PREDICTING the COOLING TIME FOR IRREGULAR SHAPED FOOD PRODUCTS

A new method for calculating the cooling time for fresh fruits and vegetables and processed foods is presented. the method uses the truncated analytical solution of the governing partial differential equation to define a cooling curve with two parameters. One parameter is the lowest eigenvalue for the product. the second parameter is a constant multiplier similar to the one that occurs in the analytical solution. the lowest eigenvalue is evaluated using a finite element analysis. the multiplying constant is evaluated using a finite element solution in time. Cooling curves for a Rome apple and a Bartlett pear are presented and discussed.     

SENSORY, NUTRIENT AND CHLOROPHYLL CHANGES IN BROCCOLI FLORETS DURING CONTROLLED ATMOSPHERE STORAGE

Sensory (color, turgor, decay) and nutritional (vitamin C, β-carotene) quality of broccoli florets were evaluated during storage at 4C in air or under a controlled atmosphere containing 2% O₂+ 6% CO₂ (CA). Shelf-life, green color and chlorophyll retention were greater under CA than in air, although loss of stem turgor was accelerated. All samples stored in air had decayed sufficiently by the fourth week to be unfit for consumption, while samples stored under CA showed a few spots of decay after five weeks. However, CA was associated with browning at the cut surface of the stem. Retention of vitamin C was slightly greater in CA than in air, while β-carotene content increased at the end of CA storage. Returning the samples to ambient conditions for 24 h after storage under either conditions resulted in chlorophyll and vitamin C losses, whereas β-carotene content remained stable.     

2012年中国硫磺市场的统计与分析

对2012年我国硫磺市场情况进行了统计与分析。2012年我国硫磺进口量为11 203 kt,较2011年增加17.6%。上半年硫磺市场波动频繁,下半年受国际宏观经济疲软的影响,市场持续下滑;年底出于对2013年春耕用肥需求增加以及磷铵出口提前集港的预期,价格有一定的回升。对影响当前硫磺市场的因素进行了分析,对2013年的中国硫磺市场进行了预测。     

2012年上半年中国硫磺市场的统计与分析

对2012年上半年中国硫磺进口情况进行统计,并对国内硫磺销售情况进行分析.2012年上半年我国共进口硫磺6011 kt,与2010年同期相比增加30.8％.1-5月硫磺市场波动明显,6月以疲软下跌收尾.2011年上半年我国硫磺主要进口国为沙特阿拉伯、阿联酋和加拿大,硫磺采购主要集中江苏、贵州、云南、湖北、山东等地.对未来硫磺市场进行了预测,并对主要影响因素进行了分析.     

MODELING THE SENSORY QUALITIES OF PROCESSED APPLES AFTER CONTROLLED ATMOSPHERE STORAGE AND FROZEN STORAGE1

Durational effects of controlled atmosphere storage (CA) and frozen storage on apple quality were studied for commercially processed pies made from Northern Spy, Idared and Nova Spy apples. Sensory tests on apple pie quality indicated that the duration of apples in CA significantly affected the quality of the processed apple. Extending the CA duration of the apples to 45 weeks resulted in a pie filling with reduced apple flavor, tartness and astringency, and with increased sweetness and off‐flavor. To minimize flavor/taste changes throughout the processing season, close attention must be given to the product's sugar/acid formulation: by week 27 for Idared apples and by week 33 for Northern Spy and Novaspy apples. The texture and appearance of processed Novaspy and Idared fruits were affected earlier in CA than Northern Spy apples. The frozen product was relatively stable for all three varieties, especially for apples processed early in the storage season (15–27 weeks). A strategy that utilizes short‐ to medium‐term CA with longer‐term frozen storage would optimize quality across the season.