氣調儲藏法

如何延長蘋果新鮮壽命?

一整年都能享用新鮮蘋果,主要是冷藏設備的進化,在日本採用「CA (Controlled Atmosphere Storage)儲藏」設備約佔整體的40%,屬最大宗。原理是將空氣中的氧氣含量自21%降低至1.8~2.5%,二氧化碳含量由0.03%提高至1.5~2.5%,溫度調節在0℃的狀態,抑制蘋果的呼吸作用,進入休眠狀態,達到長時間保存效果。

一般家庭不可能這樣設備,不過把握幾個要點,也能延長蘋果新鮮壽命。

一、 挑選當季生產的蘋果。
二、 如果您是整箱購買
先將有瘀傷、割傷、過熟、有爛斑的蘋果挑出來,因為釋放出的氣體會導致其它蘋果成熟過快,或因為接觸造成質變。
保持原狀,不可事先用水清洗。
用報紙(或其它紙類)逐一包覆後,輕放於原箱內,若使用塑膠袋,可用橡皮筋(或細繩索等)捆綁,採用此方法,建議用細針或竹籤,先將塑膠袋戳幾個細孔透氣,以免水氣聚積,促使病菌微生物滋生,也可以不須將袋口綁緊,只要反折向下擺放即可,保留透氣空間。
放置於通風陰涼處,如果冰箱空間夠大,可存放於冷藏室。
三、 如果您是零星購買
避免買到有瘀傷、割傷、過熟、有爛斑的蘋果。
依購買數量,可採取下列方式處理後,採用家庭中最實用簡便的「低溫貯藏法」,就是將蘋果保存於冰箱冷藏室。
放入紙袋(或大塑膠袋),將袋口反折向下擺放。
放進密封盒(或密封袋)。
用報紙(或其它紙類)逐一包覆,紙張可以吸收水氣,並保持袋內濕度。
將塑膠袋戳幾個細孔,逐一包覆,用橡皮筋(或細繩索等)捆綁。
包覆的目的

冰箱如同乾燥箱,容易將蘋果的水分抽出,加上家用冰箱冷藏室溫度約3℃~6℃不等,無法抑制蘋果「呼吸作用」,只是延緩進行過程,包覆的目的在防止蘋果水份流失,造成果皮皺縮或軟化,也可以吸收水氣,保持裹覆內部的濕度,及降低釋放出具有催熟作用的「乙烯」氣體,避免加速同處一室的其它水果成熟,促進葉菜類老化。

建議
儲藏蘋果最好和其它蔬果隔開,防止催熟氣體「乙烯」的作用,造成「長大」或「老化」速度加快而質變,不耐貯藏。
採用報紙包覆方式保存者,因報紙油墨多少含有重金屬成分,食用前,一定要洗淨。
任何保存方法,雖可延長保鮮壽命,但終究有極限性,貯放愈久,營養和風味也會逐漸降低,買回的蘋果,建議以一週內吃完為原則,就算做好冷藏保存,也不要超過一個月。

Controlled atmosphere

Controlled atmosphere room

Controlled atmosphere building
A controlled atmosphere is an agricultural storage method in which the concentrations of oxygen, carbon dioxide and nitrogen, as well as the temperature and humidity of a storage room are regulated. Both dry commodities and fresh fruit and vegetables can be stored in controlled atmospheres.

1 Dry commodities
2 Fruit and vegetables
3 See also
4 References
Dry commodities
Grains, legumes and oilseed are stored in a controlled atmosphere primarily to control insect pests. Most insects cannot survive indefinitely without oxygen or in conditions of raised (<30 15="" 25="" 35="" a="" above="" air="" approximately="" at="" atmosphere="" atmospheres="" be="" br="" by:="" can="" carbon="" complete="" concentration="" content="" controlled="" created="" days.="" dioxide.="" dioxide="" disinfestation="" dry="" either="" for="" grain="" grains="" in="" is="" least="" lower="" may="" moisture="" of="" schedule="" several="" such="" take="" temperatures="" these="" treatments="" typical="" v="" weeks="" with="">
adding pure carbon dioxide or nitrogen, or the low oxygen exhausts of hydrocarbon combustion, or
using the natural effects of respiration (by grain, molds or insects) to reduce oxygen and increase carbon dioxide (Hermetic storage).[2]
Fruit and vegetables[edit]
The method is most commonly used on apples and pears, where the combination of altered atmospheric conditions and reduced temperature allow prolonged storage with only a slow loss of quality.[3]

The long-term storage of vegetables and fruit involves inhibiting the ripening and ageing processes, thus retaining flavor and quality. Ripening is delayed by reducing the level of oxygen and increasing that of carbon dioxide in the cool cell so that the respiration is reduced. Under controlled atmosphere conditions the quality and the freshness of fruit and vegetables are retained, and many products can be stored for 2 to 4 times longer than usual.

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