市售洋槐蜜、紫云英蜜质量分析

通过对市售瓶装洋槐蜜、紫云英蜜质量指标的测定,了解它们的质量状况。结果:达到GB18796-2005要求的,洋槐蜜中有2、4、5、10号样本,合格率为40%;紫云英蜜中有3、4、6号样本,合格率为30%。结论:市售洋槐蜜和紫云英蜜的质量有待提高,应当加强监管。      

蜂蜜中的酶及其在蜂蜜质量控制中的应用

由于蜂蜜具有广泛的生物活性,因此在我国长期被视为药食同源食品。蜜蜂在采集酿造花蜜过程中,会不断向花蜜中添加各种物质,从而加快花蜜向蜂蜜的转变。蜂蜜中含有淀粉酶、蔗糖转化酶、葡萄糖氧化酶、β-葡萄糖苷酶、过氧化氢酶、磷酸酯酶等多种酶,它们大多来源于蜜蜂咽下腺分泌,也有少量来源于植物的花蜜或花粉。蜂蜜中的酶在蜂蜜酿造过程中发挥着不可或缺的作用,是花蜜转变为蜂蜜的关键物质,同时也是蜂蜜质量控制和品质评价的重要指标。本文对蜂蜜中主要的几种酶进行了介绍,并对其在蜂蜜品质（新鲜度、糖浆掺假和热加工等）监测中的研究进展进行了详细的综述,以期为酶活指标在蜂蜜质量控制中的进一步应用和蜂蜜品质评价体系的完善提供参考。     

Analysis of minority honey components: Possible use for the evaluation of honey quality

The minerals (Al, B, Ca, Cu, Mg, Mn, Ni, Zn) of 24 authentic Czech nectar and honeydew honey samples (2003 and 2004 harvests) were determined, to find the relationship between their content and the origin or type of honey. The concentrations of analytes in the digests, obtained via optimised dry decomposition of honey samples, were measured by flame atomic absorption spectrometry (F-AAS), as well as optical emission spectrometry with inductively coupled plasma (ICP-OES). With regard to its speed of analysis and cost, ICP-OES was the more favourable method. By combining the analytical data and electrolytic conductivities of samples, the honey samples could be divided into two groups – honeydew honeys and nectar honeys. Like Slovak and Polish honeys, samples of Czech honeys had higher nickel levels than honeys originating from other parts of the world.     

The use of ozone to extend the shelf‐life and maintain quality of fresh produce

Fresh produce has been recognised as a healthy food, thus there is increasing consumer demand for fresh fruit and vegetables. The shelf‐life of fresh produce, however, is relatively short and is limited by microbial contamination or visual, textural and nutritional quality loss. There are many methods to reduce/eliminate microorganisms present in food and ozone treatment is one of them. The use of ozone by the fresh produce industry is a good alternative to chemical treatments, e.g. the use of chlorine. The effectiveness of ozone as an antimicrobial agent has previously been reviewed and has been updated here, with the latest findings. The main focus of this review is on the effects of ozone on the fresh produce quality, defined by maintenance of texture, visual quality, taste and aroma, and nutritional content. Furthermore, ozone has been found to be efficient in reducing pesticide residues from the produce. The treatments that have the ability to reduce microbial contamination of the product without having an adverse effect on its visual, textural and nutritional quality can be recommended and subsequently incorporated into the supply chain. A good understanding of all the benefits and limitations related to the use of ozone is needed, and relevant information has been reviewed in this paper. © 2014 Society of Chemical Industry     

热烫前处理对鲜食玉米贮藏过程中保鲜品质的影响

由于鲜食玉米在贮藏期间品质会不断下降,本文利用热烫对鲜食玉米进行前处理,研究其对贮藏期间品质的影响。对鲜食玉米先进行热烫,然后用复合生物保鲜剂进行保鲜,分析含水量、质量损失率、TPA指标、气味与感官品质等,研究贮藏期间鲜食玉米的品质变化。结果表明,热烫前处理的鲜食玉米在贮藏期间,水分含量显著(p<0.05)高于对照,热烫处理可有效抑制鲜食玉米水分散失。热烫处理的鲜食玉米在贮藏0~10 d时,质量损失率略低于对照,30 d时高于对照2.2%,但差异不显著(p>0.05)。热烫处理鲜食玉米的弹性、粘性及回复性与对照差异不显著;而内聚性显著高于对照(p<0.05),硬度、胶粘性和咀嚼性均极显著高于对照(p<0.01)。热烫处理的鲜食玉米气味变化较小。热烫处理对鲜食玉米的保鲜效果较好,能较好保持色、香、味等感官品质。     

Survey of 1,2-dicarbonyl compounds in commercial honey of different floral origin

In this study we conducted a survey of the concentrations of the major 1,2-dicarbonyl compounds in 40 commercial honey samples from 12 different floral origins. 3-Deoxyglucosone (3-DG), glyoxal (GO), and methylglyoxal (MGO) were measured, using their corresponding quinoxaline derivatives, by high-performance liquid chromatography (HPLC). The analytical performance of the HPLC method for the analysis of 1,2-dicarbonyl compounds was evaluated in terms of linearity, limits of detection (LODs), limits of quantification (LOQs), and precision. Linearity over 2 orders of magnitude, LODs (0.01-0.04 mg/kg), and LOQs (0.03-0.12 mg/kg) were calculated. Instrumental precision, as measured by the repeatability relative standard deviation% (RSDr%), was found to be between 0.22% and 0.55%. Furthermore, the concentrations of factors GO and MGO with respect to 3-DG were also calculated for rapid quantification in honey. In honey samples, the concentrations of 3-DG ranged from 75.9 to 808.6 mg/kg and were significantly higher (up to 100-fold) than those of 5-hydroxymethylfurfural (HMF). Values for GO and MGO were 0.1-10.9 and 0.2-2.9 mg/kg, respectively. The chemical characteristics that most influenced the levels of 1,2-dicarbonyl compounds in honey were found to be pH and total phenols. This was supported by multivariate analysis used to classify different honey types with respect to their chemical characteristics. In addition, both dicarbonyls and phenols are believed to contribute to the development of the final color of honey.     

蜂蜜中羟甲基糠醛的近红外光谱快速测定方法

为实现蜂蜜中羟甲基糠醛的快速测定,利用近红外（NIR）光谱分析技术结合偏最小二乘法（PLS）建立了蜂蜜中羟甲基糠醛的定量分析模型,并进行了预测。通过光谱扫描,波数范围为7706⁴009cm-1、一阶导数、norris derivative平滑及10个因子数进行光谱预处理,偏最小二乘法（PLS）,交叉验证。结果表明,羟甲基糠醛定量模型的交叉验证相关系数（Rcv2）=0.99620、交叉验证均方差（RMSECV）=2.40;预测相关系数（Rp2）=0.99874、预测均方差（RMSEP）=2.02;预测值与测定值之间无显著差异,该方法适用于蜂蜜中羟甲基糠醛的快速测定。      

Evaluation of the furosine and homoarginine methods for determining reactive lysine in rumen-undegraded protein

Three samples of soybean meal (SBM), 3 samples of expeller SBM (SoyPlus, West Central Cooperative, Ralston, IA), 5 samples of distillers dried grains with solubles (DDGS), and 5 samples of fish meal were used to evaluate the furosine and homoarginine procedures to estimate reactive Lys in the rumen-undegraded protein fraction (RUP-Lys). One sample each of SBM, expeller SBM, and DDGS were subjected to additional heat treatment in the lab to ensure there was a wide range in reactive RUP-Lys content among the samples. Furosine is a secondary product of the initial stages of the Maillard reaction and can be used to calculate blocked Lys. Homoarginine is formed via the reaction of reactive Lys with O-methylisourea and can be used to calculate the concentration of reactive Lys. In previous experiments, each sample was ruminally incubated in situ for 16 h, and standardized RUP-Lys digestibility of the samples was determined in cecectomized roosters. All rumen-undegraded residue (RUR) samples were analyzed for furosine and Lys; however, only 9 of the 16 samples contained furosine, and only the 4 unheated DDGS samples contained appreciable amounts of furosine. Blocked RUP-Lys was calculated from the furosine and Lys concentrations of the RUR. Both the intact feed and RUR samples were evaluated using the homoarginine method. All samples were incubated with an O-methylisourea/BaOH solution for 72 h and analyzed for Lys and homoarginine concentrations. Reactive Lys concentrations of the intact feeds and RUR were calculated. Results of the experiment indicate that blocked RUP-Lys determined via the furosine method was negatively correlated with standardized RUP-Lys digestibility, and reactive RUP-Lys determined via the guanidination method was positively correlated with standardized RUP-Lys digestibility. Reactive Lys concentrations of the intact samples were also highly correlated with RUP-Lys digestibility. In conclusion, the furosine assay is useful in predicting RUP-Lys digestibility of DDGS samples, and the guanidination procedure can be used to predict RUP-Lys digestibility of SBM, expeller SBM, DDGS, and fish meal samples.     

贮藏温度和时间对鲜湿米粉品质的影响

研究不同贮藏温度(4,25,37℃)下,放置0~30h鲜湿米粉的菌落总数、质构特性、蒸煮特性、色差值及感官评定变化。结果表明,鲜湿米粉在4℃、30h内菌落总数在安全范围内,产品的硬度和咀嚼性高于同时间的25℃组和37℃组,弹性低于二者的;25℃、18h内菌落总数在安全范围内,整体质构特性要好于4℃组和37℃组;37℃、12h内菌落总数在安全范围内,37℃的米粉硬度、弹性、咀嚼性高于同时间的25℃组和4℃组,黏性低于二者的。鲜湿米粉的蒸煮损失率均随着贮藏温度的升高和时间的延长而增大。4℃放置的米粉亮度在30h内没有显著性变化(P0.05),25℃和37℃的米粉亮度随着放置时间的延长逐渐变暗,37℃的最暗(P0.05)。感官评定与前述测定结果基本一致。     

The application of Taguchi method to determine the optimum blend of unifloral honeys to most closely match thyme honey quality

This study was conducted to investigate the effect of four blossom honey types (orange, chestnut, heather and cotton) on a group of quality characteristics of thyme-type based mixture preparations. Mixture ratios were prepared at 0%, 50% and 100% per blossom honey-type and then were blended with thyme honey in parts 1:1. The melissopalynological, sensory and physicochemical quality characteristics for each blend were monitored. A three-level, four-factor orthogonal array according to the Taguchi method was utilised to plan the experiments maintaining the thyme component as a 'slack-variable' to contain the number of performed trials. Subsequent anova treatment revealed that only a pure orange-type blend favours the simultaneous maximisation of aroma ( P  < 0.05) and the minimisation of electrical conductivity ( P  < 0.05). Finally, there was a significant effect of chestnut-type blend content on microscopical and physicochemical characteristics ( P  < 0.05), nevertheless, their corresponding signal-to-noise ratios are maximised only at a concentration of zero value.     

水分含量对鲜湿米粉品质影响

研究不同水分含量对鲜湿米粉成品感官品质,蒸煮特性方面影响;并研究水分含量对鲜湿米粉储藏期内感官品质、微生物指标、蒸煮特性(蒸煮损失率和熟断条率)和酸度影响。结果表明,水分含量为65%鲜湿米粉成品感官评分最高;在储藏期内,随水分含量增加,鲜湿米粉感官品质变劣速度、微生物指标超标、蒸煮损失率和熟断条率及酸度增加也越快。经综合考虑,选鲜湿米粉最宜水分含量为65%。     

减压处理对水蜜桃保鲜效果的影响

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无损快速检测技术在生鲜食品品质鉴定中的应用

无损检测技术作为一种新兴的检测技术,与传统的检测技术有很大区别。该方法可以在不破坏样品的前提下完成检测,因此在食品分析中得到了广泛的应用,同时也受到了越来越多的科研人员的关注。本文根据其检测机制的不同,概述了目前在生鲜食品品质鉴定中应用广泛的几类无损检测技术,包括光学法、声学及力学法、X射线法、电学法和电磁法以及传感器法。本文简述了这些方法在生鲜食品品质鉴定中的应用,比较了各技术的方法特点。由于技术的多样化,在进行检测时需根据检测目标和目的的不同来选择不同的检测技术以获得最佳检测结果。而随着科技的发展,无损检测技术必将向着简单、微型、便携、专一、高灵敏的方向发展。     

果蜜啤酒的研制

介绍了该产品采用蜂蜜和果汁的辅料生产果蜜啤酒的生产工艺。该产品风味独特、营养价值高。其为蜂蜜的深加工、创造更高的附加值产品提供了出路。     

微气泡工艺对结晶蜂蜜热稳定性和品质的影响

目的:得到感官优异、货架期延长的结晶蜂蜜。方法:通过充入微气泡改变结晶蜂蜜物理性状,考察其热稳定性和物理特性,并优化实验室规模机械搅拌法制备微气泡结晶蜂蜜的工艺参数。结果:制备200 g结晶蜂蜜的最佳工艺参数为：搅拌机转速2 600 r/min、充氮气泡时间5 min、进气流速6 L/min,改进后产品在35℃下的热稳定时间提高了41.51%,硬度降低了33%,同时各理化指标值变化均在规定的范围内。结论:微气泡处理提高了结晶蜂蜜的耐热能力,有效延长了其货架期,同时结晶颗粒细小均匀,改善了产品的色泽和口感,并保持蜂蜜原有风味。     

Trends in the production and storage of fresh meat – the holistic approach to bacteriological meat quality

The aim of this review paper is to introduce readers to the modern approach to meat production as recommended by public authorities. No part of the food chain can be regarded alone but has to be seen as part of the whole. A holistic approach to fresh meat storage and retailing must therefore start with the living animal and cannot end with the sale of the meat. It must also include the consumers. One of the highest priority issues for consumers, producers and governments is food safety, and with it, consumer safety. Here we briefly describe the possibilities of keeping initial amounts of bacteria in meat low and modern storage of fresh meat. In future, the consumer must be incorporated in the meat food chain.     

鲜湿米粉品质改良研究

鲜湿米粉是我国南方的传统米制主食,属于高含水量产品,在实际加工过程中,品质较难保证。选择以马铃薯变性淀粉、焦磷酸钠、卵磷脂、海藻酸钠作为鲜湿米粉加工中的品质改良剂,以鲜湿米粉蒸煮损失率及感官评价为指标,比较上述4种品质改良剂不同添加量对鲜湿米粉的品质影响。以此为基础设计正交实验,发现在添加马铃薯变性淀粉5%(干物质质量分数,下同)、焦磷酸钠0.4%、卵磷脂0.4%、海藻酸钠0.3%时,鲜湿米粉蒸煮损失率为1.3%,感官评分为91.4分,在同等条件下达到最佳。然后,以断条率、蒸煮损失率、透色比、糊化度为指标,未添加品质改良剂的鲜湿米粉为对比样,以单因素实验中最适添加量添加品质改良剂制作鲜湿米粉、正交实验中最佳复合添加量添加品质改良剂制作鲜湿米粉,进行对比实验。以最佳添加量添加复合品质改良剂制作的鲜湿米粉断条率降低到1.7%,蒸煮损失率降低到1.3%,透射比提高到0.836,糊化度提升到92.1%,在对比实验中品质改良效果最佳。     

奶及奶制品中糠氨酸检测方法的研究进展

糠氨酸源于美拉德反应的早期产物,并最终经酸水解产生.它间接反映了美拉德反应的程度、赖氨酸营养功能的损失程度和食品受热程度等,被广泛应用于食品的品质评价.虽然糠氨酸在酸水解时的产率仅有30％～40％,但在相同的检测条件下,该产率是稳定的.近40年来,糠氨酸的检测方法研究主要集中于色谱分离系统和检测器的选择与优化,以及酸水...