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The aim of this work was to determine the effect of temperature and water content on the mechanical properties of convection

dried apples. Apples v. Idared were cut into slices and then air-dried at temperature in the range from 50 to 80 C. Mechanical

properties were measured by compression–relaxation test. Samples were investigated after drying and also after 5 weeks of storage

over anhydrous calcium chloride at constant temperature. Analysis showed that the observed differences between compression–

relaxation curves of apples dried at 50, 60 and 70 C were not significant. Decreasing of water content caused an increase of force

needed to compress dried apples. Drying at 80 C affected the texture of dried apples much more in comparison to those obtained at

lower hot air temperature. The use of suitable temperature and drying of apples to definite water content could be used to design the

mechanical properties of the final product.

2003Elsevier Ltd. All rights reserved.

1. Introduction

Drying is one of the widely used methods of fruits

and vegetables preservation. Water is removed to a final

concentration, which assures microbial stability of the

product and minimises chemical and physical changes of

the material during storage. In most drying processes

water is removed by convective evaporation, in which

heat is supplied by hot air.

Convection drying changes the structure of the

material, its composition and the spatial conformation

of biopolymers. As a result of water removal, destruction

of natural structures and loss of semipermeablity of

the membranes occurs, hence rheological properties also

change (Karel, 1980). The outer layers of drying material

become rigid and acquire considerable mechanical

strength (Lewicki, Witrowa-Rajchert, & Mariak, 1997).

Removal of water (a vital component for maintenance

of structure and functional integrity) from biological

membranes leads to lateral phase separation of lipids

and proteins giving rise to protein aggregation (Chapman,

1994). In consequence convective drying causes

many physical and chemical changes in plant tissue

(Lewicki, 1998).

It was ascertained that properties of materials change

during decreasing of water content from elastic-viscoplastic

to fragile body. The mechanical strength of carrot

was found to strongly decrease during drying due to

damage of the internal structure, thermal denaturation

of biopolymers and the cell plasmolysis (Szymanska,

1975).

During drying the plant material shrinks and internal

tensions are developed. The internal structure undergoes

deformation and is locally damaged, which result in

cross-linking of polymers and formation of crystalline

regions in the amorphous polymers. Removal of water

adds rigidity to the external layers and simultaneously

builds up moisture gradients, which create shrinkage

stresses. The stresses depend on the method of drying

and wetness of the plant tissue and result in fractures,

breaks and discontinuities and in general loosening of

structure of the material (Lewicki & Pawlak, 2003).

During drying the mechanical strength of material

increases and shrinkage stresses lead to formation of

cavities and voids inside of the material (Lewicki,

Rajchert, & Łazuka, 1994). During drying of florets of

* Corresponding author. Fax: +48-22-8434602.

E-mail address: jakubczyk@alpha.sggw.waw.pl (E. Jakubczyk).

0260-8774/$ - see front matter 2003Elsevier Ltd. All rights reserved.

doi:10.1016/j.jfoodeng.2003.10.014

cauliflower Jayaraman, Das Gupta, and Babu Rao

(1990) observed cellular rupture and severe tissue collapse

resulting in disruption of cell walls.

One of the main physical changes influencing the

structure of plant tissue during drying is shrinkage,

which starts at the very beginning of the drying process

(Witrowa-Rajchert & Turek, 1998). The shrinkage upon

drying depends on tissue structure of the product subjected

to drying, and for fruits and vegetables is almost

linearly related to moisture content (Sj€oholm & Gekas,

1995; Wang & Brennan, 1995). The extent of shrinkage

affects porosity of dried material, which is an important

parameter as far as the mass transfer properties,

mechanical properties and food texture are concerned

(Witrowa-Rajchert, 1999). The extent of shrinkage and

degree of damage of the internal structure of plant tissue

is dependent on the drying method applied and parameters

of the process, that is temperature and air velocity

(Nowak, Witrowa-Rajchert, & Lewicki, 1998; Ratti,

1994). Wang and Brennan (1995) investigated shrinkage

of potato during air drying at temperature in the range

from 40 to 70 C. They observed that the degree of

shrinkage of potato at low air drying temperature was

greater than that at high air drying temperature.

Methods and variables of drying affect both a kind of

the physicochemical changes in plant tissue and the

quality of the dehydrated product (Krokida &Maroulis,

1997). Convection drying is one of the most frequently

used operations for food dehydration. This method requires

high temperature and velocity of drying air and

takes long time, and final products are characterised by

low porosity and high apparent density (Tsami, Krokida,

& Drouzas, 1999). Upon drying, due to removal of

water and a dislocation of volatile substances, saccharides

and fats, changes in physical properties (including

mechanical strength) of plant tissue take place.

Numerous publications indicate that drying strongly

affects rheological properties of the dried material. Wet

materials are viscoelastic, while at low water content

they become brittle, hence rheological properties of

dried plant tissue are related either to water content or

water activity (Gabas, Menegalli, Ferrari, & Talis-

Romero, 2002; Krokida, Karathanos, &Maroulis, 2000;

Krokida, Maroulis, & Marinos-Kouris, 1998: Lewicki &

Lukaszuk, 2000). Jakubczyk, Sitkiewicz, and Lewicki

(1997) showed that convective drying of apple cubes

reduced their hardness by more than half in comparison

to raw material. Rheological properties change during

drying and the more water is removed the more plastic

apple tissue becomes. The relationship between stress

and strain was concave downwards and the concavity

increased until water content close to 2.5 g/g d.m. was

reached (Lewicki & Lukaszuk, 2000). Further lowering

of water content straighten the relationship and for dry

material developed stress was linearly dependent on

strain. The change in analysed relationship was reflected

in the increase of work of deformation. Hence, at water

content lower than 2.5 g/g d.m. convective drying

induced some stiffening of the apple tissue.

The effect of convective drying on tissue structure and

mechanical properties of the end-product has not been a

subject of extensive studies. Most of the published results

present the effect of water content on rheological properties

of the material dried at constant temperature. There

is practically no data showing the effect of hot air temperature

on mechanical properties of the dried product.

The aim of this work was to determine the effect of

drying air temperature and final water content on the

mechanical properties of convection dried apples.

2. Materials and methods

Apples v. Idared stored at 4 C and 80–90% relative

humidity for 4 months after harvest were cut into slices

15 mm in diameter and 5 mm height. Initial water

content was approximately 86.2%.

Samples were placed on the wire tray in a single layer

in a laboratory convection dryer and the average tray

load was 2 kg/m2. Then the material was air-dried at

temperatures in the range from 50 to 80 C and an air

flow velocity of 1.7 m/s. Temperature and humidity of

air were measured by digital thermometer and

hygrometer. Surrounding air temperature was 20–22 C

and humidity 50–60%. Drying was terminated when no

further mass changes were observed. Samples were

investigated immediately after drying and also after 5

weeks of storage in a constant temperature room placed

in glass jars containing anhydrous calcium chloride at 22

C (water activity of CaCl2 aw ¼ 0:001). Water activity

was measured by Hygroskop DT (Rotronic) with

accuracy ±0.001, while water content of dried apples

was examined using drier method according to Polish

Standard PN–90/A–75101. Volume of samples was

determined in accordance with the toluene method

presented by Mazza (1983).

The mechanical properties were investigated in compression

–relaxation test. Apple slices were placed in a

metal cylinder one upon the other forming a pile 40 mm

high. A piston 14.5 mm in diameter was connected with

Zwick Machine 1445 (ZWICK GmbH) and used to

compress the samples in the cylinder. The compression

was done with a piston velocity of 10 mm/min, and

terminated at 20% deformation. The measurements were

repeated 10 times.

True strain e was calculated from the equation:

e ¼ ln 1

h0 hs

h0

Stress was calculated from the equation:

r ¼

F

S

Relative relaxation stress was calculated as follows:

rr ¼

rs

r0

Volumetric shrinkage of material was calculated from

the following equation:

SV ¼ 1

Vs

V0

3. Results

Convection drying of apple slices at different hot air

temperature yielded products with different final water

content and variable volumetric shrinkage (Table 1).

Water content of dried apples varied from 0.0671 g/g

d.m. (6.29%) at 80 C to 0.0781 g/g d.m. (7.24%) at 50

C and it could affect the resistance to deformation of

dried material. On the other hand the time of drying was

longer by decreasing hot air temperature. The drying

time at 50 C was about 40% longer than it was at 70 C.

Moreover, drying time of apples at 80 C was about 15%

shorter than that of apples dried at 70 C. A short

period of constant drying rate was observed independent

of the hot air temperature. Although short, the

period was strongly affected by drying temperature and

the rate increased from 0.082 to 0.177 g/(g d.m. min)

with increase of hot air temperature from 50 to 80 C,

respectively. The drying rate at 80 C at water content

equal to 1 g/g d.m was about 30% greater than it was at

a temperature of 70 C.

The decreasing drying temperature from 80 to 50 C

caused the gradual increase of volumetric shrinkage

from 0.49 to 0.58, that is more than 18%. However, the

shrinkage of apple slices was not isometric. The diameter

of apple slices shrank about 14–20% during convection

drying. The height of apple slices decreased

about 30% for apples dried at 80 C, about 34% at 50

and 60 C and about 39% at 70 C in comparison to raw

apple. The relationship between the volumetric shrinkage

and hot air temperature in the range 50–70 C is

linear (Fig. 1). At 80 C the volumetric shrinkage is

smaller and is beyond the linear relationship observed at

lower drying temperature.

The non-isometric shrinkage results from stresses

developed in the material, which are caused by moisture

gradients. Apple slices behave like flat plates and

moisture gradients are build up mostly along the vertical

axis. Taking a flat plate symmetrically evaporating

water on both horizontal surfaces a solution of the

Second Fick’s Law can be used to calculate moisture

concentration gradients (Lewicki, 1999). Gradients calculated

for axial and radial diffusion in apple slices differ

some 27 times, therefore the moisture gradients along

the height of the slice are considerably greater than

those along its radius.

Fig. 2 shows that only high temperature of air affects

the material texture substantially. Statistical analysis

showed that the observed differences between compression

curves of apples dried at 50, 60 and 70 C are not

4 個解答

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    1 0 年前
    最佳解答

    目標的這工作是決定eff電休克療法的溫度和含水量準時地機械的財產的傳達

    蘋果乾. 蘋果v. Idared被切成片而且晾乾-乾的在溫度在50與80 C. 機械的

    財產被壓迫測量–鬆弛試驗. 採樣受到調查之後變乾和也之後5星期貯藏

    結束無水氧化鈣在定溫. 分解出示觀察數據輸入的fferences之間壓迫–

    鬆弛曲線的蘋果變乾在50,60和70 C是不signifi黑話. 減少的含水量引起增加的力量

    需要壓縮蘋果乾. 變乾在80 Cffected質地的蘋果乾更加比較起來到那些的獲得在

    放下熱氣溫度. 用途的適當的溫度和變乾的蘋果到德國fi夜間含水量可能是設計使用

    機械的財產的 final產品.

    2003 Elsevier有限公司.版權所有.

    1.介紹

    變乾是一個廣泛地使用方法水果

    和疏菜保存. 沃特被移動到 final

    集中,哪個擔保微生物的穩定性的

    產品和minimises化學藥品和物理變化的

    材料的時間貯藏. 在最多的變乾過程

    水被對流的蒸發移動,那個

    熱被熱氣補給.

    直接乾燥變化結構的

    物質,它的寫作和這個空間的構像

    的生體聚合物. 由於脫水的結果,毀滅

    的自然結構和損失的semipermeablity的

    膜出現,因此流變學的財產也

    改變(Karel,1980). 外部的層次的變乾材料

    相稱堅硬的和獲取可觀的機械的

    力(Lewicki,Witrowa-Rajchert,&Mariak,1997).

    移動的水 (重大的成分為了保持

    的結構和功能正直) 從生物學的

    膜導至橫的相位分離的油脂

    和蛋白質引起蛋白質集合 (小販,

    1994). 因此對流的變乾動機

    許多的身體的和化學變化在植物組織

    (Lewicki,1998).

    它被確定那財產的原料變化

    的時間減少的含水量從有彈性的-viscoplastic

    到脆弱的身體. 機械烈度的胡蘿蔔

    被發現到強有力地減少量的時間變乾由於

    損害的內部結構,上升熱氣流使變性

    的生體聚合物和這個囚房胞漿分離 (Szymanska,

    1975).

    的時間變乾植物材料收縮和內部的

    拉緊被發展. 內部結構經驗

    變形和是局部地受損的,結果是的

    交叉結合的聚合體和形成的水晶的

    範圍在無定形聚合物. 移動的水

    增加堅硬到外部的層次和同時發生地

    不斷增高濕氣梯度,創造收縮的

    著重. 壓力依賴方法的變乾

    和濕潤的植物組織和結果是破碎,

    暫停和中斷和一般說來放鬆的

    結構的材料 (Lewicki&Pawlak,2003).

    的時間變乾機械的材料烈度

    增加和收縮尺度引起形成的

    洞穴和空曠在裡面材料 (Lewicki,

    Rajchert, & Łazuka,1994). 的時間變乾的 florets的

    * 符合的作者. 傳真: +48-22-8434602.

    電子郵件演說: jakubczyk@最初.sggw.waw.pl (E. Jakubczyk).

    0260-8774/$ - 看前言2003 Elsevier有限公司.版權所有.

    doi:10.1016/j.jfoodeng.2003.10.014

    caulifl更欠Jayaraman,天文學博士Gupta,和先生Rao

    (1990) 觀察細胞的破裂和嚴格的薄紗倒塌

    結果是瓦解的細胞壁.

    一個主要的物理變化在fluencing

    結構的植物組織的時間變乾是收縮,

    哪個出發最初的乾燥過程

    (Witrowa-Rajchert&Turek,1998). 收縮在上

    變乾依賴薄紗結構的產品隸屬

    到變乾,和為了水果和疏菜是幾乎

    線性地關係於含水量 (Sj€oholm&Gekas,

    1995個王&Brennan,1995). 廣度的收縮

    一ff電休克療法多孔性的變乾材料,即是重要的的

    參數到質量轉移財產程度,

    機械的財產和食物組織是關心的

    (Witrowa-Rajchert,1999). 廣度的收縮和

    損失程度的內部結構的植物組織

    是依靠變乾方法申請和參數

    的過程,那是溫度和風速

    (Nowak,Witrowa-Rajchert,&Lewicki,1998 Ratti,

    1994). 王和Brennan (1995) 調查收縮

    的馬鈴薯的時間風乾在溫度在行列

    從40到70 C. 他們觀察度數的的

    收縮的馬鈴薯在低的風乾溫度是

    大於那在高的風乾溫度.

    方法和變量的變乾ff電休克療法雙方的有幾分

    物理化學的變化在植物組織和這個

    質量的脫水產品 (Krokida &Maroulis,

    1997). 直接乾燥是一個最多的常常

    使用操作為了食物脫水. 這方法需要

    高的溫度和速率的乾空氣和

    佔領長期的,和 final產品被表現特色附近

    低孔隙度和高的視密度 (Tsami,Krokida,

    &Drouzas,1999). 在上變乾,由於移動的

    水和位置錯亂的揮發性的物質,糖類

    和文件分配表,變化在身體的財產 (包括

    機械烈度) 的植物組織發生.

    眾多的出版指出變乾強有力地的

    一ff電休克療法流變學的財產的變乾材料. 弄濕

    原料是黏彈性的,一會兒在低潮滿足

    他們相稱脆的,因此流變學的財產的

    變乾植物組織是敘述的二者之一到含水量手術室

    水行動 (伽馬氨基丁酸,Menegalli,法拉利,&斜度-

    Romero,2002 Krokida,Karathanos, &Maroulis,2000

    Krokida,Maroulis,&Marinos-Kouris,1998: Lewicki&

    Lukaszuk,2000). Jakubczyk,Sitkiewicz,和Lewicki

    (1997) 出示那對流的變乾的蘋果立方體

    減少他們的堅硬附近非常比較起來

    到原始材料. 流變學的財產變化的時間

    變乾和這個更多的水被移動更多的塑膠

    蘋果薄紗相稱. 關係之間壓力

    和緊張是凹的向下和這個凹

    增加直到含水量接近2.5 g/g d.m. 是

    到達 (Lewicki&Lukaszuk,2000). 更遠的放下

    的含水量伸直關係和為了幹的

    材料發展壓力是線性相關上

    拉緊. 變化在分解關係是錸flected

    在增加的工作的變形. 因此,在水

    滿足低於2.5 g/g d.m. 對流的變乾

    引誘某些stiff在的蘋果薄紗.

    eff電休克療法的對流的變乾上薄紗結構和

    機械的財產的結束-產品沒有是

    未獨立的的廣泛的學習. 最多的的公布結果

    介紹eff電休克療法的含水量上流變學的財產

    的材料變乾在定溫. 在那裡

    是實際上無數據出示eff電休克療法的熱氣溫度

    上機械的財產的變乾產品.

    目標的這工作是決定eff電休克療法的

    變乾空氣溫度和 final含水量準時地

    機械的財產的傳達變乾蘋果.

    2.原料和方法

    蘋果v. Idared貯藏在4 C和80–90% 關係詞地

    濕氣為了4個月之後收獲被切成片

    15個毫米在直徑和5個毫米高度. 最初的水

    滿足是大概86.2%.

    採樣被放置準時地金屬絲盤子在單衣

    在實驗室傳達烘乾機和這個平均的盤子

    負荷是2公斤/m 2.然後材料被晾乾-乾的在

    溫度在50與80 C和空氣

    fl哎唷速率的1.7 m/s. 溫度和濕氣的

    空氣被數字的溫度計測量和

    濕度計. 周圍空氣溫度是20–22 C

    和濕氣50–60%. 變乾被終止不的時候

    更遠的大多數變化是observed. 採樣是

    調查接著變乾和也之後5

    星期的貯藏在恆溫室放置

    在玻璃瓶包含無水氧化鈣在22

    C (水行動的CaCl 2噢 ¼ 0:001). 沃特行動

    被Hygroskop DT測量 (Rotronic) 和

    精密±0.001,一會兒含水量的變乾蘋果

    被檢查使用烘乾機方法根據磨光

    標準PN–90/一–75101.容量的採樣是

    決定依據甲苯方法

    介紹附近Mazza (1983).

    機械的財產受到調查受壓

    –鬆弛試驗. 蘋果薄片被放置於

    金屬圓柱1個在上其他的形成一疊40個毫米

    高的. 活塞14.5個毫米在直徑被關於

    Zwick機器1445 (ZWICK股份有限公司) 和過去常常

    壓縮採樣在圓柱. 壓迫

    被完畢活塞速度的10個毫米/部長,和

    終止在20% 變形. 測定法是

    重做10個時期.

    真實的緊張e被計算從相等:

    e ¼ ln 1

    h0hs

    h0

    壓力被計算從相等:

    r ¼

    F

    S

    相對的鬆弛壓力被計算如下:

    rr ¼

    rs

    r0

    體積收縮的材料被計算從

    下列的相等:

    SV ¼ 1

    Vs

    V0

    3.結果

    直接乾燥的蘋果切在數據輸入fferent熱氣

    溫度出產產品和數據輸入fferent final水

    滿足和變量體積收縮 (桌子1).

    含水量的蘋果乾不同0.0671g/g

    d.m. ( 6.29%)在80 C到0.0781g/g d.m. ( 7.24%)在50

    C和它會ff電休克療法抗形變性的

    變乾材料. 另一方面時間的變乾是

    比較久附近減少熱氣溫度. 變乾

    時間在50 C是大約40% 長於它是在70 C.

    此外,乾燥時間的蘋果在80 C是大約15%

    短的比那的蘋果變乾在70 C. 短的

    時期的不變的乾燥率被觀察獨立自主的

    的熱氣溫度. 雖然短的,

    時期是強有力地ff電休克療法附近乾燥溫度和

    比率增加從0.082到0.177g/(g d.m. 部長)

    和增加的熱氣溫度從50到80 C,

    分別地. 乾燥率在80 C在含水量

    相等於1 g/g d.m是大約30% 大於它是在

    溫度的70 C.

    減少乾燥溫度從80到50 C

    引起逐步的增加的體積收縮

    從0.49到0.58,那是大於18%. 然而,這

    收縮的蘋果切不會等量的. 直徑

    的蘋果薄片收縮大約14–20% 的時間傳達

    乾燥用的. 高度的蘋果切減少

    大約30% 為了蘋果變乾在80 C,大約34% 在50

    和60 C和大約39% 在70 C比較起來到未加工的

    蘋果. 關係之間體積收縮

    和熱氣溫度在排列50–70 C是

    直線的(無花果. 1). 在80 C體積收縮是

    小的和是超過線性關係觀察在

    放下乾燥溫度.

    非-等量的收縮起因於壓力

    發展在材料,被潮濕引起的

    梯度. 蘋果薄片舉止像 fl在板和

    濕氣梯度是積累主要地順著垂直線

    軸線. 佔領 fl在鍍對稱地蒸發

    水上雙方的水平表面解答的

    第2 Fick’s法律能被計算潮濕使用

    飽合度梯度 (Lewicki,1999). 梯度計算

    為了軸和光線數據輸入ffusion在蘋果切數據輸入ff嗯

    某些27個時期,因此濕氣梯度往前

    高度的薄片是相當地大於

    那些的順著它的半徑.

    無花果. 2出示那僅僅高的溫度空氣ff電休克療法

    材料質地充分地. 統計分析

    出示觀察數據輸入的fferences之間壓迫

    曲線的蘋果變乾在50,60和70 C不是

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  • 5 年前

    到下面的網址看看吧

    ▶▶http://qoozoo201409150.pixnet.net/blog

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  • 匿名使用者
    1 0 年前

    這一個工作的目標是決定 e?在對流的機械財產上的溫度和含水量的 ect

    乾燥的蘋果。 蘋果 v。 Idared 被降低薄的切片然後空氣-在來自 50 到 80 C. 的範圍的溫度弄乾機械的

    財產被壓縮-鬆弛測試測量了。 樣本在弄乾之後被調查以及在 5個星期的儲藏之後

    在無水的鈣氯化物之上在持續的溫度。 分析顯示被觀察的 di?在壓縮之間的 erences-

    1. 介紹

    弄乾是水果的廣泛使用過方法之一

    而且蔬菜保存。 水被移動到一?nal

    集中,向微生物安定保證那

    產品和 minimises 化學的和實際改變

    在儲藏的時候材料。 在大部分方面弄乾程序

    水被傳達性蒸發移動在哪裡

    熱被熱氣供應。

    對流弄乾改變結構那

    材料,它的作文和空間的構造

    biopolymers。 當做一

    cauli?表示突然疼痛所發出之聲 Jayaraman , Das Gupta 和 Babu Rao

    (1990) 觀察了細胞的破裂和嚴格的薄紗織品崩潰

    造成細胞牆壁的崩潰。

    主要的身體檢查之一改變在?uencing 那

    植物薄的紗織品的結構在弄乾的時候是收縮,

    那一個在弄乾程序的最開始的開始

    (Witrowa-Rajchert &Turek, 1998). 收縮在

    弄乾仰賴被服從的產品的薄紗織品結構

    到弄乾,而且對於水果和蔬菜幾乎

    線地講到 moistu 來自 50 到 80個 C 和空氣的範圍的溫度

    ?表示突然疼痛所發出之聲 1.7 m/s 的速度。 溫度和濕度

    空氣被數位溫度計測量了和

    濕度計。 周圍的空氣溫度是 20-22個 C

    而且濕度 50-60%. 當沒有,弄乾被結束

    比較進一步的大眾改變被觀察。 樣本是

    立刻在弄乾之後調查以及在 5之後

    數個星期的儲藏在一個持續的溫度房間中放置

    在玻璃廣口瓶中在 22 點包含無水的鈣氯化物

    C (Ca 的水活動 )

    參考資料: 太多了翻的好淚
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  • 1 0 年前

    這一個工作的目標是決定 e?在對流的機械財產上的溫度和含水量的 ect 乾燥的蘋果。 蘋果 v。 Idared 被降低薄的切片然後空氣-在來自 50 到 80 C. 的範圍的溫度弄乾機械的 財產被壓縮-鬆弛測試測量了。 樣本在弄乾之後被調查以及在 5個星期的儲藏之後 在無水的鈣氯化物之上在持續的溫度。 分析顯示被觀察的 di?在壓縮之間的 erences- 1. 介紹 弄乾是水果的廣泛使用過方法之一 而且蔬菜保存。 水被移動到一?nal 集中,向微生物安定保證那 產品和 minimises 化學的和實際改變 在儲藏的時候材料。 在大部分方面弄乾程序 水被傳達性蒸發移動在哪裡 熱被熱氣供應。 對流弄乾改變結構那 材料,它的作文和空間的構造 biopolymers。 當做一 cauli?表示突然疼痛所發出之聲 Jayaraman , Das Gupta 和 Babu Rao (1990) 觀察了細胞的破裂和嚴格的薄紗織品崩潰 造成細胞牆壁的崩潰。 主要的身體檢查之一改變在?uencing 那 植物薄的紗織品的結構在弄乾的時候是收縮, 那一個在弄乾程序的最開始的開始 (Witrowa-Rajchert &Turek, 1998). 收縮在 弄乾仰賴被服從的產品的薄紗織品結構 到弄乾,而且對於水果和蔬菜幾乎 線地講到 moistu 來自 50 到 80個 C 和空氣的範圍的溫度 ?表示突然疼痛所發出之聲 1.7 m/s 的速度。 溫度和濕度 空氣被數位溫度計測量了和 濕度計。 周圍的空氣溫度是 20-22個 C 而且濕度 50-60%. 當沒有,弄乾被結束 比較進一步的大眾改變被觀察。 樣本是 立刻在弄乾之後調查以及在 5之後 數個星期的儲藏在一個持續的溫度房間中放置 在玻璃廣口瓶中在 22 點包含無水的鈣氯化物 C (Ca 的水活動 )

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