bags (2 months). Fil: Abugoch, Lilian. Universidad de Chile; Chile Fil: Castro, Eduardo. Universidad de Chile; Chile Fil: Tapia, Cristian. Universidad de Chile; Chile Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Gajardo, Pilar. Universidad de Chile; Chile Fil: Villarroel, Andrea. Universidad de Chile; Chile

Isoflavones are a group of natural phytoestrogens including the compound genistein. Health beneficial effects have been attributed to the consumption of this compound, but the fact that it has estrogen-like activity has raised doubts regarding its potential risk in infants, newborns, or in the fetus and placenta during pregnancy. This work is aimed at studying genistein effects on Ca2+ handling by smooth muscle cells of the human umbilical artery (HUA). Using fluorometric techniques, we found that in these cells genistein reduces the intracellular Ca2+ peak produced by serotonin. The same result could be demonstrated in absence of extracellular Ca2+, suggesting that the isoflavone reduces Ca2+ release from the sarcoplasmic reticulum. Force measurement experiments strengthen these results, since genistein reduced the peak force attained by intact HUA rings stimulated by serotonin in a Ca2+-free solution. Moreover, genistein induced the relaxation of HUA rings precontracted either with serotonin or a depolarizing high-extracellular K+ solution, hinting at a reduction of extracellular Ca2+ entry to the cell. This was confirmed by whole-cell patch-clamp experiments where it was shown that the isoflavone inhibits ionic currents through voltage-operated Ca2+ channels. In summary, we show that genistein inhibits two mechanisms that could increase intracellular Ca2+ in human umbilical smooth muscle cells, behaving in this way as a potential vasorelaxing substance of fetal vessels. Taking into account that genistein is able to cross the placental barrier, these data show that isoflavones may have important implications in the regulation of feto-maternal blood flow in pregnant women who consume soy-derived products as part of their meals., Facultad de Ciencias Exactas

Summary The aim of this work was to analyse the effect of rosemary extract application (200 and 500 ppm) on lipid oxidation, colour and protein modifications during the chilled storage (1.0 ± 0.7 °C) of sea salmon (Pseudopercis semifasciata). Lipid oxidation and ω3-22:6 fatty acid content modification were prevented by the addition of rosemary extract. Analysis of interaction between lipid oxidation products and proteins by fluorescence showed no relationship between their temporal changes in the aqueous phase and the lipid oxidation evolution since a similar behaviour was observed in both absence and presence of antioxidant. Protein extractability, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, differential scanning calorimetry and lysine content determinations revealed no differences between muscle untreated or treated with rosemary. Fluorescent compounds evolution in organic phase would be in relation with the appearance of lipid oxidation products. In addition, rosemary extract partially prevented the loss of red colour in chilled muscle. Although protein alterations could not be prevented, rosemary extract shows to be a promissory antioxidant in sea salmon muscle.

In this work the influence of pH and ionic strength on the stability of foams prepared with amaranthprotein isolate was analyzed. The behaviour observed was related to the physico-chemical and structuralchanges undergone by amaranth protein as a result of those treatments. The results obtained showthat foams prepared at acidic pH were more stable than the corresponding to alkaline pH. At pH 2.0the foams presented higher times and more volumes of drainage. This behaviour is consistent with thecharacteristics of the interfacial film, which showed a higher viscoelasticity and a greater flexibility atacidic pH than alkaline pH value, which in turn increased by increasing the concentration of proteins inthe foaming solution. It is also important to note that the presence of insoluble protein is not necessarilydetrimental to the properties of the foam. Detected changes in the characteristics of the interfacial filmas in the foam stability have been attributed to the increased unfolding, greater flexibility and net chargeof amaranth proteins at acidic conditions., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

Summary Chicken breast and salmon muscle were frozen either slowly or rapidly at –25°C, and then stored at –5°C for up to 83 and 47 days respectively. At intervals samples were thawed and TBA values measured on either muscle distillate or centrifugal exudates. TBA values increased slightly but significantly with storage time, but freezing rate had no effect.

Summary. Freezing of bovine muscle has a denaturating effect on myofibrillar proteins, Differ-ential Scanning Calorimetry (DSC) studies of fresh and frozen muscle at different freezing rates show a decrease on denaturation enthalpies; the lower the freezing rate the greater the loss. When measuring the specific areas (ratio between each partial area in cm', and the dry weight of the sample, in mg) of the DSC thermograms, it can be observed that the area ascribed to myosin decreases with freezing, while the area corresponding to actin is not affected. These results are in agreement with the ATPase activity decreases as a consequence of freezing observing higher losses at lower freezing rates. The denaturation observed could be a result of a partial unfolding of the myosin head being more pronounced at low freezing rate.

The effect of frozen storage on myofibrillar ATPase activity and thermal transitions in bovine muscle was investigated. Myofibrillar ATPase activity and total enthalpy of denaturation (ΔH) decreased with time of storage. The rate of decrease was lower at −20°C than at −5°C or −10°C. Differences in behaviour during storage of muscle after fast or slow freezing could be attributed to differences in ice recrystallization. The observed decreases in area of the first peak seen in the thermograms and Ca2+-myo-fibrillar ATPase activity show that the myosin head denaturated progressively during storage. The myosin tail also denaturated during storage but the thin filament remained unaltered. Kinetic analysis suggested that the denaturation of the myofibrillar proteins took place through two consecutive first order reactions; an initial rapid reaction followed by a slower one.

The influence of the conditions for isolation of soy protein on the content of genistein and its conjugated forms was studied. The major components of the genistein series isolated from soybean flour were malonyl genistin (54.3%), genistin (36.9%), and equal amounts (4.4%) of genistein and acetyl genistin. A modification in the conjugation profile of genistein between pH 4.5 and 8.0 and above pH 10 was attributed to the action of β‐glucosidase and the saponification reaction, respectively. A decrease in the content of total genistein in the insoluble flour residue and in the soy protein isolate (SPI) with increasing extraction pH was detected, while in the whey, the total genistein content was not affected by pH. The effect of pH variation during acid precipitation on the content of genistein and its conjugated forms, at a constant extraction pH (8.0), was also studied. Under these conditions, the highest absolute content of total genistein in the SPI was obtained at pH 3.5 and the lowest was obtained at pH 5.6. The total genistein content in the whey followed an inverse trend compared with that of the protein yield. A temperature increase did not substantially affect the distribution of the different genistein forms or their total contents. The content of total genistein was higher in the glycinin than in the β‐conglycinin protein fraction. The effect of the pH during the alcohol/water extraction of the isoflavones was also analyzed. The efficiency of the extraction was lower at pH values between 3.25 and 3.5 than at other pH values. Fil: Speroni Aguirre, Francisco José. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Milesi, Verónica. Universidad Nacional de la Plata. Facultad de Cs.exactas. Departamento de Cs.biológicas. Area de Anatomia y Fisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina

Today amaranth is a promising food source yet its technological properties are not well known. The modification of some properties of an amaranth starch-rich fraction by a controlled heating is studied. This fraction was obtained by the differential milling of Amaranthus cruentus grains. Tests were performed by both fluidized bed and extrusion heating, according to a factorial experimental design of two variables: temperature and moisture, at three levels 150–170–200 °C and 120–160–200 g/kg wb, respectively. Effects were evaluated by the ANOVA method. As responses, solubility and water absorption, amylographic and dynamic rheological properties, crystallinity, granular integrity and resistant starch content were evaluated. Flours obtained from samples heated by fluidized bed gave aqueous dispersions with high consistencies when cooked, and they had low solubility in water and preserved part of the starch crystalline structure. Flours obtained from extrusion-heated samples gave very high solubility in water but had lower consistency of the aqueous dispersions when cooked, and they showed a complete loss of the crystalline and granular structure. By applying each of the two heating processes, it was possible to modify, according to selected targets, the amaranth starch-rich fraction, what would allow to obtain pre-cooked amaranth flours with a wide range of hydration and rheological properties. Fil: Gonzalez, Rolando Jose. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Carrara, Carlos R.. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Tosi, Enzo Alberto. Universidad Tecnológica Nacional; Argentina Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Pilosof, Ana Maria Renata. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Cardiovascular disease (CVD) is a major cause of disability and premature death throughout the world. Diets with antithrombotic components offer a convenient and effective way of preventing and reducing CVD incidence. The aim of the present work was to assess in vivo and ex vivo effects of Amaranthus hypochondriacus proteins on platelet plug formation and coagulation cascade. Amaranth proteins were orally administrated to rats (AG, 8 animals) and bleeding time was determined showing no significant difference compared with control rats (CG, 7 animals). However, results show a strong tendency, suggesting that amaranth proteins are involved in the inhibition of thrombus formation. Non-anticoagulated blood extracted from animals was analyzed with the hemostatometer, where AG parameters obtained were twice the values showed by CG. The clotting tests, thrombin time (TT) and activated partial thromboplastin time (APTT), presented a 17 and 14% clotting formation increase respectively when comparing AG with CG. The ex-vivo assays confirm the hypothesis inferring that amaranth proteins are a potential antithrombotic agent., Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Centro de Investigaciones Cardiovasculares

Amaranth sprouts are an edible food with good nutritional qualities and potential biological activities of their proteins. The chemical composition, angiotensin converting enzyme inhibitory activity and antioxidant activity of the sprouts were determined. Sprouts showed a protein content similar to the seeds on a dry basis (16%) and a high fiber content (17%). Amaranth sprout proteins presented a capacity to inhibit angiotensin converting enzyme activity similar to other plant proteins (IC50 = 0.9 ± 0.6 mg/mL). This capacity increased after in vitro gastrointestinal digestion (IC50 = 0.26 ± 0.07 mg/mL). Besides other non protein molecules, the amaranth sprout proteins also presented ABTS+. scavenging activity (TEAC = 0.32 ± 0.05 mol/mg) that increased after in vitro gastrointestinal digestion (TEAC = 0.72 ± 0.08 mol/mg) and oxygen radical antioxidant capacity. According to these results amaranth sprouts are a nutritive food with potential health promoting properties., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The interactions between soy and wheat proteins after dough mixing and bread baking were studied. Protein extractions from gluten and breadcrumbs elaborated with mixtures of wheat flour and enzyme-active full-fat, heat-treated full-fat, and enzyme-active defatted soy flours, and commercial isolated soy proteins were analyzed by electrophoresis. Different buffer systems with specific chemical action on proteins were used to investigate the types of forces between soy and wheat proteins in gluten and breadcrumbs. The presence of protein bands of similar molecular weight to soy proteins in gluten fractions after intensive dough washing indicated association between these proteins. Nonreduced wheat–soy gluten proteins had higher amount of sodium dodecyl sulfate soluble protein aggregates than wheat gluten. Soy and wheat proteins interacted by means of noncovalent and covalent (disulfide) bonds and the extent of the interactions depended on the soy protein state.

In general, triticale is not a good raw material for bread making. However, some varieties produce flours of good quality for cookie production. It is a well-known fact that cracker quality depends on the flour used for cracker production. All over the world, a blend of hard and soft wheat is used; however, the use of soft flour is recommended. Since additional soft wheat cultivation is not allowed in Argentina, triticale represents a good alternative for cracker production. In the present study 15 triticale cultivars and a flour of optimum cracker quality were used to produce crackers in order to establish criteria to evaluate flour quality in cracker-making. The factors that determine cracker quality, as well as the relationships between different quality parameters were investigated. Electrophoretic patterns of triticale proteins extracted from flours were determined. Five cultivars produced crackers of similar quality to that of standard flour of industrial good quality. A protein band with a 110 kDa molecular mass influenced flour quality, measured as the ratio of the mean between weight and length, WL and the height of ten crackers (H 10), WL/H 10, while other flour constituents such as pentosans, soluble proteins and damaged starch could affect its weight.

The goal of the present work was to study the effects of acid treatment on the foaming properties of a soybean protein isolate (SPI) and its fractions, glycinin (11S) and β-conglycinin (7S). The structural characteristics, interfacial properties, foaming capacity and stability of the treated proteins were studied. Results from surface hydrophobicity and differential scanning calorimetry (DSC) showed that the acid treatment caused the complete denaturation of 11S and a partial denaturation of 7S. This protein unfolding affected their interfacial properties, which led to an improvement in the foaming properties of both protein fractions and isolate. Treated 7S showed the best behavior in the rearrangement process, probably due to its smaller size and its modified structural characteristics. All treated proteins showed stronger interfacial films. The foams of treated proteins were destabilized mostly due to gravitational drainage rather than Ostwald ripening., Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Consejo Nacional de Investigaciones Científicas y Técnicas

Fil: Quiroga, Alejandra V. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentina Fil: Barrio, Daniel A. Universidad Nacional de Rio Negro. Sede Atlantica. Departamento de Investigación en Ciencias Exactas, Naturales y de Ingenieria; Argentina Fil: Añon, Maria C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina The possibility of reducing the risk of cancer is one of the most important challenges facing scientists. In this work we demonstrate that the amaranth lectin presents potential antitumor activity and we propose a mechanism of action. Our results indicate that the albumins and a hydrophobic fraction (MPI-h) from the Amaranthus mantegazzianus protein isolate (MPI) are capable of inhibiting UMR106 rat osteosarcoma-derived cell proliferation. Further fractionation of the hydrophobic fraction and LC-MS/MS analyses of the tryptic peptides showed the presence of lectin fragments in one active fraction. When a partially purified A. mantegazzianus lectin and the commercial Amaranthus caudatus lectin were tested as cell-proliferation inhibitors, both lectins showed high activity with an IC50 ¼ 0.1 mg/mL and 0.08 mg/mL respectively; similar to MPI-h activity. Lectins would exert a cytotoxic effect followed by cell apoptosis, in addition to inhibiting cell adhesion. La posibilidad de reducir el riesgo de cáncer es uno de los desafíos más importantes que enfrentan los científicos. En este trabajo demostramos que la lectina de amaranto presenta una actividad antitumoral potencial y proponemos un mecanismo de acción. Nuestros resultados indican que las albúminas y una fracción hidrófoba (MPI-h) del aislado de proteína de Amaranthus mantegazzianus (MPI) son capaces de inhibir la proliferación celular derivada del osteosarcoma de rata UMR106. El fraccionamiento adicional de la fracción hidrófoba y los análisis de LC-MS / MS de los péptidos trípticos mostraron la presencia de fragmentos de lectina en una fracción activa. Cuando una lectina de A. mantegazzianus parcialmente purificada y la lectina de Amaranthus caudatus comercial se probaron como inhibidores de la proliferación celular, ambas lectinas mostraron una alta actividad con un IC50 ¼ 0.1 mg / mL y 0.08 mg / mL respectivamente; similar a la actividad MPI-h. Las lectinas ejercerían un efecto citotóxico seguido de apoptosis celular, además de inhibir la adhesión celular.

Hydration properties of soybean isolates with different processing conditions (heat treatments, pH and protein concentrations) were studied. Degree of denaturation, solubility in water, in 0.2mol/L NaCl, and in media of different sodium dodecyl sulfate concentrations, viscosity and water imbibing capacity of the different samples were determinated and correlated. Treatments at temperatures higher than 80°C denatured US and 7S proteins, leading to exposure of'Hydrophobie groups, which produced insoluble aggregates either in water or in high ionic strength media. These isolates possessed high water imbibing capacities and gave rise to viscous dispersions. Significant correlations were obtained between hydration properties and the "m" coefficient as calculated by a power law equation relating viscosity with the protein concentration of the dispersion. This "m" coefficient also correlated with the denaturation enthalpy of the protein isolates. On the basis of these results, it might be suggested that the "m" coefficient - dependent of the hydrodynamic behaviour of the particles - was a good estimator of the degree of protein denaturation., Facultad de Ciencias Exactas