Meal Suspension Research Articles

Kinetics of dissolution and Transglutaminase (TGase)-catalyzed polymerization of soy proteins from the soy meal suspension

It is important to understand the kinetics of dissolution and transglutaminase(TGase)-catalyzed polymerization process of soy proteins from the soy meal either for their extraction or utilization in the food industry. Nevertheless, it is yet still unknown that how the specie concentration, degree of denaturation, subunit composition, and aggregation state evolve with kinetics time (t). This work combines ultraviolet–visible spectroscopy (UV–vis), Fourier infrared transform spectrum (FTIR), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and size exclusion chromatography (SEC) to explore the above questions by using the soy proteins from the defatted soy meal as the model system. Our main findings include: 1) under the condition of soy meal with varied mass fraction/solid content (wtsoy meal% = 5%, 10%, 15%, and 20%) in pure water and buffer with pH = 6.4 at T = 25 °C, the dual exponential equation is found to illustrate the dissolution kinetics which is contributed by two different dissolution modes, i.e., C = − B1e−k1t − B2e−k2t + B1+ B2, where B1 and B2 denote the final concentration of protein, and k1 and k2 represent the dissolution rate for each dissolution mode, respectively; 2) the analysis of the secondary structure of soy proteins shows that the proteins keep undenatured state during the dissolution process; 3) the analysis of relative content of different subunits indicates that the relative concentration of 7S and 11S is almost constant during the dissolution process; 4) SEC results unambiguously support that the dissolution species at most of time are composed of protein aggregates with different sizes; 5) a semi-empirical equation is proposed to well describe the TGase-catalyzed polymerization kinetics, i.e., dnp/dtp = 0.5wtsoy meal%0.8±0.1wtTGase%1.5±0.1, where dnp/dtp is the generation ratio of insoluble protein particle, and wtTGase% is the concentration of TGase. We believe that the knowledge from present study is beneficial for the optimization of extraction and polymerization processes in real applications.

Characterization of transit rates in the large intestine of mice following treatment with a CGRP antibody, CGRP receptor antibody, and small molecule CGRP receptor antagonists.

ObjectiveTo characterize the effects of blocking calcitonin gene‐related peptide (CGRP) activity in a mouse model of gastrointestinal transport.BackgroundMigraine management using CGRP modulating therapies can cause constipation of varying frequency and severity. This variation might be due to the different mechanisms through which therapies block CGRP activity (e.g., blocking CGRP, or the CGRP receptor) with antibodies or receptor antagonists. The charcoal meal gastrointestinal transit assay was used to characterize constipation produced by these modes of therapy in transgenic mice expressing the human receptor activity–modifying protein 1 (hRAMP1) subunit of the CGRP receptor complex.MethodsMale and female hRAMP1 mice were dosed with compound or vehicle and challenged with a charcoal meal suspension via oral gavage. The mice were then humanely euthanized and the proportion of the length of the large intestine that the charcoal meal had traveled indicated gastrointestinal transit.ResultsAntibody to the CGRP receptor produced % distance traveled (mean ± standard deviation) of 31.8 ± 8.2 (4 mg/kg; p = 0.001) and 33.2 ± 6.0 (30 mg/kg; p < 0.001) compared to 49.7 ± 8.3 (control) in female mice (n = 6–8), and 35.6 ± 13.5 (30 mg/kg, p = 0.019) compared to 50.2 ± 14.0 (control) in male mice (n = 10). Telcagepant (5 mg/kg, n = 8) resulted in % travel of 30.6 ± 14.7 versus 41.2 ± 8.3 (vehicle; p = 0.013) in male mice. Atogepant (3 mg/kg, n = 9) resulted in % travel of 30.6 ± 12.0, versus 41.2 ± 3.7 (control; p = 0.030) in female mice. The CGRP antibody galcanezumab (n = 7–10; p = 0.958 and p = 0.929) did not have a statistically significant effect.ConclusionsThese results are consistent with reported clinical data. Selectively blocking the CGRP receptor may have a greater impact on gastrointestinal transit than attenuating the activity of the ligand CGRP. This differential effect may be related to physiologically opposing mechanisms between the CGRP and AMY1 receptors, as the CGRP ligand antibody could inhibit the effects of CGRP at both the CGRP and AMY1 receptors.

Ginsenoside Compound K Promotes Intestinal Peristalsis and the Pharmacokinetic of Metabolite 20(S)-Protopanaxadiol in Relation to Diarrhea

Ginsenoside compound K (G-CK) is a rare ginsenoside originating from the traditional herbal medicine ginseng. Recently, G-CK has been found to cause diarrhea in preclinical researches as a candidate drug. This study is aimed at the potential mechanism of G-CK-induced diarrhea. In this study, we found that the treatment of G-CK significantly increased the peristaltic index (PI) with the intragastric administration of charcoal meal suspension at 90 minutes (not 30 min) after the administration of G-CK and had a clear role in promoting defecation. The Ach and 5-HT levels in colon tissue were not affected by G-CK. Additionally, the clinical trial revealed that subjects with diarrhea had lower exposure and higher Vz / F of 20(S)-protopanaxadiol (PPD) than nondiarrhea subjects, and there were no statistical differences in the pharmacokinetic parameters of G-CK between diarrhea and nondiarrhea subjects. We therefore concluded that the increased intestinal peristalsis and metabolite 20(S)-PPD were involved in G-CK-induced diarrhea.

Modified soybean meal polysaccharide with high adhesion capacity to Salmonella

Carbohydrates are known to act as analog receptors for bacteria and therefore are promising alternatives for the control and prevention of bacterial infections. The present study evaluated the chemical structure of modified soybean meal polysaccharides and their capacity to adhere enterobacteria (Salmonella Typhimurium) and to interfere with the bacteria adhesion to the known analogue receptors, using in vitro assays. For this, soybean meal suspensions were subjected to a thermochemical extraction process and structural analyses showed that the fraction with higher adhesion and adhesion-inhibition potential, SAP, was constituted by two types of polysaccharides: a partially depolymerized pectin, of high molar mass, composed of xylogalacturonan and rhamnogalacturonan regions (SAP1, 545.5 kDa), and a (1 → 4)-linked-β-D-galactan of low molar mass (SAP2, 8.7 kDa). The results showed a high affinity of Salmonella for galactans, while high molar mass pectins showed no adhesion capacity. The chemical compositions of the fractions suggested that galactose could be responsible for the recognition process in the adhesion process. Other factors, such as structure and degree of polymerization of the polymers, may also be influencing the adhesion process. Modified soybean meal polysaccharides appear to be a promising alternative agent to antibiotics for the control and prevention of foodborne diseases.

Purification and characterization of a novel β-glucosidase from Aspergillus flavus and its application in saccharification of soybean meal

Aspergillus flavus has been regarded as a potential candidate for its production of industrial enzymes, but the details of β-glucosidase from this strain is very limited. In herein, we first reported a novel β-glucosidase (AfBglA) with the molecular mass of 94.2 kDa from A. flavus. AfBglA was optimally active at pH 4.5 and 60 °C and is stable between pH 3.5 and 9.0 and at a temperature of up to 55 °C for 30 min remaining more than 90% of its initial activity. It showed an excellent tolerance to Trypsin, Pepsin, Compound Protease, and Flavourzyme and its activity was not inhibited by specific certain cations. AfBglA displayed broad substrate specificity, it acted on all tested pNP-glycosides and barley glucan, indicating this novel β-glucosidase exhibited a β-1, 3-1, 4-glucanase activity. Moreover, the AfBglA could effectively hydrolyze the soybean meal suspension into glucose and exhibit a strong tolerance to the inhibition of glucose at a concentration of 20.0 g/L during the saccharification. The maximum amount of the glucose obtained by AfBglA corresponded to 67.0 g/kg soybean meal. All of these properties mentioned above indicated that the AfBglA possibly attractive for food and feed industry and saccharification of cellulolytic materials.

Genome and secretome of Chondrostereum purpureum correspond to saprotrophic and phytopathogenic life styles.

The basidiomycete Chondrostereum purpureum (Silverleaf fungus) is a saprotroph and plant pathogen commercially used for combatting forest “weed” trees in vegetation management. However, little is known about its lignocellulose-degrading capabilities and the enzymatic machinery that is responsible for the degradative potential, and it is not yet clear to which group of wood-rot fungi it actually belongs. Here, we sequenced and analyzed the draft genome of C. purpureum (41.2 Mbp) and performed a quantitative proteomic approach during growth in submerged and solid-state cultures based on soybean meal suspension or containing beech wood supplemented with phenol-rich olive mill residues, respectively. The fungus harbors characteristic lignocellulolytic hydrolases (GH6 and GH7) and oxidoreductases (e.g. laccase, heme peroxidases). High abundance of some of these genes (e.g. 45 laccases, nine GH7) can be explained by gene expansion, e.g. identified for the laccase orthogroup ORTHOMCL11 that exhibits a total of 18 lineage-specific duplications. Other expanded genes families encode for proteins more related to a pathogenic lifestyle (e.g. protease and cytochrome P450s). The fungus responds to the presence of complex growth substrates (lignocellulose, phenolic residues) by the secretion of most of these lignocellulolytic and lignin-modifying enzymes (e.g. alcohol and aryl alcohol oxidases, laccases, GH6, GH7). Based on the genetic and enzymatic constitution, we consider the ‘marasmioid’ fungus C. purpureum as a ‘phytopathogenic’ white-rot fungus (WRF) that possesses a complex extracellular enzyme machinery to accomplish efficient lignocellulose degradation during both saprotrophic and phytopathogenic life phases.

Initial Hunger Meal Pattern and 20% Reduction in Energy Intake

At meals, people aim to maintain their usual energy level and balance in blood and all tissues. People have subjectively refined this aim through poorly conscious months and years, i.e., outside any comparison with other people, other times or feeding conditions. The preprandial weekly mean blood glucose can assess this individual aim that differs from other people in the general fattening/ diabetes development. The evaluation of this pathogenic development in the overall stratification shows how unhealthy is the subject’s energy imbalance. After 2 - 48 hours of meal suspension, the aim arises as Initial Hunger. This Initial Hunger serves as reference sensation in the assessment of current energy availability. Recognition of three Initial Hunger arousals per day produces an even energy balance and eliminates any conditioned intake. This meal pattern seemed a useful chance to reverse current trends in overweight increase. Two reliable authorities (National Institute of Health and New England Journal of Medicine) noticed that already, all dieticians instructed to wait for hunger arousal before meals to limit energy intake for body weight loss. Dieticians’ definition and instructions on hunger for body weight loss miss any distinction from conditioned energy intake and are ineffective. Present report shows the need for improving awareness on hunger.

Pengaruh Pemberian Minyak Atsiri Daun Kemangi (Ocimum americanum L.) Terhadap Motilitas Usus Mencit Putih Jantan

Kemangi (Ocimum americanum L.) is a well known plant that contains essential oils with citral as a major compound. Citral is reported to have beneficial effect on intestinal motility. This reseach investigated the effect of essential oil of kemangi leaves (Ocimum americanum L.) on male DDY mices intestinal motility. Thirty mices were divided into six groups and each group was pretreated with 0,2 ml of 0,5% CMC (negative control), 1 mg/kg BW of atropine sulfate (positive control), 5 mg/kg BW of citral (comparative control), and three dose variation of volatile oil of kemangi leaves (25 mg/kg BW; 50 mg/kg BW; 100 mg/kg BW) orally. All mices were given charcoal meal suspension 0,2 ml orally, and the animals were sacrificed. The percentage ratio and inhibition were analysed by measure the intestinal transit of charcoal. The results showed that the essential oil of kemangi leaves dose 100 mg/kg BW significantly (p l 0.05) reduced intestinal transit in mice with the percentage inhibition value of 59,79%. This value is not significant different (pg 0.05) compared with citral and atropine sulfate. This research concluded that the essential oil of kemangi leaves has potential effect as antispasmodic agent.

Recovery of Hunger Sensations Associated with Low Preprandial Blood Glucose: An Easy Exit from Diabetes?

Background: Obesity, diabetes, asthma, autism, birth defects, dyslexia, attention deficit-hyperactivity disorder and schizophrenia have increased in children in the last half century. These increases may depend on the widespread, well known error in energy balance: the unremitting addition of fat at any will (decision) to eat. In most (60%) but not all people, the decision arises as conditioned before energy exhaustion of the energy available from previous meals. After meal suspension for few hours (up to 48 hours), healthy subjects identified the arousal of sensations of hunger that we named Initial Hunger (IH). After this identification, subjects distinguished IH from conditioned sensations before subsequent meals by mental comparison of the current arousal with the remembered IH. BG decreased to 76.6 ± 3.7 mg/dL and hunger sensations (Initial hunger, IH) arose spontaneously and corresponded to the complete exhaustion of the previous meals. Objective: Not Insulin Dependent (NID) diabetic people differ from fattening people in this: after meal suspension, they do not develop any hunger sensation nor the associated low blood glucose (BG). Methods: Meal suspension lets IH arise and after no arousal, reduction of energy intake. The two subjects consumed meals that provided at least 20 grams of animal protein and up to one kg of not-starchy vegetable (NSV) for 6 to 12 months. At reappearance of IH, we implemented an Initial Hunger Meal Pattern (IHMP). Results: We tried to implement IHMP training in two obese (BMI of 39 and 33) adults out of two consecutive recruitments of subjects who showed high fasting BG. We found an absence of BG decline to 76.6 ± 3.7 mg/dL and an absence of any hunger sensation after eating suspension. Both subjects lost 13% - 20% of their body weight and recovered 76.6 ± 3.7 mg/dL of BG and hunger sensations, i.e., went off diabetes. IHMP maintained the decreased body weight in the subsequent months. Conclusion: Diabetes develops for inveterate conditioned intake (when previous energy intake has not been fully exhausted before meals), excessive fattening (with presumed excessive post-absorption emission of fatty acids from fatty tissues), permanent loss of BG decline to 76.6 ± 3.7 mg/dL and permanent loss of physiological signals of hunger. A healthy, non-diabetic life may be recovered by painless loss of weight up to 20%. The body weight remained stable by implementing IHMP at reappearance of hunger sensations. This costs accurate energy intake planning instead of hunger endurance.

Conditioned Intake and Fattening/Diabetes

Background: Obesity, diabetes, asthma, autism, birth defects, dyslexia, attention deficit-hyperactivity disorder, and schizophrenia have increased in children in the last half century. The will (decision) to eat develops often when previous energy intake has been incompletely exhausted. Objective: The will to eat develops after stimuli (often external) that do not correlate with energy availability in blood. Training a relation between hunger sensations (Initial Hunger, IH) and Blood Glucose (BG) as an index of energy availability allows an IH Meal Pattern that is associated with low mean BG and insulin sensitivity. Lack of any relation between the will to eat and the energy availability is a widespread error that may be responsible of health deterioration in children as well as in adults. Methods: After meal suspension and with synchronous blood glucose (BG) measurements, we taught patients to distinguish hunger sensations that are conditioned from those that arise after meal suspension (Initial Hunger, IH). This hunger (after meal suspension) signals a complete exhaustion of previous intake and is appropriate for meal onset to obtain meal-by-meal fasting nutrient levels and low BG prior to the next meal and establish an even balance. This pattern has been termed the Initial Hunger Meal Pattern (IHMP). Results: In contrast with untrained control subjects, trained subjects accurately recognized IH by synchronous BG measurements. We report here the identification of Initial Hunger (the subjective limit), the daily adjustments to three arousals for weeks and months, the diffusion of the error in untrained child and adult population, the validations of the IH and BG assessments and the improvements of 18 parameters by IHMP. Conclusion: The will to eat develops as a conditioned event and this conditioned will causes positive energy imbalance and insulin resistance/fattening. The imbalancing will to eat may be corrected by becoming aware of differences between the conditioned sensations of hunger and the sensations that develop after meal suspension.

The Calcium Looping Process for Low CO2 Emission Cement Plants

The aim of this work is investigating the application of the Calcium looping process in cement plants with CO2 capture. A novel configuration with oxyfuel calciner and a carbonator integrated in the raw meal suspension preheater has been assessed by means of process simulations. The results obtained show a high potential of the proposed process, with equivalent avoided CO2 emissions (i.e. accounting for credits associated to electric power export) of about 94%, vs. 76% obtained for a competitive oxyfuel cement plant.

Using human-severe combined immunodeficiency (hu-SCID) mice as a model for testing allergenicity of genetically modified organisms (GMOs)

Background GM peas expressing the alpha-amylase inhibitor (AAI) protein derived from common Tendergreen bean were created to protect them against infestation by pea weevils. Although animal models are used for studying allergenicity of GM containing foods, the correlation with human allergy remains controversial. Methods Our aim in this study was to establish a humanized mouse model to study GMOs by adoptively transferring peripheral blood mononuclear cells from AAI-specific IgE-positive legume allergic and non-allergic individuals into SCID mice. These mice were then gavaged twice weekly for 1 month with GM pea, non-transgenic pea and Tendergreen bean seed meal suspensions or PBS. Subsequently, mice were administered 1 dose of the purified AAI protein or PBS intranasally as a read out for an in vivo allergic response. Seventy-two hours later, no eosinophilia or mucus hypersecretion were observed in the lungs of mice treated with PBS or fed the non-transgenic peas. Results In contrast, hu-SCID mice derived from allergic and nonallergic donors had intense allergic lung inflammation and mucus over production illustrating that AAI-containing seed meal feeding primed for allergic immune responses. However, there were no differences in the responses between hu-SCID mice derived from allergic and nonallergic donors. Because both donors had anti-AAI antibodies, we hypothesize that they were both sensitized to AAI and thus indistinguishable when their cells were exposed to AAI during feeding in the humanized mice. Conclusion

The effect of hydrogen peroxide bleaching of canola meal on product colour, dry matter and protein extractability and molecular weight profile

SummaryThe aim of this study was to bleach canola meal by hydrogen peroxide to understand the treatment effect on product colour, dry matter and nitrogen extractability. Meal suspensions at 2.5%, 5% and 10% (w/v) were treated in 3, 6 and 10% H2O2 at pH 3, 7 and 10. The bleached meal was extracted under acidic and alkaline conditions. The results showed a high bleaching effectiveness of canola meal by H2O2. The L* parameter was increased from 47.18 ± 0.56 up to 86.80 ± 1.05. Effect of pH was significant and the highly bleached meal was obtained at pH 10. Extractability of dry matter was increased when the meal was treated with H2O2, from 26.87 ± 0.10% for the control meal up to 83.20 ± 0.59% for the meal treated in 10% H2O2 in a 2.5% (w/v) suspension. Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis showed a depolymerisation effect of H2O2 on the high molecular weight proteins.

Interruption of scheduled, automatic feeding and reduction of excess energy intake in toddlers

Childhood obesity due to the consumption of excess calories is a severe problem in developed countries. In a previous investigation on toddlers, hospital laboratory measurements showed an association of food-demand behavior with constant lower blood glucose before meals than for scheduled meals. We hypothesize that maternal scheduling of meals for toddlers results in excess energy intake compared to feeding only on demand (previously "on request"). We tested the cross-sectional null hypothesis of no difference in energy intake between scheduled (automatic) and demanded meals (administered after evaluation) in 24 mother-toddler (21 months old at entry) pairs with chronic, nonspecific diarrhea presenting at a clinic. We tested the same hypothesis in a subset of 14 toddlers by measuring the resting (sleeping) metabolic rate 4 hours after lunch, as well as the total daily energy expenditure (TEE) in 10 toddlers. We trained mothers to recognize meal demands (as in the previous investigation) and to provide food in response, but required no blood glucose measurements before meals. Energy intake was assessed by a 10-day food diary, resting metabolic rate (RMR) by respiratory analyses (indirect calorimetry) in 14 toddlers, and TEE by doubly labeled water in 10 toddlers. Their blood parameters, anthropometry, and number of days with diarrhea were assessed before training and 50 days after training. RMR decreased from 58.6 ± 7.8 to 49.0 ± 9.1 kcal/kg/d (P < 0.001) and TEE decreased from 80.1 ± 6.9 to 67.8 ± 10.0 kcal/kg/d (P < 0.001). Energy intake decreased from 85.7 ± 15.3 to 70.3 ± 15.8 kcal/kg/d (P < 0.001). The height Z-score increased significantly, while weight growth was normal. Toddlers entering the study over the median RMR decreased their RMR significantly more than those below the median RMR (P < 0.01). Scheduled meal suspension induces meal demand frequency to increase. Demanded meals are associated with significantly lower energy intake, RMR, and TEE than scheduled meals. Feeding on demand may be an effective skill in a strategy for reducing excess energy intake in the long term and in regulating body weight in toddlers and children.

Earthworm diversity in urban habitats of Basel (Northwestern Switzerland)

The diversity and ecology of the soil fauna in Central European towns is not yet well known. There are references that earthworms, by their biomass, dominate all other animal groups in cities – surpassed only by man. Basel (11 km2) is, with its 170 000 inhabitants, Switzerland’s third largest community. Open green spaces in the city are scarce; the green belt is narrow. Nevertheless, in more than 60 locations studied between 1999 and 2010, 22 species (12 genera) of Lumbricidae were found. Eleven near-natural habitats could be sampled: private front gardens and backyards, wooded river sides, industrially watered flood plain forest plots, and a Zoological Garden with a large number of green spaces built up from imported soil. Nearly a dozen of these species are quite rare in their natural distribution area and in Basel; many of them are riparian, e.g. Aporrectodea georgii, Fitzingeria platyura depressa, and Helodrilus oculatus – while two are strictly endogeic (Allolobophora satchelli, Murchieona muldali). The sampling method “digging and hand-sorting plus mustard meal suspension” yielded the best possible quantitative results in urban habitats. A maximum of earthworm species (18) was sampled in the Zoological Garden, and the intensely used public lawns had the highest mean density and biomass (450 individuals resp. 280 g fresh mass/m2).

Ultrasound-assisted production of bioethanol by simultaneous saccharification and fermentation of corn meal

Abstract An ultrasound-assisted liquefaction as a pretreatment for bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. Ultrasound pretreatment (at a frequency of 40 kHz) was performed at different sonication times and temperatures, before addition of liquefying enzyme. An optimal duration of the treatment of 5 min and sonication temperature of 60 °C were selected, taking into account glucose concentration after the liquefaction step. Under the optimum conditions an increase of glucose concentration of 6.82% over untreated control sample was achieved. Furthermore, the SSF process kinetics was assessed and determined, and the effect of ultrasound pretreatment on an increase of ethanol productivity was investigated. The obtained results indicated that the ultrasound pretreatment could increase the ethanol concentration by 11.15% (compared to the control sample) as well as other significant process parameters. In this case, the maximum ethanol concentration of 9.67% w/w (which corresponded to percentage of the theoretical ethanol yield of 88.96%) was achieved after 32 h of the SSF process. A comparison of scanning electron micrographs of the ultrasound-pretreated and untreated samples of corn meal suspensions showed that the ultrasound stimulated degradation of starch granules and release of glucose, and thereby accelerated the starch hydrolysis due to the cavitation and acoustic streaming caused by the ultrasonic action.

A microwave-assisted liquefaction as a pretreatment for the bioethanol production by the simultaneous saccharification and fermentation of corn meal

A microwave-assisted liquefaction as a pretreatment for the bioethanol production by the simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. An optimal power of microwaves of 80 W and the 5-min duration of the microwave treatment were selected by following the concentration of glucose released from the corn meal suspensions at hidromodul of 1:3 (corn meal to water ratio) in the liquefaction step. The results indicated that the microwave pretreatment could increase the maximum ethanol concentration produced in the SSF process for 13.4 %. Consequently, a significant increase of the ethanol productivity on substrate (YP/S), as well as the volumetric ethanol productivity (P) in this process, could be achieved.

Mineralization of 14C-labelled synthetic lignin and extracellular enzyme activities of the wood-colonizing ascomycetes Xylaria hypoxylon and Xylaria polymorpha

Two wood-dwelling ascomycetes, Xylaria hypoxylon and Xylaria polymorpha, were isolated from rotting beech wood. Lignin degradation was studied following the mineralization of a synthetic [formula: see text]-labelled lignin in solid and liquid media. Approximately 9% of the synthetic lignin was mineralized by X. polymorpha during the growth on beech wood meal, and the major fraction (65.5%) was polymerized into water- and dioxan-insoluble material. Both fungi produced laccase (up to 1,200 U l-1) in an agitated complex medium based on tomato juice; peroxidase activity (<80 U l-1) was only detected for X. polymorpha in soybean meal suspension. The enzymatic attack of X. polymorpha on beech wood resulted in the formation of three fractions of water-soluble lignocellulose fragments with molecular masses of 200, 30 (major fraction) and 3 kDa, as demonstrated by high-performance size exclusion chromatography. This fragment pattern differs considerably from that of the white-rot fungus Bjerkandera adusta, which preferentially released smaller lignocellulose fragments (0.8 kDa). The finding that X. polymorpha produced large lignocellulose fragments, along with the fact that high levels of hydrolytic enzymes (esterase 630 U l-1, xylanase 120 U l-1) were detected, indicates the cleavage of bonds between the lignin and hemicellulose moieties.

Effect of heat treatment and pH on the thermal, surface, and rheological properties of Lupinus albus protein

AbstractEndosperm from hand‐dissected and‐ dehulled Lupinus albus seeds was milled into meal, sieved through a 40‐mesh screen, and suspended in phosphate buffers (pH 4, 6.8, and 8) at 20% (wt/vol). The suspensions were treated at 75, 90, or 100°C for 1 h. The heat‐treated protein was characterized by SDS‐PAGE, free zone capillary electrophoresis (FZCE), and DSC; and its surface hydrophobicity, surface tension, and rheological properties were examined. The presence of high M.W. aggregates was apparent from SDS‐PAGE and FZCE results. Solubility was lowest at pH 4 and 100°C. DSC analysis was performed on low moisture content samples (3.1%) and 20% (wt/vol) suspensions. DSC analysis at 3.1% moisture content showed a glass transition around 85°C and an exothermic transition at 160°C, whereas the protein suspension showed a more thermally stable protein as indicated by the higher ΔH values. Lupin protein was surface active as demonstrated by its effectiveness in reducing the surface tension of the aqueous phosphate buffer. Surface hydrophobicity of the heat‐treated protein decreased as the treatment temperature increased, which supports the SDS‐PAGE results. The highest level of aggregation was noted at 90°C and pH 6.8 as indicated by low surface hydrophobicity values. Rheological studies showed direct relationships between the shear storage modulus (G′) of the lupin meal suspension and both pH and temperature treatment, although this effect is minimal at the highest temperature (100°C) and pH 6.8.

Predicting Baking Performance from Rheological and Adhesive Properties of Rye Meal Suspensions During Heating

ABSTRACTRheological methods were used to study the behavior of rye meal suspensions during a time‐temperature treatment corresponding to the initial baking conditions (&lt;70°C). Eight different rye cultivars were investigated, with four of the cultivars grown during two different years. Baking experiments included pan bread and hearth bread. Viscosity, falling number, and the amount of adhesive material present during heating were measured. The storage (G′) and loss (G″) moduli increased during a temperature sweep from 45°C, reaching a maximum at 62.1–67.1°C. At the same time, the amount of adhesive material increased. A further increase in temperature caused a decrease in G′ and G″, whereas the amount of adhesive material continued to increase. The mechanical spectra (G′ or G″ vs. frequency) showed that the rye meal suspensions had gel‐like behavior at 45°C which turned into behavior typical of a strong gel at 70°C. The rye meals performing the best in hearth bread baking gave intermediate values of G′ and G″ and high values of the phase shift (δ) at 45°C. During the temperature sweep, the G′ values of these rye meal suspensions increased slowly to a maximum of 62.1–67.1°C.