穀物和麵粉中α-澱粉酶活性測定的國際標準方法。Perten Falling Number®係統測量穀物和麵粉中的α-澱粉酶活性，以檢測發芽損傷、優化麵粉酶活性並保證交易穀物的穩定性。α-澱粉酶活性對麵包、麵團、麵條和麥芽的最終產品質量至關重要。任何處理小麥、大麥、黑麥或高粱與這些應用相關的人都將受益於該Falling Number係統。
該方法由ICC、CGA、ISO和ASBC等國際機構在以下標準中進行了標準化：ICC/No. 107/1 (1968), AACC/No. 56-81.03 (1972), ISO/No. ISO/DIS 3093 (1974) 和 ASBC Barley 12-A。
世界標準 - Perten降落數值儀是唯一根據國際標準AACC/No.56-81.03、ICC/No.107/1、ISO/DIS 3093經過降落數值測試驗證的儀器。
應用
為什麼要測量α-澱粉酶活性？莊稼收割期間多雨、惡劣天氣狀況會導致發芽。當發芽發生時，α-澱粉酶開始發育。α-澱粉酶活性直接影響麵包和麵團的質量，並對製麥工藝過程產生不利影響。哪怕隻有5%的發芽顆粒與95%的完好顆粒混合，會整個混合物都不可接受。
小麥、黑麥和大麥的最終用戶在穀物發芽受損時遭受損失，需要監控他們購買的原料。為了防止發芽受損的糧食進入生產鏈，農場主和糧食接受方應該在收割莊稼期間和交付時對糧食進行檢測。
糧食貿易過程中降落數值
在莊稼收割期間多雨天氣條件下，可能會發生嚴重的芽苗損害。在這種情況下，每一車糧食在卸貨前都應在糧食進口處進行測試，並將其分裝到不同的倉庫，以避免將完好的穀物與發芽損壞的穀物混雜在一起。受損穀物可用於動物飼料或其他非烘焙用途，如生物燃料。分離是很重要的，因為不加控製地將高發芽的穀物與完好的穀物混合，會使整個混合物不適合麵包製作或其他最終產品用途。分離還允許仔細調配穀物，以滿足FN規範，特別是在麵粉廠。
降落數值的變化從62秒（對於發芽嚴重且酶活性過大的穀物）到遠遠超過400秒（對於來自溫暖和幹燥地區的穀物）。不同國家或市場的分離限值各不相同，並取決於穀物的最終用途。在歐盟，對麵包（普通）小麥的幹預限製降落數值最低為220秒。例如，小麥或硬粒小麥的出口國通常采用250秒、300秒甚至350秒的分離限。黑麥的分離限值較低，低於或高於110-140秒的範圍。
由於發芽受損穀物的質量影響，FN值被用於價格法規中，為了在國內和國際貿易中用於支付農農場主或貿易商，並用於驗證貿易合同質量規範。通常受損的小麥隻能接受到10-30%的降價，導致農場主或糧食貿易商重大經濟損失。
麵粉加工和烘焙中降落數值
一定量的α-澱粉酶是進行適當烘焙所必需的。α-澱粉酶分解澱粉提供糖以幫助發酵過程。酶的含量直接影響生產麵包的質量。當α-澱粉酶活性正確時，可以獲得細軟體積大的麵包（圖中FN=250）。如果活性太高，可能會產生粘糊糊的麵包屑且會導致麵包體積變小（圖中FN=62）。如果活性太低，可能會產生體積縮小的幹麵包屑（圖中FN=400）。FN值與α-澱粉酶活性呈反比關係，即α-澱粉酶活性越高，FN值越低，反之亦然。
工廠可以使用FN值來生產具有所需或特定FN值的產品。他們可以混合不同FN值的麵粉來生產具有特定澱粉酶活性的產品。可以以類似的方式添加麥芽來調整值。
所需的準確FN值取決於要生產的產品類型。麵包粉和餅幹粉的FN值不同。麵包師可以使用FN要求他們的供應商根據其特定最終產品提供所需的產品類型。麵點師也可以選擇加工廠一樣的方式來處理麵粉。但是通過要求加工廠提供特定的產品，麵點師可以得到一致的產品，而不必調整烘焙過程的這一特定方麵。質量控製人員可以使用FN值作為一種質量控製工具，以幫助確保輸入和輸出產品的一致性。它為節省時間和金錢提供了另一個重要的工具。
麵食和麵條製造中降落數值
用低降落數值的麵粉生產麵條很困難，伴隨麵團的處理和剪切問題以及產品粘在機器上。這也會導致最終消費品的顏色變差，煮沸後會有粘性。使用正確降落數值®的麵粉將通過提高加工和更高質量的最終產品得以節省成本。
麥芽製造領域中的降落數值
釀酒大麥的高發芽率需要健康、有活力的穀物。一些研究表明，在田間預發芽的大麥在釀酒過程中發芽能力下降，導致麥芽汁中β-葡聚糖含量高。即使是預發芽程度低的大麥也會受到影響。在貯藏過程中，發芽能力進一步降低，收割時可接受發芽率的大麥僅在幾個月後顯示的發芽率就明顯低於一般要求的95%（見圖表）。輕微的預發芽不能通過目視檢查來檢測，而是要通過a-澱粉酶的活性來檢測。
為了避免購買預發芽大麥，降落數值分析可用於大麥入口的驗收測試。該方法快速，可在5分鍾內確定大麥是否預發芽。
In years with rainy weather during harvest, significant sprout damage may occur. In such years every truckload of grain should be tested at elevators and grain intakes before unloading and risk mixing loads of sound grain with sprout damaged grain. Damaged grain can be rejected or segregated for use in animal feed or for other non-baking purposes such as biofuel. Segregation is important as a few percent of highly sprouted grain mixed with sound grain can render the entire mixture unsuitable for bread making or other end product purposes. Segregation also allows for a careful blending of grains to meet Falling Number specifications - particularly at the flour mill.
The Falling Number value can vary from 62 seconds for heavily sprouted grain to well over 400 seconds for some specific varieties of wheat. Segregation limits vary from country to country and depend on the end-use purpose of the grain. In the EU, the limit for intervention of bread (common) wheat is a minimum Falling Number of 220 seconds. Segregation limits at 250, 300 and even 350 seconds are commonly used by exporting countries for wheat and durum. Limits are lower for rye with segregation below or above the 110-140 seconds' range.
The Falling Number value is used in price regulations for payment to farmers or traders in national and international trade and for verifying trade contract quality specifications. Damaged wheat can receive a 10-30% lower price causing significant economic losses to the farmer or grain trader.
A certain amount of alpha-amylase is necessary for proper baking. Alpha-amylase breaks down starches to provide sugars to fuel the fermentation process for leavened breads. The amount of enzyme present can have a direct bearing upon the quality of bread produced. When the alpha-amylase activity is right, a high-volume bread with firm and soft texture is achieved (FN = 250 in picture). If the activity is too high, a sticky bread crumb and low volume may result (FN = 62 in picture). If the activity is too low, a dry bread crumb with diminished volume may result (FN = 400 in picture). The Falling Number value has an inverse relationship with the alpha-amylase activity meaning the higher the alpha-amylase activity the lower the Falling Number value, and vice-versa.
Millers use the Falling Number value to produce products with desired Falling Number values. They blend flours of various Falling Number values or add malt to produce a product with a specific amylase activity.
The Falling Number value desired will be dependent on the type of product to be produced. Breads flours will have different Falling Number requirements than those of cracker flours. Bakers may use the Falling Number to dictate to their suppliers the type of product they require for their specific end product. Bakers also have the option of manipulating their flours in the same manner as the miller. Quality control personnel use the Falling Number value as a quality control tool to help assure the consistency of both incoming and outgoing products helping save time and money.
Producing noodles from flour with a low Falling Number is difficult as it leads to difficulties in dough handling, cutting, extrusion, and product sticking to machinery. It also results in an off-color end consumer product which will be sticky after it is boiled. Using flour with the correct Falling Number® will result in savings through improved processing as well as a higher quality end product.
Sound, viable grains are required for a high germination rate in malting barley. Several studies have shown that barley that has pre-germinated in the field has a decreased ability to germinate during the malting process, leading to high levels of beta-glucan in the wort. Even barley with a low degree of pre-germination will be affected. The ability to germinate further decreases during storage, and barley with acceptable germination at harvest could - just months later - exhibit germinations significantly lower than the generally requested 95%. The slight pre-germination cannot be detected through visual inspection.
To avoid purchase of pre-germinated barley the Falling Number analysis can be used for screening the barley intake. The method is rapid and determines if the barley is pre-germinated within 5 minutes.
FN > 250 Sound barley, batch OK for intake
FN < 250 Pre-germinated. Risk for poor germination, further tests required.
FN 1000是最新和最現代的Falling Number®儀器型號，提供了許多新的優點和改進的功能。這是一個雙分析係統，適用於任何需要可靠分析和高容量分析。
FN 1310是我們的基本型號，它允許用戶以超值的價格購買一個原版的Perten係統。它是為快速、方便地進行降落數值試驗而設計的自動單次分析係統。FN 1310的高質量標準為您的投資提供高回報。
