Analysis of heat-damage indices in breakfast cereals: Influence of composition

To evaluate heat damage caused by processing, the content of hydroxylmethylfurfural (HMF), furfural and glucosylisomaltol (GIM) in sixty commercial breakfast cereals was analysed by HPLC. The influence of different cereal compositions on HMF, furfural and GIM content and the correlation between the three indices was explored. Samples were grouped to perform the statistical comparisons between breakfast cereals made from different cereals, according to the presence of cocoa powder or honey, the percentage of dietary fibre and the consumer focus. A statistically significant effect of added-dietary fibre on the level of furfural present in the breakfast cereals and the existence of a significant relationship between HMF and GIM was found. Due to the exclusive origin of GIM from the Maillard reaction this compound is a suitable indicator for the extent of the treatments used by the breakfast cereal industry.     

Maillard Reaction Evaluation by Furosine Determination During Infant Cereal Processing

The furosine content of infant cereals has been used to evaluate the thermal damage caused to those foods during their manufacture (toasting, amylolysis and drying steps). The mean furosine contents of raw and toasted flours were 13·7 and 13·8 mg/100 g of protein, respectively. The furosine content increased to 47·3 mg/100 g of protein after hydrolysis usingalpha-amylase. The amylolysis process raised the reducing sugar content from 0·5% for raw samples to 12·7%. The furosine content of infant cereals rose to average levels of 500 mg/100 g of protein after roller-drying. The infant cereals with the highest levels of reducing sugars, with or without soy flour, exhibited the highest furosine contents. Furosine is a useful indicator to evaluate the progress of the Maillard reaction during the amylolysis and roller-drying stages of infant cereals manufacture.     

Significance of furosine as heat-induced marker in cookies

The effects of recipe formulation in terms of leavening agents (ammonium and sodium bicarbonates), sugars (sucrose and glucose), initial moisture content, and baking conditions (temperature and time) on furosine formation in cookies were studied. The cookies were baked at different temperatures for different times to monitor the progress of the early stage of the Maillard reaction. Change in furosine levels as an indicator of the Amadori products showed a typical kinetic behavior with a rapid increase to an apparent maximum followed by exponential decrease during baking. Initial water activity of cookie dough had no remarkable effect on the apparent maximum, but lowering the water activity decreased the time required to attain it. In addition, levels of furosine in the final product are highly correlated to the initial water content of dough at the same baking conditions. The levels of furosine attained were significantly lower in cookies composed of sucrose than in cookies composed of glucose. Early stage of the MR is rapidly overcome during baking as the Amadori product degraded in the advanced stage. Among the leavening agents, ammonium bicarbonate was the most effective for the progress of the Maillard reaction in cookies during baking.     

Significance of furosine as heat-induced marker in cookies

The effects of recipe formulation in terms of leavening agents (ammonium and sodium bicarbonates), sugars (sucrose and glucose), initial moisture content, and baking conditions (temperature and time) on furosine formation in cookies were studied. The cookies were baked at different temperatures for different times to monitor the progress of the early stage of the Maillard reaction. Change in furosine levels as an indicator of the Amadori products showed a typical kinetic behavior with a rapid increase to an apparent maximum followed by exponential decrease during baking. Initial water activity of cookie dough had no remarkable effect on the apparent maximum, but lowering the water activity decreased the time required to attain it. In addition, levels of furosine in the final product are highly correlated to the initial water content of dough at the same baking conditions. The levels of furosine attained were significantly lower in cookies composed of sucrose than in cookies composed of glucose. Early stage of the MR is rapidly overcome during baking as the Amadori product degraded in the advanced stage. Among the leavening agents, ammonium bicarbonate was the most effective for the progress of the Maillard reaction in cookies during baking.     

Commercial Breakfast Cereals Available in Mexican Markets and their Contribution in Dietary Fiber, β-Glucans and Protein Quality by Rat Bioassays

The beneficial effect of dietary fiber (DF) consumption has long been recognized. The global economy and open market trade policies have increased the availability of food products in Mexican markets, resulting in a wide variety of ready-to-eat commercial breakfast cereals classified as ‘high fiber’. This research was aimed to evaluate the total dietary fiber contents, its fractions (soluble and insoluble) and β-glucan in 13 commercial ‘high-fiber’ breakfast cereals, as well as to evaluate their protein quality by rat bioassays. Commercial ‘high-fiber’ breakfast cereals had 7.42–39.82 % insoluble dietary fiber, 2.53–12.85 % soluble dietary fiber, and 0.45–4.96 % β-glucan. These ready-to-eat commercial ‘high-fiber’ breakfast cereals differed significantly in their total dietary fiber, their soluble and insoluble DF fractions, and also in their β-glucan contents. When supplied as experimental diets, in 14-day rat feeding trials, the ‘high-fiber’ breakfast cereals showed an adverse effect on the % N digestibility but protein utilization, as measured as net protein ratio (NPR), was not significantly affected. The consumption of these commercial breakfast cereals, especially those made of oats as the basic ingredient, is highly recommended, since these products, being a concentrated source of dietary fiber, do not affect their protein quality.     

Characterization of the FODMAP-profile in cereal-product ingredients

Cereal-based products, such as bread, are staple foods in the western diet. Due to the nature of their basic ingredients and the diversity of recipes, the amount of fermentable short-chain carbohydrates (FODMAPs) in those products may be high. This study characterized the FODMAP-profiles of a broad range of cereal-product ingredients, serving as a basis for low FODMAP product development. Different cereals, pseudo-cereals, gluten-free flours, pulses, pulse protein ingredients, commercial sprouts, and other cereal-product ingredients were analyzed, using anion-exchange chromatography with electrochemical detection. Wheat and related cereals were high in fructans. Pulses, such as peas contained high galactooligosaccharides (GOS) amounts. Whereas GOS levels in pulse protein ingredients varied, depending on their production. Gluten-free flours, for instance, rice-flour, showed low FODMAP-profiles. Amongst those, buckwheat, which does not contain any of the FODMAPs investigated, contained high amounts of other soluble non-digestible carbohydrates, namely fagopyritols; these may have a similar effect on a sensitive gut as GOS. Finally, ingredients contained mainly high levels of fructans and GOS. Yet, the analysis of commonly consumed commercial cereal products, including bread, pasta, crackers and biscuits, highlighted the relevance of lactose, fructose in excess of glucose and polyols. These products serve as benchmarks for further product development.     

Traditional and possible technological uses of Digitaria exilis (acha) and Digitaria iburua (iburu): A review

The focus of this article is the traditional andtechnological uses of two tropical cereal grains: Digitaria exilis (acha) and D. iburua(iburu); with emphasis on their carbohydrate andprotein components. Some useful attributes of thegrains emanating from present knowledge are discussed. The major classes of traditional foods from thesegrains are thick and thin porridges; steam cookedproducts, e.g. couscous; and nonalcoholic andalcoholic beverages. The proteins in these grains are not easilyextractable; however, the digestibility of the proteinsare better than those of sorghum and millet. The highlevels of residue protein in them may have importantfunctional properties. Technologically, acha and iburucan be utilized in ways similar to rice. The twograins require minimal processing due to grain sizeand location of constituents. Whole acha and iburugrains are now used for quick cooking,non-conventional food products including weaning foodsof low bulk density and breakfast cereal with goodfiber content. The grains could be used in a widevariety of other products. Cookies, crackers, andpopcorn, made in an almost endless array of forms areexamples. The breeding of acha and iburu cultivarswith good kernel properties is critically important totheir utilization potential.     

DNA-based methods for identification and quantification of small grain cereal mixtures and fingerprinting of varieties

The composition of cereal-based foods is a key factor in determining the quality and safety of the final product while the reliable identification of cereal species and cultivars are essential for the handling, marketing and processing of grain and for the protection of plant breeders' rights. Analytical methods have therefore been developed and applied to identify and quantify cereal species in food products and also to fingerprint and identify grain at the genotype and variety levels. DNA-based methods for the detection and quantification of mixtures of small grain cereals are reviewed, together with the recent development of molecular markers for varietal fingerprinting.     

Enrichment of cookies with glutathione by inactive yeast cells (Saccharomyces cerevisiae): Physicochemical and functional properties

Cookie is one of the favorite cereal products which could be formulated by using various ingredients for enrichment. The aim of this study was to determine the effects of the inactivate yeast cells addition to cookie formulation in terms of glutathione (GSH) content, antioxidant activities, physicochemical and sensorial properties. Also, the cookies were produced with GSH (pure, 98%) addition to compare the effects of inactive yeast GSH with pure GSH on revealed properties. According to results, The GSH contents and the antioxidant activities increased in dough and cookie samples with inactive yeast addition compared to control and pure GSH added dough and cookie samples. The increases in GSH contents and antioxidant activities were observed after baking in all samples. The pure GSH addition increased the moisture content, spread ratio and L* value while decreased the hardness and b* values of the cookies. The contrary results were obtained by inactive yeast addition in terms of the physicochemical properties where the protein content of the cookies increased with inactive yeast addition by approximately 25%. The loss of GSH content decreased while the antioxidant activities and nutritional value increased in cookies by inactivate yeast addition.     

In vitro digestion kinetics and bioaccessibility of starch in cereal food products

The study of starch digestion in cereal-based products is essential since the extent and rate of hydrolysis affects the glycemic index associated with several food-related diseases. Besides, a unique matrix is usually studied and many variations of in vitro techniques (e.g. enzymes, pH, food:enzymes ratio) are selected, then comparison of results became difficult. The recently published INFOGEST in vitro static method with international consensus (Minekus et al., 2014) was applied to several cereal-based products to address whether it is suitable for analysis of starch hydrolysis kinetics. Bread, pasta and cookies were selected taking into account the analysis of different cereal matrixes, including gluten-free products. White bread presented the highest in vitro starch hydrolysis (87%) showing significant differences compared to gluten-free bread (76.5%). Refined flour sheeted pasta (72.6%), whole-wheat extruded pasta (92.0%) and gluten-free pasta (54.3%) showed differences in the extent and rate of hydrolysis. Cookie samples presented the lowest starch hydrolysis (∼45%). The starch availability was estimated by the dializability method, which measures the maltose equivalents dialyzed after simulating digestion. Starch dializability was 35%, 25% and 15% on average for bread, pasta and cookie samples respectively, with positive correlation with rapidly digested starch. The tested in vitro method allowed discriminating the effect of different processing techniques, product types and formulation of the three most common cereal-food matrixes in starch digestion.     

Improving cereal grain carbohydrates for diet and health

Starch and cell wall polysaccharides (dietary fibre) of cereal grains contribute to the health benefits associated with the consumption of whole grain cereal products, including reduced risk of obesity, type 2 diabetes, cardiovascular disease and colorectal cancer. The physiological bases for these effects are reviewed in relation to the structures and physical properties of the polysaccharides and their behaviour (including digestion and fermentation) in the gastro-intestinal tract. Strategies for modifying the content and composition of grain polysaccharides to increase their health benefits are discussed, including exploiting natural variation and using mutagenesis and transgenesis to generate further variation. These studies will facilitate the development of new types of cereals and cereal products to face the major health challenges of the 21st century.     

Protein Nutritional Quality of Infant Cereals during Processing

The most common food for weaning at the age of 4–6 months is cereal since is that it is a good source of high quality protein. However, processing may affect this quality. The aim of the present study was ascertain the changes that take place during four processing stages of infant cereals (in the raw materials, after roasting, after enzymatic treatment and drum drying, and in the commercial product), the following protein nutritional parameters: crude and true protein (CP and TP, respectively), in vitro protein digestibility (IVPD), free amino acids (FAA), calculated protein efficiency ratio (C-PER) and total amino acids profile. Of the infant cereals studied two contained gluten (‘Multicereal’ and ‘Wheat’) and two were gluten-free (‘Growth’ and ‘Rice and carrot’). All the parameters studied were affected by the different processing stages, but none showed a clear trend. The CP and TP content decreased after heat treatment (roasting) with a consequent increase in FAA content due to protein hydrolysis and the release of amino acids. IVPD remained stable during the processing stages in all the infant cereals, except in ‘Wheat’, while C-PER increased significantly. Infant cereals containing gluten showed higher CP and TP contents, and also higher IVPD than gluten free cereals, in which a digestibility value higher than 75% was reached. The overall content of essential amino acids, including sulphur amino acids, was acceptable (equal to or higher than FAO/WHO recommendations), although lysine (Lys) was the limiting amino acid in all the infant cereals.     

Increased understanding of the cereal phytase complement for better mineral bio-availability and resource management

The present paper summarizes the current state of knowledge on cereal phytase that are particular relevant for improving mineral and phosphate bio-availability. Phytases can initiate the hydrolysis of phytate, the main storage form of phosphate in cereals and the major anti-nutritional factor for the bio-availability of micronutrients in human nutrition. The composition and levels of mature grain phytase activity (MGPA) in cereals is of central importance for efficient phytate hydrolysis. The MGPA varies considerably between species. Substantial activity is present in Triticeae tribe cereals like wheat, barley and rye whereas non-Triticeae cereals such as maize and rice have very little MGPA. Recent studies have determined the evolutionary relationships of phytases in Triticeae and non-Triticeae and highlighted the importance of the purple acid phosphatase phytases (PAPhys). In the Triticeae, PAPhys are synthesized during grain development (PAPhy_a) and during germination (PAPhy_b). In non-Triticeae species, only PAPhys that are mainly synthesized during germination were identified. The new knowledge provides new opportunities for modulating the MGPA in Triticeae cereals but also indicates that nutritionally relevant levels of MGPA are unlikely to be achieved in non-Triticeae by conventional breeding. Increasing MGPA in barley via cisgenesis is discussed.     

Reducing the incidence of allergy and intolerance to cereals

This paper reviews studies on allergy, intolerance and sensitivity to cereals, especially to wheat, barley, rye, maize, rice and oats with regard to reducing their incidences. Prevalence of allergy to cereals is generally low; prevalence of other cereal-related diseases are highest for wheat and lowest for oats. Compared to the other cereals, wheat (and its components wheat starch and vital gluten) are most abundantly applied in a broad range of food products world-wide, which justifies the major focus of this review on wheat. Current knowledge on diagnosis of the cereal-related diseases and on detection and characterization of the relevant proteins is discussed in the context of the development of prevention strategies. Aiming at their design and implementation, such strategies require building of knowledge frameworks at the primary, secondary and tertiary prevention levels. In this regard, selection and breeding of low-allergenic/low-intoleragenic crop varieties, application of processing and technological approaches, and the introduction of alternative safe cereal crops is discussed. Sustainable reduction of immune-related diseases in general (including cereal allergies and intolerances) is discussed with regard to eating habits and lifestyle factors, human genetic and physiological characteristics, and the role of the intestinal micro-flora.     

Nutritional improvement of lentils,chick pea,rice and wheat by natural fermentation

Effect of natural fermentation process (4 days) on the non-protein nitrogen, crude and true protein, amino acids content and in vitro digestibility of two kinds of legumes (lentils and chick pea) and two kinds of cereals (rice and wheat) was investigated. Non-protein nitrogen increased significantly (p<0.001) in the fermented products. Little increase has occured in the crude protein while no significant change was observed in the fermented true protein samples. It was observed that methionine and cystine which are considered the limiting amino acids in legume seeds were close to those of FAO/WHO patterns. Also, lysine content (the first limiting amino acid in cereals was higher in fermented rice than that of FAO/WHO pattern. Moreover, fermentation process improved significantly, the in vitro digestibility of both legume and cereal products.     

Insights from in vitro exploration of factors influencing iron,zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereals

Developments in genetics, agronomics and processing has positioned staple cereals as important sources of iron, zinc and provitamin A (pVA) carotenoids for nutritionally vulnerable populations. Significant effort has been placed on understanding the bioavailability of these micronutrients from cereal foods, including the exploration of underlying mechanisms by which their bioavailability can be modified. While micronutrient bioavailability is preferably assessed in clinical trials, relevant in vitro digestion and intestinal cell culture models have been applied to study effects of genetic, agronomic, post-harvest and food processing on micronutrient bioavailability. This review (1) critically assesses the application of in vitro models in the exploration of mechanisms associated with iron, zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereal foods, and (2) identifies remaining gaps in order to frame future strategies to improve the nutritional impact of cereal foods.     

辽西绿色有机杂粮生产基地建设与产品开发效益评价

辽西朝阳地区十年九旱,干旱是制约农业发展的主要因素。由于旱田和坡耕地较多,得天独厚的光热资源适宜抗旱杂粮作物生长,具备优质杂粮生产的地理气候优势。同时当地农民有种植杂粮的悠久历史和丰富经验,是开发具有地方特色的绿色有机杂粮产品的天然宝地,适合大面积发展杂粮产业。2004~2007年在绿色有机杂粮基地建设和杂粮产品开发上,创新运筹模式,获得了明显的经济效益与社会效益,推进了辽西地区的杂粮产业化的进程,实现了产品升级和农业增收。     

Direct measurement of the total antioxidant capacity of cereal products

A simple and rapid procedure was developed for the direct measurement of the antioxidant capacity of cereals. It entails grinding of cereals, mixing with 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) reagent, centrifugation and measure of the absorbance. The ABTS reagent was dissolved in a mixture of ethanol:water (50:50, v/v), instead of 100% ethanol, in order to overcome low solubility of water-soluble antioxidant compounds of some cereals. A reaction time of 30 min allowed plateau values to be reached during the antioxidant capacity measurement of cereal samples. The accuracy of the direct procedure was confirmed by measuring, in solid state, the antioxidant activity of pure phenolic compounds.The direct procedure gave results of total antioxidant capacities significantly higher than those determined by the traditional procedure (multiple extraction followed by alkaline hydrolysis) for most whole meal cereals, suggesting that such a procedure was not always sufficient to properly assess the antioxidant capacity of bound phenolic compounds in cereals. The proposed extraction-independent procedure for measuring antioxidant capacity of cereals will facilitate the inter-laboratory data comparison, the construction of reliable antioxidant capacity database and the screening of large sampling of cereals for their nutraceutical characteristics.     

The nutritive value of amaranth grain (Amaranthus caudatus)

Digestibility of dietary fibre (DF) and energy of three pale-seeded and one darkseeded variety ofAmaranthus caudatus were studied in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 8% of DF and the black seeds about twice as much. The soluble DF fraction made up 33–44% of the total DF (TDF) fraction in the pale-seeded varieties, but only 18% in the black seeds. The monomer sugar composition of the DF was very similar in all products. However, the black seeds were very high in lignin, and DF of the black-seeded products were more resistant to digestion than that of the pale-coloured products. In the pale amaranth products digestible energy (DE) varied between 86 and 91%. In the dark-seeded products DE was lower, and there was a significant negative correlation (r=–0.92) between DE and TDF. Processing of pale seeds had only minor effects on TDF and DE, but increased the proportion of soluble DF and the digestibility of DF in one variety. The food intake tended to be lower in rats fed raw pale seeds compared with those consuming processed products, indicating the presence of heat-labile factors reducing palatability.In conclusion, the pale seeds had a lower content of DF than most cereal grains and the DF was more easily digested. As a source of energy, amaranth grains seem to be comparable to other cereals.