新鮮果蔬的含水量可達65~96%,dancaihoushiquleshuifendebuchong,zaizhuzangheyunshuzhongzhujianshishuiweinian,shichanpinzhongliangbuduanjianshao,zhijiezaochengjingjisunshi。ciwai,shishuihaihuiyinqichanpinshixian,yibanqingkuangxia,guoshushishui5%就出現萎蔫和皺縮,在溫暖、幹燥的環境中幾個小時,大部分果蔬都會萎蔫。有些果蔬雖然沒有達到萎蔫程度,但是失水已影響到果蔬的口感、脆度、顏色和風味。
weinianhuiyinqiguoshudaixieshitiao,shishuijiemeihuoxingtigao,rufenggandeganshubiantian,shiyinweituoshuiyinqidianfenshuijieweitangdejieguo。guoshuyanzhongtuoshuishi,xibaoyenongduzenggao,youxieliziruanheqinglizinongduguogaohuiyinqixibaozhongdu,shenzhipohuaiyuanshengzhidejiaotijiegou。zuzhiguodushishuihuiyinqituoluosuanhanliangzengjiahecijiyixihecheng,jiasuqiguandeshuailaohetuoluo。yinci,zaishuiguoheshucaidecaihouchulijizhuzang、運輸過程中應盡量控製失水。但是也有一些例外情況,如洋蔥、大蒜在貯藏前要進行適當晾曬,加速鱗片的幹燥,促進產品休眠,大白菜適度晾曬使葉片輕度失水,可以降低冰點,提高抗寒能力。
失(shi)水(shui)萎(wei)蔫(nian)破(po)壞(huai)了(le)果(guo)蔬(shu)的(de)正(zheng)常(chang)代(dai)謝(xie),水(shui)解(jie)過(guo)程(cheng)加(jia)強(qiang),細(xi)胞(bao)膨(peng)壓(ya)下(xia)降(jiang)造(zao)成(cheng)機(ji)械(xie)結(jie)構(gou)特(te)性(xing)改(gai)變(bian),必(bi)然(ran)影(ying)響(xiang)水(shui)果(guo)和(he)蔬(shu)菜(cai)的(de)耐(nai)藏(zang)性(xing)和(he)抗(kang)病(bing)性(xing)。組(zu)織(zhi)脫(tuo)水(shui)萎(wei)蔫(nian)的(de)程(cheng)度(du)越(yue)大(da),越(yue)容(rong)易(yi)遭(zao)受(shou)微(wei)生(sheng)物(wu)侵(qin)染(ran),抗(kang)病(bing)性(xing)下(xia)降(jiang)得(de)越(yue)快(kuai)。
果蔬采後防止失水的措施
1.包裝、打蠟或塗膜
減少果蔬失水的最簡單方法是用塑料薄膜或其它防水材料將產品罩起來,也可將產品裝在袋子、xiangzihuozhihezhong。juyixibomoshijiaohaodefangshuicailiao。danshiwomenbixuzhuyideshibaozhuangzaijianshaochanpinshishuidetongshiyejiangdilechanpindelengquesudu。ciwai,baozhuangcailiaodexishuinengliyebukehushi,yongfuhelahuosongxiangchulibaozhuangkefangzhibaozhuangxishui,suiranzaojiajiaogao,danzaishangyeshangyoushiyongjiazhi。lingwaiwomenhaikeyizaichanpinbiaomiandalahuotuliao,ranhouzaijiashangshidangdebaozhuang,fangzhichanpinshishui。
2.增加空氣濕度
減(jian)少(shao)水(shui)果(guo)和(he)蔬(shu)菜(cai)失(shi)水(shui)的(de)另(ling)一(yi)個(ge)有(you)效(xiao)方(fang)法(fa)是(shi)增(zeng)加(jia)空(kong)氣(qi)的(de)相(xiang)對(dui)濕(shi)度(du),然(ran)而(er)高(gao)濕(shi)度(du)對(dui)黴(mei)菌(jun)生(sheng)長(chang)有(you)利(li),可(ke)配(pei)合(he)使(shi)用(yong)殺(sha)菌(jun)劑(ji)。增(zeng)加(jia)空(kong)氣(qi)濕(shi)度(du)可(ke)用(yong)自(zi)動(dong)加(jia)濕(shi)器(qi)向(xiang)庫(ku)內(nei)噴(pen)迷(mi)霧(wu)或(huo)噴(pen)蒸(zheng)氣(qi),也(ye)可(ke)以(yi)在(zai)地(di)麵(mian)灑(sa)水(shui)或(huo)在(zai)庫(ku)內(nei)掛(gua)濕(shi)草(cao)簾(lian);或者適當提高蒸發器冷凝管的濕度,使其維持在低於貯藏溫度2~3℃的範圍內。總之,將庫內的相對濕度保持在95%左右,產品失水就可以避免。
3.適當通風
不管是機械冷庫還是自然通風庫中足夠的通風量是必須的,它可以將庫內的熱負荷帶走和防止庫內溫度不均,但是要盡量減低風速,0.3~3米/秒的風速對產品水分蒸發的影響不大。
4.使用夾層冷庫
夾jia層ceng冷leng庫ku的de庫ku體ti由you兩liang層ceng牆qiang壁bi組zu成cheng,中zhong間jian有you冷leng空kong氣qi循xun環huan,外wai層ceng牆qiang既ji隔ge熱re又you防fang潮chao,內nei層ceng牆qiang不bu隔ge熱re,將jiang蒸zheng發fa器qi放fang置zhi在zai兩liang層ceng牆qiang之zhi間jian,通tong過guo傳chuan導dao使shi用yong與yu庫ku內nei進jin行xing熱re交jiao換huan。由you於yu蒸zheng發fa器qi不bu在zai庫ku內nei,不bu會hui奪duo取qu產chan品pin中zhong的de水shui分fen而er結jie霜shuang,庫ku內nei的de濕shi度du很hen高gao,可ke防fang止zhi產chan品pin失shi水shui。
5.使用微風庫
微風庫內的冷風是經過庫頂上的多孔送入庫內或使冷空氣先經過加濕再送到庫中,可以有效地防止失水。
手機版




