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帥哥 發問時間: 教育與參考其他:教育 · 2 0 年前

食品化學(教育)

我想請問有誰可以說明以下英文含意?必且翻譯?

(1) Vapor above a Solution

1.A solution will lose moisture to the atmosphere

2.The partial pressure of water above the solution is reduced by the presence of solute

3.Vapor pressure depends on concentration of solute as well as temperature

(2) Water activity (AW)

1.Moisture content (%) given on product labels does not indicate the ability of the water to take part in different reactions

2.aW: defined as RH, which must prevail in the surrounding atmosphere to avoid water exchange between material and air; the ratio of the vapor pressures of pure water and a solution:

3.Where:

p = partial pressure of water in a food

p0 = vapor pressure of water at the same temperature

pequ = partial pressure of water vapor in equ with the food at temperature T and 1 atmosphere total pressure

psat = saturation partial pressure of water in air at the same temperature and pressure

(3)Sorption isotherms

1.Sorption Isotherms: presents the relationship between water content and relative humidity

2.Adsorption isotherm → hygroscopic products (steep slope in graph – small increase in relative humidity causes large increase in moisture content, e.g. foods with high salts or sugar contents)

3.Desorption isotherm → drying process

Sorption isotherms have a sigmoid shape – 3 areas (monolayer, additional layers, condensation on capillaries)

correspond to different conditions of water present in the food

(4.)Moisture Sorption Isotherms

1.Highly product specific (physical and chemical structure)

2.Highly temperature dependant

3.Show sorption/desorption hysteresis

4.Affect both physical/chemical reactivity of the food and the dynamics of water transport

1 個解答

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  • 匿名使用者
    2 0 年前
    最佳解答

    (1)高于一個解決辦法的蒸汽

    1.一個解決辦法將對空氣失去水分

    2.高于溶液的水的部分壓力因為溶質的存在被降低

    3.汽壓取決于溶質的集中和溫度

    (2)水活動(AW)

    1.向的含水量(百分之)產品標籤不表明參加不同的回應的水的能力

    2.aW︰ 定義為萊茵鋼鐵公司,必須在避免水的環境空氣裡流行在材料和空氣之間交換; 純水和溶液的汽壓的比率︰

    3.在那裡︰

    p = 在一種食品裡的水的部分壓力

    p0 = 在相同的溫度的水的汽壓

    pequ = 水蒸汽在equ與食品一起的部分壓力在溫度T 和1空氣總壓力

    psat = 在在相同的溫度和壓力的空氣裡的飽和水的部分壓力

    (3)Sorption等溫線

    1.Sorption等溫線︰ 提出在含水率和相對濕度之間的關係

    2.吸附等溫線 △ 吸溫產品(例如食品與高鹽或者糖內容一起把斜率浸在小的增加相對濕度引起大的增加含水量的圖V中)

    3.Desorption等溫線 △ 干過程

    Sorption等溫線有一個sigmoid 形狀V個3個地區(monolayer,另外的壓條,在毛細管上的凝結)

    符合存在于食品的水的不同的條件

    (4.)水分Sorption等溫線

    1.非常產品細節(物理和化學架構)

    2.非常溫度從屬人

    3.顯示sorption/desorption 滯后傾向

    4.影響兩個食品的物理/ 化學reactivity 和水的力學運輸

    參考資料: Me
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