Purification, thermal stability, and antigenicity of the immunodominant soybean allergen P34 in soy cultivars, ingredients, and products.

Protein P34 (Gly m Bd 30K) is the immunodominant allergen in soybean (Glycine max L.). The objectives of this study were (1) to study the effect of thermal treatment on P34 antigenicity and secondary structure after isolation and purification of P34 from soybean by chromatographic techniques; (2) to identify the variability of P34 allergen within 138 accessions from a diverse USDA soybean germplasm collection by ELISA; and (3) to quantify P34 immunoreactivity in various commercial soy ingredients and products. Thermal processing decreased P34 antigenicity. Soybean accessions with the highest P34 content were ancestral (12 mg/g defatted flour) followed by modern (10 mg/g defatted flour) and exotic (8 mg/g defatted flour). The cultivar that emerged as the lowest-expressing P34 accession was PI548657 (2.3 mg/g defatted flour). Among commercial soy ingredients, soy flour yielded the highest P34 antigenicity (32 mg/g extracted protein) followed by soy protein isolate (29 mg/g extracted protein) and soy protein concentrate (24 mg/g extracted protein). Among soy consumer products, soymilk presented the highest P34 antigenicity, ranging from 7 to 23 mg/g extracted protein, followed by tempeh (8 mg/g extracted protein), soy infant formula (3.4 mg/g extracted protein), soy powder (2 mg/g extracted protein), and soy cheese products (0.50 mg/g extracted protein). Korean miso, soy sauce, soy chili mix, soy nuts, soy cream cheese, soy meat patty, texturized soy protein, and soy cereal exhibited undetectable P34 antigenicity (detection limit = 0.45 ng). Selecting soybean varieties with low levels of this allergen, or via processing, could potentially make soybean products less antigenic.

Yerba Mate Tea (Ilex paraguariensis): a comprehensive review on chemistry, health implications, and technological considerations.

Yerba Mate tea, an infusion made from the leaves of the tree Ilex paraguariensis, is a widely consumed nonalcoholic beverage in South America which is gaining rapid introduction into the world market, either as tea itself or as ingredient in formulated foods or dietary supplements. The indigenous people have used it for centuries as a social and medicinal beverage. Yerba Mate has been shown to be hypocholesterolemic, hepatoprotective, central nervous system stimulant, diuretic, and to benefit the cardiovascular system. It has also been suggested for obesity management. Yerba Mate protects DNA from oxidation and in vitro low-density lipoprotein lipoperoxidation and has a high antioxidant capacity. It has also been reported that Yerba Mate tea is associated to both the prevention and the cause of some types of cancers. Yerba Mate has gained public attention outside of South America, namely the United States and Europe, and research on this tea has been expanding. This review presents the usage, chemistry, biological activities, health effects, and some technological considerations for processing of Yerba Mate tea. Furthermore, it assesses in a concise and comprehensive way the potential of Ilex paraguariensis as a source of biological compounds for the nutraceutical industry.

Safety of a filtrate of fermented garambullo fruit: biotransformation and toxicity studies.

Betalains are important natural pigments for the food industry. The purpose of this study was to evaluate the toxicological and toxicokinetic effects of betalain pigments from a cactaceous fruit (garambullo) on male and female Wistar rats. The pigments did not cause death with any of the doses tested, up to 5 g/kg body weight. In the digestibility studies, there was a degradation of the pigment of 26-29% in the large intestine, 20-26% in the small intestine and 24-29% in the stomach. The pigments were eliminated in the urine as betalains. The pigments had no metabolic effect on the hepatocytes for up to 7 hours. Furthermore, there was no increase in the heart rate when the pigments were administered by oral intubation, up to a dose of 5 g/kg. The data suggest that garambullo fruit pigments do not cause acute toxicity.

Antimutagenic effects of natural phenolic compounds in beans.

Polyphenols in fruits, vegetables (e.g., flavonols like quercetin) and tea (e.g., catechins such as epigallocatechin gallate) are good antioxidants with antimutagenic and anticarcinogenic properties. In the present study, the Salmonella typhimurium tester strain YG1024 was used in the plate-incorporation test to examine the antimutagenic effect of phenolic compounds, extracted from common beans (Phaseolus vulgaris), on 1-NP and B[a]P mutagenicity. Dose-response curves for 1-NP and B[a]P were obtained; the number of net revertants/plate at the peak mutagenic dosage were 880 for 1-NP and 490 for B[a]P. For the antimutagenicity studies doses of 0.1 microg/plate and 2 microg/plate for 1-NP and B[a]P, respectively, were chosen. We obtained a dose-response curve of ellagic acid (EA) against B[a]P and 1-NP mutagenicity. To test the bean extract, a dose of 300 microg/plate of EA was chosen as the antimutagenic control. The EA and bean extracts were not toxic to the bacteria at the concentrations tested. The inhibitory effects of the bean extracts and EA against B[a]P mutagenicity were dose-dependent. The percentages of inhibition produced against B[a]P (2 microg/plate) using 300 microg/plate of EA and for the extracts 500 microg equivalent catechin/plate were 82%, 83%, 81% and 83% for EA, water extract, water/methanol extract and methanol extract, respectively. However, for 1-NP mutagenicity, only the methanolic extract from beans showed an inhibitory effect. These results suggest that common beans, as other legumes, can function as health-promoting foods.

Inhibitory effects of ellagic acid on the direct-acting mutagenicity of aflatoxin B1 in the Salmonella microsuspension assay.

Ellagic acid (EA) is a phenolic compound that exhibits both antimutagenic and anticarcinogenic activity in a wide range of assays in vitro and in vivo. It occurs naturally in some foods such as strawberries, raspberries, and grapes. In the previous work, we used the Salmonella microsuspension assay to examine the antimutagenicity of EA against the potent mutagen aflatoxin B1 (AFB1) using tester strains TA98 and TA100. Briefly, the microsuspension assay was approximately 10 times more sensitive than the standard Salmonella/microsome (Ames) test in detecting AFB1 mutagenicity, and EA significantly inhibited mutagenicity of all AFB1 doses in both tester strains with the addition of S9. The greatest inhibitory effect of EA on AFB1 mutagenicity occurred when EA and AFB1 were incubated together (with metabolic enzymes). Lower inhibition was apparent when the cells were first incubated with EA followed by a second incubation with AFB1, or when the cells were first incubated with AFB1 followed by a second incubation with EA alone, all with metabolic enzymes. The result of these sequential incubation studies indicates that one mechanism of inhibition could involve the formation of an AFB1-EA chemical complex. In the present study, we further examine the effect of EA on AFB1 mutagenicity, but without the addition of exogenous metabolic enzymes. We report the mutagenicity of AFB1 in the microsuspension assay using TA98 and TA100 without the addition of S9. Neither the concentrations of AFB1 (0.6, 1.2, and 2.4 microg/tube) nor the concentrations of EA (0.3, 1.5, 3, 10, and 20 microg/tube) were toxic to the bacteria. The results indicate that AFB1 is a direct-acting mutagen, and that EA inhibits AFB1 direct-acting mutagenicity.

Effect of carotenoids on cytotoxicity of T-2 toxin on chicken hepatocytes in vitro.

The antioxidant properties of lutein, lycopene and apocarotenoic ester were examined in vitro regarding their capacity to reduce the cytotoxic effect of the T-2 toxin on chicken hepatocytes. The protective effect was evaluated with a reduction of glutathione and lactate dehydrogenase leakage. Cellular damage was observed at a concentration of 5 x 10(-4) m T-2 toxin, and with at least 10(-5) M for all the carotenoids tested. A partial protective effect against mycotoxin was observed when hepatocytes were exposed simultaneously to lutein (10(-6) m) and T-2 toxin (5 x 10(-4) m). Lycopene (10(-6) m) was able to reduce the cytotoxic effect of the T-2 mycotoxin (5 x 10(-4) m) when both we're in contact with cells, either simultaneously or previously exposed to the toxin (incubation time 60 min). The apocarotenoic ester did not protect these cells against the T-2 toxin effect. The results suggest that lutein and lycopene helped maintain the integrity of the cellular membrane structure in the presence of T-2 toxin.

Antitumor effect of plant lectins.

This review examines the literature data concerning the biological activity of plant lectins. Numerous studies have reported that these substances possess toxic, cytotoxic, antitumor, and anticarcinogenic properties. A brief description of the biological properties of plant lectins, as well as the effect of plant lectins on normal and malignant cells and the antitumor properties of these lectins in vivo and in vitro, are included. These findings are interpreted and possible mechanisms of the antitumor effect of plant lectins are discussed.

[Effect of growing location on sensory properties and nutritional characteristics of black beans (Phaseolus vulgaris L.)]. / Efecto de la localidad de siembra sobre la aceptacion sensorial y otras caracteristicas nutricionales y de calidad del grano en frijol comun (Phaseolus vulgaris L.).

The present research consisted of an evaluation of five genotypes harvested from six growing locations. Variables of sensory properties, cooking quality and nutritional characteristics were determined. Genotype with longer cooking time was BV which also present hard shell. Those of shorter cooking time were FMB and PV. In Calera frosting during pod filling, drastically reduced cooking time, sensory properties and tannins. Taking this location off, the analysis show little effect of genotype or growing location in regard to determined properties. The genotypes with lower content of tannins were PV and BV. The content of lectins were in general low for all samples and the diferences between genotypes were not statistically significant (p<0.05) but they did for growing location.