火焰原子吸收分光光度法测定爆米花中铅含量

对传统爆米花机制作的玉米花进行重金属铅含量测定,为其食用安全提供科学依据。采用干灰化法预处理样品,火焰原子吸收分光光度法测定。通过对传统爆米花机加工成的4个批次的玉米花的测定,其中铅含量最高达0．36mg/kg。所以用传统爆米花机制作的玉米花不宜过多食用。     

Fine and ultrafine particle emissions from microwave popcorn

This study characterized fine (PM_2.5) and ultrafine particle (UFP, diameter < 100 nm) emissions from microwave popcorn and analyzed influential factors. Each pre‐packed popcorn bag was cooked in a microwave oven enclosed in a stainless steel chamber for 3 min. The number concentration and size distribution of UFPs and PM_2.5 mass concentration were measured inside the chamber repeatedly for five different flavors under four increasing power settings using either the foil‐lined original package or a brown paper bag. UFPs and PM_2.5 generated by microwaving popcorn were 150–560 and 350–800 times higher than the emissions from microwaving water, respectively. About 90% of the total particles emitted were in the ultrafine size range. The emitted PM concentrations varied significantly with flavor. Replacing the foil‐lined original package with a brown paper bag significantly reduced the peak concentration by 24–87% for total particle number and 36–70% for PM_2.5. A positive relationship was observed between both UFP number and PM_2.5 mass and power setting. The emission rates of microwave popcorn ranged from 1.9 × 10¹⁰ to 8.0 × 10¹⁰ No./min for total particle number and from 134 to 249 μg/min for PM_2.5.     

无铅焊接爆板之成因及控制

主要从板材、PCB制程、焊接过程和受潮吸湿等方面论述了无铅焊接爆板产生的原因并提出相应的控制措施。     

Diacetyl in Foods: A Review of Safety and Sensory Characteristics

Diacetyl, noted for its appealing butter‐like aroma, is present naturally in many foods, and humans have been exposed to it since the beginning of civilization. The advent of microwave (MW) cooking technology has led to the development of a significant market for MW popcorn, to which diacetyl and other flavoring compounds have been frequently added. Based upon reported associations between diacetyl inhalation and lung disease in employees of MW popcorn processing facilities, a very conservative safe level of occupational exposure to diacetyl has been proposed by the American Conference of Governmental Industrial Hygienists. Yet there is conflicting evidence that diacetyl causes lung disease in workers, and no evidence to condemn diacetyl as the cause of lung problems in MW popcorn consumers. Consumer dietary exposure to diacetyl in foods is below levels of health concern while common airborne levels of diacetyl from MW popcorn are far below the conservatively established limit to protect workers.     

Effect of Sodium Chloride Particle Size and Shape on Nonelectrostatic and Electrostatic Coating of Popcorn

ABSTRACT: Sodium chloride of different shapes (hollow pyramid, crushed flake, cube, and porous cube) and sizes (50-200 mesh) were applied by nonelectrostatic and electrostatic powder coating to popcorn coated with 1.2 to 3.3% soybean oil. Electrostatic coating was more efficient than nonelectrostatic in all cases. The smaller the particles, the higher the coating efficiency for both electrostatic and nonelectrostatic coating. Crushed flake and hollow pyramid were more efficient than cube and porous cube shapes. Coating efficiency improved as the oil content increased for nonelectrostatic but not electrostatic coating. Use of electrostatic coating can reduce waste and provide a more efficient coating method by decreasing seasoning or oil needed to reach the target level.     

食品中铅含量的快速分析

以点滴分析法分析玉米花中铅含量为例,介绍了点滴分析在食品检验中的应用。该法操作简便、快捷、灵活,并且有较高的灵敏度。     

酥核裹衣花生碎加工参数的优化

以爆玉米花为核,外裹粉状辅料和花生碎,微波膨化制作酥核裹衣花生碎。试验确定加工参数为:花生碎粒径在3 mm以下、爆玉米花膨化度101.14 g/L、裹衣层数2层、糖浓度50%、淀粉占裹衣粉比例30%、烘烤温度中火、烘烤时间6 min。产品口感酥脆,有花生和爆玉米花的香味,是一种新型健康的花生休闲食品。     

丁二烯抽提装置自聚物的预防

在不断的实践和探索过程中,对丁二烯自聚物、过氧化物的产生、危害及预防上认识也是逐渐加深的。丁二烯自聚物的存在不仅增大了单体消耗,而且往往堵塞设备、管线、阀门等,影响装置的长周期运行,严重时,会使设备损坏,造成火灾爆炸等恶性事故,对安全生产威胁极大。因此,为了确保安全、稳定、长周期、满负荷生产,必须采取积极措施,防止丁二烯自聚物的形成。本文旨在根据本套装置实际,结合日常生产管理上的一些做法,对长周期开车过程中防止丁二烯自聚物生成的预防做进一步探讨。     

双硫腙分光光度法测定爆米花中微量铅

研究了双硫腙分光光度法测定爆米花中微量铅的方法.采用双硫腙为显色剂,控制溶液的pH为8.5,在513nm波长处测定吸光度,利用标准曲线求出铅含量.并讨论了溶液pH、反应时间、络合剂用量对吸光度的影响.测定结果表明样品中铅含量5.0 mg/kg,明显高于国家标准0.5 mg/kg.     

不同油爆条件对不同类型爆裂玉米爆花特性影响

为研究不同油爆条件对不同类型爆裂玉米爆花特性影响,选取蝶型和球型两类爆裂玉米,分析不同加油量和处理温度对其特性的影响。研究表明,对于膨爆倍数,加油量和处理温度对不同类型爆裂玉米的影响不显著,而膨爆倍数在40%~50%的加油量时为最佳,等体积下的蝶型需油量更多,蝶型的适宜处理温度低于球型。爆花温度受加油量影响明显且呈显著正相关,而处理温度影响不明显,不同加油量和处理温度下,蝶型平均爆花温度高于球型。爆花起始和总时间受加油量影响并呈显著负相关,处理温度影响不显著,但随处理温度增加呈下降趋势。由此可见,油爆时爆花温度和时间主要受加油量影响,而蝶型和球型爆裂玉米适宜处理温度不同。