不同加工方式对胡萝卜中胡萝卜素保留率的影响

为科学高效地利用胡萝卜中的胡萝卜素,设计了以不同季节、不同部位的胡萝卜为原料研究其胡萝卜素的含量及分布,及以不同的烹饪和干制方式对其胡萝卜素保留率的影响。并采用索氏抽提及分光光度法提取测定胡萝卜中胡萝卜素的保留率。实验结果表明,冬季产的胡萝卜中胡萝卜素是春季的1.67倍,整根胡萝卜中胡萝卜素含量的分布:纵向是上段>中段>下段,横向则是外皮层>肉质层>内芯层。不同加工方式中烹饪对胡萝卜中胡萝卜素保留率的影响顺序是水蒸>鲜创丝>打浆渣>炒制>油炸>水煮,且加盐与不加盐对胡萝卜素保留率几乎没有影响,水蒸烹饪较水煮的胡萝卜素保留率高12倍;干制中则是微波干燥>减压热风烘干>常压热风烘干>自然晒干,且微波干制较自然晒干保留率高2.2倍。经L(934)正交试验优化得到微波干制的最佳工艺条件为:微波时间5 min、微波功率400 W,间隙式微波方式。在此条件下胡萝卜素的保留率可达325.9%。     

Consumer Preferences and Customer Satisfaction Analysis: A New Method Proposal

The organic food market is currently the fastest growing food sector in the United States, with growth rates in organic food sales averaging 17% per year between 1998 and 2006. The largest segment within the organic market is fresh produce, comprising 34% percent of retail sales in 2006. This analysis focuses on identifying the demographic characteristics of households buying organic vegetables (in total) along with prepackaged organic salads and organic carrots, by examining the factors that influence the probability that a consumer will buy organic vegetables, and which factors influence the household share of organic vegetables purchased. We use Nielsen Homescan data for the year 2004. Households with high levels of education are more likely to purchase organic vegetables, while the probability of purchasing organic vegetables is lower for African Americans and for older households.