Soy Samples Research Articles

Chemical Composition, Microbial Properties and Sensory Evaluation of Yoghurt Made from Admixture of Buffalo, Cow and Soy Milk

The impact of using soy milk on various yoghurt properties was investigated. Five treatments of yoghurt were made from soy, buffalo or cow milk or from their mixtures. Soy milk yoghurt possessed the lowest acidity, redox potential, total solids, fat, total nitrogen, ash, total volatile fatty acids, saturated fatty acids and total amino acids contents while the buffalo’s milk yoghurt had the highest values for all the previous. Also, mixing of soymilk with buffalo or cow milk decreased these values in the resultant yoghurt. Conversely, Soymilk yoghurt had the highest level of unsaturated fatty acids and linoleic acid and α-linolenic acid. The count of Str. thermophillus was almost similar for fresh samples of soy, buffalo and cow milk yoghurt. Utilization of soy milk only or mixed with buffalo or cow milk in yoghurt manufacture clearly decreased the count of L. bulgaricus. In conculosion mixing of buffalo or cow milk with soy milk increased the sensory evaluation scores of yoghurt produced.

New approach to the fast screening of plant oil samples for F-, Cl-, Br- and S-organic compounds on the trace level

The fast method of the simultaneous determination of F−, Cl−, Br− and SO42− anions in the deionized water on the trace level by ion chromatography using thorough cleaning of respective water containers, 10μM NaHCO3 water solution as eluent, short Metrohm (50×4mm) separation column and a large water volume injection is proposed. Calculated detection limits are 10−9–10−8% depending on the element.The method for the fast screening of plant oil samples for the total fluorine-, chlorine-, bromine- and sulfur-organic compounds content (calculated for the respective elements) on the trace level is developed.It is based on the high temperature combustion of oil sample in oxygen flow, absoption of the conversion products in deionized water and whole absorbate volume analysis for F−, Cl−, Br− and SO42− anions, corresponding to the respective elements, using the developed method of these anions analysis by ion chromatography.The samples of soya, olive, sunflower and cotton seed oil were analyzed. The method detection limits (for 1mg sample) were 2×10−6%, 2×10−6%, 5×10−6% and 5×10−6% for fluorine, chlorine, bromine and sulfur, respectively. The relative standard deviation was≤15%. The method gives the compressed information about the total content of all target and nontarget fluorine-, chlorine-, bromine- and sulfur-organic compounds in plant oils.

Compositional differences in soybeans on the market: Glyphosate accumulates in Roundup Ready GM soybeans

This article describes the nutrient and elemental composition, including residues of herbicides and pesticides, of 31 soybean batches from Iowa, USA. The soy samples were grouped into three different categories: (i) genetically modified, glyphosate-tolerant soy (GM-soy); (ii) unmodified soy cultivated using a conventional “chemical” cultivation regime; and (iii) unmodified soy cultivated using an organic cultivation regime. Organic soybeans showed the healthiest nutritional profile with more sugars, such as glucose, fructose, sucrose and maltose, significantly more total protein, zinc and less fibre than both conventional and GM-soy. Organic soybeans also contained less total saturated fat and total omega-6 fatty acids than both conventional and GM-soy. GM-soy contained high residues of glyphosate and AMPA (mean 3.3 and 5.7mg/kg, respectively). Conventional and organic soybean batches contained none of these agrochemicals. Using 35 different nutritional and elemental variables to characterise each soy sample, we were able to discriminate GM, conventional and organic soybeans without exception, demonstrating “substantial non-equivalence” in compositional characteristics for ‘ready-to-market’ soybeans.

Food and feed biotechnology researches regarding the presence of genetic modification at laboratory examined soy samples

Food and feed biotechnology researches regarding the presence of genetic modification at laboratory examined soy samples

The effects of soy on freezable bread dough: A magnetic resonance study

Hygroscopic soy ingredients were hypothesised to slow the rate of water migration in unleavened bread dough during frozen storage. Thawed soy (18% dry weight) and wheat dough samples were assessed using non-destructive nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) for up to 8wks frozen storage time. MRI suggested a spatially homogeneous, net increase in proton mobility with frozen storage and, with solution state proton NMR, distinct “free” and “bound” states were discerned. T2 relaxation times of the majority proton population suggested increased mobility with frozen storage time, and statistical difference from the fresh sample was seen later for the soy samples than the wheat samples. As seen by 13C-solid state NMR, the crystallinity of the starch was not affected by either soy addition or frozen storage. In conclusion, addition of soy to bakery products led to slightly enhanced preservation of “fresh” characteristics of the dough during frozen storage.

Preparation and selective recognition of a novel solid‐phase microextraction fiber combined with molecularly imprinted polymers for the extraction of parabens in soy sample

A prepared molecularly imprinted polymer with ethyl p-hydroxybenzoate as template molecule was applied for the first time to a homemade solid-phase microextraction fiber. The molecularly imprinted polymer-coated solid-phase microextraction fiber was characterized by scanning electron microscopy and thermogravimetric analysis. Various parameters were investigated, including extraction temperature, extraction time, and desorption time. Under the optimum extraction conditions, the molecularly imprinted polymer-coated solid-phase microextraction fiber exhibited higher selectivity with greater extraction capacity toward parabens compared with the nonimprinted polymer-coated solid-phase microextraction fiber and commercial fibers. The molecularly imprinted polymer-coated solid-phase microextraction fiber was tested using gas chromatography to determine parabens, including methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, and propyl p-hydroxybenzoate. The linear ranges were 0.01-10 μg/mL with a correlation coefficient above 0.9943. The detection limits (under signal-to-noise ratio of 3) were below 0.30 μg/L. The fiber was successfully applied to the simultaneous analysis of three parabens in spiked soy samples with satisfactory recoveries of 95.48, 97.86, and 92.17%, respectively. The relative standard deviations (n=6) were within 2.83-3.91%. The proposed molecularly imprinted polymer-coated solid-phase microextraction method is suitable for selective extraction and determination of trace parabens in food samples.

Detection of pesticides in crops: A modified QuEChERS approach

The general term “pesticide” includes a large number of substances that belong to many different chemical classes. Pesticides are applied to crops at various stages of cultivation to provide protection against weeds and pests, and during post-harvest storage to preserve quality. The list of which pesticides are authorized for use in Europe is available on EU pesticides Database. The QuEChERS approach is a method designed for the analysis of pesticides in fruits and vegetables. This method is based on an extraction and clean-up step; it has been designed to be Quick Easy Cheap Effective Rugged and Safe. The aim of this study was to modify the QuEChERS method to be applied in the analysis of 9 organophosphate and 1 pyrethroid pesticides in raw materials for animal feeding introducing an additional liquid–liquid partition step. This additional step allowed us to concentrate the samples, avoiding any solvent evaporation, prior to the instrumental analysis. Once the method was optimized, it was carried out a pesticides quantization study using a GC–MS SIM multi-residue analysis. 45 samples of maize and soy coming from Northern Italy (Piedmont Region) were analysed during ten months. In 30 samples organophosphate pesticides were found up to 12.4 mg kg−1 of Chlorpyrifos, while no Deltamethrin was detected.

Preparation and evaluation of molecularly imprinted microspheres for solid‐phase extraction of 1,4‐hydroxybenzoic acid esters in soy

Molecularly imprinted microspheres (MIMs) were prepared by precipitation polymerization for the binding and recognition of 1,4-hydroxybenzoic acid esters. Ethyl p-hydroxybenzoate (EtPHB) was used as the template molecule, methacrylic acid as the functional monomer, ethylene dimethacrylate as the linking agent. It was evaluated by solid-phase extraction column packed with MIMs combined with liquid chromatography to determine trace preservatives including benzoic acid, methyl p-hydroxybenzoate, EtPHB, propyl p-hydroxybenzoate in food products. A solid-phase extraction based on MIM procedure was used to isolate four additives from the food matrix before quantitative analysis. The Scatchard plot suggested that the template-polymer system had two-site binding behavior with the dissociation constants of 0.3577 and 3.952 mg/g, respectively. The rebinding test, based on the molecularly imprinted solid-phase extraction column technique, showed the recoveries of soy samples spiked with four additives within 88.4-110.6%, with the relative standard deviations of 1.97-3.82%. Finally, the method was successfully applied for the analysis of parabens in foodstuff without traditional pretreatment.

Qualitative PCR Method for Roundup Ready® Soybean: Interlaboratory Study

Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated. Each participant extracted DNA from 1.0 g each of the soy samples containing 0, 0.05, and 0.10% of RR soy, and performed PCR with primer pairs for an internal control gene (Le1) and RR soy followed by agarose gel electrophoresis. The PCR product amplified in this PCR system for Le1 was detected from all samples. The sensitivity, specificity, and false-negative and false-positive rates of the method were obtained from the results of RR soy detection. False-negative rates at the level of 0.05 and 0.10% of the RR soy samples were 6.0 and 2.3%, respectively, revealing that the LOD of the method was somewhat below 0.10%. The current study demonstrated that the qualitative method would be practical for monitoring the labeling system of GM soy in kernel lots.

Fast analysis of isoflavones by high-performance liquid chromatography using a column packed with fused-core particles

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of an fast analysis method for the most relevant soy isoflavones. A step-by-step strategy was used to optimize temperature (25–50 °C), flow rate (1.2–2.7 mL/min), mobile phase composition and equilibration time (1–5 min). Optimized conditions provided a method for the separation of all isoflavones in less than 5.8 min and total analysis time (sample-to-sample) of 11.5 min. Evaluation of chromatographic performance revealed excellent reproducibility, resolution, selectivity, peak symmetry and low limits of detection and quantification levels. The use of a fused-core column allows highly efficient, sensitive, accurate and reproducible determination of isoflavones with an outstanding sample throughout and resolution. The developed method was validated with different soy samples with a total isoflavone concentration ranging from 1941.53 to 2460.84 μg g −1 with the predominant isoflavones being isoflavone glucosides and malonyl derivatives.

FORMULATION OF A SOY–COFFEE BEVERAGE BY RESPONSE SURFACE METHODOLOGY AND INTERNAL PREFERENCE MAPPING

ABSTRACT Coffee consumers (n = 60) tasted and rated samples of a new soy–coffee beverage made from instant coffee, soymilk powder and sugar. Ingredient concentrations (independent variables) varied according to a 23central composite design for overall degree of acceptance. Data were analyzed by analysis of variance (ANOVA), least square difference and response surface methodology, followed by internal preference mapping (IPM) with cluster analysis. ANOVA from the consumers' acceptance data revealed that samples differed significantly (P ≤ 0.05). Although soymilk content did not influence significantly the consumers' acceptance in the tested range, IPM with cluster analysis indicated that at least part of the acceptance differences was based on the soy beverage consumption habit. The final beverage formulation was evaluated cold and hot for overall acceptability (9‐point structured hedonic scale) by 112 coffee consumers and the cold beverage reached a good acceptability mean score (6.2) among the participants.PRACTICAL APPLICATIONSThe consumption of soy products has been reported to reduce the risk of several diseases and a number of recent studies have found beneficial health properties attributed to coffee. Considering the current consumer trend for healthier alternatives in food products, we decided to combine the health benefits of these two important Brazilian commodities in a functional beverage. In order to optimize the formulation and maximize sensory acceptance, we performed consumers' tests using response surface methodology. Internal preference mapping and cluster analyses were also applied to provide information on the variability of the consumer individual opinions and segment them in groups of similar preference criteria.

Characterization of 2-propanol soluble seed proteins in mutant soybean (Glycine max[L.] Merr.) lines

Seed protein pattern of control and M 10 mutant soybean ( Glycine max [L.] Merr.) lines in defatted and non-defatted raw flour was studied after 60% 2-propanol extraction, SDS-PAGE separation, colloidal staining and densitometric evaluation to detect a new variant of the protein KTI and/or BBI, furthermore to find new protein(s) of low molecular weight. Electrophoretic separation of defatted and non-defatted control soybean samples showed the same protein patterns. On the densitograms of mutant lines quantitative and qualitative differences could be observed. Defatted raw soy samples reflected more differences in the number of peaks than non-defatted ones. Beside soy trypsin inhibitors, several more soy proteins of low molecular weight are dissolved. KA mutant line 9 has a unique 2-propanol soluble protein pattern, and a new protein band of Rf=0.37 compared to the control line. Sixty percent 2-propanol soluble soybean seed proteins are suitable for cultivar identification and characterization, furthermore...

Antioxidant capacity, phenolics and isoflavones in soybean by-products

This study aimed to determine proximate composition, antioxidant capacity, total phenolic content, isoflavones and free phenolic compounds in soy by-products. High carbohydrate and protein contents were found in grade A soymilk powder (GASP) compared to grade B soymilk powder (GBSP) and soy husk powder (SHP). Ash, moisture and total dietary fibre contents were reported to be the highest in soy husk, while GBSP had the highest fat content. Antioxidant capacity as assessed using β-carotene bleaching assay was in the order of SHP ≈ GBSP > GASP, and the ranking order of the Trolox Equivalent Antioxidant Capacity (TEAC) value was GASP ≈ GBSP > SHP, while the Ferric Reducing Antioxidant Power (FRAP) value was GASP > GBSP > SHP. The total phenolic content was in the range of 62.44–103.86 mg GAE/100 g wet weight, and the major phenolic compounds in free form were ferulic, vanilic as well as gallic acids. Acid hydrolysis increased the amount of total extractable isoflavone in all soy samples.

Using multiple PCR and CE with chemiluminescence detection for simultaneous qualitative and quantitative analysis of genetically modified organism

In this paper, an ultrasensitive CE-CL detection system coupled with a novel double-on-column coaxial flow detection interface was developed for the detection of PCR products. A reliable procedure based on this system had been demonstrated for qualitative and quantitative analysis of genetically modified organism-the detection of Roundup Ready Soy (RRS) samples was presented as an example. The promoter, terminator, function and two reference genes of RRS were amplified with multiplex PCR simultaneously. After that, the multiplex PCR products were labeled with acridinium ester at the 5'-terminal through an amino modification and then analyzed by the proposed CE-CL system. Reproducibility of analysis times and peak heights for the CE-CL analysis were determined to be better than 0.91 and 3.07% (RSD, n=15), respectively, for three consecutive days. It was shown that this method could accurately and qualitatively detect RRS standards and the simulative samples. The evaluation in terms of quantitative analysis of RRS provided by this new method was confirmed by comparing our assay results with those of the standard real-time quantitative PCR (RT-QPCR) using SYBR Green I dyes. The results showed a good coherence between the two methods. This approach demonstrated the possibility for accurate qualitative and quantitative detection of GM plants in a single run.

Effects of extraction temperature, ionic strength and contact time on efficiency of bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micellar backward extraction of soy protein and isoflavones from soy flour

AbstractBACKGROUND: Soy protein enriched with isoflavones has been linked to various disease‐preventing and health‐promoting activities owing to the antihypertensive, hypocholesterolaemic, antiobesity and antioxidative properties of isoflavones. The isoflavone profiles of soy‐based products are known to be highly dependent on the various chemical and physical treatments to which the products have been subjected. The aim of this research was to increase the efficiency of backward extraction of soy protein and isoflavones from bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles by studying the effects of extraction temperature, ionic strength of the aqueous stripping solution and contact time on the amounts of soy protein and isoflavones backward extracted from an AOT/H2O/isooctane reverse micellar system.RESULTS: By modifying the extraction temperature, ionic strength and contact time, 47.0–60.2% of protein, 43.3–68.4% of daidzin, 43.8–74.6% of genistin, 39.0–88.8% of glycitin, 20.8–92.6% of malonyl genistin, 20.2–52.0% of malonyl glycitin, 32.7–75.6% of acetyl genistin, 49.7–76.8% of daidzein and 19.6–38.1% of genistein present in the AOT reverse micellar solution were backward extracted into the aqueous stripping phase. Statistical analysis showed that there were significant linear and interactive effects of temperature and contact time on the backward extraction of daidzin, genistin, glycitin and daidzein. Significant linear and interactive effects of ionic strength and contact time were found in the backward extraction of daidzin and genistin. The backward extraction of genistein was only influenced by contact time and its interaction with temperature.CONCLUSION: This study showed the potential of reverse micelles as a protocol for extracting isoflavones from soy samples for analytical purposes. By modifying the extraction temperature, contact time and ionic strength, soy protein enriched with daidzin, genistin, daidzein and genistein could be produced from soy flour. The results represent an important contribution to current knowledge on utilising reverse micellar extraction in food technology. Copyright © 2007 Society of Chemical Industry

Effect of Heat Damage in an Autoclave on the Reactive Lysine Contents of Soy Products and Corn Distillers Dried Grains with Solubles. Use of the Results To Check on Lysine Damage in Common Qualities of These Ingredients

The suitability of the homoarginine reaction for determining the reactive lysine in soy products and corn distillers dried grain with solubles (DDGS) was tested. For this purpose, some batches were subjected to deliberate heat damage for up to 30 min in an autoclave with 135 degrees C hot steam, and the samples were analyzed for total lysine and reactive lysine. In addition, 84 samples of common soy and 80 samples of corn DDGS were tested for their content of total and reactive lysine, and the contents were compared with those of the autoclave tests. For soy products conclusive results were obtained. In the case of heat treatment, both total lysine and reactive lysine decrease, but the latter is clearly a more sensitive indicator of lysine damage. Most normal products are quite similar, with toasting-induced damage to reactive lysine of ca. 15% compared to untoasted beans. The cause of the constantly occurring residual lysine after guanidination and the poorer reaction balance in the case of damage were explained. For common DDGS samples, however, less favorable results were obtained. Reactive and total lysine decreased almost in parallel due to heat damage, showing a great gap between them. Results showed indeed that variation of total and reactive lysine in DDGS is high, proving that its production conditions are not yet optimal for a feed ingredient.

A Proteomic Study to Identify Soya Allergens – The Human Response to Transgenic versus Non-Transgenic Soya Samples

Background: In spite of being among the main foods responsible for allergic reactions worldwide, soybean (Glycine max)-derived products continue to be increasingly widespread in a variety of food products due to their well-documented health benefits. Soybean also continues to be one of the elected target crops for genetic modification. The aim of this study was to characterize the soya proteome and, specifically, IgE-reactive proteins as well as to compare the IgE response in soya-allergic individuals to genetically modified Roundup Ready soya® versus its non-transgenic control. Methods: We performed two-dimensional gel electrophoresis of protein extracts from a 5% genetically modified Roundup Ready flour sample and its non-transgenic control followed by Western blotting with plasma from 5 soya-sensitive individuals. We used peptide tandem mass spectrometry to identify soya proteins (55 protein matches), specifically IgE-binding ones, and to evaluate differences between transgenic and non-transgenic samples. Results: We identified 2 new potential soybean allergens – one is maturation associated and seems to be part of the late embryogenesis abundant proteins group and the other is a cysteine proteinase inhibitor. None of the individuals tested reacted differentially to the transgenic versus non-transgenic samples under study. Conclusion: Soybean endogenous allergen expression does not seem to be altered after genetic modification. Proteomics should be considered a powerful tool for functional characterization of plants and for food safety assessment.

Evaluation of Accuracy of Electrochemical Isoflavonoid Index for the Determination of Total Isoflavones in Soy Samples

AbstractThe accuracy of a novel electroanalytical route to determine total isoflavones using a secondary standard from Drug Master File (SW/1211/03) as metrological reference with well‐known traceability and its applicability using representative soy samples is demonstrated. Calibration protocols were used i) for choosing a suitable isoflavone standard to determine the total isoflavone content, ii) to evaluate matrix effects and, iii) to evaluate the overall reliability and performance of the method in analytical operations, extraction and analysis. The inherent electroactivity of both, aglycones and glycoside structures and the similar analytical sensitivity exhibited by the prominent soy isoflavones was relevant to determine the total amount with reliability in terms of accuracy (E<10%) and precision (RSDs<7%) in soy samples. In consequence, the introduction of the term isoflavonoid index as the total amount of isoflavones obtained when they are amperometrically monitorized at +1.0 V as a particular case of the electrochemical index concept is proposed.

Detection of Genetically Modified Soy in Doughs and Cookies

ABSTRACTIn many countries, including the European Union member states, Switzerland, Australia, New Zealand, and Japan, legislation has been set up for labeling of genetically modified organisms (GMOs) in food and feed products. To comply with these regulations, reliable detection methods are necessary. If the detection is based on DNA, a GMO analysis may contain several steps where qualitative and quantitative species‐specific, GMO screening, GMO construct, and GMO line‐specific polymerase chain reactions (PCRs) are used. A limit of detection (LOD) thereby defines to what extent a target molecule may be detected in a sample. In this study, cookies were made with variable levels of a soy sample containing 2 wt% Roundup Ready soy. For all PCRs described, detection limits based on dilution series and practical LODs were determined. The practical LODs are used to determine to what extent a GMO ingredient may be detected in a real food product. Results reveal that, due to the baking process, the overall DNA fragment length is reduced, rendering GMO analyses more difficult. Furthermore, Roundup Ready soy line‐specific and real‐time quantitative PCR are less sensitive than GMO screening PCRs, whereas just these PCRs are crucial in the decision‐making process regarding the presence of GMOs in a food product. Moreover, high standard deviations and errors render the precise quantification of GMOs difficult.

Method validation for the analysis of 169 pesticides in soya grain, without clean up, by liquid chromatography–tandem mass spectrometry using positive and negative electrospray ionization

Part of a comprehensive study on the comparison of different extraction methods, GC–MS(/MS) and LC–MS/MS detection methods and modes, for the analysis of soya samples is described in this paper. The validation of an acetone-based extraction method for analysis of 169 pesticides in soya, using LC–MS/MS positive and negative electrospray ionisation (ESI) mode, is reported. Samples (5 g) were soaked with 10 g water and subsequently extracted with 100 mL of a mixture of acetone, dichloromethane and light petroleum (1:1:1), in the presence of 15 g anhydrous sodium sulphate. After centrifugation, aliquots of the extract were evaporated and reconstituted in 1.0 mL of methanol, before direct injection of the final extract (corresponding with 0.05 g soya mL −1) into the LC–MS/MS system. Linearity, r 2 of calibration curves, instrument limit of detection/quantitation (LOD/LOQ) and matrix effect were evaluated, based on seven concentrations measured in 6-fold. Good linearity (at least r 2 ≥ 0.99) of the calibration curves was obtained over the range from 0.1 or 0.25 to 10.0 ng mL −1, corresponding with pesticide concentrations in soya bean extract of 2 or 5–200 μg kg −1. Instrument LOD values generally were 0.1 or 0.25 ng mL −1. Matrix effects were negligible for ≈90% of the pesticides. The accuracy, precision and method LOQ were determined via recovery experiments, spiking soya at 10, 50, 100 μg kg −1, six replicates per level. In both ESI modes, method LOQ values were mostly 10 or 50 μg kg −1 and more than 70% of pesticides analysed by each mode met the acceptability criteria of recovery (70–120%) and RSD (≤20%), at one or more of the three levels studied. A fast, easy and efficient method with acceptable performance was achieved for a difficult matrix as soya, without cleanup.