Understanding the Characteristics and Staling of “Pan de Muerto”: A Traditional Mexican Bread by Relating Its Fat Content to Starch Retrogradation

“Pan de Muerto” is a traditional bread type, emblematic of Mexican bakery. This work’s objectives were defining its characteristics, determining the effect of fat content, fat type, and storage conditions on its staling, and examining the relative impact of these conditions on fat crystallization and starch retrogradation. Staling was evaluated via changes in Young’s modulus. Fat crystallization and starch retrogradation were studied considering the thermal and crystalline properties of unmodified and freeze-dried-defatted crumb. This bread is a hybrid of bakery and pastry products. Fat type, fat proportion, and storage conditions resulted in different staling behaviors not directly dependent on water content. Only butter crystallization depended on storage conditions. Starch retrograded over eight days of storage. The starch crystals’ properties depended on fat content, whereas storage conditions impacted the rate of retrogradation. New relations between fat content and starch retrogradation are shown.

阿根廷奥布莱莫埃尔多盐湖钾锂资源潜力分析

阿根廷奥布莱莫埃尔多盐湖位于南美安第斯高原“锂三角”地区,钾锂资源丰富;为了研究该盐湖卤水特征,分析其钾锂资源远景,利用遥感数据提取钾、锂异常信息,并在湖区施工浅井采集卤水样品进行验证。盐湖钾锂一般赋存于含盐细砂中,靠近盐湖中部赋存于石盐为主的盐类矿物晶体间的孔隙之中;卤水分析结果表明,KCl含量0.60%~2.11%,平均品位1.03%,LiCl含量146~4977mg/L,平均含量2407mg/L;遥感解译显示湖区存在高矿化度卤水,钾锂异常主要集中分布于湖区岛屿北部、东北部及南部靠近岛屿地带。奥布莱莫埃尔多盐湖遥感信息显示钾、锂异常,浅井卤水分析富含锂钾,部分样品达到工业品位,盐湖找矿潜力巨大。