米糠发酵过程中脂肪酸组分及含量变化的研究

以新鲜米糠为原料,以料水比1:9(w:v)配成培养基,接入红曲(Monascus anka)M180和木耳(Auricularia auricular)A900,在30℃、200r/min摇床培养,培养时间分别为4d和7d。利用气相色谱法,对米糠发酵过程中脂肪酸组分及含量的变化进行分析。结果显示,米糠中主要脂肪酸为C16:0、C18:1、C18:2,占总脂肪酸的95.05%,C16:1、C18:1、C18:2等不饱和脂肪酸占总脂肪酸的80.09%,在红曲和木耳发酵过程中,脂肪酸含量一直呈下降趋势,总脂肪酸含量由最初的200.75mg/g分别下降至68.35mg/g和79.95mg/g,红曲M180比木耳A900利用脂肪酸速度快。发酵结束后,红曲发酵米糠和木耳发酵米糠中不饱和脂肪酸占总脂肪酸的比例分别为83.76%和80.84%,与发酵前相比,没有得到明显提高。利用红曲和木耳发酵米糠不能达到富集不饱和脂肪酸的目的,但可作为除去米糠中脂肪,抑制酸败的潜在途径。     

加强质量管理工作,促进食品工业健康发展(一)

本文为中国食品工业协会黄圣明秘书长在全国食品质量效益型先进企业、优秀领导者及模范工作者表彰会上的讲话,本刊特约刊发。质量是企业的生命,质量是效益的载体,质量第一百年大计。     

Anthocyanin content and antioxidant capacity in bran extracts of some Thai black rice varieties

This study investigated both the anthocyanin content and the antioxidant capacity of a set of genetically related glutinous and nonglutinous Thai black rice varieties. The ethanol/water extracts of the brans of these black rice varieties showed relatively potent antioxidant activities compared with those of tocopherol. These antioxidant activities were determined by thiocyanate, H₂O₂‐scavenging chemiluminescence (XYZ), Cu⁺⁺/bathocuproine colorimetry (PAO) and 1,1‐diphenyl‐2‐picrylhydrazyl radical‐scavenging assay. The structural identification and quantification of the black rice anthocyanins performed by high‐performance liquid chromatography coupled with electrospray ionisation and tandem mass spectrometry found cyanidin‐3‐O‐glucoside and peonidin‐3‐O‐glucoside as the major anthocyanins in the ranges of 16.01–34.40 and 2.43–7.36 μg mL^?1, respectively. The comparative study in terms of quantity of these phytochemicals and antioxidant capacity of the black rice bran extracts suggested the contribution of overall phenolic components rather than that of the particular anthocyanin pigments.     

微波辅助萃取米糠油的工艺优化

通过微波辅助提取米糠油。通过单因素试验考察了溶剂种类、微波功率、萃取温度、萃取时间和料液(米糠与溶剂)比对米糠油提取率的影响,并通过正交试验确定了最佳提取工艺参数。结果表明:萃取温度65℃,微波功率600 W,微波处理时间100 s,料液比1∶5,米糠油提取率为19.16%。微波辅助提取法具有提取时间短、效率高、毛油质量好等优点。     

微波辐射条件下米糠中解脂酶活性的研究

以新鲜米糠为原料,研究了微波辐射对米糠中解脂酶活性的影响.实验结果表明,微波辐射具有很好的降低米糠中解脂酶活性的作用,并随着微波功率的增大,辐射时间的延长,解脂酶活性变得更低.实验条件下,微波处理250g米糠的最佳条件为:高火处理,辐射时间为8 min,物料含水12%～14%.经过处理,米糠可安全贮藏一个月,米糠油酸值增加值小于25mKOH/g.     

微波膨化麦麸米饼工艺的研究

采用蒸汽爆破技术对麦麸进行预处理,其可溶性膳食纤维由2.36%增加到7.41%;以大米粉和汽爆麦麸为原料,采用微波膨化技术制备麦麸米饼。以膨化率和感官评分为指标,通过单因素及正交试验,优化膨化麦麸米饼制备工艺。结果表明:马铃薯淀粉的膨化效果最好,在大米粉和马铃薯淀粉质量比5∶1、老化时间14 h、水分含量9%、微波功率1 000 W、微波时间55 s、麦麸添加量6%的条件下,麦麸米饼的综合品质最好,硬度适中,米饼内部形成均匀的微观网络结构。     

Chemical, nutritional and toxicological studies of rice bran oil

Rice bran oil (RBO) is an unconventional oil of very high potential availability in India. Edible grade RBO obtained by improved technology was systematically evaluated for its chemical, nutritional and toxicological properties using the protocol developed by the author.

RBO is similar to groundnut oil (GNO), in fatty acid composition, having 36% linoleic acid. The unsaponifiable matter of RBO (4·1%) is higher than GNO. Nutritional evaluation was carried out in weanling albino rats of the Wistar strain by feeding a diet containing 20% protein and 10% RBO, and adequate in other nutrients, for 3 months. A similar group with 10% GNO served as a control group. Growth, feed efficiency, mineral balance, fat absorption and serum haematology were comparable in both RBO- and GNO-fed animals. Serum and liver lipids showed a marked lowering effect in rats fed RBO, indicating its hypocholesterolemic effect. The hypocholesterolemic effects of RBO and its unsaponifiable matter were evaluated in a separate experiment in hypercholesterolemic diet-fed rats as well as in humans and were reported earlier.

Toxicological studies of RBO by the food safety evaluation protocol of WHO/FDA/DGHS were carried out in rats for three generations. The reproductive performance was comparable to GNO-fed animals. The results indicated that there were no abnormalities in any of the parameters studied, indicating the safety of RBO for human consumption.     

不同品种米糠营养成分含量的相关性分析及米糠与稻米成分的聚类分析

以24个品种的稻谷为实验材料,对不同品种间稻谷米糠营养成分含量的差异性进行分析比较。结果表明,不同品种间米糠的水分含量、灰分含量、蛋白质含量、可溶性多糖含量、脂肪含量和粗纤维含量差异极显著。米糠中灰分与脂肪和蛋白质之间存在着极其显著的正相关(P<0.01),相关系数分别为0.695和0.568,可溶性多糖和粗纤维存在显著负相关(P<0.05),相关系数为-0.475。通过聚类分析将24个品种的稻谷按米糠和稻米各分成品质由高到低的3组,通过平行对比米糠和稻米的数据发现,同种稻谷中稻米的品质并不能直接决定米糠的品质。     

Chemical composition, mineral content and antioxidant activity of Verbena officinalis L.

Aqueous and hydroalcoholic extracts from Verbena officinalis L. were obtained and characterised. The analysis by HPLC-DAD and LC-MS allowed the detection and identification of three iridoids, fifteen flavonoids and four phenolic acid derivatives. Four flavonoids, scutellarein 7-diglucuronide (9), scutellarein 7-glucuronide (13), pedalitin 6-galactoside (15) and scutellarein 7-glucoside (19) are reported for the first time from this plant. In addition, three new flavonoids have been isolated: scutellarein 7-O-(2-O-feruloyl)-diglucuronide (5), pedalitin 6-O-diglucuronide (6) and pedalitin 6-O-(2-O-feruloyl)-diglucuronide (13). To our knowledge, these flavonoids have not been reported as natural products. Both extracts showed significant antioxidant activity using three in vitro model systems and the results have been correlated with total phenolic and total flavonoid contents. The results have allowed establishing an important relation structure-activity and significant correlations have also been found between the mineral content and the flavonoids present in both extracts.     

酶解米糠蛋白制备米糠营养液的工艺研究

研究酶解米糠蛋白制备米糠营养液的最佳工艺条件.以脱脂米糠为原料,将米糠磨浆后用α-淀粉酶进行预处理,考察在碱性蛋白酶酶解条件下的蛋白质提取率,通过单因素试验和正交试验确定最佳酶解条件:固液比1:5(W:V)、温度50℃、pH值8.5、蛋白酶用量750 U/g、时间3 h,在此条件下的蛋白质提取率可达45.1%.     

冲击粉碎米糠的成分变化研究

采用机械冲击粉碎对米糠进行粉碎、分级，米糠超微粉平均粒径达到7μm 以下，细胞充分破壁；并分析了其成分蛋白质、氨基酸、V_(B1)和 V_(B2)含量的增加，膳食纤维含量减少的机理。对现有的几种膳食纤维测量方法做了对比讨论。     

米糠蛋白碱法提取联合微波与酶法改性工艺的优化

以新鲜脱脂米糠为原料,以乳化性为指标,将米糠蛋白碱法提取和微波与酶法共同改性相联合,应用Plackett-Burman试验设计筛选出提取时间、提取温度和酶用量3个主要影响因素;采用最陡爬坡法得出响应面试验中心点为提取时间95 min、提取温度39℃、酶用量4 900 U/g;通过Box-Behnken试验得到米糠蛋白最佳改性工艺参数为提取时间100 min、提取温度38℃、酶用量4 960 U/g,预测米糠蛋白的乳化性达到26.69 m~2/g,实际乳化性达到26.53 m~2/g。同时,在优化条件下,吸水性、吸油性和乳化稳定性分别提高了7.81%、67.52%和84.12%。米糠蛋白的提取和改性连续进行,提高了米糠蛋白功能特性。     

响应面法优化米糠微波灭酶工艺探讨

该试验在考察微波功率、米糠初始水分含量、微波时间、料层厚度对米糠中过氧化物酶活及谷维素含量影响的基础上,选取影响残留过氧化物酶活显著的因素做响应面分析,对微波灭酶工艺条件进行优化,结果表明,三个因素影响大小顺序依次为初始水分含量>微波功率>微波时间;各因素间均有显著的交互作用,最佳工艺为微波功率619.45 W、初始水分含量29.4%、微波时间109.4 s。在此条件下,残留过氧化物酶活理论值为0.655%,实际值0.662%,相对偏差1.80%。     

米糠一次浸出及米糠油物理精炼

米糠作为中低含油量的一种特殊油料,很适于通过一次浸出提取毛糠油.米糠一次浸出需经历米糠预处理和米糠浸出两个阶段,米糠预处理的方法有3种:蒸炒、造粒、膨化,其中膨化又分为千式膨化和湿式膨化两种方式;米糠的浸出制油工艺过程具有与其他大宗油料不尽相同的工艺、设备要求,主要体现在物料浸出与湿粕脱溶两道工序上.米糠浸出所得到的毛糠油为一种高酸值毛油,采用物理精炼工艺在提高油脂精炼率和经济效益方面具有明显的优势.米糠油物理精炼工艺过程包括脱胶、脱色、脱酸、脱蜡、脱脂,关键工序是蒸馏脱酸,脱胶、脱色是其至关重要的前处理工序.米糠油物理精炼工艺在实际生产应用中可根据毛糠油的原料情况和精糠油的成品质量等级要求,结合化学精炼工艺进行综合精炼或进行各种档次成品油的生产调节,取得物尽其用的效益.     

The effect of oil content and insecticides on insects attacking rice bran

Ephestia cautella (Walker) was unable to survive on rice bran of less than 5 per cent oil content and even on bran with 10 per cent oil it developed slowly and mortality was high. Tribolium castaneum (Herbst) survived on rice brans with oil contents of 0–10 per cent but the mortality and time taken for development increased as the oil content decreased. Latheticus oryzae Waterhouse survived and bred better on de-oiled rice bran than T. castaneum.Adult T. castaneum and L. oryzae were placed on batches of de-oiled rice bran treated with 20 or 16 ppm malathion, 8 or 4 ppm pirimiphos methyl, 8 or 4 ppm phoxim or 6 or 3 ppm fenitrothion, and mortality assessments were made over a period of 8 weeks after treatment. In general L. oryzae was more susceptible to the insecticides than was T. castaneum. Phoxim at 8 ppm gave highest mortality of T. castaneum and phoxim and pirimiphos methyl, both at 8 ppm, were equally effective in causing the highest mortality of L. oryzae. Malathion at 20 ppm or 16 ppm gave high mortality of both insects initially but began to lose effectiveness after 31 days. Fenitrothion did not give adequate control of either species. Phoxim at 8 ppm was the most successful treatment in preventing breeding of both species.The highest level of insecticide residue found 50 days after treatment was 13·7 ppm for malathion initially at 20 ppm, and by this time the other insecticides had lost about 60 per cent of their initial residue levels.     

米糠膨化浸出制油工艺

简述了米糠的物理特性及加工特点。主要介绍了米糠膨化浸出制油工艺,并对各个工艺过程的操作参数以及在操作过程中应该注意的问题进行了详细的说明,以期为米糠的利用,米糠油的生产提供参考。     

谷维素含量对米糠油透明度与酸值的影响

高谷维素米糠油作为一种高品质食用油日益受到关注,而高含量谷维素的存在会影响米糠油的品质,进而影响其销售.为此,通过在米糠油中定量添加谷维素,研究其对米糠油透明度和酸值的影响.结果表明,20℃时谷维素在米糠油中的溶解度最大可达6.67 g/100 g,10℃时谷维素含量在15 g/kg以内对米糠油的透明度没有显著影响,而米糠油的酸值与谷维素含量之间呈显著的线性关系.     

黄酒矿质元素与原料糯米矿质元素含量的相关性研究

以60个糯米品系为原料在相同条件下酿造黄酒,测定黄酒中原料糯米中矿质元素含量,进行了糯米矿质元素和黄酒矿质元素间的相关性与回归分析。结果表明,糯米矿质元素总量和黄酒矿质元素总量的相关系数为0.326,黄酒中矿质元素与糯米中矿质元素相关性明显。糯米中矿质元素与黄酒口味推算得分的相关性不明显,糯米中矿质元素对黄酒口味无明显影响。     

米糠油精炼及糠蜡的制取技术

米糠油是国际上公认的营养油,其油酸与亚油酸含量之比大致符合国际卫生组织所推荐的最佳比例1∶1。由于毛米糠油的特殊性,米糠油的精炼存在一定的困难。针对米糠油的特殊性,对米糠油的化学精炼和物理精炼以及糠蜡制取工艺,各个工序进行了较为详细的叙述,以期为米糠油的开发利用提供参考。     

脱脂米糠中清蛋白和球蛋白的提取工艺及氨基酸组成分析

脱脂米糠是重要的优质全价植物蛋白质营养源,其蛋白质中清蛋白含量最高,球蛋白其次.对米糠中清蛋白和球蛋白提取工艺进行了研究,探讨不同工艺因素对蛋白得率的影响,确定最佳提取工艺,并对产品的氨基酸组成进行测定.研究表明,清蛋白最佳提取工艺为料液比1:14,提取时间3h,温度45℃,清蛋白得率可达14.64％;球蛋白最佳提取工艺为NaCl浓度为3％,料液比1∶10,提取时间2h,温度50℃,球蛋自得率为4.28％;两种蛋白质中必需氨基酸含量接近FAO/WHO推荐模式,是优质植物蛋白质来源.