clusters of four water molecules may come together to form water bicyclooctamers. z ( A) is high-density, low volume, high active, high enthalpy, high entropy z ( B) with additional hydrogen bonds (shown green), with 60 ° relative twist, is low density, high volume, low active, low enthalpy, low entropy. strongly associated (low-density) water Water clustering in liquid water
clusters of four water molecules may come together to form water bicyclooctamers. z ( A) is high-density, low volume, high active, high enthalpy, high entropy z ( B) with additional hydrogen bonds (shown green), with 60 ° relative twist, is low density, high volume, low active, low enthalpy, low entropy. strongly associated (low-density) water Water clustering in liquid water
ES: 0.94 g cm-3 The stability of the network is finely balanced, being able to fluctuate between an expanded low-density structure (ES, left) and a more dense collapsed one (CS, right) without breaking any hydrogen bonds and consequent on small changes in the hydrogen bond strength relative to the non-bonded interactions. CS:1.30 g cm-3
ES: 0.94 g cm-3 The stability of the network is finely balanced, being able to fluctuate between an expanded low-density structure (ES, left) and a more dense collapsed one (CS, right) without breaking any hydrogen bonds and consequent on small changes in the hydrogen bond strength relative to the non-bonded interactions. CS:1.30 g cm-3
概述 z 水是食品中非常重要的一种成分，也是构成大多数食品 的主要成分 z 水对食品的结构、外观、质地、风味和新鲜程度产生极 大的影响
概述 z 水是食品中非常重要的一种成分，也是构成大多数食品 的主要成分 z 水对食品的结构、外观、质地、风味和新鲜程度产生极 大的影响
水 分 活 度 与 食 品 稳 定 性
水 分 活 度 与 食 品 稳 定 性
z 水分活度ɑ w通过影响化学反应和微生物生长影响食品的 感官品质。 z 水分活度影响干燥、半干燥食品的质地，如饼干、膨化 玉米花和油炸马铃薯片的脆性，砂糖、奶粉和速溶咖啡 结块，以及硬糖果、蜜饯等粘结。 z 对含水较多的食品，如冻布丁、果糕等，需防止水分蒸 发
z 水分活度ɑ w通过影响化学反应和微生物生长影响食品的 感官品质。 z 水分活度影响干燥、半干燥食品的质地，如饼干、膨化 玉米花和油炸马铃薯片的脆性，砂糖、奶粉和速溶咖啡 结块，以及硬糖果、蜜饯等粘结。 z 对含水较多的食品，如冻布丁、果糕等，需防止水分蒸 发