标准加入直读法快速测定南阳彩色小麦面粉中硝酸根的研究

为了建立一种快速测定小麦面粉中硝酸根的新方法,以南阳彩色小麦为材料,用微波快速浸提样品,与超声波浸提法对照,用离子选择性电极标准加入———浓度直读法快速测定样品中的硝酸根,并进行了测定条件的优化。结果表明:用二次重复加入标准溶液的方法,测定的回收率为89.5%~102.0%。测定结果的相对标准偏差RSD为2.8%~4.7%(n=11),硝酸根的最低检出限为0.040 mg.L-1,测定的线性范围为0.100~100.0 mg.L-1,相关系数为0.997。该方法具有直观、快速、简便、灵敏、准确、适于现场进行测定的显著优点,结果令人满意。     

我国优质面粉业发展面临的机遇和挑战

我国面粉加工业正处于兼并、组合及大发展的特殊时期,其面临的诸多问题引起了研究者的关注。详细考察了我国优质面粉加工业发展面临的机遇和挑战,并提出了进入该行业的策略。     

Preparation of protein and mineral rich fraction from grain amaranth and evaluation of its functional characteristics

Grain amaranth was fractionated to prepare a seed coat rich fraction along with the fine seed coat, middling and flour fractions. The nutritional content of the coarse seed coat fraction and its antioxidant potential were evaluated. It was observed that, the coarse seed coat fraction contained highest protein (17.81 g/100 g), dietary fiber (25.78 g/100 g), free sugar (2.25 g/100 g), calcium (1115 mg/100 g), sodium (279 mg/100 g), magnesium (178.4 mg/100 g) and potassium (398.8 mg/100 g) contents compared to all other fractions. The carbohydrate and protein digestibility of all the fractions were more than 80%. A slight decrease in linoleic acid and a concurrent increase in palmitic acid contents were observed in coarse seed coat fraction. The total phytic acid increased and total polyphenols contents decreased in the coarse seed coat fraction compared to the native grain. The DPPH, ABTS and total antioxidant activities are comparatively high in this particular fraction. The study indicated a possibility of preparation of a protein, fiber and mineral rich fraction from grain amaranth with good antioxidant potential which can be used as a functional food ingredient.     

Improved functional properties of pasta: Enrichment with amaranth seed flour and dried amaranth leaves

The present investigation evaluated the effects of dried amaranth leaves (DAL) and amaranth seed flour (AF) as ingredients for pasta production and their contribution to antioxidant activity. Cooking quality, proximal and aroma analysis, antioxidant capacity and sensory evaluations were performed. The results demonstrated that pastas with amaranth ingredients had decreased cooking time, increased cooking loss percentage, and decreased luminosity values compared with semolina control pasta. Pastas with both AF and DAL demonstrated the highest protein, crude fiber and ash contents. The addition of DAL resulted in higher contents of iron, zinc, magnesium and potassium compared with the control pasta. TC, FRAP and ORAC assays showed that the pastas exhibited an important reduction in antioxidant capacity by cooking process. Formulas with DAL showed the higher antioxidant capacity values after cooking. The addition of AF and DAL has proved to increase the functional benefits of the pasta.     

HACCP在小麦粉生产中的应用研究

贯彻HACCP应用准则,应用HACCP原理,对小麦粉生产进行HACCP应用研究,确立了小麦接收、微量成分添加、磁选检测3个关键控制点及其关键限值、监控方法和纠正措施,提高了小麦粉生产的安全性和质量水平.     

球磨对胡桑木粉可及度影响的研究

为了提高木粉改性反应时试剂对木粉的可及度,采用行星式球磨机对胡桑木粉进行球磨预处理,研究了干磨、加水湿磨以及球磨时间对木粉的粒度、结晶度和可及度的影响。研究结果表明:胡桑枝条木粉干磨4 h粒度达到最低值,中位径(D50)为8.982μm,纤维素结晶度明显降低;4 h后由于发生团聚现象,粒度反而随球磨时间延长而增大,结晶度不再变化;干磨木粉的粒度越小,木粉的可及度越高。湿磨时,由于水的分散阻聚作用,粒度随球磨时间的延长逐渐减小,球磨12 h原料D50达到4.357μm;木粉湿磨后不同干燥方式对木粉的结晶度和可及度影响很大:湿磨木粉经烘箱干燥后的结晶度显着高于冷冻干燥的;烘箱干燥的湿磨木粉可及度比未球磨木粉小,且随湿磨木粉粒度的减小而降低;冷冻干燥的湿磨木粉可及度与未球磨木粉相比明显提高,而且高于干磨时间相同的木粉。     

竹塑复合材料流变行为分析

以竹粉和聚丙烯粉剂为原料,马来酸酐接枝聚丙烯为相容荆,通过转矩流变仪测试混合物料在熔合状态下扭矩、温度及时间的变化情况,同时分析了不同粒径竹粉对混合体系流变性能的影响.试验结果表明:混合体系的最大扭矩、平衡扭矩及平衡时间与竹粉粒径的关系基本都呈类抛物线关系,随着竹粉粒径的增大呈现先增大后减小的趋势,即竹粉粒径在20～40目、200目时,流变参数值较小,流变性能比较好.     

不同土壤钾素对强筋小麦产量形成因子的影响

摘要：本试验先后通过对中牟潮土、南阳黄褐土、镇平砂姜黑土、许昌褐土几个土类钾肥不同处理水平，以田间小区试验为主，结合盆栽试验、池栽试验，系统地研究了不同土类上6种钾素水平（纯N、P2O5施用量一致）对土壤有效氮、有效钾，强筋小麦9023群体动态，植株养分含量，产量及产量因子的影响，结果表明：收获后速效成份分析，碱解N：南阳黄褐土＞中牟池栽黏土＞中牟盆栽壤土＞中牟大田轻壤＞中牟池栽砂土；速效K：中牟盆栽壤土＞中牟池栽黏土＞中牟池栽砂土＞中牟大田轻壤＞南阳黄褐土；缓效K：中牟池栽黏土＞南阳黄褐土＞中牟大田轻壤＞中牟盆栽壤土＞中牟池栽砂土。在中牟大田轻壤、镇平砂姜黑土、许昌褐土条件下，适量施钾（适宜施钾量为180kg/hm2～240 kg/hm2），可提高强筋小麦越冬群体、最高群体和有效群体。多点钾肥试验结果表明：钾肥主要通过增加千粒重显示其肥力效应。增产幅度一般在10%左右。如果单从产量角度考虑，中牟大田轻壤、镇平砂姜黑土、南阳黄褐土上经济最佳施钾量分别为180 kg/hm2、220 kg/hm2、190kg/hm2。土质越黏，经济最佳施钾量也越高。在氮磷充足的前提下，小麦对钾的吸收存在着“奢侈吸收”现象。综合比较施钾量对强筋小麦生理、群体、土壤养分、植株养分、产量及产量因子的影响，从经济效益和产量综合指标分析，适宜的K2O用量应在120 kg/hm2～180kg/hm2之间。     

Multi-elemental analysis of flour types and breads by using laser induced breakdown spectroscopy

Bread and flour are most commonly used products in human diet, which makes it susceptible to adulteration, mislabeling and addition of unpermitted amount of different flour types. The objective of this work was to evaluate the potential of employing laser induced breakdown spectroscopy to differentiate different flour types and quantify the white wheat flour addition to rye and oat flour and breads. In the principal component analysis, score plot represents pure flour types with 97.64% of the variance. In the calibration study, the measured coefficient of determination values was 0.989, 0.989, 0.992 and 0.991 for refined wheat flour: rye flour, refined wheat flour: oat flour, breads made with the blend of refined wheat: rye flour and the blend of refined wheat: oat flour, respectively. The limit of detection values were calculated as 3.82, 5.97, 4.59 and 4.92% for refined wheat flour: rye flour, refined wheat flour: oat flour, refined wheat: rye bread and refined wheat: oat bread, respectively.     

Optimization of High-Protein Glutinous Rice Flour Production Using Response Surface Method

A response surface method was employed to study the effect of α-amylase concentration, hydrolysis temperature and time on the production of high protein glutinous rice flour (HPGRF). The suspension of glutinous rice flour (15%) that contained 6.52% protein was gelatinized and subsequently hydrolyzed by thermostable α-amylase. The hydrolysis yielded 0.144–0.222 g/g HPGRF with 29.4%–45.4% protein content. Hydrolysis time exerted a significant effect, while enzyme concentration and hydrolysis temperature showed insignificant effect on the protein content and production yield of HPGRF. The result of response surface method showed that the optimum condition for the production of HPGRF that contained at least 36% protein was treating gelatinized 15% glutinous rice flour suspension with 0.90 Kilo Novo α-amylase Unit (KNU)/g α-amylase at 80 °C for 99 min. By carrying out the predicted hydrolysis condition, HPGRF with 35.9% protein and 61.8% carbohydrates was resulted. The process yielded 0.172 g/g HPGRF. HPGRF contained higher amount of essential amino acids compared to glutinous rice flour. HPGRF had higher solubility and lower swelling power, and also showed no pasting peak compared with glutinous rice flour.