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奶粉的细菌污染情况,与消费者的身体健康有极为密切的关系,这是人所皆知的;另外,它既可反映原料的新鲜度,又可表明加工过程中各个工序环节的卫生情况,对于分析某些工艺条件是否合理也有参考作用。然而,我国目前生产的奶粉,细菌污染情况究竟如何呢?回答这个问题,是生产者与消费者共同关心的事。另外,随着四化建设的 相似文献
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分析87例市售不同品牌中老年奶粉产品的能量和各营养素含量分布和营养强化比例,根据食用方法折算出各样品每天可提供各营养素的量,与中国居民膳食营养素参考摄入量(DRIs)中老年人群营养素推荐摄入量(RNI)数值进行比较,研究发现,不同品牌产品提供的能量和大部分营养素(蛋白质、碳水化合物、维生素A、维生素D、维生素C、维生素B_2、维生素B_6、叶酸、锌、镁、磷)含量比较接近,产品中含量的最大值与最小值比值小于10,而脂肪、钠、钙、维生素E、铁的含量范围波动较大,最大值与最小值比值分别为21.78、37.56、18.26、43.14、32.56。营养强化方面,维生素A、维生素D、维生素E、维生素C,矿物质钙、铁、锌的强化比例均高于75%,而叶酸、镁和牛磺酸的强化比例相对较低,仅为20.69%、12.64%和9.20%,铜、锰的强化比例则不足10%。目前市售的中老年奶粉产品除少部分钙含量可以达到RNI数值,其他营养素含量均不能满足老年人群营养需要,建议建立中老年食品相关标准,进一步规范和保障中老年食品营养安全。 相似文献
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对婴配奶粉中氯酸盐和高氯酸盐的污染情况进行调查分析,采用超高效液相色谱-串联质谱(UPLC-MS-MS)法,同位素内标法定量测定,对测定结果进行分析。结果显示,婴配奶粉中氯酸盐的检出率为49.8%,高氯酸盐的检出率为34.4%,氯酸盐的检出率高于高氯酸盐。不同段数婴配奶粉氯酸盐和高氯酸盐的平均暴露量随着段数的增加呈下降趋势。1、2段婴配奶粉氯酸盐超过限量占比均超过10%,3段婴配奶粉氯酸盐超过限量占比在10%以下。不同段数婴配奶粉高氯酸盐超过限量占比均在10%以下。婴配羊奶粉中氯酸盐超过限量占比高达22.1%,高氯酸盐超过限量占比高达23.2%。对0~12月龄的婴儿,氯酸盐摄入的健康风险需引起重点关注。高氯酸盐污染风险相对较低,但是婴配羊奶粉氯酸盐和高氯酸盐污染较为严重。 相似文献
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于景华 《食品科学技术学报》2015,33(6):7-10
主要分析了目前我国奶粉包括原料奶粉和婴儿配方奶粉行业的技术发展现状和质量控制水平,并着重探讨了乳粉加工过程中的质量控制与食品安全现状,同时对未来奶粉行业的技术发展方向、质量控制措施和食品安全管理进行了展望。 相似文献
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将来源于嗜热脂肪芽孢杆菌的启动子连同β-半乳糖苷酶bgaB基因经PCR扩增后,连接在T载体上,再取代枯草杆菌载体pZ01-bgaB的启动子,将其在枯草杆菌宿主WB600中表达.经摇瓶发酵20h,得到乳糖酶活力6.37U/mL,比活力3.814U/mg,SDS-PAGE电泳显示有明显重组蛋白质条带.证明了嗜热脂肪芽孢杆菌来源的启动子在枯草杆菌中是完全适用的. 相似文献
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我国婴儿配方奶粉发展历史简要回顾及内在质量分析 总被引:1,自引:1,他引:0
简要回顾了我国婴儿配方奶粉I-Ⅲ的发展历史,同时对其产品的内在质量(脂肪、蛋白质、碳水化合物和灰分)作了较为详细的分析并作了评价,指出当前在婴儿配方奶粉生产中质量问题存在的原因,以及目前仍在生产婴儿配方奶粉Ⅱ的企业如何解决存在的产品质量问题。 相似文献
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The physical characteristics of milk powders used in chocolate can have significant impact on the processing conditions needed to make that chocolate and the physical and organoleptic properties of the finished product. Four milk powders with different particle characteristics (size, shape, density) and "free" milk fat levels (easily extracted with organic solvent) were evaluated for their effect on the processing conditions and characteristics of chocolates in which they were used. Many aspects of chocolate manufacture and storage (tempering conditions, melt rheology, hardness, bloom stability) were dependent on the level of free milk fat in the milk powder. However, particle characteristics of the milk powder also influenced the physical and sensory properties of the final products. 相似文献
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S.I. Murphy D. Kent J. Skeens M. Wiedmann N.H. Martin 《Journal of dairy science》2021,104(3):2615-2631
Contamination of dairy powders with sporeforming bacteria is a concern for dairy processors who wish to penetrate markets with stringent spore count specifications (e.g., infant powders). Despite instituted specifications, no standard methodology is used for spore testing across the dairy industry. Instead, a variety of spore enumeration methods are in use, varying primarily by heat-shock treatments, plating method, recovery medium, and incubation temperature. Importantly, testing the same product using different methodologies leads to differences in spore count outcomes, which is a major issue for those required to meet specifications. As such, we set out to identify method(s) to recommend for standardized milk powder spore testing. To this end, 10 commercial milk powders were evaluated using methods varying by (1) heat treatment (e.g., 80°C/12 min), (2) plating method (e.g., spread plating), (3) medium type (e.g., plate count milk agar), and (4) incubation time and temperature combinations (e.g., 32°C for 48 h). The resulting data set included a total of 48 methods. With this data set, we used a stepwise process to identify optimal method(s) that would explain a high proportion of variance in spore count outcomes and would be practical to implement across the dairy industry. Ultimately, spore pasteurized mesophilic spore count (80°C/12 min, incubated at 32°C for 48 h), highly heat resistant thermophilic spore count (100°C/30 min, incubated at 55°C for 48 h), and specially thermoresistant spore enumeration (106°C/30 min, incubated at 55°C for 48 h) spread plating on plate count milk agar were identified as the optimal method set for reliable enumeration of spores in milk powders. Subsequently, we assessed different powder sampling strategies as a way to reduce variation in powder spore testing outcomes using our recommended method set. Results indicated that 33-g composite sampling may reduce variation in spore testing outcomes for highly heat resistant thermophilic spore count over 11-g and 33-g discrete sampling, whereas there was no significant difference across sampling strategies for specially thermoresistant spore enumeration or spore pasteurized mesophilic spore count. Finally, an interlaboratory study using our recommended method set and a modified method set (using tryptic soy agar with 1% starch) among both university and industry laboratories showed increased variation in spore count outcomes within milk powders, which not only was due to natural variation in powders but also was hypothesized to be due to technical errors, highlighting the need for specialized training for technicians who perform spore testing on milk powders. Overall, this study addresses challenges to milk powder spore testing and recommends a method set for standardized spore testing for implementation across the dairy industry. 相似文献
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Víctor Alonso García Londoño Martín Puñales Marcela Reynoso Silvia Resnik 《Food Additives and Contaminants: Part B: Surveillance Communications》2018,11(1):15-19
Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. Trichloroacetic acid and acetonitrile were used to extract and precipitate milk proteins previously to clean up of the samples by solid-phase extraction and then were determined by liquid chromatography coupled to ultraviolet detection. The limit of detection (LOD) and limit of quantification (LOQ)of MEL were 0.006 and 0.019 mg kg?1, respectively. Milk was fortified with MEL at three levels, producing average recoveries higher than 83.8%. The values for positive samples ranged from 0.017 to 0.082 mg kg?1. Nine samples were positive. Three of them had concentrations between LOD and LOQ. The mean MEL contamination was 0.028 mg kg?1. Consumption of milk powder containing these levels of MEL does not constitute a health risk for consumers. 相似文献
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目的考察婴幼儿配方乳粉的微生物污染情况,分析婴幼儿配方乳粉的菌相构成。方法采用国标方法测定30批次1段、2段、3段婴幼儿配方乳粉菌落总数,使用基质辅助激光解吸电离飞行时间质谱对检出的优势菌落进行鉴定。结果 30批次婴幼儿配方乳粉的菌落总数均符合国家限量要求,其中1段乳粉菌落总数显著性低于2段和3段乳粉(P0.05)。婴幼儿配方乳粉中检出的细菌主要为芽孢杆菌属、类芽孢杆菌属、球形芽孢杆菌属、肠球菌属、葡萄球菌属和链球菌属,其中芽孢杆菌属检出率最高。此外, 9批次样品中检出蜡样芽胞杆菌。结论我国婴幼儿配方乳粉质量仍存在一定的风险,监管部门应加强日常监管工作。 相似文献
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从风味、状态、营养成分和卫生质量、综合控制及管理四大方面对花生乳、豆乳的品质控制进行了较为全面的论述,并试图从作用机理上对一些现象进行深层次的探讨,以求对生产实际起到一定的指导作用。 相似文献
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目的建立乳粉中亚硝酸盐检测的质量控制图,以判断检测过程与结果是否处于控制状态。方法以有证标准样品作为控制样品,依据GB 5009.33-2016《食品安全国家标准 食品中亚硝酸盐与硝酸盐的测定》检测控制样品中亚硝酸盐的含量。子组数设为25,每个子组平行测定2次,利用Microsoft Office Excel软件,绘制极差控制图与均值控制图,分析受控状态。结果乳粉中亚硝酸盐含量的平均值为5.15mg/kg,标准偏差为0.357 mg/kg,极差的平均值为0.157 mg/kg,极差的标准偏差为0.139 mg/kg。结论乳粉中亚硝酸盐的检测过程中,平行样的检测处于统计控制状态,重复性稳定良好。平行样的均值都处于统计控制状态,检测过程、方法与结果受控。 相似文献
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Milk powder is an important source of protein for adults and children. Protein is very sensitive to heat, which may influence people’s usage of nutrients in milk powder. In this study, we describe the temperature-induced secondary structure of protein in milk powders. In this study, whole milk powder containing 24% protein and infant formula containing 11% protein were heated from 25 to 100°C. Attenuated total reflectance (ATR) spectra in the mid-infrared range 400–4,000 cm?1 were used to evaluate the heat effect on the secondary structure of protein in these 2 milk powders. The spectral changes as a function of temperature were maintained by difference spectra, second-derivative spectra and Gauss curve-fitted spectra. The secondary structures of protein in the whole milk powder began to change at 70°C and in the infant formula at 50°C. The β-sheet and β-turn structures in the whole milk powder both decreased in the range of 70 to 85°C, whereas α-helix structures increased. The loss of β-sheet and β-turn may contribute to the formation of α-helix in the whole milk powder. In infant formula powder, the β-sheet structure showed a decrease and then increase, whereas the β-turn structure showed an increase and then decrease in the range of 50 to 75°C, and no change was found for α-helix structures. This implies that heating may induce the transformation from β-sheet to β-turn. Overall, whole milk powder had better temperature stability than infant formula powder, probably because of the lower content of lipid in the former than in the latter. These results help us understand the thermal stability of protein in milk powder. 相似文献