美国食品安全管理法规与举措

以美国国会研究服务部对第107届国会就食品安全方面的一份报告为基础,主要对美国的公共健康问题现状、美国食品安全的联邦规范框架组成、美国食品安全控制最新进展和国会对食品安全提出的新议题做了综述,对我国的食品安全控制和管理体系的建设发挥一点借鉴作用。     

Effect of dose rate and length of storage on the ESR signal strength in irradiated chicken bone

One hundred and twenty-five pairs of chicken drumsticks were randomly allocated to one of five dose rates: 5, 10, 15, 20 or 600 kGyh-. The highest dose rate was obtained using a linear accelerator whilst the remaining dose rates were provided using a ⁶⁰Co gamma source. Each batch of 25 pairs was further divided into groups five of which were stored at 4°C for 0, 7, 14, 21 or 28 days. ESR spectroscopy was used to measure the intensity of the radiation-induced signal. There was a quadratic relationship between ESR signal strength and dose rate, which although statistically significant is unlikely to be of practical importance. The magnitude of the ESR signal declined by about 20% over the first 14 days of storage at 4°C and thereafter the decrease was minimal.     

Phytic Acid Degradation in Complementary Foods Using Phytase Naturally Occurring in Whole Grain Cereals

Complementary foods based on cereals and legumes often contain high amounts of phytic acid, a potent inhibitor of mineral and trace element absorption. The possibility to degrade phytic acid during the production of complementary foods by using whole grain cereals as the phytase source was investigated. Whole grain rye, wheat, or buckwheat (10%) were added to cereal‐legume‐based complementary food mixtures, and phytic acid was shown to be completely degraded in a relatively short time (1.5 to 3 h) when incubated at optimal conditions for cereal phytase. The potential usefulness of the method for industrial production was demonstrated with a complementary food based on wheat and soybean.     

Changes in polymer foils used in food packaging tested by using differential scanning calorimetry

This work is an experimental study of the differential scanning calorimetry characterisation of polymer materials used in food packaging materials, such as polypropylene (0.03 mm), polyethylene (0.1 and 0.03 mm), poly(D-(-)-Β-hydroxybutyrate) (powder), two-layered polypropylene (0.064 mm), and two-layered polypropylene with poly-vinylidene-chloride (0.012/0.021). The polymer stability was checked by simulation of conditions during food preparation in microwave ovens, sterilisation or rapid freezing. The materials were tested in the temperature range from 40 to 200‡C at different scan rates from 2 to 30°C min⁻¹ during heating or cooling. The enthalpies show a high correlation coefficient (0.964) with scan rate. All samples undergo phase change in the temperature range from 107 to 173°C during heating and enthalpies are in the range from 31.8 to 71.1Jg⁻¹. Upon subsequent cooling from 200°C, the temperature range of phase changes is shifted to lower temperatures from 86 to 102°C with enthalpies ranging from 30.4 to 57.8 J g⁻¹. Experiments with exposure of polymers to microwave radiation and freezing prove that the phase change considering the temperature range is very similar in all experiments.     

Persistence of conditioned flavor preferences is not due to inadvertent food reinforcement.

Almond preferences were produced by giving rats a mixture of almond and sucrose (Experiments 1-4) or saccharin (Experiment 4). A subsequent extinction procedure consisted of either repeated 2-bottle almond versus water tests (Experiment 1) or repeated exposure to almond alone (Experiments 2-4). The main independent variable was whether access to food following a session was given immediately, 30 min later, or 120 min later. No effect of extinction was found in any experiment. An important finding was that varying the delay until food access had no detectable effect. It was concluded that inadvertent flavor-food associations do not maintain preference for the flavor under extinction conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

食品高压装置

高压装置是研究高压食品科学、开发和生产高压食品的核心设备，能否提供性能优良、价格相对便宜的装置是高压食品产业化的关键。本文系统介绍食品高压处理装置的类型、结构、性能、特点及最新研究进展，并就如何降低高压装置造价，提高生产能力等关键问题进行探讨。     

红外光控器在蜜丸包装机上的应用

中药大蜜丸及所用包装材料软、粘、轻、小、光,较难实现机械化自动包装。通常的监控方法不适合蜜丸的自动包装。采用红外线光电控制器,解决了自动包装蜜丸时出现的瞬间无纸、无丸等自动控制。     

微波萃取在食品化学中的应用

介绍了微波萃取技术在食品化学中的应用。其实质是用微波对萃取溶剂及物料加热，使溶剂的渗透率和扩散率大大提高，因此对食品营养成分或风味物质可以有铲地萃取分离。     

INHIBITION OF BEER-SPOILAGE LACTIC ACID BACTERIA BY NISIN

149 strains of bacteria, mostly brewery contaminants able to spoil wort or beer, and 12 brewing strains of yeast (8 ale and 4 lager strains) have been screened using a well-test assay for sensitivity to the food preservative, Nisin (E234), Nisin inhibited growth of 92% of the gram-positive strains, predominantly lactic acid bacteria of the genera Lactobacillus and Pediococcus. In contrast, all 32 gram-negative strains tested, except 3 Flavobacter strains, were Nisin-resistant; in addition none of the brewing yeasts showed Nisin-sensitivity. Therefore. Nisin has potential applications in preventing spoilage of worts or beers by lactic acid bacteria.     

Process optimisation in sunflower oil extraction by supercritical CO2

A continuous process for the extraction of sunflower oil using supercritical CO₂, featuring multiple extractors, one oil separator and three cascaded CO₂ recovery vessels operating at different pressures, was devised and studied. For every single equipment of the plant making up the process a mathematical model was built. Experimental tests—consisting in measurements of oil solubility in supercritical CO₂—were carried out in a laboratory-scale apparatus to characterise the behaviour of sunflower oil in the separation from the supercritical fluid. The mathematical model of the whole process was coded in the commercial gPROMS process modelling environment where both its simulation and optimisation—this latter assuming the overall oil production cost as the objective function—were carried out. The process- and economics-related results are discussed and compared with those obtained with traditional and cold-pressing extraction.