内蒙古荞麦和燕麦矿物质测定与分析

甜荞麦和裸燕麦是内蒙古优势特色粮食资源,但其营养成分,尤其矿物质谱特征缺乏系统的检测评价。对内蒙古6个主产旗县两年度60份甜荞米和30份裸燕麦米的27种矿物质元素谱进行测定和特征分析。结果显示内蒙古甜荞麦和裸燕麦矿物质十分丰富,多数必需常量和微量矿物质元素显著高于我国食物成分表2004数据,尤其Mg和P显著高于其它谷物,且甜荞显著高于裸燕麦,荞麦可作为Mg元素的最佳天然来源之一。矿物质谱主成分分析(principal component analysis,PCA)显示甜荞和裸燕麦有明显的物种和地区聚类特征。最东部库伦旗荞麦Li、Cr和Pb显著高于最西部的固阳县,而Se、Ti、Sn、Cd、Cs和Cu则相反。地理位置越往东荞麦Se元素越低,库伦旗荞麦Se显著低于固阳县。重金属远低于谷物允许残留限量。     

Optical thin-film biochips for multiplex detection of eight allergens in food

An innovative method for the rapid detection of food allergens is developed and validated. Here we reported the development of silicon-based optical thin-film biochip technology that simultaneously permits visible detection of eight food allergens including celery, almond, oat, sesame, mustard, lupine, walnut and hazelnut on the basis of two tetraplex PCR systems. The biochip detection time was about 30 min after PCR amplification. Briefly, the optical thin-film biochip detects the presence of PCR fragment targets by enzymatically converting the formation of nucleic acid hybrids to molecular thin films. The mass contributed by the thin film alters the interference pattern of light on the biochip surface, resulting in a visible color change on the chip surface. Therefore, this assay permits sensitive, specific and high-throughput detection of allergens in food samples.     

Highly sensitive PCR-based detection method specific for Aspergillus flavus in wheat flour

Aspergillus flavus is frequently found in food, producing a wide variety of toxins, aflatoxins being the most relevant in food safety. A specific PCR-based protocol for this species is described which allowed discrimination from other closely related species having different profiles of secondary metabolites from the Aspergillus Section Flavi, particularly A. parasiticus. The specific primers were designed on the multi-copy internal transcribed region of the rDNA unit (ITS1-5.8S-ITS2 rDNA) and were tested in a wide sample of related species and other fungal species commonly found in food. The PCR assay was coupled with a fungal enrichment and a DNA extraction method for wheat flour to enhance the sensitivity of the diagnostic protocol. The results indicated that the critical PCR amplification product was clearly observed for wheat flour contaminated by 10(2) spores after 16 h of incubation.     

Effect of banana and plasticizer types on mechanical,water barrier,and heat sealability of plasticized banana‐based films

Unripe banana flour and starch were used to formulate plasticized banana‐based films (flour film, PBF; starch film, PBS) with two types of plasticizers (glycerol, Gly; sorbitol, Sor) and a mixture of Gly‐Sor on film properties. PBS showed greater water barrier, elongation at break, toughness, and transparency, but lower efficiency in heat sealability than PBF. However, the easier and a higher yield in the preparation process of PBF lead to higher UV and visible light barrier than PBS which could be due to its protein content and the presence of phenolic compounds in PBF. Both banana films plasticized with Sor showed high glossiness, high efficiency in heat sealability, and mechanical and water barrier properties; however, the undesirable recrystallization of white crystals resulted in lower film flexibility. Thus, Gly‐Sor was preferred without change of water barrier but strengthened heat sealability. Therefore, banana‐based film might be considered as a green food packaging material.

Practical applications

Banana flour and starch from unripe bananas can be used as safe food ingredients for food products and as green biodegradable packaging materials. Banana flour film showed similar mechanical properties as banana starch film but involved easier processing and higher yield in the preparation of banana flour. Moreover, banana flour films had higher efficiency in heat sealability with the potential to protect the packed food from UV–visible light deterioration. Furthermore, an easier way to modify proper film properties is by the proper selection of the plasticizer. A mixture of plasticizers (glycerol and sorbitol) showed high potential to improve long‐term physical stability such as through UV–visible light prevention, and improved mechanical properties and heat sealability of plasticized banana‐based films. Briefly, plasticized banana flour film with a mixture of plasticizer will be potential, alternative biodegradable packaging material to reduce the use of nonbiodegradable synthetic plastic materials in food applications.     

基于金属有机骨架（ZIF-8）的酶联免疫法灵敏检测米粉中的黄曲霉毒素B1

为解决黄曲霉毒素B1（aflatoxin B1,AFB1）快速检测方法中信号标记物稳定性差的问题,建立基于金属有机骨架的酶联免疫法检测米粉中AFB1。该研究采用仿生矿化方法将辣根过氧化物酶（horse radish peroxidase,HRP）封装在沸石咪唑骨架结构材料（zeolite imidazole frameworks-8,ZIF-8）中作为信号标记物。发现HRP@ZIF-8复合材料在碱性条件、高温等极端条件下能保持稳定的催化活性。在此基础上建立间接竞争免疫比色法检测AFB1,通过肉眼可直接分辨含有AFB1样品。在最佳条件下,随着AFB1浓度的增加,吸光度在0.01~20 ng/mL内递减,具有明显的线性关系y=0.03×C[AFB1]+0.79,R2=0.99,检测限为72 pg/mL,同时精密度和特异性都达到可接受的水平,AFB1在米粉和面粉中的添加回收率分别在96.00%~105.00%、82.00%~110.00%之间,相对标准偏差均小于5%。该法操作简单、快速、灵敏、特异性好,可用于米粉、面粉等谷类食品中AFB1的痕量检测。     

热处理温度对玻璃纤维表面氧化锡薄膜光电性能的影响

 为在玻璃纤维表面制备透明导电薄膜,使其具有导电性的同时保持良好的透光性,采用溶胶凝胶法制备纳米SnO2溶胶,利用浸渍提拉法在玻璃纤维表面涂覆纳米SnO2溶胶,经过热处理后在纤维表面形成纳米SnO2薄膜。本文利用X射线衍射仪（XRD）、场发射扫描电镜（SEM）、原子力显微镜（AFM）、四探针法和紫外可见分光光度计分别来表征纤维表面薄膜的物相、表面形貌、纤维电阻率以及薄膜透光率。分析了热处理温度对薄膜结构、玻璃纤维导电性能以及薄膜透光率的影响。结果表明,采用溶胶凝胶法制备的溶胶稳定性好,最佳热处理温度是550℃,得到的薄膜晶粒平均大小可达17.18nm,纤维电阻率可达5×10-5Ω·m,同时纤维表面薄膜透光率在88%左右。     

Highly sensitive PCR-based detection method specific for Aspergillus flavus in wheat flour

Aspergillus flavus is frequently found in food, producing a wide variety of toxins, aflatoxins being the most relevant in food safety. A specific PCR-based protocol for this species is described which allowed discrimination from other closely related species having different profiles of secondary metabolites from the Aspergillus Section Flavi, particularly A. parasiticus. The specific primers were designed on the multi-copy internal transcribed region of the rDNA unit (ITS1-5.8S-ITS2 rDNA) and were tested in a wide sample of related species and other fungal species commonly found in food. The PCR assay was coupled with a fungal enrichment and a DNA extraction method for wheat flour to enhance the sensitivity of the diagnostic protocol. The results indicated that the critical PCR amplification product was clearly observed for wheat flour contaminated by 10² spores after 16 h of incubation.     

Thin Film Rheology and Tribology of Chocolate

We investigated relations between food texture and thin film properties rather than bulk properties. Such thin film rheological or‘tribological’effects may characterize physical behavior and physical perceptions of food products. Experiments were done on three chocolate samples. The Surface Forces Apparatus (SFA) proved to be effective for studying the very complex chocolate system. Very complex thin film behavior was found to be quite different for the three samples. Fat constitution and average particle size were important in determining the type of friction forces generated between shearing/sliding surfaces separated by thin films of chocolate. Such studies can help characterize specific physical qualities of chocolate.     

Comparative study on the properties of flour and starch films of plantain bananas (Musa paradisiaca)

Biodegradable films were prepared by using the flour and starch isolated from plantain bananas of the variety “Terra” (Musa paradisiaca). Since the non-starchy fraction present in the banana flour represents 29.4% (on dry basis) of its composition, we considered it would be interesting to compare the properties of the film elaborated from this natural blend with that of the film produced from the banana starch only. Both films were characterized on the basis of their mechanical, barrier, optical, structural, and thermal properties. The banana flour film was less mechanically resistant but more flexible than the banana starch film. Despite the differences in the microstructure of the flour and starch films, the former was slightly soluble in water, and its water vapor permeability was similar to that of the starch film. Regarding the optical properties, the flour film was yellowish, which can be attributed to its protein content and the presence of phenolic compounds. The starch film, on the other hand, was lighter and less opaque. The FTIR spectra revealed the presence of the amide I group related to proteins only in the case of the flour film. Both plantain banana films displayed a C-type X-ray pattern and one glass transition temperature each, which was higher for the starch film (46.4 °C) as compared to the flour film (30.2 °C). The presence of other components (protein, lipids, and fiber) in the flour film had important effects on its properties. In general, the banana flour and starch are very promising materials for the formulation of coatings and films.     

Rheological properties of wheat flour substitutes/alternative crops assessed by Mixolab

Wheat is one of the most common cereals used in the world. However, due to greater public awareness of celiac disease and gluten intolerance as well as consumers demands for healthy food and variety in food products, in many widely consumed staples, such as bread, wheat flour is fully or partially replaced with flour from other cereals, pseudocereals or legumes. Although wheat flour alternatives are readily available in the market, these products are often of inferior quality. The aim of this paper was to predict the suitability of alternative crops such as rice, corn, buckwheat, amaranth and soya for the production of quality bread. Their rheological properties were studied, and compared to the properties of wheat flour which served as a benchmark. The tested alternative cereals, pseudocereals and legumes were selected in order to represent the widely used ones in gluten-free products as well as the ones found to be nutritionally improved according to recent publications. Moreover, the differences between wheat and buckwheat flour, and their wholegrain counterparts were also studied. The determination of rheological properties of wheat flour dough as well as the dough from other raw materials (rice, corn, buckwheat, amaranth and soya) was performed by Mixolab. According to results obtained by Mixolab measurements, flours from different raw materials exhibited Mixolab profiles which greatly differ from wheat flour profile. Samples of rice and both types of buckwheat flour expressed the most similar rheological behaviour to wheat flour. However, since, there was no tested material which exactly mimic wheat flour dough properties, it was concluded that their mixtures would give the optimal rheological profile. Although it is a very challenging task to mimic wheat flour unique breadmaking properties, it is possible to create products having similar rheological behaviour to wheat flour dough, but improved functional properties.     

莜麦蔓越莓面包的工艺优化

以莜麦粉、蔓越莓为主要原料研制莜麦蔓越莓面包。以感官评分、面包比容为评价指标,采用单因素和正交试验优化工艺参数。结果表明:最佳工艺参数为小麦粉270.0 g、莜麦粉30.0 g、水130.0 mL、蔓越莓25.0 g、酵母6.0 g、白砂糖20.0 g、奶粉20.0 g、盐3.0 g、鸡蛋60.0 g、醒发时间60.0 min、搅打时间17.0 min、烘烤时间18.0 min,在此条件下,制备出的莜麦蔓越莓面包蔓越莓风味浓郁,接受度高。     

Innovative Biological Systems for Anaerobic Treatment of Grain and Food Processing Wastewaters

The application of two innovative fixed film and suspended growth anaerobic biological systems to the treatment of grain and food processing wastewaters is discussed. A fluidized bed fixed film system and a suspended growth membrane system are described. The technical and economic factors dictating which system is selected for treatment of a specific industrial wastewater are discussed. Case history results from successful operation of full-scale, demonstration, and pilot-scale systems treating respectively, soy whey, cheese whey, and wheat flour processing wastewaters are presented.     

冷冻面片制作工艺的优化

以市售标准粉为材料,利用二次回归正交旋转试验设计,分别以冷冻面片质构特性参数破碎力和延展性为响应值建立了冷冻面片制作的二次多项数学模型,验证了模型的有效性,采用响应曲面法(response surface methodology,RSM)考察了交互作用的影响,并根据方程求解出稳定点的水平值,从而确定出冷冻面片制作工艺的优化参数为:和面速度240 r/min,和面时间5 min,和面加水量40%,静置时间30 min,冷冻温度-30℃,冷冻时间5h。冷冻面片制作工艺参数对其质量有显著影响。     

Can food technology innovation change the status of a food security crop? A review of cassava transformation into “bread” in Africa

Reducing both hunger and high expenditure on food imports is a priority for most developing African countries. Countries that hitherto have relied heavily on food imports are seeking new approaches to increase the utilization of locally grown crops. This review uses the case of cassava to propose that scientific and technological innovations, supported by public investment and appropriate policies, offer opportunities for better utilizing locally grown crops, encouraging agro-industrial development, reducing import expenditure, and providing much-needed income (bread) to smallholders. This review highlights areas that require further research in order to achieve sustainable development in the processing of raw cassava root into cassava flour for bread production.     

Phytochemicals and heavy metals content of hairless canary seed: A variety developed for food use

Canary seed is one of the top four specialty crops grown in Western Canada. Currently it is used entirely in food mixtures for caged birds but our previous studies have shown its unique composition and potential use in food and non-food applications. Through improvements by plant breeding a hairless variety was developed for human consumption and animal feeding. This study was aimed at investigating phytochemicals and heavy metals in hairless canary seed in comparison with the hairy variety and common wheat using three milling fractions (wholegrain, starchy flour and bran). The levels of bound and unbound phenolic acids, phytate, trypsin and amylase inhibitors tended to be similar in the three grains at a given level of processing. This was also true for most heavy metals tested although hairy canary seed exhibited a significantly higher concentration of copper while both canary seed varieties contained more nickel and zinc than wheat. Condensed tannins, alkaloids and deoxynivalenol (DON) were not detected in any of the crops while very low levels of aflatoxin were detected in all three grains. The results show that both hairless and hairy canary seed possess phytochemicals and heavy metals profile close to that of wheat demonstrating the potential of hairless canary seed as a food crop due to the absence of harmful hairs.     

Properties and Food Uses of Chestnut Flour and Starch

This review summarised the compositional, thermal, and rheological properties and food applications of chestnut (Castanea spp.) flour systems. The compositional, structural, and physicochemical properties of chestnut starch, which is a major determinant for product quality, were also reviewed. Future research directions on how to better utilise chestnut flour and starch for food product developments were suggested. Chestnuts are important food items for many people around the world. The world production of chestnuts has kept increasing during the last decade. There has been growing interest to utilise chestnut flour for various food applications (e.g. gluten-free food products). The major component of chestnut is starch which amounts to over 50% of the dry weight of the fruit. Chestnut starch may as well have potential for food and non-food applications. Overall, this review provides a scientific basis to develop chestnuts as sustainable and cash crops.     

Specific detection and quantification of Aspergillus flavus and Aspergillus parasiticus in wheat flour by SYBR® Green quantitative PCR

Aflatoxins are important mycotoxins that represent a serious risk for human and animal health. These mycotoxins are mainly produced by Aspergillus flavus and Aspergillus parasiticus, two closely related species with different array of aflatoxins. In this work, two specific quantitative PCR (qPCR) assays were developed to detect and quantify both species in wheat flour using primers based on the multicopy ITS2 rDNA target sequence. The species specificity of the assays was tested in a wide range of strains of these species and others colonizing the same commodities. The sensitivity of the assay was estimated in 2.5 pg/reaction in both species. Discrimination capacity for detection and relative quantification of A. flavus and A. parasiticus DNA were analyzed using samples with DNA mixtures containing also other fungal species at different ratios. Both qPCR assays could detect spore concentrations equal or higher than 10⁶ spores/g in flour samples without prior incubation. These assays are valuable tools to improve diagnosis at an early stage and in all critical control points of food chain integrated in HACCP strategies.     

基于表面诱捕装置的不同食料引诱嗜卷书虱效果比较研究

及时检查监测常见微小害虫书虱的发生动态有利于其早防早治和避免危害，谷物食料诱捕害虫具有取材方便、有利于提高诱捕效率以及对书虱类害虫的种群控制。在20、24和28℃温度下，研究了粮堆表面波纹板诱捕器内置小麦粉、玉米粉、稻谷粉、酵母粉、发霉小麦粉、发霉玉米粉以及发霉稻谷粉等食料后不同时间引诱嗜卷书虱Liposcelis bostrychophila的数量动态。温度28℃时，实验食料中引诱效果最好的酵母粉在14 d内可引诱嗜卷书虱数量达827头，同时发霉小麦粉、发霉玉米粉和发霉稻谷粉中引诱嗜卷书虱的数量分别达662、605和604头，未霉变小麦粉、玉米粉和稻谷粉引诱嗜卷书虱数量分别为479、460和451头。20℃和24℃温度下，以上不同食料同时引诱嗜卷书虱的数量随温度降低相应减少，如酵母粉在对应温度下引诱嗜卷书虱的数量分别降至450和628头。采用GC-MS法测定出小麦粉、玉米粉、稻谷粉、酵母粉、发霉小麦粉、发霉玉米粉以及发霉稻谷粉的挥发物种类数量分别为17、24、20、20、20、23和25种，引诱效果最好的酵母粉的挥发物中芳樟醇、异戊醇、2-甲基丁酸乙酯以及正己醇相对含量较高，同样谷物粉发霉后引诱效果显著增加且这几种挥发物含量也明显增加，初步分析桧烯、1-辛烯-3-醇、2-戊基呋喃、肉桂醛等一定量的存在可能与较好的引诱效果有关，它们对嗜卷书虱的引诱作用值得进一步关注和研究。     

Film preparation with high protein defatted peanut flour: characterisation and potential use as food packaging

The purpose of this study was to prepare a defatted peanut flour‐based film (DPFF); to characterise their physicochemical, optical, barrier and mechanical properties; and to evaluate the defatted peanut flour package efficacy to preserve the chemical quality of sunflower oil during storage. The film presented high lightness values (L* = 86.83). The water vapour permeability was 5.44 × 10^?11 g m^?1 s^?1 Pa^?1. Tensile strength and percentage of elongation were 1.01 MPa and 84.01%, respectively. Sunflower oil samples packaged in defatted peanut flour packages (DPFP) were stored during 67 days at room temperature. Peroxide value and conjugated dienes increased less for sunflower oil conditioned in DPFP and high barrier plastic pouches (EVOH) during storage than sunflower oil conditioned in Petri dishes (C). The use of DPFP improved the chemical stability of sunflower oil during storage. The DPFF showed suitable film properties, and also, the capacity to be incorporated in food packaging applications.     

PCR-restriction fragment length analysis of aflR gene for differentiation and detection of Aspergillus flavus and Aspergillus parasiticus in maize

Contamination of food and feedstuffs by Aspergillus species and their toxic metabolites is a serious problem as they have adverse effects on human and animal health. Hence, food contamination monitoring is an important activity, which gives information on the level and type of contamination. A PCR-based method of detection of Aspergillus species was developed in spiked samples of sterile maize flour. Gene-specific primers were designed to target aflR gene, and restriction fragment length polymorphism (RFLP) of the PCR product was done to differentiate Aspergillus flavus and Aspergillus parasiticus. Sterile maize flour was inoculated separately with A. flavus and A. parasiticus, each at several spore concentrations. Positive results were obtained only after 12-h incubation in enriched media, with extracts of maize inoculated with A. flavus (101 spores/g) and A. parasiticus (104 spores/g). PCR products were subjected to restriction endonuclease (HincII and PvuII) analysis to look for RFLPs. PCR-RFLP patterns obtained with these two enzymes showed enough differences to distinguish A. flavus and A. parasiticus. This approach of differentiating these two species would be simpler, less costly and quicker than conventional sequencing of PCR products.