Reduction of fumonisin B₁ in corn grits by twin-screw extrusion

Abstract: This study was designed to investigate the fate of fumonisins in flaking corn grits during twin‐screw extrusion by measuring fumonisin B₁ (FB₁) and its analogs with a mass balance approach. Food grade corn grits and 2 batches of grits contaminated with FB₁ at 10 and 50 μg/g by Fusarium verticillioides M‐2552 were processed with or without glucose supplementation (10%, w/w) with a twin‐screw extruder. Extrusion reduced FB₁ in contaminated grits by 64% to 72% without glucose and 89% to 94% with added glucose. In addition, extrusion alone resulted in 26% to 73% reduction in the levels of fumonisin B₂ and fumonisin B₃, while levels of both mycotoxins were reduced by >89% in extruded corn grits containing 10% glucose. Mass balance analysis showed that 38% to 46% of the FB₁ species detected in corn extruded with glucose was N‐(deoxy‐D‐fructos‐1‐yl)‐FB₁, while 23% to 37% of FB₁ species detected in extruded corn grits with and without added glucose was bound to the matrix. It was also found that the hydrolyzed form of FB₁ was a minor species in extruded corn grits with or without added glucose, representing <15% of the total FB₁ species present. Less than 46% of FB₁ originally present in corn grits could be detected in the fumonisin analogues measured in this study. Research is needed to identify the reaction products resulting from extrusion processing of fumonisin‐contaminated corn products. Practical Application: Twin‐screw extrusion is widely used in food industry for its versatility. This technology may reduce the level of fumonisins in corn particularly with added glucose.     

Fumonisin B1 in cereal mixtures marketed in Brazil

The aim of this study was to detect and quantify fumonisin B₁ (FB₁) in cereal mixtures marketed in Brazil. Fifteen samples from different lots were acquired each month by internet from supermarkets during seven months, adding up to 105 analysed samples. The unit sample constituted of an original package with a minimum of 250 g. Extraction and clean-up of samples for FB₁ determination were carried out using immunoaffinity columns. Identification and quantification of FB₁ were performed by high performance liquid chromatography. Eighty-eight (83.8%) samples were contaminated with FB₁ and four (3.8%) presented levels above 500 µg kg^?1 (634, 703, 1269 and 1876 µg kg^?1). Maximum FB₁ + FB₂ levels allowed by Brazilian regulations will reach 1500 µg kg^?1 for corn flour in 2016 and 1000 µg kg^?1 for others corn products. This study showed that even at levels below the legislative limits, human exposure to this toxin can occur constantly.     

Fumonisins B1, B2 and B3 in corn products,wheat flour and corn oil marketed in Shandong province of China

In this study a total of 522 samples were collected from Shandong province of China in 2014 and analysed for the occurrence of fumonisin B1 (FB₁), FB₂ and FB₃ by isotope dilution ultrahigh performance liquid chromatography–tandem mass spectrometry. Fumonisins were detected in 98.1% of the corn products, with the average total level of 369.2 μg kg^?1. The individual average values of FB₁, FB₂ and FB₃ in corn products were 268.3, 53.7 and 47.2 μg kg^?1, respectively. The simultaneous occurrence of FB₁, FB₂ and FB₃ was observed in 76.7% of the corn products. Especially, the results demonstrated that the difference in the contamination levels for fumonisins in these three types of corn products was apparent. In addition, 6.2% of the wheat flour samples were contaminated with FB₁, with concentrations ranging from 0.3 to 34.6 µg kg^?1. No FB₂ or FB₃ was detected in wheat flour. In corn oil samples no fumonisins were detected.     

Application of Hydrothermically Treated Barley in Beer Production

Production of beer using native and hydrothermically treated barley (extruded barley flakes) as malt substitute was examined in this work. Nine samples of beer were produced on a laboratory scale, and malt was substituted (10–40%) by native barley flour or hydrothermically treated barley. Infusion mashing was employed, and native barley flour was pretreated by cooking. Worts were boiled with 150 g/hl native hops for one hour. Saccharomyces uvarum strain 112 was used for the fermentation, at 8°C, for 10 days. The results showed that the fermentation was normal in all samples. The use of hydrothermically treated barley in beer production produced beers, similar to those made with native barley as malt substitute, minimising the time needed for beer production and maximising the capacity of the brewhouse.     

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 B₁ (FB₁) and B₂ (FB₂) 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 FB₁ and of 100, 200 and 300?µg?kg^?1 FB₂ gave overall mean recoveries of 99% (±6%) for FB₁ and 88% (±6%) for FB₂. Good recoveries (higher than 90% for both FB₁ and FB₂) 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 FB₁ and 17?µg?kg^?1 for FB₂. The method was tested on different commercial corn masa flours as well as on white and yellow corn tortilla chips, showing fumonisin contamination levels (FB₁?+?FB₂) up to 1800?µg?kg^?1 (FB₁?+?FB₂) 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.     

Extrusion Cooking Reduces Recoverability of Fumonisin B1 from Extruded Corn Grits

A split-split plot design was used to determine the effects of extrusion cooking on the recoverability of the mycotoxin Fumonisin B₁ (FB₁). Unextruded and extruded samples of spiked corn grits were analyzed for FB₁ by two methods, commercial enzyme linked immunosorbant assay (ELISA) and HPLC. Extrusion cooking resulted in more apparent loss of FB₁ with mixing screws than nonmixing screws. Losses of recoverable FB1 (p≤0.05) were observed at 120°C and 160°C with the mixing screws. A linear increase in loss of recoverable FB₁ was observed (with the nonmixing screws) as the moisture content increased.     

Fate of Fusarium mycotoxins in maize flour and grits during extrusion cooking

Extrusion technology is used widely in the manufacture of a range of breakfast cereals and snacks for human consumption and animal feeds. To minimise consumer exposure to mycotoxins, the levels of deoxynivalenol (DON) and zearalenone (ZON) in cereals/cereal products and fumonisins B₁ and B₂ (FB₁ and FB₂) in maize are controlled by European Union legislation. Relatively few studies, however, have examined the loss of Fusarium mycotoxins during processing. The behaviour of FB₁, FB₂ and fumonisin B₃ (FB₃), DON and ZON during extrusion of naturally contaminated maize flour and maize grits is examined using pilot-scale equipment. DON and ZON are relatively stable during extrusion cooking but the fumonisins are lost to varying degrees. There is some loss of ZON when present in low concentrations and extruded at higher moisture contents. The presence of additives, such as reducing sugars and sodium chloride, can also affect mycotoxin levels. Moisture content of the cereal feed during extrusion is important and has a greater effect than temperature, particularly on the loss of fumonisins at the lower moistures. The effects are complex and not easy to explain, although more energy input to the extruder is required for drier materials. However, on the basis of these studies, the relationship between the concentration of Fusarium toxins in the raw and finished product is toxin- and process-dependent.     

Fumonisins B1 and B2 in the corn-milling process and corn-based products,and evaluation of estimated daily intake

The distribution of fumonisins (FBs: FB₁ and FB₂) in the corn-milling process and in corn-based products, as well as daily intake estimates for the Brazilian population were evaluated. Among corn fractions samples, corn meal had the highest mean concentration of FB₁ (1305 µg kg^?1) and FB₂ (651 µg kg^?1) and a distribution factors of 452% and 256% in relation to corn grain, respectively. On the other hand, the distribution factor of FB₁ and FB₂ in corn flour was found to be 144% and 88% respectively, which demonstrates that fumonisins in this fraction were reduced compared with corn grain. As a result, almost half the corn meal samples (47%) would be non-compliant with future Brazilian regulation (2017) for fumonisins. However, corn-based products, such as corn flakes and popcorn, were in compliance with the regulation. The average probable daily intake and maximum probable daily intake of fumonisins estimated for the Santa Catarina state (Brazil) population were below the provisional maximum tolerable daily intake of 2 µg kg^?1 body weight day^?1 for all corn samples. Despite this, the adoption of practices to control the occurrence of fumonisins should be applied to the corn-milling fractions that may contain a higher concentration of this toxin, such as corn meal, often used for animal feed in Brazil.     

Occurrence of fumonisins and aflatoxins in cereals from markets of Hebei province of China

Fumonisins B₁, B₂ and B₃ (FB₁, FB₂ and FB₃) and aflatoxins B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) are both major mycotoxins of food concern, because of their wide range of concentration and possible co-occurrence. Therefore, a contamination survey in corn and wheat flour by liquid chromatography–tandem mass spectrometry was carried out. Quantification of fumonisins and aflatoxins was based on internal calibration (by the use of ¹³C₃₄-fumonisin) and external calibration, respectively. Fumonisins were detected in 95% of corn samples and in 7% of wheat flour samples, with the mean level (FB₁?+?FB₂?+?FB₃) of 441?µg?kg^?1 and 0.09?µg?kg^?1, respectively. Low levels of aflatoxins were detected in 37% of the samples with a mean level (B₁?+?B₂?+?G₁?+?G₂) of 0.12?µg?kg^?1. Fumonisins and aflatoxins were not detected in 29% of the samples analysed. Simultaneous occurrence of fumonisins and aflatoxins was observed in 12% of samples.     

THE USE OF EXTRUDED BARLEY,WHEAT AND MAIZE AS ADJUNCTS IN MASHING

The principles of extrusion cooking are summarised. In small scale trials good extracts were obtained from extruded barley when it was mashed with industrial enzymes, using a programmed temperature cycle. Extruded barley, wheat and maize and wheat flour yielded acceptable levels of extract when mashed with lager malt (70%) using a programme with 1 hour rests at 50°C and 65°C. The extracts obtained from these grists were increased above those obtained from grists of lager malt alone and the viscosities of the worts were reduced when the mashes were supplemented by preparations of bacterial enzymes. Enzyme additions also improved extract recoveries from all-malt mashes and reduced the viscosities of the derived worts. Using a temperature programmed mashing cycle and supplementary enzymes beers were prepared from a lager malt grist and grists in which the lager malt was partly replaced, by 30%, with extruded barley or extruded wheat, or extruded maize or wheat flour pellets. In every case wort was recovered relatively easily, the worts fermented normally and the beers were all fully acceptable, although their flavours did differ. However, in contrast to results of preliminary brewing trials, the head retentions of the beers made with adjuncts were unusually low, possibly because of particular enzyme additions.     

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.     

Occurrence of certain mycotoxins in corn and corn‐based products and thermostability of fumonisin B1 during processing

A total of 57 samples of corn and corn‐based products collected from various districts of Egypt were analyzed for Fusarium mycotoxins (T‐2, diacetoxyscripenol (DAS( deoxynivalenol (DON) and fumonisin B₁ (FB₁) and aflatoxins. FB₁ was detected in about 80%, 53.85%, 33.3%, and 28.57% of yellow corn, corn meal, white corn, and popcorn samples, respectively. The levels of FB₁ ranged from 10 to 780 μg/kg. T‐2 and DAS were detected in 5% and 10% of yellow corn samples, respectively, and DON was detected in white corn and popcorn samples at levels of 28.8 and 10.1 μg/kg, respectively. Starch samples were found to be free from Fusarium mycotoxins. Baking balady bread at 450°C/min reduced FB₁ to 72.4% while baking Franco bread at 250°C/20 min reduced FB₁ to 57.4%. Boiling of macaroni and corn in water completely removed FB₁ from contaminated samples. On the other side, corn flakes samples were found to be contaminated with aflatoxins B₁ and G₁ at levels ranging from 6 to 10 ppm, whereas 2.9% of samples were contaminated with aflatoxin B₁ > 35 ppm and G1 > 16 ppm.     

Recent research on fumonisins: a review

Fumonisins are well known mycotoxins produced by Fusarium verticillioides, F. proliferatum and other Fusarium species. Many new fumonisins and fumonisin-like compounds have been detected by mass spectrometry in cultures of F. verticillioides. Recently, fumonisins B₂ and B₄ were produced by Aspergillus niger isolated from coffee and fumonisin B₂ in A. niger from grapes. Fumonisin B₂ was itself detected in coffee beans, wine and beer, adding to the list of foodstuffs and feedstuffs other than corn (maize) and sorghum in which fumonisins have been found in recent years. Fumonisin B₁ (FB₁) can bind to proteins (PB FB₁) and to other matrix components during food processing involving heat. The occurrence of bound fumonisins in processed corn foods is common. Another type of binding (or association) relates to observed instability of fumonisins in rice flour, corn starch and corn meal at room temperature; this can affect the immunoaffinity column clean-up procedure in analysis of naturally contaminated starch-containing corn foods for fumonisins. The occurrence of N-fatty acylated fumonisin derivatives in retail fried corn foods has also been demonstrated. Bioaccessibility of free FB₁ and total bound FB₁ (TB FB₁) present in corn flakes has been estimated by in vitro digestion experiments. Intentional binding of fumonisins to cholestyramine has been demonstrated in vivo and is a potential means of detoxification of animal feed.     

Loss of Fuminosin B1 in Extruded and Baked Corn-Based Foods with Sugars

The objective of this work was to determine the effect of added sugars on fumonisin B₁ (FB₁) levels in baked corn muffins and extruded corn grits. Muffins containing added glucose had significantly lower FB₁ levels than muffins with sucrose, fructose, or no added sugar. Extrusion cooking of the grits resulted in significant (p< 0.05) reductions of FB₁ in all treatments relative to unextruded controls, but use of glucose resulted in greater reductions of FB₁ (45.3 to 71%) than did the use of fructose (29.5 to 53%) or sucrose (19.2 to 39%). When extrusion conditions were optimized, 92.1% loss of FB₁ was found when grits were extruded with glucose. Adding glucose to thermally processed food can result in a substantial reduction in FB₁ levels.     

Fumonisins in corn (Zea mays L.) from Southern Brazil

A total of 232 samples of corn commercialised in Santa Catarina state, Southern Brazil (temperate zone climate), were evaluated from 2007 to 2012 for fumonisins (FBs: FB₁ and FB₂). Before performing this study, a FBs method with liquid chromatography and fluorescence detection (ex. 335; em. 440 nm) was validated first. FBs were detected in 46.6% (108 samples), with values ranging from 66 to 7832 µg kg^?1 for FB₁ and 110 to 1201 µg kg^?1 for FB₂. The number of contaminated corn samples for FB₁ and FB₂ varied and often presented contamination of FB₁ only. Per year of analysis, the numbers were: n = 22/8(FB₁/FB₂), 44/5(FB₁/FB₂), 25/12(FB₁/FB₂), 4(FB₁), 6(FB₁) and 7(FB₁) in 2007, 2008, 2009, 2010, 2011 and 2012, respectively. The contamination percentage was 42.3/15.4, 59.5/6.8, 43.8/21.1, 36.4, 35.3 and 33.3%, respectively, during these years. Consumers can be exposed to these mycotoxins and their health can be at risk through the consumption of contaminated corn.     

Fumonisin occurrence in wheat-based products from Argentina

In Argentina, wheat is the most consumed cereal by the human population. Since fumonisins occurence in wheat grains and wheat-based products have been reported worldwide, a survey was conducted in order to determine fumonisin contamination in 91 wheat-based products (white wheat flour samples, wheat flour used at bakery products and whole-wheat flour samples) collected from different retail stores of Rio Cuarto city in Argentina using HPLC-MS/MS. Sixty-seven samples (74%) showed contamination by fumonisins. From these samples, 16 showed fumonisin levels between LOD and LOQ (between 0.01 to 0.05 ng/g), while fumonisins (FB₁ + FB₂) in quantifiable samples ranged from 0.05 ng/g to 18.9 ng/g. Although FB₁ was more prevalent, FB₂ was foun3d in higher levels than FB₁. Overall, fumonisin prevalence was high, but concentrations were far below EU or USA limits set for maize and maize-based products.     

Fatty acid esters of fumonisins: first evidence of their presence in maize

Fumonisin derivatives obtained by esterification of fumonisin B₁ (FB₁) with palmitic, oleic and linoleic fatty acids have been recently described, but never reported in raw maize so far. In this study, the presence of oleoyl-EFB₁ (EFB₁OA) and linoleoyl-EFB₁ (EFB₁LA) in raw maize is reported by means of a suitable LC-ESI-MS/MS method. In addition, the production of EFB₁ derivatives by three Fusarium verticillioides strains is described on malt extract–based media and on corn meal–based growth media. EFB₁OA and EFB₁LA were produced by all considered strains in corn meal medium, with EFB₁LA > EFB₁OA. On the contrary, EFB₁OA and EFB₁LA were never observed in Fusarium cultures grown on a malt extract medium, suggesting that the esterification of FB₁ can occur only in a complex matrix such as maize.     

Survey of fumonisins B1, B2 and B3 in conventional and organic retail corn products in Spain and Italy and estimated dietary exposure

A survey was conducted to determine the occurrence of fumonisin B₁, B₂ and B₃ during 2007 in 186 samples of organic and conventional locally available corn products. Samples included baby food (n = 62), corn flour (11), cornflakes (23), pasta (14), cookies (17) and other corn products (59) were obtained from popular markets of Valencia (Spain) and Perugia (Italy). The analytical method used pressurized liquid extraction and liquid chromatography/electrospray ionization tandem mass spectrometry with a triple quadrupole (QqQ) analyser. Of the 104 Spanish samples, 22% contained levels in the range of 2–449 µg kg^?1, 2–229 µg kg^?1 and 6–105 µg kg^?1 for FB₁, FB₂ and FB₃, respectively, while 19 (23%) of the 82 Italian samples were positive with quantifiable levels between 2–235 µg kg^?1, 3–187 µg kg^?1, and 4–40 µg kg^?1 for fumonisins B₁, B₂ and B₃, respectively. Overall, none of the Italian samples and only one organic baby food sample from a Spanish market was above the maximum permitted levels established by European legislation. Fumonisins were found mostly in corn flour followed by cookies and cornflakes. Eleven samples from Spain and nine samples from Italy were organic products, being contaminated the 72% and 77% of the samples, respectively. Analysis of the results showed that levels of fumonisins in corn products were similar in Italy and Spain. The safety of fumonisin intake through corn products was demonstrated by the calculation of the estimated daily intake of both populations considering organic and conventional products separately, which ranged from 1.7 × 10^?3 to 0.72 µg kg^?1 bw day^?1 and comparing them with the provisional maximum total daily intake (PMTDI) of 2 µg kg^?1 bw day^?1 established by the European Union.     

Development of protein-Rich Sorghum-Based Expanded Snacks Using Extrusion Technology

Sorghum is an important staple crop in semi-arid regions of Africa and India because of its drought tolerance. But low protein content and quality limit its widespread use. This project focused on developing sorghum-based extruded snacks. Results from preliminary lab-scale extrusion experiments were used to design a 2×5 factorial pilot-scale study. Two blends of sorghum flour and corn flour were prepared (6:1 and 5:2 w/w ratios) as the controls. Three different sources of protein—whey protein isolate, defatted soy flour, and mixed legume flour—were added to the sorghum/corn flour blends at 30%. A 50:50 blend of defatted soy flour and whey protein isolate was also added at 30% to the sorghum/corn flour blends. The resultant ten formulations were extruded on a pilot-scale twin-screw extruder to investigate the effects of sorghum/corn flour ratio and protein addition on product expansion, microstructure, mechanical properties, and sensory attributes. Expansion ratio of extruded product increased at the higher level of corn flour, and decreased with the incorporation of protein sources. Extrudates with defatted soy flour had a lower expansion ratio (5.3–5.4) than those with whey protein isolate (7.7–7.9), legume flour (7.1–9.9), or whey protein isolate-defatted soy flour (6.1–6.9). Extrudate microstructure, obtained by X-ray microtomography, corresponded well with expansion characteristics. Extrudates with defatted soy flour had the lowest cell diameter. Average crushing force (ranging from 40.9 to 154.87 N) was lower for extrudates with a higher level of corn flour. However, contrary to expectations, crushing force and crispness work both decreased with incorporation of protein sources. Consumer acceptability results showed that the addition of protein sources enhanced taste and overall acceptability of the extruded snacks, with the treatment sorghum/corn flour 5:2 and whey protein isolate-defatted soy flour as the protein source having significantly higher ratings than the other treatments.     

青稞低GI挤压面条制作工艺优化及营养与抗氧化活性分析

为了提高青稞低血糖生成指数(Glycemic Index,GI)挤压面条品质,以青稞粉为主要原料,比较了青稞生粉与熟粉制作低GI挤压面条的品质,优化了挤压法制作青稞低GI值挤压面条的工艺条件及配方,考察了冷冻老化技术对其品质的影响,评价了青稞低GI值面条的营养品质及抗氧化活性。分析得到青稞生粉制作的低GI值挤压面条的品质较优;以青稞生粉为原料制作低GI值挤压面条的工艺参数为青稞粉含水量45%,pH 7.0,青稞粉粒度80目;在此优化条件下,采用单因素及正交实验优化了青稞低GI值挤压面条的配方,以青稞生粉为基础,豌豆粉添加量为20%、荞麦粉添加量5%、藜麦粉添加量为5%,在-18℃冷冻时间15 h制作的青稞挤压面条煮熟后无断条,感官评价达93.65分,GI值为42.73,具有较高的营养价值和多酚含量与抗氧化活性。