Nitrogen-to-Protein Conversion Factors for Common Vegetables in Japan

Twenty (JAPANESE) vegetables in Japan were analyzed for total nitrogen, amino acid nitrogen, amide nitrogen, and nonprotein nitrogen and then calculated nitrogen-to-protein conversion factors were calculated. The average conversion factor based on quantitative amino acid composition data was 6.00. However, the use of this factor for estimating protein content led to a considerable difference from estimates based on amino acid residue concentrations, due to the presence of high levels of nonprotein nitrogen. The distribution of protein nitrogen to total nitrogen averaged 73%. Adjusted conversion factors, defined as the proportion of amino acid nitrogen to total nitrogen, averaged 4.39. Protein contents estimated with this factor agreed well with contents determined by amino acid residues.     

乳酸菌发酵在谷物产品中的应用及研究进展

谷物食品是人类能量摄入的主要来源之一,随着人们生活水平的提高,谷物食品的营养价值和食用品质受到了广泛关注。发酵是改善食品性质、功能及营养缺陷的重要方法,也是谷物加工的重要手段。乳酸菌能够利用碳水化合物进行生长代谢,在食品工业中被广泛应用于各种发酵制品,其发酵产生的代谢产物有许多重要的生理功能,包括调节肠道菌群平衡、提高免疫力、抗菌和抗肿瘤等。因此,乳酸菌发酵在谷物食品中的研究与应用,对提升食品品质具有重要意义。本文综述了乳酸菌发酵对谷物营养成分、生物功能和结构、理化性质的影响,总结了乳酸菌发酵谷物产品的优势以及乳酸菌发酵在多种谷物产品中的应用,分析了乳酸菌发酵谷物食品目前研究的不足及可能的发展方向, 拟为乳酸菌发酵在谷物中的研究与开发提供参考。     

焙烤类谷物食品糖基化产物的定性、定量评价方法

糖基化产物与心血管疾病、糖尿病等多种慢性病的发生有关,因此对食品中糖基化产物含量的评价尤为重要。研究了不同酶解条件对结合态糖基化产物的释放,并且建立了以色度、吸光度、荧光强度等为考察指标综合评价不同反应途径的糖基化产物含量的体系。结果表明:分别采用E320μg/mL和640μg/mL酶解焙烤类谷类食物,40℃酶解36 h,结合态糖基化产物释放较为充分。谷物早餐中美拉德反应产物含量低于饼干和面包;荧光性晚期糖基化终产物含量大小依次为:饼干(1 890 AU/mg)面包(1 886 AU/mg)谷物早餐(1 678 AU/mg)。另外,早餐谷物中初期(A_(208))、中期糖基化产物(A_(360))显著高于饼干和面包(P0.05),而早餐谷物中期和末期糖基化反应产物(戊糖素、5-HMF和HMF)含量显著低于面包和饼干(P0.05)。     

Understanding the texture of low moisture cereal products: mechanical and sensory measurements of crispness

The texture of extruded starch products has been measured sensorially and instrumentally. The instrumental data were analyzed using different approaches such as fractal analysis and peak analysis. The data showed useful correlations between sensory crispness and crackliness and a parameter obtained from the application of a newly developed fractal method to analyze the force deformation curve obtained from a penetration test of the cereal samples. This suggests that fractal analysis of the force‐deformation plots could be used instead of sensory analysis. Moreover, it was observed that an increase in water content altered the texture of starch based samples from crispy to crackly, whereas the texture of starch‐sucrose samples remained unchanged in the same hydration range. © 2000 Society of Chemical Industry     

济南部分地区谷物制品中脱氧雪腐镰刀菌烯醇及玉米赤霉烯酮的污染状况

目的 了解济南部分地区常见的即食谷物加工制品中脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)和玉米赤霉烯酮(zearalenone, ZEN)的污染情况。方法 在济南市区内4个不同地点随机采集即食谷物加工制品共50份, 酶联免疫吸附法(enzyme-linked immunosorbent assay, ELISA)检测DON、ZEN的含量, 根据食品安全国家标准GB 2761-2017食品中真菌毒素限量对结果进行分析。结果 50份样品中, DON和ZEN的检出率分别为90.0%、76.0%, 超标率分别为48.0%、16.0%, 中位数分别为975.0、39.2 μg/kg。12份有食品包装批号和38份无食品包装批号的样品中, DON超标率分别为33.3%、52.6%, ZEN超标率分别为8.3%、18.4%, 差别均无统计学意义(DON: X2=1.361, P=0.243>0.05; ZEN: X2=0.144, P=0.704>0.05)。DON、ZEN超标率在不同采样点的差别均无统计学意义(DON: X2=2.985, P=0.225>0.05; ZEN: X2=1.453, P=0.484>0.05)。在零食类谷物制品和主食类谷物制品中, DON超标率的差别无统计学意义(P=0.749>0.05), ZEN超标率的差别有统计学意义(P=0.010<0.05)。结论 济南部分地区即食谷物加工制品中存在一定程度的DON、ZEN污染, 其中DON污染更严重, 这种污染情况同时存在于两种包装形式、零食和主食两大类以及不同售卖地点的谷物制品中。提示济南部分地区谷物加工制品的DON、ZEN污染情况应引起相关监管机构的重视。     

Analysis of the intake of sodium with cereal products by the population of Poland

The study aimed to analyse the intake of Na with cereal products by the population of Poland. In addition, based on available literature, changes in the content of Na in bread sold in the Polish market from 2009 to 2018 were analysed with regard to Na intake reduction campaigns held in Poland since 2009 popularising information about the adverse effect of sodium on the human cardiovascular system. The results led to the conclusion that the analysed products contained 3.042 ± 3.4 g of Na per 1 kg of fresh product. The content of Na in the analysed products was bread > bread rolls > grains > pasta > rice. Cereal products provide 48.3 % of an adult’s intake of Na, where as much as 48.2 % is covered by bread, with only 0.04 % by grains, 0.04 % by pasta, and 0.01 % by rice. According to information available in reference literature from 2009–2017 the content of Na in baked goods has not been subject to significant modifications. In Poland, with regard to an excessive consumption of Na, efficient strategies must be developed to increase the awareness of consumers and to reduce the use of table salt in the most popular products, and in particular in baked goods. One of the ways to reduce the intake of Na would be consumers’ selection of an adequate range of foodstuffs naturally poor in this element or having its content reduced by means of a suitable technology. This can be a significant component of practices preventing the development of hypertension. However, the fact that information about the content of Na in cereal products is often missing from product labels makes consumer choice difficult.     

谷氨酰胺转胺酶在谷物制品中的应用

介绍了微生物谷氨酰胺转胺酶的理化性质和作用机理.详细描述了谷氨酰胺转胺酶在谷物制品中的应用,重点叙述了其在面制品中的用途,并展望了其在食品中的广阔的应用前景.     

豆制品和粉干中乌洛托品的气质联用测定

目的 建立豆制品(如腐竹、豆腐干等)和粉干中乌洛托品的气质联用(GC-MS)测定方法。方法 样品中乌洛托品经三氯乙酸水溶液提取、阳离子交换柱净化后GC-MS测定。 结果 该方法的线性范围为0.1~5 mg/kg, 相关系数r为0.998; 检测限为0.05 mg/kg; 回收率为78.5%~97.0%; 相对标准偏差(RSD)为5.7%~10.9%。结论 该方法准确、操作简单, 可用于实际样品中乌洛托品的含量测定。     

冲调谷物制品污染菌相的调查分析

目的 了解冲调谷物制品中的微生物污染情况及主要污染菌种类,探讨传统形态学鉴定法、分子生物学鉴定法和基质辅助激光解吸电离飞行时间质谱法（matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF-MS）鉴定微生物的适用效果。方法 以流通领域抽取的冲调谷物制品为研究对象,采用国家标准方法对其菌落总数和霉菌进行计数,分离纯化不合格产品中的污染菌,以基质辅助激光解吸电离飞行时间质谱（matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF-MS）结合16S rRNA序列分析方法对污染细菌进行鉴定,以MALDI-TOF-MS方法结合传统形态学鉴定方法对污染霉菌进行鉴定。结果 110批次冲调谷物制品的菌落总数不合格率为3.6%,霉菌计数不合格率为4.5%;分离得到的159株细菌可归于28个种,芽孢杆菌属（Bacillus）细菌为优势菌群,分离频率达到71.7%;分离得到的98株霉菌可划分至25个属,青霉属（Penicillium）和曲霉属（Aspergillus）为优势菌群,分离频率分别为12.4%和7.1%。污染菌中含有克罗诺杆菌（Cronobacter）等条件致病细菌和多种常见产毒真菌,存在一定的食品安全风险。结论 冲调谷物制品的微生物污染情况较为严重,生产企业应重视生产加工过程中的微生物污染问题,相关部门应加强对冲调谷物制品的食品安全监管。MALDI-TOF-MS方法在鉴定细菌时具有较大优势;受限于真菌数据库的不足,其用于食品来源霉菌鉴定的准确率有待提高。     

国内外谷物蛋白发展概况

本文综述谷物蛋白组成特性、应用和改性方面最新研究概况。开发利用谷物蛋白，已成为谷物科学领域研究热点。     

Composition and functionality of wheat bran and its application in some cereal food products

Production of wheat bran (WB) for human consumption is estimated to be about 90 million tonnes per year. WB is a cheap and abundant source of dietary fibre which has been linked to improved bowel health and possible prevention of some diseases such as colon cancer. It also contains minerals, vitamins and bioactive compounds such as phenolic acids, arabinoxylans, alkylresorcinol and phytosterols. These compounds have been suggested as an aid in prevention of noncommunicable diseases such as cardiovascular disease. This article discusses WB extraction, its nutritional properties, potential health benefits, effects on quality and sensory properties of some cereal foods, and its application in some baked products as well as in fried cereal snacks, as an additive for oil reduction and fibre enrichment.     

Application of enzyme-treated corn starches in breakfast cereal coating

Presently ready-to-eat cereals are coated with high levels of sugar coating to extend the bowl life. Because of health concerns of added sugar, there is a need to identify alternative coating materials. This study was designed to test the efficacy of debranched corn starches with varying amylose contents as a cereal coating. Hylon VII (70% amylose), common, and waxy corn starches were gelatinized and debranched, and then sprayed onto ready-to-eat breakfast cereal flakes. The surface morphology, milk absorption, texture, and digestibility of coated cereals were determined. A starch film with a thickness of 50 to 130 μm was observed with scanning electron microscopy on the surface of the cereals coated with Hylon VII. All starch-coated cereals had a lower milk absorption value than the uncoated and glucose-coated controls. Among starch coatings, common corn starch and Hylon VII resulted in lower milk absorption than did waxy corn starch. After soaking in milk for 3 min, the peak force and work to peak of the cereals coated with corn starches were higher than those of the glucose control and uncoated reference. The cereals coated with Hylon VII were found to have an increase in dietary fiber content. The results suggest that debranched amylose-containing corn starches could extend the bowl-life of ready-to-eat cereals. Practical Application: Currently, many cereals are coated with sugar to keep them from becoming soggy in milk. However, added sugar has been linked to obesity, hyperactivity, and dental caries. This has led to the investigation of alternative coating materials. This study employed the film-forming properties of enzyme-treated corn starch to function as a coating material in breakfast cereal flakes. In addition, the enzyme-treated high amylose corn starch also increased the dietary fiber content of the cereal flakes.     

Nitrogen-to-Protein Conversion Factors for Some Common Edible Mushrooms

Mushrooms (13) common to Japan were analyzed for total nitrogen (TN), amino acid nitrogen (AAN), amide-N and nonprotein nitrogen. The distribution of protein nitrogen averaged 67% to TN. Averaged nitrogen-to-protein conversion (N:P) factor was 5.99. Application of the factor for estimation of protein content resulted in a considerable difference from amino acid residue (AAres) levels, due to the high level of nonprotein nitrogen. A net N:P factor, defined as the proportion of AAN to TN, was proposed. The averaged value of 3.99 was derived from analytical TN and AAN data of mushrooms. Calculated protein values using this factor were in good agreement with AAres.     

气相色谱-质谱法测定粮油制品中的二甲基黄和二乙基黄含量

目的建立气相色谱-质谱法测定粮油制品中二甲基黄和二乙基黄的含量的分析方法。方法试样以1%醋酸的乙腈提取,采用油基质萃取管净化和HP-5MS色谱柱分离,质谱采用全扫描和选择离子模式测定,以外标法定量。同时考察了不同的提取溶剂及净化方式对回收率的影响。结果在添标水平为1、10和25 mg/kg时,二甲基黄和二乙基黄的平均回收率为76.3%~89.3%,相对标准偏差为3.0%~8.7%,二甲基黄的方法检出限为0.002 mg/kg,二乙基黄的检出限为0.001 mg/kg,符合检测方法参数的确认要求。结论该方法快速、准确,适用于粮油制品中的二甲基黄和二乙基黄含量。     

谷物蛋白分离纯化方法的研究进展

谷物蛋白由于具有高度异质性、低溶解度和容易聚集等因素,导致其非常难以分离纯化和鉴定。为充分了解谷物蛋白的结构与功能,实现对谷物蛋白的分离纯化,阐述了几种常见谷物蛋白的组成及特点,对近年来国内外有关谷物蛋白的分离纯化原理与模式的研究进展进行了综合评述,同时展望今后谷物蛋白分离纯化的研究方向。     

Ergot alkaloids in some rye-based UK cereal products

UK rye-based cereal products were analysed for six major ergot alkaloids using an in-house-validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method that distinguished -ine and -inine epimers (isomers). Ergot alkaloids were detected in 25 of 28 samples subject to quantification limits of 1–3 µg kg^?1, including all of eleven rye crispbreads that had up to 340 µg kg^?1. Continental-style rye breads contained up to 121 µg kg^?1. Loaf breads, bread-mix flours, and crackers contained only low levels of alkaloids. Ergotamine, ergocristine, and ergosine were the predominant ergot alkaloids in terms of level and frequency of occurrence. There were no apparent differences in the ergot levels between the organic and non-organic products, although the numbers tested were low. Most rye breads had a ratio of -ines to -inines of about 1.5, and rye crispbreads had lower and more variable -ine to -inine ratios.     

感官评价及其在谷物制品中的应用现状

简要介绍了感官评价的定义、应用及其在食品工业中的重要性。重点阐述了感官评价在部分谷物制品评价中的应用,包括大米食味和小麦粉制品食用品质的感官评价。详细描述了大米、面条、面包、馒头品质的感官评价方法、相关研究及存在的问题等。     

Dietary fibre fractions in cereal and cereal-containing products in Britain

The values for dietary fibre in the current UK food tables were obtained using a fractionation method which involved digestion of starch with a takadiastase preparation. For the revision of the food tables new values for the dietary fibre in cereal and cereal-containing meat products were obtained by an improved fractionation method which used a mixture of amyloglucosidase and α-amylase to digest starch. The full details of this analytical method are given, along with the fibre components which were found in 138 cereal-containing foods. This method produced higher values than the previous method in most processed cereal products. Also the levels of pentoses in the non-cellulosic polysaccharide fraction and of lignin residues are greater. The study considerably extends the range of cereal-containing foods for which the amount of dietary fibre and its components has been determined.     

Effect of source of rumen-degraded protein on production and ruminal metabolism in lactating dairy cows

Twenty-eight (8 with ruminal cannulas) lactating Holstein cows were assigned to seven 4 × 4 Latin squares in a 16-wk trial to study the effects on production and ruminal metabolism of feeding differing proportions of rumen-degraded protein (RDP) from soybean meal and urea. Diets contained [dry matter (DM) basis] 40% corn silage, 15% alfalfa silage, 28 to 30% high-moisture corn, plus varying levels of ground dry shelled corn, solvent- and lignosulfonate-treated soybean meal, and urea. Proportions of the soybean meals, urea, and dry corn were adjusted such that all diets contained 16.1% crude protein and 10.5% RDP, with urea providing 0, 1.2, 2.4, and 3.7% RDP (DM basis). As urea supplied greater proportions of RDP, there were linear decreases in DM intake, yield of milk, 3.5% fat-corrected milk, fat, protein, and solids-not-fat, and of weight gain. Milk contents of fat, protein, and solids-not-fat were not affected by source of RDP. Replacing soybean meal RDP with urea RDP resulted in several linear responses: increased excretion of urinary urea-N and concentration of milk urea-N, blood urea-N, and ruminal ammonia-N and decreased excretion of fecal N; there was also a trend for increased excretion of total urinary N. A linear increase in neutral detergent fiber (NDF) digestibility, probably due to digestion of NDF-N from lignosulfonate-treated soybean meal, was observed with greater urea intake. Omasal sampling revealed small but significant effects of N source on measured RDP supply, which averaged 11.0% (DM basis) across diets. Increasing the proportion of RDP from urea resulted in linear decrease in omasal flow of dietary nonammonia N (NAN) and microbial NAN and in microbial growth efficiency (microbial NAN/unit of organic matter truly digested in the rumen). These changes were paralleled by large linear reductions in omasal flows of essential, nonessential, and total amino acids. Overall, these results indicated that replacing soybean meal RDP with that from urea reduced yield of milk and milk components, largely because of depressed microbial protein formation in the rumen and that RDP from nonprotein-N sources was not as effective as RDP provided by true protein.