Effect of sourdough on quality and acceptability of wheat flour tortillas.

As an alternative on the search for functional food products, this study evaluated the use of sourdough in the preparation of wheat flour tortillas. The sourdough was elaborated with Lactobacillus sanfranciscensis and the wheat flour tortillas were prepared with different concentrations of mother sponge (5%, 15%, and 25%) and fermentation times (1 and 3 h) at room temperature (25 ± 2 °C). Quality (diameter, height, color, pH, stretchability scores, and Kramer shear cell results) of wheat tortillas was evaluated after 24 h of preparation. The mother sponge concentration and fermentation time affected some quality parameters and acceptability properties (taste, aroma, color, opacity, and rollability). In addition, the sourdough tortillas had higher stretchability values than control tortillas. Since most of the prepared sourdough tortillas had acceptability values similar to those of tortilla controls, the introduction of sourdough is a viable means to incorporate additional nutritional and nutraceutical value into wheat tortillas.

Influence of extrusion on the bioactive compounds and the antioxidant capacity of the bean/corn mixtures.

The aim of this investigation was to examine the influence of extrusion on the bioactive compounds and the antioxidant capacity of bean/corn mixtures. Whole bean flour and nixtamalized corn were mixed in a 60:40 proportion and extrusion was performed in different moisture (14.5%, 15.4%, 17.1% and 18.0%) and temperature (150°C, 160°C, 170°C, 180°C and 190°C) conditions in order to find the optimal extrusion conditions. According to their functional properties and antioxidant status, the mixtures 142°C/16.3% H, 170°C/16.3% H and 198°C/16.3% H were defined as optimal, moderate and bad, respectively. Total polyphenols and flavonoids in the mixture of 142°C/16.3% H (15.09±1.7 mg gallic acid equivalent [GAE]/g dry weight [DW] and 1.57±0.2 mg catechin equivalent [CE]/g DW) were significantly higher (P<0.05) than in the sample 170°C/16.3% H (9.42±1.1 mg GAE/g DW and 1.4±0.1 mg CE/g DW) and the mixture 198°C/16.3% H (6.46±0.8 mg GAE/g DW and 0.78±0.1 mg CE/g DW). The antioxidant activity (37.02±3.8 and 25.01±2.5 µM Trolox equivalent [TE]/g DW) of mixture 142°C/16.3% H, determined by the cupric reducing antioxidant capacity with Trolox equivalent antioxidant capacity and ß-carotene-linoleic acid (ß-carotene,% of inhibition) assays, was significantly higher (P<0.05) than in 170°C/16.3% H (25.69±2.8 and 17.02±1.8 µM TE/g DW) and in mixture 198°C/16.3% H (13.93±1.5 and 8.94±0.9 µM TE/g DW), respectively. The free polyphenols, flavonoids and the antioxidant activities showed lower results than the hydrolyzed ones. The correlation coefficients between polyphenols, flavonoids, and cupric reducing antioxidant capacity capacities were between 0.93 and 0.99. In cereal proteins extracted and separated by electrophoresis, some differences were found in the sodium dodecyl sulfate-protein bands in the region from 36 to 45 kDa for 142°C/16.3% H, in comparison with other samples. Therefore, there is a need to find such conditions for the extrusion procedures that would take into consideration the contents of the bioactive compounds and the antioxidant capacity in the end product.

Comparative study of health properties and nutritional value of durian, mangosteen, and snake fruit: experiments in vitro and in vivo.

In vitro and in vivo studies of the health and nutritional properties of durian (Durio zibethinus Murr.) were compared with snake fruit (Salacca edulis Reinw.) and mangosteen (Garcinia mangostana). Dietary fibers, minerals, and trace metals were comparable. Total polyphenols (mg of GAE/100 g of FW) and flavonoids (85.1+/-6.1) were significantly higher (p<0.05) than in snake fruit (217.1+/-13.2 (mg of CE/100 g of FW)), durian (309.7+/-19.3 and 61.2+/-4.9), and mangosteen (190.3+/-12.1 and 54.1+/-3.8). Antioxidant activity (microM TE/100 g of FW) of durian measured by DPPH and ABTS assays (228.2+/-13.4 and 2016.3+/-81.1) was significantly higher (p<0.05) than in snake fruit (110.4+/-7.9 and 1507.5+/-70.1) and mangosteen (79.1+/-5.9 and 1268.6+/-62.3). HPLC/DAD analysis of durian (microg/100 g of FW) showed that quercetin (1214.23+/-116.7) was present at levels three times that of caffeic acid, and twice as high as p-coumaric and cinnamic acids. The correlation coefficients between the bioactive compounds of fruits and their antioxidant activities were high (R2=0.99). Male Wistar rats (25) were divided into five dietary groups: the control group was fed the basal diet (BD); in addition to BD, the cholesterol (Chol) group was supplemented with 1% of Chol; the diets of the Chol/Durian, Chol/Snake, and Chol/Mangosteen groups were supplemanted with 5% of these fruits, respectively. It was found that diets supplemented with durian, and to a lesser degree with snake fruit and mangosteen, significantly hindered the rise in plasma lipids and the decrease in antioxidant activity. The nutritional values were comparably high. In conclusion, it could be suggested that inclusion of studied tropical fruits, especially durian, in known disease-preventing diets could be beneficial.

Effect of ethylene treatment on kiwifruit bioactivity.

UNLABELLED: The consumption of fruits and vegetables with high antioxidant activities leads to best healthful results. Therefore, in the present investigation we tried to find the peak of the kiwifruits antioxidant activity during the first 10 days of ethylene treatment (100 ppm at 20 degrees C). In order to receive the most reliable data five different antioxidant assays were used: ferric-reducing/antioxidant power (FRAP); cupric reducing antioxidant capacity (CUPRAC); trolox equivalent antioxidant capacity (TEAC); 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH); and Folin-Ciocalteau. It was found by all applied methods that kiwifruit samples have the highest contents of polyphenols and flavonoids and the highest antioxidant activity on the 6-th day of the ethylene treatment. The correlation coefficients between polyphenols, flavonoids and antioxidant activities of kiwifruit methanol extracts with TEAC and CUPRAC, were as followed: 0.81 and 0.63, and 0.23 and 0.17, respectively, and showed that the free polyphenols correlation coefficients were higher than that of the flavonoids. IN CONCLUSION: during ethylene treatment the bioactivity of kiwifruit is increasing and reaches its maximum at the 6th day and therefore it is the optimum time for kiwifruit consumption; total polyphenols were the main contributor to the overall antioxidant activity of kiwifruit; the most sensitive test for antioxidant activities determination is FRAP.

Changes in plasma lipid and antioxidant activity in rats as a result of naringin and red grapefruit supplementation.

The aim of this investigation was to compare the influence of naringin versus red grapefruit juice on plasma lipid levels and plasma antioxidant activity in rats fed cholesterol-containing and cholesterol-free diets. The antioxidant activity of a correlated quantity of red grapefruit juice was higher than that of naringin. Forty-two male Wistar rats were randomly divided into six groups of 7 named control, naringin, grapefruit, Chol, Chol/naringin, and Chol/grapefruit. The rats of the control group were fed basal diet (BD) and 1-2 mL of distilled water. To the BD of the other five groups were added 0.46-0.92 mg of naringin dissolved in 1-2 mL of distilled water (naringin), 1-2 mL of red grapefruit juice (grapefruit), 1% of nonoxidized cholesterol (NOC) and 1-2 mL of distilled water (Chol), 1% of NOC and 0.46-0.92 mg of naringin in 1-2 mL of water (Chol/naringin), and 1% of NOC and 1-2 mL of red grapefruit juice (Chol/grapefruit). After 30 days of different feeding, it was found that diets supplemented with red grapefruit juice and to a lesser degree with naringin improved the plasma lipid levels mainly in rats fed cholesterol and increased the plasma antioxidant activity. In conclusion, naringin is a powerful plasma lipid lowering and plasma antioxidant activity increasing flavonone. However, fresh red grapefruit is preferable than naringin: it more effectively influences plasma lipid levels and plasma antioxidant activity and, therefore, could be used as a valuable supplement for disease-preventing diets.

Fresh Israeli Jaffa blond (Shamouti) orange and Israeli Jaffa red Star Ruby (Sunrise) grapefruit juices affect plasma lipid metabolism and antioxidant capacity in rats fed added cholesterol.

The bioactivity of Israeli Jaffa blond (Shamouti) fresh orange and Israeli Jaffa red Star Ruby (Sunrise) grapefruit juices was investigated in vitro and in vivo. The contents of bioactive compounds of these juices were determined. The influence of bioactive compounds on plasma lipids and plasma antioxidant activity in rats fed cholesterol-containing and cholesterol-free diets was assessed. Significant differences in the contents of dietary fibers were not found. The contents of total polyphenols, flavonoids, and anthocyanins in fresh orange and grapefruit juices were 962.1 +/- 27.2 and 906.9 +/- 27.1; 50.1 +/- 3.3 and 44.8 +/- 3.2; and 69.9 +/- 5.6 and 68.7 +/- 5.5 microg/mL, respectively. The antioxidant potential measured by the scavenging activity against nitric oxide, the beta-carotene-linoleate model system (beta-carotene), and the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diamonium salt assays was higher in orange juice but not significantly. A high level of correlation between contents of total polyphenols and flavonoids and antioxidant potential values of both juices was found. Diets supplemented with orange and to a lesser degree with grapefruit juices improved plasma lipid metabolism only in rats fed added cholesterol. However, an increase in the plasma antioxidant activity was observed in both groups. In conclusion, fresh orange and grapefruit juices contain high quantities of bioactive compounds, which guarantee their high antioxidant potential, and the positive influence on plasma lipid metabolism and plasma antioxidant activity could make fresh orange and grapefruit juices a valuable supplement for disease-preventing diets.

Identification and differences of total proteins and their soluble fractions in some pseudocereals based on electrophoretic patterns.

Genetic diversity and relationships of 11 species and cultivars belonging to different Angiosperms families were examined using sodium dodecyl sulfate seed protein markers. The protein was resolved into 36 bands (for soybean), 41 (for quinoa), 35 (for buckwheat), and 28 to 39 bands of Amaranth species, respectively. All species and cultivars can be distinguished from each other. Soybean, quinoa, and buckwheat species had a characteristic protein pattern showing a high degree of polymorphism. The protein patterns of soybean were considerably different from other species. Amaranth species had similar seed protein electrophoretic profile. The similarity coefficients calculated on the basis of presence and absence of bands ranged from 0.08 to 0.97. Following the UPGMA algorithm of similarity coefficients, the examined species and varieties could be clustered into two similarity groups. Our results did not confirm the Tachtadzjan hypothesis that Polygonales (e.g., buckwheat) and Caryophyllales (e.g., quinoa and amaranth) are closely related. Our data rather indicate occurrence of significant genetic distance (similarity coefficients 0.05-0.10). Also, it is doubtful that amaranth and quinoa species are also closely related (similarity coefficients varied from 0.16 to 0.25). It seems that soybean, quinoa, buckwheat, and amaranth (as a genus) can be considered as phylogenetic distant taxa. Differences and similarities in the secondary structure were observed by circular dichroism spectra. Some similarity was found between these plants in their soluble protein fractions and amino acid composition. These plants can be a substitution of each other as well as for cereals.

Inter-relationship between electrophoretic characteristics of pseudocereal and cereal proteins and their microscopic structure for possible substitution based on nutritional evaluation.

Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-soluble protein and buffer-soluble protein fractions were extracted from seeds and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The comparison of the identity and differences between investigated plants was carried out by the obtained SDS-PAGE electrophoretic patterns, and their microstructure was determined by scanning electron microscopy. Electrophoretic patterns of extracted proteins have shown that the main protein subunits were concentrated between 10 and 50 kDa. Variations were found in major fractions and minor bands as well as in the fine structure. The microstructure of pseudocereal and cereal protein fractions was inter-related with the results obtained by their electrophoretic separation. Pseudocereal amaranth can be used as a nutritive substitute of cereal maize in functional foods.

Structural changes in plasma circulating fibrinogen after moderate beer consumption as determined by electrophoresis and spectroscopy.

The effects of short-term moderate beer consumption (MBC) on plasma circulating fibrinogen (PCF) in patients suffering from coronary atherosclerosis were investigated by use of 2-dimensional electrophoresis (2-DE), circular dichroism (CD), and Fourier transform infrared spectroscopy (FT-IR). Forty-eight volunteers after coronary bypass surgery were divided into experimental (EG) and control (CG) groups, each of 24. Patients of the EG group consumed 330 mL of beer/day (about 20 g of alcohol) for 30 consecutive days, and CG volunteers drank mineral water instead of beer. Blood samples were collected before and after the experiment. In 21 out of 24 patients after beer consumption the plasma circulating fibrinogen was compromised: changes in its secondary structure were found. These changes were expressed in relatively low electrophoretic mobility and charge heterogeneity, decrease in alpha-helix and increase in beta-sheet, and in slight shift of amide I and II bands. Our findings indicate that one of the positive benefits of moderate beer consumption is to diminish the production of fibrinogen and its stability, which reduces the potential risk exerted by this protein. Thus, in most of beer-consuming patients some qualitative structural changes in plasma circulating fibrinogen were detected.