世界食品網

降低微生物“誤檢出率” | 微生物檢測采樣方法能幫上你~

   2018-06-28 食品實驗室服務公眾號504
核心提示:微生物主要通過空氣、原輔材料、作業人員、制造裝置、包裝容器的途徑來污染產品,而食品微生物的風險管理重在強化過程控制,微生
 微生物主要通過空氣、原輔材料、作業人員、制造裝置、包裝容器的途徑來污染產品,而食品微生物的風險管理重在強化過程控制,微生物檢驗采樣是過程控制是否滿足要求的重要判斷依據之一。

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; text-indent: 2em; font-size: 15px;">有些食品企業會對產品的成品和原材料進行理化和微生物的檢測。portant; word-wrap: break-word !important;">特別是微生物的檢測就需要注意樣品的采樣流程,包括人員服裝、環境和取樣方式。portant; word-wrap: break-word !important; text-indent: 2em; font-size: 15px;">不然在抽檢采樣過程中沒注意污染了樣品,導致檢測結果異常豈不是白費功夫?因此,我們今天著重聊聊如何實施食品微生物檢驗采樣。

portant; word-wrap: break-word !important; font-size: 18px;">一、采樣方案

 

portant; word-wrap: break-word !important; font-size: 15px;">目前最為流行的采樣方案為國際食品微生物規范委員會(ICMSF)推薦的采樣方案和隨機采樣方案,ICMSF的采樣方案是依據事先給食品進行的危害程度劃分來確定的,將食品分成3種危害度:

 

portant; word-wrap: break-word !important; color: rgb(192, 0, 0);">portant; word-wrap: break-word !important; font-size: 15px;">I類危害,portant; word-wrap: break-word !important; font-size: 15px;">老人和嬰幼兒食品及在食用前可能會增加危害的食品;

portant; word-wrap: break-word !important; color: rgb(192, 0, 0);">portant; word-wrap: break-word !important; font-size: 15px;">II類危害,portant; word-wrap: break-word !important; font-size: 15px;">立即食用的食品,在食用前危害基本不變;

portant; word-wrap: break-word !important; color: rgb(192, 0, 0);">portant; word-wrap: break-word !important; font-size: 15px;">III類危害,portant; word-wrap: break-word !important; font-size: 15px;">食用前經加熱處理,危害減小的食品。

 

portant; word-wrap: break-word !important; font-size: 15px;">采樣方法是從統計學原理來考慮,將檢驗指標對食品衛生的重要程度分成一般、中等、和嚴重3檔。根據以上危害度的分類,又將將采樣方案分成二級法和三級法。

portant; word-wrap: break-word !important;">二級法

portant; word-wrap: break-word !important; font-size: 15px;">設定n、с及m值,采樣數只設合格判定標準m值,超過m值的,則為不合格品。例如,生食海產品魚,n=5,c=0,m=100,n=5即采樣5個,c=0即意味著在該批檢樣中,未見到有超過m值的檢樣,此批貨物為合格品。

portant; word-wrap: break-word !important;">三級法則有n、c、m及M值

portant; word-wrap: break-word !important; font-size: 15px;">設有微生物標準m及M值兩個限量如同二級法,超過m值的檢樣,即算為不合格品。其中以m值到M值的范圍內的檢樣數,作為c值,如果在此范圍內,即為附加條件合格,超過M值者,則為不合格。

portant; word-wrap: break-word !important; font-size: 15px;">例如:冷凍生蝦的細菌數標準n=5,c=3,m=10,M=100,其意義是從一批產品中,取5個檢樣,經檢樣結果,允許≤3個檢樣的菌數是在m--M值之間,如果有3個以上檢樣的菌數是在m--M值之間或一個檢樣菌數超過M值者,則判定該批產品為不合格品。

portant; word-wrap: break-word !important; color: rgb(192, 0, 0);"> portant; word-wrap: break-word !important; font-size: 15px;">n:portant; word-wrap: break-word !important; font-size: 15px;">系指一批產品采樣個數。

portant; word-wrap: break-word !important; font-size: 15px; color: rgb(192, 0, 0);">c:portant; word-wrap: break-word !important; font-size: 15px;">系指該批產品的檢樣菌數中,超過限量的檢樣數,即結果超過合格菌數限量的最大允許數。

portant; word-wrap: break-word !important; font-size: 15px; color: rgb(192, 0, 0);">m:portant; word-wrap: break-word !important; font-size: 15px;">系指合格菌數限量,將可接受與不可接受的數量區別開。

portant; word-wrap: break-word !important; font-size: 15px; color: rgb(192, 0, 0);">M:portant; word-wrap: break-word !important; font-size: 15px;">系指附加條件,判定為合格的菌數限量,表示邊緣的可接受數與邊緣的不可接受數之間的界限。

 

portant; word-wrap: break-word !important;">

portant; word-wrap: break-word !important; font-size: 15px;">portant; word-wrap: break-word !important; font-size: 16px;">采樣方法

portant; word-wrap: break-word !important; font-size: 15px;">指標重要性

portant; word-wrap: break-word !important; font-size: 15px;">指標菌

portant; word-wrap: break-word !important; font-size: 15px;">食品危害度

portant; word-wrap: break-word !important; font-size: 15px;">III

portant; word-wrap: break-word !important; font-size: 15px;">食品危害度

portant; word-wrap: break-word !important; font-size: 15px;">II

portant; word-wrap: break-word !important; font-size: 15px;">食品危害度

portant; word-wrap: break-word !important; font-size: 15px;">I

portant; word-wrap: break-word !important; font-size: 15px;">三級法

portant; word-wrap: break-word !important; font-size: 15px;">一般

portant; word-wrap: break-word !important; font-size: 15px;">菌落總數

portant; word-wrap: break-word !important; font-size: 15px;">大腸菌群

portant; word-wrap: break-word !important; font-size: 15px;">大腸桿菌

portant; word-wrap: break-word !important; font-size: 15px;">金黃色葡萄球菌

portant; word-wrap: break-word !important; font-size: 15px;">n=5 

portant; word-wrap: break-word !important; font-size: 15px;">c=3

portant; word-wrap: break-word !important; font-size: 15px;">n=5 

portant; word-wrap: break-word !important; font-size: 15px;">c=2

portant; word-wrap: break-word !important; font-size: 15px;">n=5 

portant; word-wrap: break-word !important; font-size: 15px;">c=1

portant; word-wrap: break-word !important; font-size: 15px;">三級法

portant; word-wrap: break-word !important; font-size: 15px;">中等

portant; word-wrap: break-word !important; font-size: 15px;">金黃色葡萄球菌

portant; word-wrap: break-word !important; font-size: 15px;">蠟樣芽孢桿菌

portant; word-wrap: break-word !important; font-size: 15px;">產氣莢膜梭菌 

portant; word-wrap: break-word !important; font-size: 15px;">n=7 

portant; word-wrap: break-word !important; font-size: 15px;">c=2 

portant; word-wrap: break-word !important; font-size: 15px;">n=5 

portant; word-wrap: break-word !important; font-size: 15px;">c=1

 

portant; word-wrap: break-word !important; font-size: 15px;">n=5

portant; word-wrap: break-word !important; font-size: 15px;">c=1

portant; word-wrap: break-word !important; font-size: 15px;">二級法

portant; word-wrap: break-word !important; font-size: 15px;">中等

portant; word-wrap: break-word !important; font-size: 15px;">沙門氏菌

portant; word-wrap: break-word !important; font-size: 15px;">副溶血性弧菌

portant; word-wrap: break-word !important; font-size: 15px;">致病性大腸桿菌

portant; word-wrap: break-word !important; font-size: 15px;">n=5 

portant; word-wrap: break-word !important; font-size: 15px;">c=0

portant; word-wrap: break-word !important; font-size: 15px;">n=10 

portant; word-wrap: break-word !important; font-size: 15px;">c=0

portant; word-wrap: break-word !important; font-size: 15px;">n=20 

portant; word-wrap: break-word !important; font-size: 15px;">c=0

portant; word-wrap: break-word !important; font-size: 15px;">二級法

portant; word-wrap: break-word !important; font-size: 15px;">嚴重

portant; word-wrap: break-word !important; font-size: 15px;">肉毒梭菌

portant; word-wrap: break-word !important; font-size: 15px;">霍亂弧菌

portant; word-wrap: break-word !important; font-size: 15px;">傷寒沙門氏菌

portant; word-wrap: break-word !important; font-size: 15px;">副傷寒沙門氏菌 

portant; word-wrap: break-word !important; font-size: 15px;">n=15 

portant; word-wrap: break-word !important; font-size: 15px;">c=0 

portant; word-wrap: break-word !important; font-size: 15px;">n=30 

portant; word-wrap: break-word !important; line-height: 1.75em; font-size: 15px;">c=0 

portant; word-wrap: break-word !important; font-size: 15px;">n=60

portant; word-wrap: break-word !important; line-height: 1.75em; font-size: 15px;">c=0 

 

portant; word-wrap: break-word !important; font-size: 18px;">二、現場采樣注意事項

 

確定了采樣方案以后,采樣方法對采樣方案的有效執行和保證樣品的有效性代表性至關重要。

portant; word-wrap: break-word !important; font-size: 15px; line-height: 1.75em; text-indent: 0em; white-space: pre-wrap;">1、采樣必須遵循無菌操作程序,采樣工具如整套不銹鋼勺子、鑷子、剪刀等應當高壓滅菌,防止一切可能的外來污染。
portant; word-wrap: break-word !important; font-size: 15px; line-height: 1.75em; text-indent: 0em; white-space: pre-wrap;">2、容器必需清潔、干燥、防漏、廣口、滅菌,大小適合盛放檢樣。
portant; word-wrap: break-word !important; font-size: 15px; line-height: 1.75em; text-indent: 0em; white-space: pre-wrap;">3、采樣全過程中,應采取必要的措施防止食品中固有微生物的數量和生長能力發生變化。
portant; word-wrap: break-word !important; font-size: 15px; line-height: 1.75em; text-indent: 0em; white-space: pre-wrap;">4、確定檢驗批,應注意產品的均質性和來源,確保檢樣的代表性。
portant; word-wrap: break-word !important; font-size: 15px; line-height: 1.75em; text-indent: 0em; white-space: pre-wrap;">5、當用自動采樣器取不需要冷卻的粉狀或固定食品時,必須履行相應的管理辦法,保證產品的代表性不被人為地破壞。

 

portant; word-wrap: break-word !important; font-size: 18px;">三、現場采樣工作要求

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important;">1.直接食用的小包裝食品:   

portant; word-wrap: break-word !important; text-indent: 28px;">盡可能取原包裝,直到檢

portant; word-wrap: break-word !important; text-indent: 28px;">      驗前不要開封,以防污染。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important;">2.液體樣品:   

portant; word-wrap: break-word !important; font-size: 16px;">(1)采樣前搖動或用滅菌棒攪拌液體,盡量使其達到均質;

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; font-size: 15px; line-height: 28px;">(2)portant; word-wrap: break-word !important; line-height: 1.75em; font-size: 15px;">以無菌操作開啟包裝,用100mL無菌注射器抽取,注入無菌容器。

portant; word-wrap: break-word !important; font-size: 16px;">(3)如為非冷藏易腐食品,應迅速將所采樣品冷卻至0-4℃。portant; word-wrap: break-word !important; font-size: 15px;">
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important;">3 半固體樣品:   

portant; word-wrap: break-word !important; text-indent: 2em;">以無菌操作拆開包裝,用無菌勺子從幾個部位挖采樣品,放入無菌容器。

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important;">4.固體樣品:   

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 0em; white-space: pre-wrap;">(1)portant; word-wrap: break-word !important; font-size: 16px; text-indent: 0em; white-space: pre-wrap;">每份樣品應用滅菌采樣器由幾個不同部位采取,一起放入一個滅菌容器內;

portant; word-wrap: break-word !important; font-size: 16px; text-indent: 2em;">(2)大塊整體食品應用無菌刀具和鑷子從不同部位割取,割取時應兼顧表面與深部,注意樣品的代表性; 小塊大包裝食品應從不同部位的小塊上切采樣品,放入無菌容器。

portant; word-wrap: break-word !important; font-size: 16px; text-indent: 2em;">(3)若為檢驗食品的污染情況,可取表層樣品;若為檢驗食品品質的情況,應從深部采樣。

portant; word-wrap: break-word !important; text-indent: 2em; font-size: 16px;">(4)注意不要使樣品過度潮濕,以防食品中固有的細菌增殖。

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; display: inline-flex; color: rgb(227, 108, 9); border-width: 1px; border-style: solid; border-color: rgb(194, 201, 42) rgb(194, 201, 42) rgb(194, 201, 42) transparent; line-height: 26px;">5.冷凍樣品:   

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 2em;">(1)對大塊冷凍食品,應從幾個不同部位用滅菌工具采樣,使之有充分的代表性。

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 2em;">(2)大包裝小塊冷凍食品按小塊個體采取;大塊冷凍食品可以用無菌刀從不同部位削采樣品或用無菌小手鋸從凍塊上舉采樣品,也可以用無菌鉆頭鉆取碎屑狀樣品,放入容器。

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 2em;">(3)冷凍食品的采樣還應注意檢驗目的,若需檢驗食品污染情況,可取表層樣品;若需檢驗其品質情況,應取深部樣品。

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 2em;">(4)在將樣品送達實驗室前,要始終保持樣品處于冷凍狀態。樣品一旦融化,不可使其再凍,保持冷卻即可。

portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important;">6.生產過程中的采樣:  

portant; word-wrap: break-word !important; text-indent: 2em; line-height: 1.75em;"> (1)車間用水。自來水樣從車間各水龍頭上采取冷卻水;湯料等從車間容器不同部位用100mL無菌注射器抽取。portant; word-wrap: break-word !important; line-height: 1.75em; color: blue;">如用固定在貯液桶或流水作業線上的采樣龍頭采樣時,應事先將龍頭消毒;

portant; word-wrap: break-word !important; text-indent: 2em;">(2)車間臺面、用具及加工人員手的衛生監測。用5portant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 18px;">cmportant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 10px; vertical-align: super;">2portant; word-wrap: break-word !important; text-indent: 2em;">孔無菌采樣板及5支無菌棉簽擦拭25portant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 18px;">cmportant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 10px; vertical-align: super;">2portant; word-wrap: break-word !important; text-indent: 2em;">面積。若所采表面干燥,則用無菌稀釋液潤濕棉簽后擦拭;若表面有水,則用干棉簽擦拭,擦拭后立即將棉簽頭用無菌剪刀剪入盛樣容器。

portant; word-wrap: break-word !important; text-indent: 2em;">(3)車間空氣采樣(空氣塵降法)。將5個直徑90mm的普通營養瓊脂平板分別置于車間的四角和中部,打開平皿蓋,暴露采樣后,蓋蓋送檢。

portant; word-wrap: break-word !important; font-size: 15px; text-indent: 2em;">(4)設備采樣

portant; word-wrap: break-word !important; color: blue;">涂抹法(適用于表面平坦的設備和工器具產品接觸面

portant; word-wrap: break-word !important; text-indent: 2em;"> 取經過滅菌的50portant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 18px;">cmportant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 10px; vertical-align: super;">2portant; word-wrap: break-word !important; text-indent: 2em;">鋁片框放在需檢查的部位上,用無菌棉簽蘸上無菌生理鹽水擦拭后放入盛樣容器。

portant; word-wrap: break-word !important; text-indent: 2em; color: blue;"> portant; word-wrap: break-word !important; color: blue;">貼紙法(適用于表面不平坦的設備和工器具接處面)

portant; word-wrap: break-word !important; text-indent: 2em;"> 將兩張紙面積共50portant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 18px;">cmportant; word-wrap: break-word !important; font-family: Helvetica; letter-spacing: 0px; font-size: 10px; vertical-align: super;">2portant; word-wrap: break-word !important; text-indent: 2em;">的無菌規格紙用無菌生理鹽水泡濕后,分別貼于需測部分,后放入盛樣容器。

portant; word-wrap: break-word !important; font-size: 16px;">我國食品企業已經進入一個規范發展的新階段,對微生物的認識也逐步加強,食品企業需要根據自身情況,加強微生物監測,有針對性的采取措施,將微生物風險控制在最低水平,進而獲得質量與成本的最優化,只有這樣,才能立足于激烈的市場競爭。



 
反對 0舉報 0 收藏 0 打賞 0
 
更多>同類商務指南
推薦圖文
推薦商務指南
點擊排行
 
鹽池灘羊