比较2型糖尿病患者进食富强粉馒头、全麦粉馒头和抗性糊精馒头对空腹及餐后2 h血糖的影响.结果表明,受试者进食不同配方馒头,各组之间空腹血糖相比较没有显著性差异,全麦粉馒头组(2 hPG 8.36 mmol/L)和抗性糊精馒头组(2 hPG 8.44 mmol/L)餐后2 h血糖显著低于富强粉馒头组(2 hPG 9.19 mmol/L).进食不同种类馒头后的血糖变化量(△2 hPG),全麦粉馒头组(△2 hPG 1.2 mmol/L)及抗性糊精馒头组(△2 hPG0.9 mmol/L)均显著低于富强粉馒头组(△2 hPG2.1 mmol/L),全麦粉馒头组和抗性糊精馒头组之间的血糖变化量没有统计学差异(P＞0.05).3种配方馒头的口感差异有统计学意义(P＜0.01).富含膳食纤维的全麦粉馒头和抗性糊精馒头可改善2型糖尿病患者的餐后血糖.与日常食用富强粉馒头相比,全麦粉馒头和抗性糊精馒头更适合糖尿病患者食用.
研究采用超声和酶法联合酶解豌豆蛋白(PP),借助酶促反应一级动力学方程、圆二色谱和荧光光谱分析,探讨了超声对碱性蛋白酶酶活的影响机制,明确了超声调控酶法对豌豆蛋白酶解产物(PPH)的乳化特性和抗氧化活性的影响规律.与对照组相比,超声作用下的碱性蛋白酶的酶活可得到提高(最高可提高22.09％).超声可显著提高碱性蛋白酶的酶促反应速率常数.圆二色谱和荧光光谱分析可知,超声处理使碱性蛋白酶结构更加规律且更具灵活性,暴露更多的活性位点,促进了酶促反应.利用熵值法对超声调控酶解PP产物的乳化特性和抗氧化活性进行综合评价,结果表明:在超声功率密度2.71 W/cm3、时间25 min和温度45℃时,超声调控酶解PP产物具有较好的乳化活性和抗氧化活性.
With the fast advancement in grain storage facilities and technology in our country， the storage conditions of grain have been greatly improved. However， the damage of stored grain pests and mites still exist， which has caused unnecessary grain loss and affected the quality of grain storage. To effectively control insects and ensure grain security， the investigation in species and distribution of grain storage insects in Fujian province were carried out from 2015 to 2016. There are 12 grain storages， 13 flour mills， 4 feed mills， 4 farmers markets， 2 farmers farms， tobacco warehouse， beer factory， Chinese herbal medicine warehouse and shoe storage were investigated in 7 cities of Fujian Province. The results showed that a total of 82 insects species out of 9 orders， 34 families were found among the surveyed sites in Fujian Province. There were 55 insect species of 19 families belonging to Coleoptera， 16 species of 6 families belonging to Lepidoptera， 3 species of Blattaria， Hymenoptera and Corrodentia own 2 species， Zygentoma， Isoptera， Dermaptera， and Pseudoscorpionida own 1 species respectively.
火麻富含优质蛋白,因在预防和缓解某些疾病方面有重要的利用价值,日益受到国内外研究人员以及消费者的关注,被认为是可提供具有良好营养和生理功效的优质植物基蛋白来源.但由于天然火麻蛋白主要是11S储藏蛋白,其溶解性、持水性等加工特性略有不足,从而限制了其在食品工业领域的应用.本文综述了火麻蛋白的加工特性、改性、功能活性肽及其作用机制研究进展,为火麻蛋白未来精深加工及综合利用提供研究思路.
研究高温烘烤对葛根淀粉颗粒形貌、粒径分布、糊化特性、热特性、流变学特性、结构特征及消化特性的影响.结果表明:140℃以上烘烤处理使葛根淀粉颗粒聚集成大团块状,颗粒粒径和分布跨度显著增大.高温烘烤显著降低了葛根淀粉的糊化黏度、凝胶化温度及凝胶化热焓值.150～160℃烘烤处理后,葛根淀粉糊液的稠度指数显著下降,最高减少了 81.99％,而流动指数之间无显著性差异;所有样品糊液均呈现剪切稀化与非牛顿假塑性流体特征,且抗剪切性随着焙烤温度的升高而显著增强.高温烘烤减少了葛根淀粉的短程有序度、双螺旋度及快速消化淀粉含量,而增加了缓慢消化淀粉和抗性淀粉含量.
Using complex plant protein sources as raw materials， the effects of mixed fermentation on anti-nutritive factors and nutrients of complex plant protein sources were studied through the orthogonal optimization experiments of mixed bacteria inoculation ratio and mixed bacteria fermentation. The results showed that the maximum degradation rate of free gossypol was 61.67%， which was significantly higher than that of the other groups when the inoculation ratio of Cyberlindnera jadinii and Bacillus subtilis was 1:3 （P＜0.05）. The optimum fermentation conditions of compound plant protein source were as follows: temperature 32℃， time 24h， ratio of material to water 1:0.6， inoculum 8%. Under the optimum conditions， the degradation rate of free gosseol and glucosinolate in fermented compound plant protein source was 77.38%， 66.98%， 12.98% and 4.87%， respectively. The tannin content decreased from 5.00 g/kg to 4.49 g/kg， the contents of calcium and total phosphorus increased from 0.61% and 1.52% to 0.67% and 1.54%， respectively， and threonine， valine， isoleucine， leucine and lysine increased by 9.56%， 7.64%， 6.70%， 7.10% and 10.37%， respectively.
本研究以198个糯玉米主栽品种为材料,从适宜种植区角度测定了糯玉米淀粉糊化特征值和食味品质,并分析二者相关关系.结果表明,品种对糊化特征值的影响最大,峰值黏度、崩解值、终值黏度、回复值等糊化特征值基本呈正态分布,80％的材料峰值黏度集中在2 300～3 000 cP,超过3 000 cP有16个品种.峰值黏度、谷值黏度、崩解值、终值黏度、回复值间为极显著正相关,与糊化时间、糊化温度呈极显著负相关.东南区的食味品质总评分最高,为86.8分,显著高于西南区、黄淮海区和东华北区,而西南区、黄淮海区、东华北区间差异不显著.峰值黏度、谷值黏度和崩解值与食味品质总分呈正相关且相关系数均在0.753以上,可用于评价糯玉米食味品质优劣.
建立气相色谱-电子捕获检测器法测定小麦和稻米中11种代表性多溴联苯醚的分析方法.全麦粉或糙米粉经水化后,采用乙酸乙酯提取和5 g酸性硅胶(44％,m∶m)固相净化柱净化,使用气相色谱-电子捕获检测器进行检测,外标法定量.小麦和稻米中,11种多溴联苯醚的定量线性范围分别为0.1～50 ng/g、0.2～50、0.5～50 ng/g,线性相关系数R2均大于0.998;方法检出限在0.03～0.15 ng/g之间,定量限为0.1～0.5 ng/g之间;方法回收率为67.6％～99.7％,相对标准偏差为0.4％～17.8％.本方法的样品前处理简单,对仪器要求低,准确度和精密度较好,适用于小麦和稻米中多溴联苯醚的检测分析.
食用植物油是日常膳食中不可或缺的重要组成部分,研究表明,几乎所有的食用植物油都天然含有有益于人体健康的营养伴随物,近些年来食用植物油中微量营养伴随物的重要性引起了越来越多的关注.综述了常见食用植物油中维生素E、植物甾醇、角鲨烯、多酚类物质、谷维素、芝麻木酚素和亚麻木酚素等营养伴随物的分布情况、分析测定方法以及植物油通过适度精炼增加营养伴随物保留率、植物油精炼副产物中营养伴随物精制方面的研究进展,以期为食用植物油的营养伴随物研究和生产消费提供参考.
为制备一种血管紧张素转换酶(ACE)抑制糖肽并研究其结构及稳定性,选用嗜热链球菌和米根霉混合发酵青稞,单因素和响应面法优化发酵条件,凝胶色谱、反相高效液相色谱(RP-HPLC)分离纯化ACE抑制糖肽,红外光谱和β-消除法分析其结构,考察ACE抑制糖肽物理化学和体外胃肠模拟消化稳定性.料液比1.0∶15.5 g/mL,接菌量2.4％,嗜热链球菌∶米根霉1∶1,发酵6.4 d,ACE抑制率达65.79％;Sephadex G-15分离获得的A2组分ACE抑制活性最高(IC50=2.0 mg/mL);RP-HPLC分离得到的组分F5纯度达95.17％;ACE抑制糖肽具有糖和多肽的典型结构,糖苷键为O-糖肽键;高温、强碱、高NaCI含量及体外胃肠模拟消化显著影响ACE抑制糖肽活性.
超声波联合蛋白酶K酶解马铃薯蛋白酶抑制剂,研究酶解产物(PPIHs)的理化性质、抗氧化稳定性及其超滤后各组分的抗氧化活性及结构特性.结果表明,超声联合酶解处理后,PPIHs的溶解度和乳化及乳化稳定性增强;抗氧化稳定性在80 ℃以下较好,超过80℃有下降趋势;在酸性或非碱性环境下,除对ABTS自由基的抗氧化稳定性较差,PPIHs对其他自由基的抗氧化稳定性较好.PPIHs经过超滤得到PPIHs-Ⅰ(＞10 ku)、PPIHs-Ⅱ(3～10 ku)和PPIHs-Ⅲ(＜3 ku)3种超滤产物,PPIHs-Ⅰ对ABTS自由基的清除能力最强,Zeta电位的绝对值显著增大;PPIHs-Ⅱ的抑制油脂氧化以及对-OH和DPPH自由基的清除能力较强,粒径显著减小.紫外吸收光谱、红外光谱和荧光光谱表明,酶解产物的结构发生改变,如无规卷曲和β-转角含量提高,β-折叠和α-螺旋减少,疏水性增强等,进而改善其抗氧化活性.
In order to improve the fatty acid composition diversity in dietary， the study developed the microencapsulated powders embedding multi-oils with diverse fatty acids profiles （corn oil， butter， coconut oil， algae oil）as core material， applying maltodextrin （MD）， whey protein concentrate （WPC）， sodium caseinate （SC） as the main wall materials， the uniform O/W type emulsion were prepared by microjet treatment coupled with food emulsifiers， then spray-dried as final products. Single factor experiments along with the response surface optimization were used to evaluate the critical factors influencing the oil encapsulation rate， and the optimal preparation conditions were found at 170 ℃ inlet air temperature， 31 MPa homogenization pressure， and the addition of 0.3% （w/w） emulsifiers， and the oil encapsulation rate is up to 85.75%. The FTIR analysis found that all oils were well-loaded inside the microcapsules， SEM images showed that the surfaces were slightly depressed， but the entire substance was dense and complete. The results indicated that the average particle sizes of the powder-redissolved emulsion was 241.8 nm， with a zeta-potential as -33.1 mV， showing an excellent dissolving capacity and chemical stability; the CLSM images also illustrated a completed oil encapsulation with evenly suspension， indicating a strong protective effect on oils in the re-dissolving microencapsulation emulsion.
模拟食用植物油储存过程可能受环境因素影响的温度即常温储存(25℃)、夏季高温储存(45℃)、低温库储存(15 ℃)分别对浓香菜籽油进行储存,并在45 ℃和25℃各增加1个添加TBHQ浓香菜籽油样的储存,对储油定期取样检测其中挥发性风味成分及酸价、过氧化值和维生素E、甾醇含量,分析研究不同储油温度及添加TBHQ对浓香菜籽油风味保鲜和质量保鲜的影响.结果表明:空白浓香菜籽油中初始挥发性成分质量分数为8 439.75 μg/kg,其中赋予菜籽油独特风味的硫苷降解产物的质量分数为3 559.35 μg/kg,在相同储期(112 d)内随温度升高(15、25、45℃)硫苷降解产物质量分数分别降低至3 262.50、2 141.46、1 660.59μg/kg,醛类物质含量从初始的893.15 μg/kg分别升高至2 441.07、2 690.49、4 185.69 μg/kg.添加TBHQ的浓香菜籽油,在相同储期(112 d)内随温度升高(25℃、45 ℃)其中挥发性成分总量大幅升高,这缘于TBHQ分解产物-醌类物质的形成,为此虽然硫苷降解产物质量分数(分别为2 301.73、1 784.75 μg/kg)比空白菜籽油中含量高,但在挥发性成分质量分数中所占比例则从初始的42.17％分别降低至16.71％和12.78％(而同期空白菜籽油中硫苷降解产物的占比分别为27.51％、16.63％),因最终醌类物质成为含量最高的挥发性成分,致使浓香菜籽油的特征辛辣香味明显减弱和不良风味产生.
To understand the effect of refining process on the flavor of camellia seed oil， headspace solid-phase microextraction and gas chromatography-mass spectrometry （HS-SPME-GC-MS） was used to analyze the changes of volatile compounds in camellia seed oil during refining. The results showed that a total of 76 volatile compounds were identified in camellia seed oil with different refining processes， among which 37 volatile compounds were key flavor compounds with odor activity value than one. The volatile compounds and key flavor compounds of crude oil， degumming oil， deacidified oil， deodorized oil and dewaxed oil were 56 and 29， 51 and 30， 51 and 30， 54 and 33， 42 and 25， 39 and 24， respectively. The volatile compounds in camellia seed oil were mainly composed of esters， aldehydes， alcohols， acids， heterocycles， ketones， and alkenes， which were 24， 15， 13， 7， 6， 5 and 4 respectively. Among the volatile compounds of different samples， the concentration of aldehydes was the highest， followed by alcohols and esters. With the increase of refining degree， the types of volatile compounds in camellia seed oil gradually decreased， especially the types of esters， alcohols and heterocycles decreased obviously， from 18， 11 and 6 in crude oil to 13， 7 and 1 in dewaxed oil. In terms of the concentration of volatile compounds， the concentrations of aldehydes， ketones， alcohols， acids， and esters increased at first and then decreased. In a word， decolorization and deodorization had a great influence on the on the flavor of camellia seed oil. In the process of decolorization， acids increase significantly， resulting in bad odors such as mildew， decay and sweat. After deodorization， the type and concentration of volatile compounds decreased obviously and the intensity of oil flavor reduced，which was not conducive to the production of strong fragrant camellia seed oil.
以玉米淀粉和红薯全粉为原料应用于粉丝的制作中,研究玉米淀粉质量分数对混合粉凝胶特性及粉丝品质的影响.结果显示,玉米淀粉质量分数为40％～50％时,混合粉的回生值、G'、凝胶硬度和内聚性逐渐提高,粉丝断条率、浑汤透光率和烹煮损失率下降,硬度、咀嚼性增加.与红薯全粉凝胶相比,混合粉凝胶形成了连续、不均匀的网孔状结构.玉米淀粉质量分数为50％～60％时,混合粉凝胶老化能力减弱,粉丝耐煮性和咀嚼性下降.扫描电镜结果显示:当玉米淀粉质量分数为50％时,混合粉凝胶网络结构最致密,粉丝剖面孔洞数量最少且孔径最小,耐煮性和咀嚼性最佳.红薯全粉粉丝的膳食纤维含量是红薯淀粉粉丝的47.93倍,表明以红薯全粉为原料可以制作富含膳食纤维的粉丝.
为探究烘干稻谷在储藏过程中脂肪酸值的变化规律,将安徽、黑龙江2019年产的不同品种的稻谷样品以及辽宁地区2020年产的稻谷样品在烘干后进行实仓预埋储藏实验,对预埋样品进行跟踪检测,同时进行实验室模拟储藏实验.结果表明:随着储存时间的增加,稻谷脂肪酸值整体呈现上升趋势,温度越高,脂肪酸值上升越快,上升速率随着储存时间的增加有所放缓,脂肪酸值上升趋势更多受温度影响.初始脂肪酸值较高的样品在后续储藏中也较快的发展为不宜存;在实验室模拟储藏实验数据基础上建立脂肪酸值预测模型并进行实仓验证,拟合效果良好.
对我国市场上全麦面包配料、所采用的标准、营养成分等信息充分调研的基础上,系统分析了全麦面包的理化品质、质构品质和感官品质等,讨论了全麦面包产业现状及发展方向.调查结果显示:在采购的44个全麦面包中,47％的样品标注了膳食纤维含量,81.8％的全麦面包直接或间接标注了全麦粉含量,45.5％的全麦面包添加了黑小麦粉或/和黑全麦粉.全麦面包的水质量分数在23.08％～46.65％之间,保质期≥30 d的全麦面包,水质量分数低于31.35％,保质期≤20 d的全麦粉面包水质量分数均高于30％.全麦面包的比容范围为2.40～5.61 mL/g,均值为4.29 mL/g,硬度值从350～3 455 g之间,个体之间差异较大.感官评价居中的全麦面包数量最多,良和差的较少,没有能够达到优的全麦面包产品.总体上看,全麦面包品质总体不高.
为研究湿热和韧化改性荞麦淀粉的消化机制,分别在体系水质量分数为15％、20％、25％、30％,温度为100 ℃的条件和料液比为1∶5,体系温度为30、40、50、60 ℃对荞麦淀粉进行湿热和韧化处理,测定了湿热和韧化处理前后荞麦淀粉的理化性质和消化特性.结果表明:湿热和韧化处理并未改变荞麦淀粉原有的A-型结晶结构,但淀粉的糊化焓显著降低,从7.96 J/g分别降低到6.68 J/g和2.77 J/g.微观结构表明,淀粉颗粒表面出现裂痕和凹陷.同时,经过湿热和韧化处理后的荞麦淀粉中慢消化淀粉(SDS)和抗性淀粉(RS)含量出现不同程度的改变,表现为湿热处理过程中SDS含量增加(HMT-25,HMT-30除外),RS含量减少,而韧化处理只有(ANN-50)提高了 RS的含量,SDS含量也出现了增加(ANN-40,ANN-60除外).荞麦淀粉可以通过湿热和韧化改变理化结构从而改变消化速率.
In this paper， walnut oil and octanoic acid were used as experimental raw materials， and the preparation process of walnut oil octanoic acid structured lipids was optimized by box benhnken response surface. The enzyme with the highest octanoic acid insertion rate was selected from the immobilized lipases Novozym 435， Lipozyme TL IM and Lipozyme RM im based on its octanoic acid insertion rate. The molar ratio of substrate， the amount of enzyme added The effects of reaction time and temperature on the insertion rate of octanoic acid in walnut oil octanoic acid structured grease were studied. On the basis of single factor test， the preparation process of walnut oil octanoic acid structured grease was determined by four factor three level response surface method. The results showed that the immobilized lipase Lipozyme TLIM was more suitable for the preparation of walnut oil octanoic acid structured lipids. The optimum acidolysis conditions were as follows: the molar ratio of substrate （octanoic acid: walnut oil） was 3:1， the amount of enzyme added was 10wt%， the reaction time was 12.6h， the reaction temperature was 44.8 ℃， and the insertion rate of octanoic acid was 32.37%. This condition is suitable for the preparation of walnut oil octanoic acid structured grease. The optimization of the preparation process of walnut oil octanoic acid structured grease can provide a theoretical reference for the development and application of structured grease.
研究萌发条件及加工方法对藜麦主要营养成分含量的影响.结果表明:在浸泡温度25℃、浸泡时间3 h、萌发时间48～60 h、萌发温度25～28℃、淋水间隔8～10 h的萌发条件下藜麦中蛋白质、还原糖、多酚、黄酮和γ-氨基丁酸含量达到最高值,脂肪、淀粉和多糖含量达到最低值.通过蒸煮、炒制、烘烤处理后,除藜麦中粗纤维含量随蒸煮时间延长变化不显著(P＞0.05),藜麦中蛋白质、脂肪、粗纤维、多酚、γ-氨基丁酸、多糖和黄酮含量随加工时间和温度不断提升均呈显著下降趋势(P＜0.05).对各加工条件制得的藜麦进行感官评定,得出藜麦最佳蒸煮时间为25 min,最佳蒸煮温度为95℃,最佳炒制时间为10 min,最佳炒制温度为180℃,最佳烘烤时间为25 min,最佳烘烤温度为120℃.
