Amaranth,millet and buckwheat flours affect the physical properties of extruded breakfast cereals and modulates their potential glycaemic impact

Three non‐traditional pseudo‐cereal flours (amaranth, buckwheat and millet) were used in the manufacture of extruded breakfast cereal products as a replacement for wheat and maize flour. The use of these flours altered the physical and nutritional quality of extruded breakfast cereals. Extruded products made using the flours exhibited an increased product and bulk density. However the extruded products were not significantly different compared to the control sample in terms of expansion ratio (excepting Amaranth at the 65% inclusion rate). All of the extruded products made with the inclusion of pseudo‐cereals showed a significant reduction in readily digestible carbohydrates and slowly digestible carbohydrates compared to the control product during predictive in vitro glycaemic profiling. The results illustrate the potential use of these non‐traditional cereal flours in lowering the glycaemic response to the ingestion of extruded breakfast cereals.     

Influence of sodium chloride on colour,residual volatiles and acrylamide formation in model systems and breakfast cereals

To elucidate the salt action in breakfast cereals to decrease its amount without a quality loss, a model system was developed. This model, composed of native maize starch, glucose and a mixture of five amino acids (glucose/amino acids molar ratio = 1/1) generated similar colour and volatiles (m/z = 45, 59, 69, 73, 87 and 103 g mol^?1) after heating compared to commercial breakfast cereals. A designed experiment used this model to study the influence of salt concentration (0–5.44%), heating time (0–25 min) and temperature (180–230 °C) on colour, residual volatiles and acrylamide formation. The higher the salt concentration, heating time and temperature, the darker were the products (P < 0.05). The L* values of the model systems containing 5 % salt and heated for 25 min at 230 °C were twelve points lower than the same systems without salt heated in the same conditions. Presence of salt significantly decreased acrylamide formation in the model systems (up to 50 % decrease when 2.5 % salt is added). However, salt did not have a significant impact on volatile levels. These findings were confirmed by observations made on four types of commercial breakfast cereals.     

Relationship between acrylamide and thermal-processing indexes in commercial breakfast cereals: a survey of Spanish breakfast cereals

Breakfast cereals are significant contributors to the daily intake of food-derived acrylamide in Western countries. Acrylamide was determined by LC-MS in 60 commercial breakfast cereals marketed in Spain. Several SPE cartridges were evaluated for clarification of the aqueous extract. LOQ was 62 microg/kg . Acrylamide content ranged from < 62-803 microg/kg (average 292 microg/kg , and median 258 microg/kg , with an estimated acrylamide intake from breakfast cereals of 2.68 microg acrylamide/person/day. According to the German concept of minimization, a signal value 450 microg/kg was calculated. Relationships among acrylamide and some parameters of the studied samples such as type of cereal, its physical form (puffed and flaked) or certain ingredients in the formulation (proteins and dietary fibre content) were also investigated. Wheat-based cereals contained significantly higher levels of acrylamide, as did samples with higher fibre or protein content. In addition, puffed breakfast cereals also contained significantly higher levels of acrylamide. There was no significant correlation between acrylamide levels and contents of 5-hydroxymethylfurfural, furosine or cereal browning.     

Effect of inclusion of soluble and insoluble fibres into extruded breakfast cereal products made with reverse screw configuration

Five dietary fibre rich ingredients were used at 5%, 10% and 15% replacement levels in a white flour cereal base to produce an extruded cereal product. The inclusion of the dietary fibres into the flour bases had no significant effect on the expansion ratio of the products. However, the bulk density of the extruded products increased with inulin addition. The pasting properties of the raw flour and fibre base as well as the extruded products were altered with the incorporation of dietary fibre, with guar gum enriched products showing elevated peak and final viscosity readings. This appeared to be related to moisture manipulation and hence the regulation of gelatinisation. In vitro starch hydrolysis of the raw bases and the extruded samples illustrated that the extrusion process significantly increased the availability of carbohydrates for digestion. Additionally, the inclusion of dietary fibres in the raw bases significantly reduced the rate and extent of carbohydrate hydrolysis of the extruded products. As such the addition of dietary fibres to extruded products reduced the amount of readily digestible starch components of breakfast products, and increased the amount of slowly digestible carbohydrates.     

Effect of digestive process on Maillard reaction indexes and antioxidant properties of breakfast cereals

Extrusion, drying and toasting are the most representative manufacturing processes suffered by breakfast cereals, conjugating thermal/moisture conditions that allow the Maillard reaction (MR) and caramelisation development, as well as the destruction of thermally labile antioxidant compounds. However, other compounds – like Amadori products and hydroxymethylfurfural (HMF) – are originated from the MR and caramelisation, showing different biological activities, as the antioxidant activity. But breakfast cereals are ingested and then affected by the digestive process, and so that the aim of this work was to analyse the effects of the digestion on the bioaccessibility of certain MR products (Amadori compound and HMF) and on the antioxidant activity of corn-based breakfast cereals, using a standardized in vitro gastrointestinal digestion. After digestion approx. 90% HMF remained soluble, but in some cases HMF distribution between soluble/insoluble fractions was higher than the initial HMF measured in the raw cereal, suggesting a release of initially bound Amadori products and its conversion to HMF during the digestion process. The Amadori compound was uniformly distributed between both fractions. The antioxidant activity of the soluble fraction was always higher than that from the raw cereal in any of the antioxidant method employed; therefore the digestion increased the solubility of the antioxidant compounds.     

Liquid chromatographic method for fumonisin B1 in sorghum syrup and corn-based breakfast cereals.

The fungus Fusarium verticillioides has been found on corn and sorghum, so it is possible that one or more of these toxins may be found in corn products such as breakfast cereals and syrup prepared from sorghum. Published methods when applied to syrups spiked with fumonisins gave low recoveries, less than 50%. A method was therefore developed which would be applicable to the syrup and breakfast cereals as well. Test samples were extracted with methanol-0.1 M sodium phosphate buffer (pH3) (1 + 1). The extract was diluted with water and applied to a 1 g C18 column. The column was washed with acetonitrile-water (2 + 8). Fumonisin B1 (FB1) was eluted with acetonitrile-trifluoroacetic acid (1000 + 1). The purified extract was evaporated and the toxin was derivatized with ophthaldialdehyde mercaptoethanol. The reaction mixture was resolved on a C18 liquid chromatographic column using acetonitrile-water-acetic acid (500 + 550 + 10.5) as the mobile phase at 37 degrees C, and FB1 measured with a fluorescence detector (excitation 335 nm, emission 440 nm). Recoveries of FB1 added to samples of sorghum syrup at levels ranging from 0.1 to 1.0 microgram/g were 94-132%. Recoveries of FB1 added to samples of breakfast cereal (corn flakes) at levels ranging from 0.2 to 1.6 micrograms/g were 96-100%. The method was applied to the analysis of 35 samples of sorghum syrup collected from 15 states in the US. One sample was found to contain FB1 at 0.12 microgram/g. A total of 32 samples of breakfast cereals collected by the Food and Drug Administration inspectors from grocery stores around the Kansas City area were analysed; no FB1 was found in the breakfast cereals (< 0.01 microgram/g). Results of this study indicated that FB1 possibly is not a problem in sorghum syrup and corn-based breakfast cereals in the US.     

Relative Protein Efficiency Ratios for Wheat-Based Breakfast Cereals

Male weanling rats were subjected to standard 28-day PER trials following the outline by the AOAC (1984) except that the diets contained 8.5% protein (N × 6.25) as one of six wheat-based breakfast cereals, white flour, whole wheat flour or casein. One of the cereals was an extrusion puffed product, three were flaked and toasted cereals and two were extruded cereals. Of the two extruded cereals, one was lightly toasted and the other was more heavily toasted. Relative PER (R-PER) was lowest for the puffed cereal (- 15.3) and highest for the extruded-lightly toasted cereal (69.9). R-PER for the flaked cereals ranged from 1.7 to 16.3; the other extruded cereal had a R-PER of 2.8 and each of the two flours had a R-PER of 42.9.     

Application of Portable and Handheld Infrared Spectrometers for Determination of Sucrose Levels in Infant Cereals

Sucrose coating of breakfast cereals is used to enhance the flavor and attractiveness of the final product but there is a need for monitoring its levels to meet consumer health concerns associated with sugar consumption. Our objective was to evaluate the use of portable (mid-infrared, MIR) and handheld (near-infrared, NIR) systems for rapid, simple and reliable determination of sucrose content in breakfast cereal products. Cereal-based and sucrose-coated samples were provided by an Ohio snack food company. Samples were ground and spectra were collected using portable ATR-MIR (Cary 630) and handheld NIR (microPHAZIR) spectrometers. Reference sucrose levels were determined by high-performance liquid chromatography (HPLC). Partial least squares regression (PLSR) was used to develop calibration regression models for prediction of sucrose levels in breakfast cereals based on spectral data. Sucrose levels in uncoated (n?=?28) and coated (n?=?62) cereal samples were on average of 1.2?±?0.7 and 11.8?±?3.5 g/100 g, respectively. Similar calibration (n?=?85) model performances were obtained for determination of sucrose content by using the portable MIR and handheld NIR instruments with standard error of cross-validation (SECV) of 1.45 %. However, superior predictive ability was obtained with the portable MIR unit using a validation set (n?=?20, SEP?=?1.27 % and RPD?=?4.41). Regression models using NIR spectrum of the cereal through a polyethylene bag resulted in reduction of the model goodness of fit and RPD values. Results support the application of handheld NIR and portable MIR spectrometers for close-to-real-time analysis of sucrose levels in breakfast cereals providing simple, rapid and reliable prediction for quality assurance.     

CONTAMINATION OF SEVERAL BREAKFAST CEREALS BY METHYL CHLOROFORM

The analysis of several breakfast cereals has shown that methyl chloroform (MCF, 1,1,1-Trichloroethane), a solvent found to be present in the adhesive of the outer box, can migrate from the adhesive through the box and the waxed liner into the cereal. The levels of MCF in the adhesive, the outer box, the waxed liner and the cereal were found to range from 0 to 2.3%, 0 to 19.4 ppm, 0 to 4.8 ppm, and 0 to 0.40 ppm, respectively, in 11 breakfast cereals. The MCF residues were determined using a closed system-vacuum distillation gas chromatographic technique with both electron capture and electrolytic conductivity detection. The results were confirmed by high resolution mass spectrometry.     

In vitro chromium availability in breakfast cereals

Chromium (Cr) availability (expressed as percentage dialysed Cr) in breakfast cereals (n = 93) was evaluated by an in vitro method of simulated human gastrointestinal digestion followed by GFAAS measurement of dialysed Cr. The dialysed Cr ranged from 0.48 ± 0.07 to 3.26 ± 0.04%. The Cr dialysability was independent of the total amount of this mineral in the breakfast cereals. Correlations between chromium and other breakfast cereal components (lipids, carbohydrates, minerals, vitamins) were also studied. The dialysed Cr values were significantly correlated with the total and unsaturated lipids (p < 0.005). Such other food components as starch, sucrose, fibre, proteins, and various micronutrients were not significantly correlated with the dialysable Cr.     

Mycotoxins in infant/toddler foods and breakfast cereals in the US retail market

The objective of this study was to conduct a mycotoxin survey of commercial infant/toddler foods (cereals and teething biscuits) and breakfast cereals in the United States. A total of 215 retail samples were collected from three geographical locations and analysed for aflatoxins, fumonisins, deoxynivalenol, HT-2 toxin, ochratoxin A, T-2 toxin, and zearalenone using a stable isotope dilution liquid-chromatography tandem mass spectrometry (LC-MS/MS) method. One or more mycotoxins were found in 69% (101/147) of the infant/toddler foods and 50% (34/68) of breakfast cereals. Mycotoxin co-occurrence was observed in 12% of infant/toddler foods and 32% of breakfast cereals. However, the concentrations of detected mycotoxins were lower than the current FDA action and guidance levels. Aflatoxins and HT-2 toxin were not detected in any of the samples, while deoxynivalenol was the most frequently detected mycotoxin. Rice-based cereals appeared to be less susceptible to mycotoxin contamination than other cereal types.     

Extrudate gluten-free breakfast cereals from rice and corn flours with different amylose content: technological and sensory properties

The objective of this study was to evaluate the effects of different amylose content and conditioning moisture on the technological and sensorial properties of extrudate gluten-free breakfast cereals from rice and corn flours. Extrusion was applied to develop breakfast cereals from low-, medium- and high-amylose rice flours combined with corn flour (70:30 w/w), and different conditioning moisture (15% and 17%). When the conditioning moisture was 15%, the extrudates presented lower expansion, hardness and fracturability, when compared to 17% moisture. Extrudates obtained from the combination of rice and corn flours provided light and slightly yellow products, with low values of hardness and fracturability. The micrographs showed the presence of pores, air bubbles and an uneven surface. For industry application, the extrudate with low-amylose rice flour and conditioning moisture of 15% is recommended due to greater expansion and less retrogradation, features that extend shelf life. This cereal was best accepted sensorially.     

Survey of breakfast and infant cereals for aflatoxins B1, B2, G1 and G2.

Three hundred and forty-nine breakfast and infant cereal samples were collected at retail level across Canada from 2002 to 2005. They included rice-, soy-, barley-based and mixed-grain infant cereals, corn-, wheat-, rice-based and mixed-grain breakfast cereals, and were analysed for aflatoxins B1, B2, G1 and G2 using a modified AOAC International official method. An immunoaffinity column was used for the cleanup and purification of extracts. Determination of aflatoxins was by LC using post-column derivatization with pyridinium hydrobromide perbromide and fluorescence detection. Results indicated that 50% of both breakfast and infant cereals had detectable levels (limit of detection = 0.002 ng g-1) of aflatoxin B1, which is the most toxic of the four toxins. The levels found varied from 0.002 to 1.00 ng g-1 for aflatoxin B1, from 0.002 to 0.14 ng g-1 for aflatoxin B2, from 0.008 to 0.27 ng g-1 for aflatoxin G1, and from 0.008 to 0.048 ng g-1 for aflatoxin G2. Only 4% of the breakfast cereals and 1% of the infant cereals had aflatoxin B1 levels exceeding 0.1 ng g-1, which is the European Union maximum limit for aflatoxin B1 in baby foods and processed cereal-based foods for infants and young children.     

Effects of Product Formulation, Processing, and Meal Composition on In Vitro Estimated Iron Availability from Cereal-Containing Breakfast Meals

The effects of breakfast cereal composition, breakfast cereal processing, and breakfast meal composition on relative iron availability from breakfast meals were estimated using an in vitro method. Addition of wheat bran and germ to cereals and meals reduced iron availability. Presweetening caused a slight increase in iron availability. Comparisons among meals containing cereals that were similar except for type of processing showed that processing may affect iron availability. Addition of orange juice to breakfast meals caused a dramatic enhancement of iron availability. Ascorbic acid fortified apple and grape juice increased iron availability but the effect was small compared with the orange juice effect. Studies with purified organic acids showed that ascrobic and citric acids present in the juices caused the observed enhancement of iron availability. Citric acid was a more potent enhancer than ascorbic acid.     

Physical properties and sixth graders' acceptance of an extruded ready-to-eat sweetpotato breakfast cereal

ABSTRACT: Extruded ready-to-eat breakfast cereals (RTEBCs) were made from varying levels of sweetpotato flour (SPF), whole-wheat bran (WWB), and extrusion cooking. Moisture, protein, and ash contents were lower in the 100% SPF than the 100% WWB. Carbohydrate, β-carotene, and ascorbic acid contents were higher in the 100% SPF. Fat, thiamin, riboflavin contents, bulk densities, and the water absorption index were similar for the cereals. However, the expansion ratio was highest in the 100% SPF cereal. The 100% WWB had the lightest color and most fibrous morphology. Extruded RTEBC containing 100% SPF and 75%/25% SPF/WWB were well-liked and acceptable to sixth graders attending an elementary school in Auburn, Alabama, but the 100% WWB was unacceptable.     

Recent Trends in Ready-to-eat Breakfast Cereals in the U.S

Data in the USDA National Nutrient Database for Standard Reference (SR) were examined to discern trends in ready- to-eat breakfast cereals resulting from manufacturers’ reformulations, many in response to public health concerns and consumer demand. The majority of the nutrient data for breakfast cereals in SR are supplied by manufacturers. Nutrient data and ingredients for Kellogg and General Mills ready-to-eat cereals within SR were examined, as those brands represent 62% of the U.S. market. Mean values for total sugar, total dietary fiber, and sodium were calculated for those manufacturers’ breakfast cereals within SR releases 18 through 24 (2005-2011). Values from SR18 (n=120 products) were compared to those from SR24 (n=151 products) using unpaired Student's t-tests. Sugar levels fell from 27.5 to 24.8 g/100 g and sodium from 511 to 438 mg/100 g, a reduction of 10% (not significant; p=.057) and 14% (p<.05), respectively. Fiber levels rose from 7.1 to 9.4 g/100 g, a 32% increase (p<.05). Nutrient comparisons were made using paired t-tests on a subset of 83 products, which excluded cereals that had been added or dropped between SR18 and SR24. From 2005 to 2011, sugar and sodium levels decreased by 7.6% and 11.2%, respectively, while fiber levels increased by 13.4% (all p<.0001). Whole grain ingredients were found in at least 2/3 of the cereals examined in SR24. Trends observed in this important breakfast category demonstrate positive changes in the nutrient composition which may have an important impact on public health.     

Application of enzyme-treated corn starches in breakfast cereal coating

Presently ready-to-eat cereals are coated with high levels of sugar coating to extend the bowl life. Because of health concerns of added sugar, there is a need to identify alternative coating materials. This study was designed to test the efficacy of debranched corn starches with varying amylose contents as a cereal coating. Hylon VII (70% amylose), common, and waxy corn starches were gelatinized and debranched, and then sprayed onto ready-to-eat breakfast cereal flakes. The surface morphology, milk absorption, texture, and digestibility of coated cereals were determined. A starch film with a thickness of 50 to 130 μm was observed with scanning electron microscopy on the surface of the cereals coated with Hylon VII. All starch-coated cereals had a lower milk absorption value than the uncoated and glucose-coated controls. Among starch coatings, common corn starch and Hylon VII resulted in lower milk absorption than did waxy corn starch. After soaking in milk for 3 min, the peak force and work to peak of the cereals coated with corn starches were higher than those of the glucose control and uncoated reference. The cereals coated with Hylon VII were found to have an increase in dietary fiber content. The results suggest that debranched amylose-containing corn starches could extend the bowl-life of ready-to-eat cereals. Practical Application: Currently, many cereals are coated with sugar to keep them from becoming soggy in milk. However, added sugar has been linked to obesity, hyperactivity, and dental caries. This has led to the investigation of alternative coating materials. This study employed the film-forming properties of enzyme-treated corn starch to function as a coating material in breakfast cereal flakes. In addition, the enzyme-treated high amylose corn starch also increased the dietary fiber content of the cereal flakes.     

Determination of acrylamide in coffee and coffee products by GC-MS using an improved SPE clean-up

An improved gas chromatography-mass spectrometry (GC-MS) method to determine acrylamide (AA) in coffee and coffee products was developed. The method was based on two main purification steps: the first with ethanol and Carrez solutions in order to precipitate polysaccharides and proteins, respectively; and the second with a layered solid-phase extraction (SPE) column which proved to be efficient in the elimination of the main chromatographic interferences. The method is applicable to a wide range of coffee products. Twenty-six samples of different coffee products were analysed. The levels of AA were in the range 11.4-36.2 µg l^-1 for 'espresso coffee' and 200.8-229.4 µg l^-1 for coffee blends with cereals. The results indicate that the presence of cereals significantly increased the levels of AA.     

Study on fluorescence of Maillard reaction compounds in breakfast cereals

During the advanced stage of the Maillard reaction (MR) in food processing and cooking, Amadori rearrangement products undergo dehydration and fission and fluorescent substances are formed. Free and total (free + linked to the protein backbone) fluorescence (FIC) due to Maillard compounds in 60 commercial breakfast cereals was evaluated. Pronase was used for efficient release of linked fluorescent Maillard compounds from the protein backbone. Results were correlated with some heat-induced markers of the extent of the MR or sugar caramelisation during cereal processing, such as hydroxymethylfurfural, furfural, glucosilisomaltol and furosine. The effect of sample composition (dietary-fibre added, protein, etc.) on levels of FIC, expressed as fluorescence intensity (FI) per milligram of sample, is discussed. FIC is significantly correlated to the protein content of the sample and fluorescent Maillard compounds are mainly linked to the protein backbone. The ratio of total-FIC to free-FIC was 10.4-fold for corn-based, wheat-based and multicereal-based breakfast cereals but significantly higher in rice-based samples. Addition of dietary fibre or honey increased the FIC values. Data support the usefulness of FIC measurement as an unspecific heat-induced marker in breakfast cereals.