Insect-corn kernel interaction: Chemical signaling of the grain and host recognition by Sitophilus zeamais
Virginia Lara Usseglio, José Sebastián Dambolena, Carolina Merlo, María Laura Peschiutta, María Paula Zunino
In living organisms, the cuticle has structural functions and is involved through chemical signaling in biological interactions such as plant-insect and provides protection against biotic and abiotic factors, thereby avoiding desiccation or the attack of predators. The objective of this study was to investigate the participation of the epicuticle in the maize kernel-Sitophilus zeamais interaction. The GC-MS analysis of the epicuticle extract demonstrated the presence of aliphatic hydrocarbons, alcohols, ethers, fatty acids, sterols and their derivatives. The results of bioassays show that the epicuticle of maize has a primordial role in its interaction with S.zeamais, and participates in the recognition and attraction to the food source, as well as regulating its reproduction. In addition the compounds present in the epicuticle extract may act as signal molecules and development regulators. This study reveals the effect of the maize kernel cuticle on Sitophilus behavior and contributes to the understanding of the interaction.
Journal of Stored Products Research，2018，79（12）： 66-72
Storage stability and composition changes of three cold-pressed nut oils under refrigeration and room temperature conditions
Adrián Rabadán, Manuel Álvarez-Ortí, José Emilio Pardo, Andrés Alvarruiz
Pistachio oil had higher stability than almond and walnut oils.Peroxide values increased faster at room temperature than at lower temperatures.The induction period decreased during the storage stage.Polyunsaturated fatty acids decreased slightly throughout the storage.Storage temperature within the range 5–20?℃ is not relevant for oil stability.
1‐Methylcyclopropene (1‐MCP) effects on natural disease resistance in stored sweet potato
Robert S Amoah，Leon A Terry
The potential of 1‐methylcyclopropene (1‐MCP) to maintain postharvest storage of sweet potato was studied. In two separate experiments, the orange‐fleshed sweet potato cv. Covington was treated with 1‐MCP (1.0 µL L−1, 24 h) and roots stored at 15 ℃. During storage, samples were evaluated for the respiration rate, sprout growth, weight loss, incidence of decay and changes in dry matter. The roots were further assayed for the temporal changes in individual non‐structural carbohydrates and phenolic compounds in the skin and flesh tissues of the proximal (stem end), middle and distal (root end) regions.
以绿豆皮为原料,主要研究了绿豆皮黄酮的纯化工艺。首先比较了AB-8,LSA-10,HPD-100和ADS-7型4种大孔树脂对绿豆皮黄酮的吸附和解析特性,选择其中最好的树脂,对其吸附和解析条件进行了研究。结果表明,AB-8型是纯化绿豆皮黄酮较好的大孔树脂,其最佳吸附条件为上样速率1.98 m L/min,上样质量浓度0.045 9 mg/m L,上样量10 m L时,最大吸附率可达88.89%;其最佳解析条件为解析液乙醇体积分数70%,解析液洗脱流速1.98 m L/min,解析液用量25 m L时,解析率可达69.51%。绿豆皮黄酮的纯度由10.57%提高至72.19%,表明该纯化工艺具有较好的纯化效果,可为绿豆皮黄酮的纯化及进一步开发应用提供参考。
以高筋面粉为主要原料,添加全麦粉、黑啤酒、白砂糖、酵母和食盐制作硬式面包。在单因素试验的基础上,通过正交试验优化产品配方,探讨全麦粉、黑啤酒、酵母和食盐的添加量对产品品质的影响。结果表明,在全麦粉添加量30%、黑啤酒添加量62%、酵母添加量1.4%、食盐添加量1.0%时,产品色泽金黄,外脆内软,组织细密,呈现天然麦香,产品比容4.27 m L/g,感官评分92分,各项理化及卫生指标均符合国家标准。由此制成的面包风味独特、营养健康,同时也为全谷物食品的开发及黑啤酒资源的综合开发利用提供参考。
Enzymatically Hydrolyzed Wheat Gluten as a Foaming Agent in Food
Arno G.B. Wouters，Ine Rombouts，Ellen Fierens，Kristof Brijs，Jan A. Delcour
There is a growing interest in substituting animal proteins with plant protein sources in food systems. A notable example is the replacement of hen egg white (EW) protein, which is used in a wide range of food products because of its excellent foaming characteristics. Here, enzymatically hydrolyzed wheat gluten, which has greater solubility and better foaming properties than wheat gluten itself, was prepared and incorporated in a classical meringue recipe to investigate its potential as a foaming agent. Meringues based on gluten hydrolysates (GHs) had batters with lower density and greater apparent viscosity than those based solely on EW protein. Furthermore, after baking, these GH containing meringues had greater specific volume than those based on EW protein alone and no notable differences in color or texture between the different samples were noted. These outcomes were related to basic insights in the air–water interfacial behavior of GHs obtained in earlier studies. More specifically, the greater foaming capacity of GH than of EW protein solutions was related to their superior meringue batter (density and apparent viscosity) and product (specific volume) properties. While EW protein solutions had better foam stability than GH solutions (in the absence of sugar), this was apparently less relevant for meringue properties, probably due to the very high viscosity of the sugar rich batter, which could obscure differences in the intrinsic foam stabilizing ability of the samples.
journal of food science，2018，83（8）: 2015-2274
Alkali extraction of rice residue protein isolates: Effects of alkali treatment conditions on lysinoalanine formation and structural characterization of lysinoalanine-containing protein
Zhaoli Zhang, Yang Wang, Chunhua Dai, Ronghai He, Haile Ma
The influence of alkali extraction conditions on the formation of lysinoalanine (LAL) and the structural characterization of lysinoalanine-containing protein in rice residue protein isolates (RRPI) were explored in this study. It was found that LAL content increased from 0.256 to 13.079?g/kg as NaOH concentration increased from 0.03 to 0.09?M and then decreased to 1.541?g/kg at 0.13?M NaOH. The extraction temperature and time were found to have a positive correlation with LAL content. The highest LAL content (25.679?g/kg) was observed with alkali extraction using 0.09?M NaOH at 75?℃ for 120?min. The comparative structural analysis results showed that alkali treatment could degrade cystine, lysine, threonine and arginine to generate LAL; increasing alkali content would cause variations in secondary structure and micropore appearance on the surface of lysinoalanine-containing protein, whereas increasing alkali treatment temperature and time could enlarge the surface particle size of the protein.
Milling performance of waxy wheat and wild‐type wheat using two laboratory milling methods
Bin Xu,Andrew Mense,Kingsly Ambrose,et al
Flour and starch from waxy wheat (Triticum aestivum L) have unique properties such as high water‐holding capacity, low pasting temperature, low syneresis, and high resistance to retrogradation. However, the milling performance of waxy wheat was not well documented. In this study, the milling quality of a waxy wheat (Mattern) was evaluated by comparing its flour yield, chemical composition, flow properties, and particle size distribution with that of two wild‐type hard red winter (HRW) wheats (Wesley and Everest) using two laboratory milling methods. The effects of moisture level and tempering time on milling behavior for the waxy wheat (Mattern) were examined and compared with that of wild‐type wheat.Waxy wheat (Mattern) seemed to require more moisture during tempering than wild‐type wheats to achieve a similar drop in SKCS hardness. For Mattern, the overall grain hardness drop was minimal when tempering to moisture contents below 17.5%. When the tempering moisture content increased from 13% to 17.5%, the flour yield increased, but decreased after 17.5% moisture content. Tempering Mattern to 16% and higher resulted in a higher bran yield compared with shorts yield, although the yield of the shorts from Mattern was significantly greater than that of the shorts from both wild‐type wheats. The flour yield of Mattern was 65.1%, which was significantly lower than that of both wild‐type wheats (73.1% for Wesley and 72.2% for Everest).At the same moisture content (16%), the hardness of the waxy wheat (Mattern) kernel decreased at a slower rate than the wild‐type wheat during tempering for 48 hr. The flour yield of the waxy wheat (Mattern) was significantly lower than that of wild‐type wheat. Mattern flour was less free‐flowing and more adhesive than the wild‐type HRW flour, mainly due to its smaller particle size and higher fat content.
Superheated steam processing improved the qualities of oats flour and noodles
Nachuan Zhang, Yuqi Gao, Litao Tong, Zaigui Li
To investigate the effects of superheated steam on the quality attributes of oats and oats noodles, the properties of oats flour and noodles prepared with or without superheated steam (200?℃ for 2?min) and steam (100?℃ for 20?min) processing were characterized. As the results, the residual lipase activity and damaged starch contents in superheated steam processed (SSP) oats were significantly decreased compared with steam processed (SP) oats (P ? 0.05). SSP improved morphology and water hydration properties of oat flour and development time of oats dough significantly compared with SP (P ? 0.05). Moreover, SSP also improved a part of the texture characteristics and taste quality in sensory evaluations of oat noodles compared with SP (P ? 0.05). It indicated that the SSP might provide the protective effects on the characteristics of oats flour, which could be used to produce the better qualities of oats noodles than the SP.
Journal of Cereal Science，2018（9）:96-100
High amylose wheat: A platform for delivering human health benefits
Anthony R. Bird, Ahmed Regina
Non-communicable diseases such as diabetes, cardiovascular diseases and certain cancers are now the leading cause of death and disability, and their prevalence is rising worldwide. Poor diet is a major modifiable risk factor but changing eating habits has had limited success. Enhancing the nutritional quality of staple foods offers a complimentary intervention strategy for alleviating the burden of diet-related chronic disease. Wholegrain cereals, such as wheat, are prime targets. Their nutritional credentials and health-promoting potential are well established. Wheat is the major source of protein, minerals and vitamins, and dietary fibre for most people. Importantly, wheat is a versatile ingredient for producing foods that have high consumer appeal. Their popularity is expanding globally and small improvements in wheat grain composition conceivably translate to substantial dietary change across entire populations. A newly developed, high amylose wheat line illustrates the capacity for developing healthier processed staple food products with potential for remediating chronic disease risk. Dietary fibre density of this novel grain is markedly improved due to a >10 fold increase in resistant starch content. The sensory attributes of finished products are not compromised and preliminary studies demonstrate that consumption of the new wheat significantly improves indices of metabolic and digestive health.
Journal of Cereal Science，2018（7）:99-105
Creation of internal structure of mashed potato construct by 3D printing and its textural properties
Zhenbin Liu, Bhesh Bhandari, Sangeeta Prakash, Min Zhang
3D printing was used for printing mashed potatoes (MP) constructs with variable internal structures. The dimensional properties, textural and structural qualities of the printed objects were investigated as a function of infill levels (10, 40 and 70%), infill patterns (rectilinear, honeycomb and hibert curve), and number of shell perimeters (3, 5 and 7). The printed samples significantly matched the designed geometries. Hardness and gumminess were strongly related to infill levels and perimeters, but the printing paths being performed to fill the samples showed no effect on them. Firmness and Young's modulus were only affected by infill percentage but not by perimeters and printing paths. Further, comparative assessment of 3D printed and cast samples were also conducted on the textural properties and microstructure features. Microstructure analysis indicated a uniform internal structure was obtained for cast sample. In comparison, an obvious layered structure was observed in longitudinal-sectional direction while a porous structure was obtained in cross-sectional view of 3D printed samples regardless of infill levels. 3D printed samples, even at 100% infill, were significantly (p?<?.05) less hard, by up to 26.75% and 28.36% in terms of hardness and gumminess, compared to cast samples. The results suggest that 3D printing considerably changes the properties of printed samples, possibly offering a new way for tailoring textural properties of printed samples through creating their internal structure.
Food Research International，2018（9）: 534-543
Combined effect of xanthan gum and water content on physicochemical and textural properties of gluten-free batter and bread
Christian R. Encina-Zelada, Vasco Cadavez, Fernando Monteiro, José A. Teixeira, Ursula Gonzales-Barron
The objective of this study was to evaluate the combined effect of xanthan gum (XG) on physicochemical, rheological and textural properties of gluten-free batter and bread. To prepare gluten-free batter, different levels of XG (1.5, 2.5 and 3.5%) and water (90, 100 and 110%) were added to a base formula of rice (50%), maize (30%) and quinoa flours (20%); and the batters were evaluated in a factorial design. Several properties on both batter (stickiness and back extrusion) and its corresponding bread (loaf specific volume, baking loss, water activity and pH, texture profile, mean cell area, mean cell density, cell size uniformity, void fraction, mean cell compactness and mean cell aspect ratio) were then evaluated. Higher XG doses (p?<?.001) tended to produce batters of lower stickiness, adhesion and cohesive-strength, yet, of higher firmness, consistency, cohesiveness and viscosity index. After baking, these loaves presented lower specific volume; lower crumb aw, pH, hardness, springiness, mean cell area and void fraction; and higher (p?<?.001) chewiness, resilience, mean cell density, cell size uniformity and mean cell compactness. The sticker and less consistent batters produced with higher WC rendered larger bread loaves of softer and more springy/resilient crumbs with greater mean cell size and void fraction. Gluten-free loaves of good appearance in terms of higher specific volume, lower crumb hardness, higher crumb springiness, and open grain visual texture were obtained in formulations with 110% WC and XG doses between 1.5 and 2.5%.
Food Research International，2018（9）: 544-555
Oats in healthy gluten-free and regular diets: A perspective
Marinus J.M. Smulders, Clemens C.M. van de Wiel, Hetty C. van den Broeck,et al
Five approved EFSA health claims apply to oats.Long-term food studies confirm the safety of oats for coeliac disease patients.Oat products may be sold as gluten-free in the EU and the USA.A separate gluten-free oat production chain is required to avoid contamination.The Oat Global initiative aims to strengthen oat through worldwide cooperation.
Food Research International，2018（8）: 3-10
Novel approaches for enzymatic gluten degradation to create high-quality gluten-free products
Katharina Anne Scherf, Herbert Wieser, Peter Koehler
Food-grade plant, fungal and bacterial peptidases are capable of degrading gluten.An Aspergillus niger prolylendopeptidase removed gluten from wheat starch and bran.Special sourdough fermentation leads to high quality gluten-free wheat-based foods.Peptidase-active barley malt extract was used to make gluten-free barley-based beer.Using suitable peptidases creates a greater choice of gluten-free products.
Food Research International，2018（8）62-72
Triticale-oat bread as a new product rich in bioactive and nutrient components
Anna Fra?, Damian Go??biewski, Kinga Go??biewska, Dariusz R. Mańkowski, et al
Nowadays non-bread cereals, including oats, due to their healthy properties are increasingly used as additives in bread production. The aim of the present study was to evaluate new healthy triticale-oat bread by replacement as much as possible of triticale flour by high fibre oat concentrate (COF), without decreasing technological quality of bread. The flours obtained from 4 winter triticale varieties were enriched with 2.5%, 5% and 10% of COF. An increasing COF level resulted in significantly increased nutritional parameters content as well as dietary fibre (up to 11.5%), including six-fold increase in β-glucan content (from 0.3% for control breads to 1.0% and 1.8% for 5% and 10% COF, respectively) and as a consequence even two-fold increase in viscosity of water extracts (WEV). Obtained results were compared to popular, available in bakery wheat and wheat-rye breads. All obtained triticale-oat breads can be included as food products high in fibre (over 6?g per 100?g). The dough properties and bread parameters, especially bread volume, shape and crumb texture decreased with the addition of COF. Results show that triticale flour replaced by up to 5% of COF makes it possible to prepare new kind of healthy bread.
Journal of Cereal Science，2018（7）:146-154
Slowly Digestible‐ and Non‐Digestible α‐Glucans: An Enzymatic Approach to Starch Modification and Nutritional Effect
Waraporn Sorndech, Sunanta Tongta, Andreas Blennow
Escalating diabetes, obesity, cardiovascular disease, and bowel syndrome have increased consumer awareness of nutrition and energy values of starch products. Slowly digestible starch (SDS), slowly digestible maltooligosaccharides (SDM), and highly branched maltooligosaccharides, so called isomaltooligosaccharides (IMOs), generated by enzyme modification of starch, provide a new concept to meet consumer demands and solve urgent health‐associated problems. The combination of starch‐active enzymes in the glucanotransferase and glucanohydrolase families to produce slowly digestible‐ and non‐digestible α‐glucans has been widely studied, mainly focusing on the activities of branching enzyme (BE), amylomaltase (AM), and α‐transglucosidase (TGase). Products obtained from the action of these enzymes have resulted in completely novel types of maltooligosaccharides that are slowly degraded and therefore digested in the small intestine to maintain regulated blood glucose levels and suppressed glycemic‐index response. Some IMOs can even escape the small intestine and become fermented by micro‐organisms in the large intestine to produce health‐promoting short‐chain fatty acids such as butyric acid. Such slowly digested α‐glucans can regulate and trigger health‐promoting gut hormone release. Different novel production strategies of health‐promoting α‐glucans, their structures and nutritional effects are discussed here.
Structure and Physicochemical Properties of Resistant Starch Prepared by Autoclaving‐Microwave
Jiangtao Li, Wenfang Han, Binjia Zhang,et al
This work is focused on evaluating the structure (granular morphology, crystalline structure, molecular order structure), and properties (resistant starch content, swelling power, amylose leaching) of resistant starch (RS) prepared from corn starch by an autoclaving and autoclaving‐microwave method. The results indicated that compared with native starch, all of the RS granules became loose, bigger, and rough fragmented, and displayed a B + V crystalline structure. Meanwhile, the relative crystallinity, helix content, molecular orders for RS samples decrease. The RSs displayed mainly RS3 and RS5 types, with enhanced thermal stability. Compared to autoclaving method, the autoclaving‐microwave treatment significantly increases the RS content from 30.15% to 40.70%, since microwave could promote the formation of the double helix in RS. In particular, the RS prepared by autoclaving‐microwave (HRS‐CM) exhibits the highest degree of crystallinity, ordered structure, and degree of double helical structure as confirmed by XRD, FT‐Raman, and 13C NMR.
Physicochemical and Antioxidant Properties of Rice Flour Based Extrudates Enriched with Stabilized Rice Bran
Peng Wang, Qingyu Yang, Dongmei Zheng,et al
Broken rice‐based flour is incorporated with 15, 30, and 45% w/w of stabilized rice bran and extruded by a co‐rotating twin‐screw extruder at temperatures of 90, 120, and 150 ℃ to produce extrudates with potential health benefits. The changes in physicochemical and antioxidant properties of the rice flour after the incorporation with SRB and extrusion are determined. The peak viscosity and thermal enthalpy (ΔHg, J g−1) of the rice flour decline as the incorporated amount of SRB and extrusion temperature increase. The incorporation of SRB improve the water absorption and reduce the water solubility of the rice flour; while both indexes enhance after extrusion at certain temperatures. The incorporation of SRB and extrusion results in extrudates with higher content of resistant starch. Furthermore, the incorporation of SRB enhance the free, bound, and total phenolic content of the rice flour. However, free and total phenolics content tend to decrease with the increase in extrusion temperature. DPPH, ABTS, and FRAP activities are found to be consistent with the phenolic content of samples. The obtained results suggest that rice flour based extrudates with potential health benefits can be produced through the incorporation of rice flour with stabilized rice bran and extrusion cooking.
Influence of Wheat Starch on the Structural Changes and Size Distribution of Gluten Induced by Adding Wheat Bran Dietary Fiber
Wen Han, Sen Ma, Li Li, Xueling Zheng, Xiaoxi Wang
This study investigates the particle size distribution and structural changes in the gluten system with and without starch induced by adding wheat bran dietary fiber (WBDF). The results show that adding WBDF tends to disturb the particle size distribution of gluten considerably and causes changes in the hydrophobic group microenvironment. The presence of starch can reduce the destructive effects of gluten by forming a more open but solid gluten matrix, which led to larger‐sized particles. Moreover, the gluten‐starch system exhibited a significantly higher surface hydrophobicity value of 3694.4 but a lower fluorescence intensity possibly due to the quenching effect. Both systems had similar zeta potentials ranging from 17.4 to 18.4 mV, suggesting little impact of WBDF and starch on gluten electrostatic interactions. There results indicate that the changes in the gluten protein are determined not only by the amount of WBDF but also by the cooperation of starch.
Phosphorylated and Cross‐Linked Wheat Starches in the Presence of Polyethylene Oxide and Their Application in Biocomposite Films
Graziella Pinheiro Bruni,Jean Paulo de Oliveira, Shanise Lisie Mello El Halal，et al
Wheat starch is modified by phosphorylation and cross‐linking. Starches are evaluated for phosphorus content, amylose content, swelling power, solubility, pasting properties, crystallinity, and morphology. Films are made with phosphorylated and cross‐linked starches, and with addition of 10% (w/w) polyethylene oxide (PEO). The films are evaluated for morphology, water vapor permeability, mechanical properties, crystallinity, roughness, and angle of contact with water. Phosphorylated starch shows higher phosphorus content, amylose content, swelling power, and solubility than cross‐linked starch and native starch did. The starch film containing PEO presents discontinuous morphology, is more crystalline and rugged, and less hydrophilic than starch films without PEO. The biocomposite proves promising for usage in flexible packaging.
Sweet Potato Starch‐Based Nanocomposites: Development, Characterization, and Biodegradability
Aseel T. Issa，Keith A. Schimmel，Mulumebet Worku，et al
The primary objective of this study is to develop and characterize a novel active biodegradable nanocomposite film using sweet potato starch (SPS) for food packaging. Montmorillonite (MMT) nanoclay at a constant weight of 3% and thyme essential oil (TEO) at three levels (2%, 4%, and 6% v/v) are incorporated into SPS film. The results show that incorporating MMT and TEO into SPS film greatly enhanced (P < 0.05) water resistance by 50%. MMT incorporation also hinders the degradation rate of the film. Furthermore, the combined effect of MMT and TEO (up to 4%) improve tensile strength, elongation, and tristimulus color values (P < 0.05). Fourier transform infrared (FT‐IR) spectroscopy and X‐ray diffraction (XRD) results confirm that the noted improvements are related to MMT exfoliation and good interaction between SPS and MMT in the presence of TEO. These results suggest that SPS may provide a viable solution to the waste disposal of plastic packaging materials used for food products.
Fortification effects of different iron compounds on refined wheat flour stability
Ana Paula Rebellato, Bruna Klein, Roger Wagner, Juliana Azevedo Lima Pallone
The characterization of the modifications that may occur during the storage of iron-fortified wheat flour is an important tool for understanding the variations in the product quality, since iron may present pro-oxidant activity. Therefore, the aim of this study was to evaluate the effect of refined wheat flour fortification with different iron compounds (ferrous sulfate, ferrous fumarate, reduced iron, sodium iron ethylenediaminetetraacetic acid, microencapsulated ferrous sulfate, and microencapsulated ferrous fumarate) on quality and stability parameters. For this purpose, it was evaluated the following parameters: titratable acidity, color, peroxide value, and hexanal during 120 days of storage. The iron content was in average 1.0?mg/100?g in unfortified flour (control) and it varied from 4.4 to 5.8?mg/100?g in fortified samples. It was observed that wheat flour fortification, with different iron compounds, caused modifications on quality and stability parameters during storage. Ferrous sulfate was the compound that most affected flour quality parameters. The microencapsulated compounds (ferrous sulfate and fumarate) also altered flour quality and stability. In contrast, the reduced iron was the compound that promoted the most stability to flour. These results indicate the influence of different iron compounds on wheat flour quality and stability during storage.
Journal of Cereal Science，2018（7）:1-7
Breads fortified with wholegrain cereals and seeds as source of antioxidant dietary fibre and other bioactive compounds
Vanesa Benítez, Rosa M. Esteban, Eva Moniz, Natalia Casado, et al
Antioxidant dietary fibre (DF) and bioactive compounds are considered important factors for nutritional and health-promoting properties of cereal products. Breads fortified with wholegrain cereals and seeds are increasingly demanded, making it necessary to investigate the influence of these ingredients on nutritional value of breads. The aim of this study was to assess the impact of wheat flour fortification on the composition in antioxidant DF, non-glycemic oligosaccharides, polyphenols (PC), and antioxidant activity (AA) of the final bread products. Breadmaking affected bioactive compounds in different way depending on flour composition. Although wholegrain flour was the most sensitive to breadmaking process, both multigrain and wholegrain breads stood out for their level in DF, PC and AA, whereas white bread showed higher fructan content. Results showed that replacing of refined flour with other cereals (rye, oat), fibre (wheat bran, wheat fibre) and seeds (flaxseeds, sunflower, sesame) would improve the potential health benefits of breads.
Journal of Cereal Science，2018（7）:113-120
Brans of the roller-milled barley fractions rich in polyphenols and health-promoting lipophilic molecules
Nirupama Gangopadhyay, Sabine M. Harrison, Nigel P. Brunton, José L. Hidalgo-Ruiz, et al
Three different roller-milled fractions namely bran, middlings, and flour of five commonly grown Irish barley varieties were investigated for the presence of β-glucan, polyphenols, and health-promoting lipophilic molecules. β-glucan was predominantly located in barley middlings. Polyphenols, as indicated by total phenolic content and the antioxidant activities, were abundant in the outermost bran fractions of barley. Similarly the health-promoting lipophilic molecules including phytosterols, unsaturated fatty acids, and tocols were most abundant in the barley bran fraction. However, the distribution of individual polyphenols and lipophilic compounds varied within the grain; for example ferulic acid and procyainidin C were not detected in flour fraction. Principal component analysis (PCA) clearly indicated a higher distribution of most bioactive molecules in bran as compared to middlings and flour fractions. The PCA also established possible correlations between the five barley varieties and their fractions based on their clustering in the plot.
Journal of Cereal Science，2018（9）:213-221
A compendium of wheat germ: Separation, stabilization and food applications
Fatma Boukid, Silvia Folloni, Roberto Ranieri, Elena Vittadini
Wheat germ is a precious by-product deriving from the milling industry, as it is a natural concentrated source of essential amino and fatty acids, minerals, vitamins, tocopherols, and phytosterols. However, the presence of high enzymatic activities together with a high content of unsaturated oil, induce a fast decrease in the nutritional value of wheat germ during storage and, consequently, strongly limit product's shelf-life.In recent decades, flour blends from raw or/and processed wheat germ received great interest from nutritional and technological perspectives. Nevertheless, the quality of the end-product strongly depended on the supplementation level, as well as the type and the severity of separation and stabilization techniques that wheat germ went through. Hence, in this review, the newest advances in wheat germ pre-handling approaches and food applications are discussed to provide relevant and updated information about its worthiness to be a part of the human diet.To fully valorize and preserve the nutritious potential of wheat germ, effective pre-treatments of separation and stabilization are needed to guarantee its stability and suitability to meet food quality and safety standards. Such an underutilized ingredient might be a valuable fortifying component for a spectrum of foodstuffs.
Trends in Food Science & Technology，2018（8）：120-133
Bioactive peptides as natural antioxidants in food products – A review
Jose M. Lorenzo, Paulo E.S. Munekata, Belen Gómez,et al
Bioactive peptides' content and profile differ according to the matrix studied and the method used. The utilization of fermentation processes and enzymes has been established to obtain antioxidant bioactive peptides from proteins, being isolated enzymes the most commonly used method, due to their superior control over releasing and obtaining targeted peptides. Antioxidant peptides have the ability to reduce the formation of oxidative products along with the induction of antioxidant enzymes in vivo. However, at this stage of development more in vivostudies are needed in order to evaluate the specific effects on the health of selected antioxidant peptides. In food technology, successful application in meat products strengthens the role of selected peptides as antioxidant additives, although there is a need to observe the effects of the isolated bioactive peptides in other food matrices along with studies to scale-up its production.
Trends in Food Science & Technology，2018（9）：136-147
Wheat lipid species distribution in the different stages of straight dough bread making
Frederik Janssen, Arno G.B. Wouters, Bram Pareyt,et al
Although wheat endogenous lipids strongly impact bread quality, knowledge on their detailed distribution throughout the different stages of straight dough bread making is lacking. We here compared the lipid populations in hexane [containing free lipids (FLs)] and water-saturated butanol extracts [containing bound lipids (BLs)] of wheat flour, freshly mixed and fermented doughs, and bread crumb using high-performance liquid-chromatography [for nonpolar lipids, i.e. mainly free fatty acids (FFA) and triacylglycerols] and electrospray ionization tandem mass spectrometry (for polar lipids). Freshly mixed doughs had lower FL and higher BL levels than flour, a phenomenon referred to as lipid-binding. Furthermore, probably due to the disintegration of flour particles, the overall extractability of nonpolar lipids was higher in freshly mixed dough than in flour. Dough fermentation decreased the extractability of glycolipids, but increased that of nonpolar lipids and phospholipids. We hypothesize that these phenomena result from stretching of the gluten network due to gas cell expansion, which leads to the replacement of some lipids associated with gluten proteins by others. Baking increased the extractability of bound lysophospatidylcholine (LPC) levels, but decreased that of free FFA. This is probably due to in situ dissociation of amylose-LPC inclusion complexes and formation of amylose-FFA inclusion complexes during bread baking and cooling, respectively.The approach and ESI-MS/MS methodology we developed provided valuable insights regarding the distribution of lipids at the different stages of bread making. Hence, it opens perspectives for future efforts to relate differences in lipid composition between wheat cultivars to their bread making quality.
建立了一种柱前衍生化高效液相色谱法(HPLC)测定荞麦中D-手性肌醇(D-CI)含量的方法,对衍生化试剂及方法的重复性、稳定性、精密性及加标回收率进行了考察。得到衍生化条件为:苯甲酰氯0.2 m L,吡啶0.6 m L,反应温度70℃,反应时间60 min;色谱条件为:C18柱(4.6 mm×250 mm,5μm),以乙腈和超纯水为流动相进行梯度洗脱,流速为1.0 m L/min,柱温30℃,UV检测波长230 nm。结果表明,荞麦中的D-CI获得了很好的分离,D-CI在0.004~0.04 mg/m L内线性相关性好,R~2为0.999,加标回收率为98.40%~100.67%,所建立的方法稳定、灵敏、重现性好,可用于测定荞麦中D-CI含量定量分析。
Proteomic analysis of the impacts of powdery mildew on wheat grain
Jie Li, Xinhao Liu, Xiwen Yang, Yongchun Li, et al
Powdery mildew of wheat is one of the major foliar diseases, causing significant yield loss and flour quality change. In this study, grain protein and starch response to powdery mildew infection were investigated. Total protein, glutenin and gliadin exhibited a greater increase in grains from infected wheat, while the content of total starch and amylopectin was decreased. Comparative proteomic analysis demonstrated that the overabundant protein synthesis-related proteins might facilitate the accumulation of storage proteins in grains from infected plants. The significant increase in triticin, serpin and HMW-GS in grains from infected wheat might relate to the superior gluten quality. In addition, overabundant carbohydrate metabolism-related proteins in grains from infected wheat were conducive to the depletion of starch, whereas the decreased abundance of ADP glucose pyrophosphorylase might be related to the deficiency of starch synthesis. These results provide a deeper understanding on the change of wheat quality under powdery mildew infection.
Food chemistry，2018，261（9）: 30-35
Rapid Prediction of Low (<1%) trans Fat Content in Edible Oils and Fast Food Lipid Extracts by Infrared Spectroscopy and Partial Least Squares Regression
Sanjeewa R. Karunathilaka，Samantha Farris，Magdi M. Mossoba
The United States Food and Drug Administration (FDA) ruled that partially hydrogenated oils (PHO), the major dietary source of industrially produced trans fat (TF), were no longer “generally recognized as safe (GRAS)” for any use in human food. Consequently, the objective of this study was to develop a rapid screening procedure using attenuated total reflection Fourier‐transform infrared (ATR‐FTIR) spectroscopy in conjunction with partial least squares regression (PLSR) for the quantitative and accurate prediction of low concentrations of trans fatty acid (TFAs) (<1% of total fatty acids (FAs)). Broad‐based calibration models were developed for a combined set of samples consisting of edible oils and fast food lipid extracts. Predicted concentrations of TFAs in the two matrices showed good correlation with the primary reference data generated by gas chromatography (GC) (R2 > 0.99) and high accuracy as evidenced by low root‐mean‐square error of cross‐validation (RMSECV) values. The lowest TFA concentration, determined by GC to be 0.13% of total FAs, was accurately predicted by ATR‐FTIR/PLSR as 0.18% of total FAs. This simple, rapid ATR‐FTIR/PLSR methodology has the potential for use as a screening alternative to conventional gas chromatographic methods for predicting the TFA content of edible oils and food lipid extracts for regulatory purposes and quality control of raw material and processed food.
Journal of food science，2018，83（8）: 2101-2108
Effect of breadmaking process on mycotoxin content in white and whole wheat breads
Casiane Salete Tibola，Martha Zavariz de Miranda，Flávia Fernandes Paiva，et al
Fusarium graminearum may reduce the wheat flour yield, technological quality, and breadmaking performance. The objective was to evaluate the effect of breadmaking on the mycotoxin content in white and whole wheat breads to obtain information about the safety of wheat products. The wheat samples were contaminated via the addition of Fusarium‐damaged kernels to produce different levels of deoxynivalenol (DON), ranging from <500 to >5,000 μg/kg.Because of the breadmaking process, a significant reduction in the DON concentration was observed in both the white and whole wheat breads at the upper DON levels (>2,000 μg/kg) compared with the flours. The DON reduction was 49% and 39%, respectively, in whole and white breads, compared with the original flours. ZON was only detected in the two higher levels of DON in the whole wheat flour (mean 33.1 μg/kg) and in the two whole wheat breads (mean 42.4 μg/kg).The breadmaking process can be a complementary strategy to reduce the mycotoxin content in wheat products.These results are important for wheat supply chain to meet the legislation requirements and to produce safer foods.
Identification of rice varieties and determination of their geographical origin in China using Raman spectroscopy
Ling Zhu, Juan Sun, Gangcheng Wu, Yanan Wang,et al
The processing and quality properties of rice are significantly influenced by its variety and region of origin. However, discriminating between varieties and geographic regions is an urgent but difficult and time-consuming endeavor in China. In this study, an effective and reliable identification method was established by combining Raman spectroscopy (RS) with multivariate data analysis methods. Numerous RS spectra were collected, and the sensitive fundamental vibrations of less polar groups and bonds in rice were analyzed. Principal component analysis (PCA) was used for preliminary identification. Subsequently, different modeling methods were compared and seemed to reliably identify rice types, varieties, and region of origin, with accuracies of between 80 and 100%. As a result, a soft independent modeling of class analogy (SIMCA) model was shown to be the superior model for rice identification. The SIMCA model can deliver high precision detection of adulterated rice (i.e., rice of high quality blended with rice of inferior quality), and this study lays the foundations for an advanced rice quality identification technology system.