Calcium montmorillonite clay reduces urinary biomarkers of fumonisin B₁ exposure in rats and humans

Fumonisin B? (FB?) is often a co-contaminant with aflatoxin (AF) in grains and may enhance AF's carcinogenicity by acting as a cancer promoter. Calcium montmorillonite (i.e. NovaSil, NS) is a possible dietary intervention to help decrease chronic aflatoxin exposure where populations are at risk. Previous studies show that an oral dose of NS clay was able to reduce AF exposure in a Ghanaian population. In vitro analyses from our laboratory indicated that FB? (like aflatoxin) could also be sorbed onto the surfaces of NS. Hence, our objectives were to evaluate the efficacy of NS clay to reduce urinary FB? in a rodent model and then in a human population highly exposed to AF. In the rodent model, male Fisher rats were randomly assigned to either FB? control, FB??+?2% NS or absolute control group. FB? alone or with clay was given as a single dose by gavage. For the human trial, participants received NS (1.5 or 3?g?day?1) or placebo (1.5?g?day?1) for 3 months. Urines from weeks 8 and 10 were collected from the study participants for analysis. In rats, NS significantly reduced urinary FB? biomarker by 20% in 24?h and 50% after 48?h compared to controls. In the humans, 56% of the urine samples analysed (n?=?186) had detectable levels of FB?. Median urinary FB? levels were significantly (p?90% in the high dose NS group (3?g?day?1) compared to the placebo. This work indicates that our study participants in Ghana were exposed to FB? (in addition to AFs) from the diet. Moreover, earlier studies have shown conclusively that NS reduces the bioavailability of AF and the findings from this study suggest that NS clay also reduces the bioavailability FB?. This is important since AF is a proven dietary risk factor for hepatocellular carcinoma (HCC) in humans and FB? is suspected to be a dietary risk factor for HCC and oesophageal cancer in humans.     

In vitro inhibitory effect of tetrahydrocurcuminoids on Fusarium proliferatum growth and fumonisin B₁ biosynthesis

Many plant pathogens produce toxic metabolites when growing on food and feed. Some antioxidative components seem to prevent fungal growth and mycotoxin formation. Recently, we synthesized a new class of powerful antioxidative compounds, i.e. tetrahydrocurcuminoids, and its structure/antioxidant activity relationships have been established. The South West of France produces large amounts of corn, which can be infected by Fusarium species, particularly F. proliferatum. In this context, the efficiency of tetrahydrocurcuminoids, which can be obtained from natural curcuminoids, was investigated to control in vitro the growth of F. proliferatum and the production of its associated mycotoxin, fumonisin B?. The relation between structure and antifungal activity was studied. Tetrahydrocurcumin (THC1), with two guaiacyl phenolic subunits, showed the highest inhibitory activity (measured as radial growth on agar medium) against the F. proliferatum development (67% inhibition at a concentration of 13.6 μmol ml?1). The efficiencies of THC2 (36% at a concentration of 11.5 μmol ml?1), which contains syringyl phenolic units, and THC3 (30% at a concentration of 13.6 μmol ml?1), which does not have any substituent on the aromatic rings, were relatively close. These results indicate that the simultaneous presence of guaiacyl phenols and the enolic function of the β-diketone moiety play an important role in the inhibition mechanisms. The importance of this combination was confirmed using n-propylguaiacol and acetylacetone as molecular models. Under the same conditions, ferulic acid and eugenol, other natural phenolic antioxidants, were less efficient in inhibiting fungal growth. THC1 also reduced fumonisin B? production in liquid medium by approximately 35, 50 and 75% at concentrations of 0.8, 1.3, and 1.9 μmol ml?1, respectively. These very low inhibitory concentrations show that tetrahydrocurcuminoids could be one of the most promising biobased molecules for the control of mycotoxinogen fungal strains.     

A sensitive immunochromatographic assay using colloidal gold–antibody probe for rapid detection of fumonisin B1 in corn

A sensitive immunochromatographic assay (ICA) using a colloidal gold–antibody probe for the rapid detection of fumonisin B₁ (FB₁) in corn samples was developed. The colour density of the test line correlated with the concentration of FB₁ in the range 2–40 ng ml^–1 by the assay, and the detection limit for FB₁ was 2 ng ml^–1. The linear range for FB₁ was 50–1000 µg kg^–1, and the visual limit detection of the test was 1000 µg kg^–1 in corn samples. The ICA to detect FB₁ is sensitive, specific and rapid. Specific anti-FB₁ monoclonal antibody (mAb) and FB₁-ovalbumin (FB₁-OVA) conjugate antigen were prepared. FB₁ mAb, labelled with colloidal gold, was used as the probe on the immunochromatographic strip. FB₁-OVA and goat-anti-mouse IgG were coated onto a nitrocellulose (NC) membrane as test lines and control lines, respectively. FB₁ in samples will competitively combines the FB₁ mAb with the FB₁-OVA in an NC membrane and the results are directly observed by the colour of the detection and quality control lines. The concentrations of FB₁ mAb labelled with colloidal gold, detecting antigen and goat anti-mouse IgG, were optimised. The results indicate that the test strip is specific for FB₁, with no cross-reactivity to other toxins. The strip assay for FB₁ was simple, only needing one step without complicated assay performance and expensive equipment, and the total time for visual evaluation was less than 10 min. A survey of 24 corn samples from Hefei, China, was performed with the test strip and HPLC, and the detection results showed that the developed ICA and the HPLC were in excellent agreement. Hence, the developed ICA can be used as a method for rapid detection of FB₁ in corn samples.     

Comparison of methods and optimisation of the analysis of fumonisins B₁ and B₂ in masa flour, an alkaline cooked corn product

A comparison study of different extraction and clean-up procedures for the liquid chromatographic analysis of fumonisins B(1) (FB(1)) and B(2) (FB(2)) in corn masa flour was performed. The procedures included extraction (heat or room temperature) with acidic conditions or EDTA-containing solvents, and clean-up by immunoaffinity or C18 solid-phase extraction columns. Thereafter an analytical method was optimised using extraction with an acidic mixture of methanol-acetonitrile-citrate/phosphate buffer, clean-up through the immunoaffinity column and determination of fumonisins by liquid chromatography with automated pre-column derivatisation with o-phthaldialdehyde reagent. Recovery experiments performed on yellow, white and blue masa flours at spiking levels of 400, 800 and 1200 μg kg(-1) FB(1) and of 100, 200 and 300 μg kg(-1) FB(2) gave overall mean recoveries of 99% (±6%) for FB(1) and 88% (±6%) for FB(2). Good recoveries (higher than 90% for both FB(1) and FB(2)) were also obtained with corn tortilla chips. The limits of quantification of the method (signal-to-noise ratio of 10) were 25 μg kg(-1) for FB(1) and 17 μg kg(-1) for FB(2). The method was tested on different commercial corn masa flours as well as on white and yellow corn tortilla chips, showing fumonisin contamination levels (FB(1) + FB(2)) up to 1800 μg kg(-1) (FB(1) + FB(2)) in masa flour and 960 μg kg(-1) in tortilla chips. Over 30% of masa flours originating from Mexico exceeded the European Union maximum permitted level.     

Identification of the first fumonisin mycotoxins with three acyl groups by ESI-ITMS and ESI-TOFMS following RP-HPLC separation: palmitoyl, linoleoyl and oleoyl EFB₁ fumonisin isomers from a solid culture of Fusarium verticillioides

The aim of this study was to apply RP-HPLC/ESI-ITMS and RP-HPLC/ESI-TOFMS to investigate and characterise six new higher molecular weight fumonisins (three pairs of isomers) extracted from a Fusarium verticillioides-infected solid rice culture. The ITMS and ITMS2 spectra clearly indicated the m/z values (960, 984 and 986) of the protonated molecules and the FB? toxin-like structures of these compounds, respectively. Moreover, the data evaluation software of the TOFMS equipment unambiguously demonstrated the exact masses of the protonated molecules and the suggested empirical formulae (C??H??NO??, C??H??NO?? and C??H??NO??) of the new fumonisins, with mass accuracy in the range between 0.1 and -1.1 ppm. Subtraction of the empirical formula of FB? toxin (C??H??NO??) from these formulae and correction for the mass of water split-off from the fumonisin molecule during ester formation resulted in the empirical formulae of the fumonisin backbone esterifying agents (fatty acids): C??H??O? (palmitic acid, PA), C??H??O? (linoleic acid, LA) and C??H??O? (oleic acid, OA). We denoted the new compounds as esterified FB? (EFB?) toxins, with the suggested names EFB? PA, iso-EFB? PA, EFB? LA, iso-EFB? LA, EFB? OA and iso-EFB? OA. The total amount of these new compounds comprised 0.1% of the FB? concentration, which may be rated as significant when it is considered that these new components are significantly more apolar than earlier-described fumonisins, and their uptake into and toxicity elicited in the various tissues of living organisms may therefore also be significantly different from those of other fumonisins.     

Indirect determination of aflatoxin B₁ in beer via a multi-commuted optical sensor

This paper reports the determination of aflatoxin B? (AFB?), one of the most carcinogenic substances known. A multi-commuted flow injection-solid phase spectroscopy (FI-SPS) system combined with photochemically induced fluorescence (PIF) was developed, for the first time, for its quantitative determination. A strongly fluorescent degradation product was obtained on-line by irradiation with ultraviolet light. The determination was carried out by measuring the fluorescence intensity of the photo-product at 353/424 (λ (ex)/λ (em)), once retained on C?? silica-gel filling the flow-cell. A linear dynamic range of 0.09-12?μg?l?1, detection limit as sensitive as 29?ng?l?1 and a relative standard deviation (RSD) of 1.4% were obtained. The method proposed was satisfactorily applied to the determination of AFB? in different types of beer (normal and non-alcoholic). Hydrophobic compounds were eliminated from beer samples and AFB? was extracted with acetonitrile by solid-phase extraction on C?? sorbent. Recoveries of the target compound from spiked beers were between 94 and 106%. The results obtained in the analysis of real samples are in good agreement with those provided by a reference chromatographic method.     

Management of fumonisin contamination in maize kernels through the timing of insecticide application against the European corn borer Ostrinia nubilalis Hübner

The European corn borer (ECB), Ostrinia nubilalis, is the principal pest of maize in Central and South Europe. It is known to promote Fusarium verticillioides infection in maize grain, a recognized producer of fumonisins. Field experiments were performed in 2006 and 2007 in two sites in NW Italy to determine the effects of the timing of insecticide application on ECB damage, fungal ear rot and fumonisin contamination under natural conditions. Different insecticide application timings were compared, from maize flowering to approximately 15 days after the flight peak of adult ECB. At harvest, the ears were rated for incidence and severity of ECB damage, fungal ear rot symptoms and fumonisin (FB₁ + FB₂) contamination. In all years/sites, treatments applied at the beginning of consistent ECB flight activity were most effective in controlling insect damage on ears. Fungal ear rot and fumonisin contamination were significantly affected by ECB control. The efficacy of the best timing of insecticide application in controlling fumonisin contamination was, on average, 93% compared to the untreated control. Contamination levels of these mycotoxins increased with either an earlier or later treatment. Furthermore, an earlier insecticide application showed lower fumonisin contamination than a treatment applied after the adult flight peak. Production of maize kernels and maize-based foods that do not exceed the maximum international and EU permitted levels for fumonisins could be enhanced by appropriate insecticide treatment against second generation ECB. The optimum time for insecticide application is between the beginning of consistent adult flight activity and the flight peak.     

Mechanical and microstructural properties of soy protein – high amylose corn starch extrudates in relation to physiochemical changes of starch during extrusion

Mechanical and microstructural properties of expanded extrudates prepared from blends of high amylose corn (Zeamays L. ssp. Mays) starch (HACS) and soy protein concentrate (SPC) were studied in relation to the physicochemical changes in starch. Effects of screw speed (230 and 330 rpm) and SPC level (10%, 20%, 30% and 50%) on expansion and mechanical properties were determined. Compared with 230 rpm, screw speed at 330 rpm resulted in increased specific mechanical energy, expansion ratio, water absorption and water solubility indices and decreased bulk density and piece density. Varying screw speeds did not significantly affect the mechanical strength of extrudates or starch molecular weight distribution. Bulk and piece densities, and water absorption index (WAI) only slightly increased or exhibited no significant trends as SPC level increased to 20%. A substantial increase in bulk and piece densities and decrease in expansion ratio and WAI were observed as SPC level increased from 20% to 30%. The trends were either reversed or moderated as SPC increased to 50%. These results in combination with average crushing force and water solubility index data provided a significant insight into the interactions between HACS and SPC during extrusion processing. As compared to an earlier baseline study by our research group on normal corn starch – SPC extrudates, results from the current study indicated that the expansion of extrudate containing HACS alone was lower than that of extrudates containing normal corn starch. However, expansion of the HACS–SPC blends was not significantly impacted at 10–20% SPC levels, whereas the expansion of normal corn starch was significantly reduced.     

Effect of the time interval from harvesting to the pre-drying step on natural fumonisin contamination in freshly harvested corn from the State of Paraná, Brazil

Natural mycoflora and fumonisins were analysed in 490 samples of freshly harvested corn (Zea mays L.) (2003 and 2004 crops) collected at three points in the producing chain from the Northern region of Paraná State, Brazil, and correlated to the time interval between the harvesting and the pre-drying step. The two crops showed a similar profile concerning the fungal frequency, and Fusarium sp. was the prevalent genera (100%) for the sampling sites from both crops. Fumonisins were detected in all samples from the three points of the producing chain (2003 and 2004 crops). The levels ranged from 0.11 to 15.32 µg g^?1in field samples, from 0.16 to 15.90 µg g^?1in reception samples, and from 0.02 to 18.78 µg g^?1in pre-drying samples (2003 crop). Samples from the 2004 crop showed lower contamination and fumonisin levels ranged from 0.07 to 4.78 µg g^?1in field samples, from 0.03 to 4.09 µg g^?1in reception samples, and from 0.11 to 11.21 µg g^?1in pre-drying samples. The mean fumonisin level increased gradually from ≤ 5.0 to 19.0 µg g^?1as the time interval between the harvesting and the pre-drying step increased from 3.22 to 8.89 h (2003 crop). The same profile was observed for samples from the 2004 crop. Fumonisin levels and the time interval (ρ = 0.96) showed positive correlation (p ≤ 0.05), indicating that delay in the drying process can increase fumonisin levels.     

Method for determination of aflatoxin M₁ in cheese and butter by HPLC using an immunoaffinity column

A rapid, sensitive convenient method for determination of aflatoxin M? (AFM?) in cheese and butter by HPLC was developed and validated. The method employs a safe extraction solution (mixture of acetonitrile, methanol and water) and an immunoaffinity column (IAC) for clean-up. Compared with the widely used method employing chloroform and a Florisil column, the IAC method has a short analytical time and there are no interference peaks. The limits of quantification (LOQ) of the IAC method were 0.12 and 0.14 μg/kg, while those of the Florisil column method were 0.47 and 0.23 μg/kg in cheese and buffer, respectively. The recovery and relative standard deviation (RSD) for cheese (spiked at 0.5 μg/kg) in the IAC method were 92% and 7%, respectively, while for the Florisil column method the corresponding values were 76% and 10%. The recovery and RSD for butter (spiked at 0.5 μg/kg) in the IAC method were 97% and 9%, and those in the Florisil method were 74% and 9%, respectively. In the IAC method, the values of in-house precision (n=2, day=5) of cheese and butter (spiked at 0.5 μg/kg) were 9% and 13%, respectively. The IAC method is superior to the Florisil column method in terms of safety, ease of handling, sensitivity and reliability. A survey of AFM? contamination in imported cheese and butter in Japan was conducted by the IAC method. AFM? was not detected in 60 samples of cheese and 30 samples of butter.     

The presence of aflatoxin B₁-FAPY adduct and human papilloma virus in cervical smears from cancer patients in Mexico

The carcinogenic biomarker aflatoxin B(1)-formamidopyrimidine 2,3-dihydro-2-(N-formyl)-2',5',6'-triamino-4'-4'-oxy-N-pyrimidyl-3-hydroxy-AFB(1) called AFB(1)-FAPY adduct, and Human Papilloma Virus (HPV) types 16 and 18 were quantified from DNA cervical scrapes from 40 women with cervical cancer (CC) and 14 healthy women as controls. The relationship between the AFB(1)-FAPY adduct and HPV types 16 and 18 was determined. Competitive inhibitory indirect ELISA was validated with 94% inhibition to quantify the AFB(1)-FAPY adducts in picograms per milligram of DNA (limit of detection = 0.1 pg/mg, and limit of quantification = 10 pg/mg), polymerase chain reaction and DNA sequencing to identify HPV types. The average concentration of AFB(1)-FAPY adducts/mg DNA in the CC cases was 1025 pg, 1420 pg with HPV16 and 630 pg sharing HPV18 (p = 0.03). In comparison, healthy controls had ≤ 2.6 pg/mg DNA, a statistically significant difference (p = 0.00006). The presence of AFB(1)-FAPY adduct increased six-fold the risk for CC between cases and controls, the odds ratio was 6.1 (95% CI = 1.4-25.4). There was a close relationship between the AFB(1)-FAPY adducts and HPV16 in CC samples.     

Mycotoxicological quality evaluation of corn samples used by processing industries in the Northern region of Paraná State,Brazil

Based on fungal and fumonisin contamination of 870 freshly harvested samples, the quality of corn used by processing industries in the Northern region of Paraná State, Brazil (2003 and 2004 crop-year) was evaluated. Sampling was carried out for each crop at two points in the production chain, i.e. at reception by the processors and at the pre-drying step. Corn samples were more frequently contaminated with Fusarium sp. (100%) and Penicillium sp. (84.1–95.3%) than Aspergillus sp. (5.6–19.8%). Fumonisin B₁ (FB₁) was detected in all samples from the two points in both crop-years. FB₁ levels ranged 0.02–11.83 µg g^?1 in the reception and 0.02–10.98 µg g^?1 in the pre-drying samples of the 2003 crop. Samples from the 2004 crop showed FB₁ levels ranging 0.03–12.04 µg g^?1 in the reception and 0.06–7.74 µg g^?1 in the pre-drying samples. FB₂ levels ranged 0.02–5.25 µg g^?1 in the reception and 0.01–7.89 µg g^?1 in the pre-drying samples (2003 crop-year). In samples from the 2004 crop, FB₂ levels ranged 0.02–6.12 µg g^?1 in the reception and 0.05–3.47 µg g^?1 in the pre-drying samples. Low fumonisin levels were detected in most corn samples used by processors in the Northern region of Paraná State, showing a decreasing trend in fumonisin contamination over the years.     

Co-occurrence of aflatoxins B₁, B₂, G₁ and G₂, ochratoxin A, zearalenone, deoxynivalenol, and citreoviridin in rice in Brazil

A total of 230 samples of processed rice and its sub-products or derived products were analysed to establish the co-occurrence of several mycotoxins. Samples were analysed in the period 2007-2009 due to the outbreak of beriberi associated with the consumption of rice stored in inappropriate conditions in Brazil. According to data from the Ministry of Health, 323 cases of disease were registered in 2006, of which at least 47 cases resulted in death. The occurrence of total aflatoxin (AFT) (aflatoxin B(1)?+ B(2)?+ G(1)?+ G(2)), ochratoxin A (OTA), zearalenone (ZON), deoxynivalenol (DON), and citreoviridin (CTV) was 58.7%, 40.0%, 45.2%, 8.3% and 22.5%, respectively. From 166 rice samples analysed, 55% had levels <0.11 μg kg(-1) for AFT. For OTA and ZON, of 165 rice samples analysed, 28% and 29% were contaminated with levels from 0.20 to 0.24 μg kg(-1) and from 3.6 to 290.0 μg kg(-1), respectively. One sample (0.6%) was contaminated with 4872.0 μg kg(-1) of ZON. A total of 91% of rice samples (n = 165) did not contain detectable DON (<30.00 μg kg(-1)), although the highest level of contamination was found to be 244?μg?kg(-1). From the total of 65 samples analysed, 94% had no detectable CTV (<0.9?μg?kg(-1)), with a range from 0.9 to 31.1?μg?kg(-1) in 6% of the samples. The highest levels of contamination were found in rice sub-products or derived products from the husk and rice bran. Co-occurrence was observed for AFT and ZON in 17.0%, AFT and OTA in 24.2%, AFT and CTV in 6.2%, OTA and CTV in 4.6%, and ZON and CTV in 3.1%. These fractions were also the major contributors for the co-occurrence. The results found show the necessity of monitoring rice production.     

Reduction of Furan Formation by High-Pressure High-Temperature Treatment of Individual Vegetable Purées

The present study addressed the need for furan mitigation measures at the level of food production, where the effects of extrinsic (process-related) and intrinsic (product-related) properties on furan formation in vegetable-based systems were investigated. For the first time in the literature, the effect of high-pressure high-temperature (HPHT) processing on the formation of furan was demonstrated. HPHT processing was proven to be an interesting alternative for furan reduction in vegetable-based systems, when aiming for sterilization intensities. Following HPHT treatment, the furan concentrations of a wide range of individual vegetable purées dropped to levels close to the analytical limits (1–2 ng/g purée). A higher processing cost might limit the use of HPHT processing to high-value added products, which means that for many other conduction-heated food products, conventional heating would remain the standard technology. As a first step towards control of furan formation in the latter products, a mixed model regression was used to identify the major precursors in vegetable-based systems. Significant correlations were observed for vitamin C and sugars, which were attributed to the efficiency of the conversion and high concentrations, respectively. Next to furan, the HPHT- and thermally treated purées were analyzed for 2- and 3-methylfuran, which are likely to undergo the same metabolic fate as furan. For most of the vegetables tested, the total amount of methylfuran found in the thermally treated purées could not be ignored. Similarly to furan, there was a clear reduction in the concentrations found in the HPHT-treated purées.     

Validation of a confirmatory analytical method for the determination of aflatoxins B₁, B₂, G₁ and G₂ in foods and feed materials by HPLC with on-line photochemical derivatization and fluorescence detection

A sensitive and selective analytical method for the simultaneous separation and quantitative determination of aflatoxins B1, B2, G1 and G2 in foodstuffs and materials for feed has been validated. The method is based on high performance liquid chromatography with on-line post-column photochemical derivatization and fluorescence detection. The chromatographic separation of aflatoxins was accomplished using a C18 column eluted with an isocratic mobile phase consisting of water, methanol and acetonitrile. The sample preparation required a simple extraction of aflatoxins with MeOH/H2O (80:20, v/v) and a purification step by immunoaffinity column cleanup. The total analysis time, including sample preparation and chromatographic separation, did not exceed 40 min with a run time of 10 min. The on-line photochemical derivatization ensures better results in terms of simplicity, sensitivity and reproducibility with respect to chemical derivatization techniques, and provides an increase of the peak resolution and an extent of automation in comparison with the electrochemical ones. The procedure for the determination of aflatoxins in food samples and cereals for animal consumption was extensively validated following Regulation (EC) No. 882/2004. Detection limits in wheat bran samples of 0.08 μg kg1 for AFB1, 0.02 μg kg1 for AFB2, 0.16 μg kg1 for AFG1 and 0.04 μg kg1 for AFG2 were attained. The method allows high recovery with mean values ranging from 72 to 94% and it satisfies the necessary requirements for sensitivity, linearity, selectivity, precision and ruggedness, demonstrating the conformity of the method with provisions of Regulation (EC) No. 401/2006.     

Production of L-arabinose from corn hull arabinoxylan by Arthrobacter aurescens MK5 α-L-arabinofuranosidase

Arabinoxylans, which are comprised of a xylan backbone to which are attached glycosyl units that are primarily L-arabinofuranosyl units, are ubiquitous among plant species where it is a constituent of the cell wall. Arabinoxylan has attracted much attention as a potential biomass resource and L-arabinose has recently been reported to possess functional properties that are effective in the treatment of diabetes. Here, we report an α-L-arabinofuranohydrolase, isolated from the soil microbe Arthrobacter aurescens strain MK5, effective in releasing L-arabinose from corn hull arabinoxylan. When A. aurescens strain MK5 was grown in a liquid medium, corn hull arabinoxylan, which has a higher arabinose content (Ara/Xyl = 0.6) than oat spelts xylan (Ara/Xyl = 0.12), induced more efficient arabinoxylan hydrolase production. Analysis of enzyme activity in the culture broth revealed that arabinoxylan hydrolase activity was high, and α-L-arabinofuranosidase and β-xylosidase activities were low. The optimum pH of the MK5 arabinoxylan hydrolase at 40 °C was around 7 and enzyme activity was relatively stable at an alkaline pH up to 9.5. The optimum temperature at pH 7 was around 50 °C and enzyme activity was stable under 50 °C. During the hydrolysis of corn hull arabinoxylan, only L-arabinose was released and 45.1% maximum sugar recovery was achieved. The A. aurescens MK5 enzyme was a typical arabinoxylan α-L-arabinofuranohydrolase and was most effective at releasing L-arabinose from corn hull arabinoxylan, which has a high arabinose content. This enzyme may have important industrial applications.     

Reduction of α-galactoside content in red gram (Cajanus cajan L.) upon germination followed by heat treatment

BACKGROUND: Red gram (Cajanus cajan L.) is an important crop for human and animal nutrition. However, raffinose family oligosaccharides present in red gram seed hinder its consumption as it is not digested by normal human carbohydrases and is further fermented by intestinal microflora, which induces flatulence. In order to make the grain legume more amenable for human consumption, we have tried to shed some light on the effect of germination followed by heat treatment methods such as autoclaving, cooking and pressure cooking on the raffinose family of sugars. These techniques, however, are primary prerequisites before consumption of the gram. RESULTS: The percent removal of raffinose, stachyose and verbascose after germinating red gram seeds for 8 h followed by autoclaving was 65.6%, 58.9% and 65.3% respectively; and after cooking was 61.6%, 69.2% and 72.5%. Germinating for 16 h followed by autoclaving led to a mean decrease of 53.3% for raffinose, 60.3% for stachyose and 62.3% for verbascose. Germination of red gram seeds for 16 h followed by cooking led to a mean decrease of 71.7% for raffinose, 76.2% for stachyose and 74.0% for verbascose, respectively. The results for the percent removal of raffinose, stachyose and verbascose after germination of red gram seeds for 16 h followed by pressure cooking was 68.3%, 73.3% and 68.2% respectively. CONCLUSION: This study demonstrates that local methods of processing reduce raffinose family oligosaccharides in red gram. The technique of germinating the seeds for 16 h followed by autoclaving, cooking and pressure cooking for the reduction of raffinose family oligosaccharides is a promising solution to overcome flatulence and increase the overall acceptance of red gram among general populace. Copyright © 2011 Society of Chemical Industry     

Quality assessment of corn snacks enriched with soybean ferritin among young healthy people and patient with Crohn’s disease: the effect of extrusion conditions

Fortified extruded snacks are convenient products to supplement malnourished patients’ diet, e.g. suffering from Crohn’s disease. The snacks were extruded with different additions of iron-biofortified sprouts under varying process conditions (temperature and humidity). The sensory profiling showed the correlation between extrusion temperature and snack stickiness (R = 0.835), crispiness (R = 0.727), hardness (R=−0.485), as well as the intensity of corn (R = 0.888), powder (R=−0.795), metallic (R=−0.606) and bitter (R=−0.901) tastes. The sprouts addition affected metallic taste (R = 0.606) and aroma (R = 0.666) intensity. The product desirability was compared between healthy people (HP) and Crohn’s patients (CP). Overall desirability positively correlated with taste desirability in both groups. In the HP group, taste desirability was associated with metallic taste (R=−0.857) and Fe(III) content (R=−0.717). Also, aroma desirability (connected with pyrazines) was more significant to HP. Higher tolerance of CP to metallic and bitter flavours was observed. This confirms that the taste and aroma preferences of CP and HP are different.     

Apocynin exerts neuroprotective effects in fumonisin b1–induced neurotoxicity via attenuation of oxidative stress and apoptosis in an animal model

The Fusarium verticillioides produces a mycotoxin, that is, fumonisin b1 (Fb1), which commonly infects corn and agricultural commodities. The Fb1 showed hepatotoxicity, neurotoxicity, and carcinogenicity in animals. Hence, the present investigation aimed to evaluate the effect of apocynin (AP) on Fb1-induced neurotoxic effects and its mechanism in the mice model and cell line. The male Balb/c mice, with the 6.75 mg/kg bwt of Fb1 were injected subcutaneously for 5 days to induce neurotoxicity. A significant elevation of serotonin (5-HT) was observed in mice treated with Fb1 in the whole brain showing biogenic amines may reflect Fb1 neurotoxicity, but the negatively regulated mechanisms were attenuated by the pretreatment of AP. In addition, AP pretreatment normalized apoptotic changes in histology and immunohistochemistry studies. In Western blotting studies, apoptotic genes were upregulated and oxidative stress genes were downregulated due to Fb1 treatment; while treating with AP, these gene expressions were rectified. Further cell cytotoxicity was investigated by MTT and lactate dehydrogenase (LDH) assays in SH-SY5Y cell line. MTT and LDH assays indicated the IC₅₀ value to be 150 µM of Fb1, which was protected by 100 µg of AP. The electron microscopy evaluated the Fb1-induced apoptotic conditions and its cell morphology recovery by AP. These results suggest that nicotinamide adenine dinucleotide phosphate hydrogen oxidase–mediated reactive oxygen species is the primary upstream signal leading to increased Fb1-mediated neurotoxicity in mice. The use of the antioxidant AP reversed the toxin-induced oxidative stress and apoptosis by its antioxidant potency.