谷物和面粉中α-淀粉酶活性测定的国际标准方法。Perten Falling Number®系统测量谷物和面粉中的α-淀粉酶活性，以检测发芽损伤、优化面粉酶活性并保证交易谷物的稳定性。α-淀粉酶活性对面包、面团、面条和麦芽的最终产品质量至关重要。任何处理小麦、大麦、黑麦或高粱与这些应用相关的人都将受益于该Falling Number系统。
该方法由ICC、CGA、ISO和ASBC等国际机构在以下标准中进行了标准化：ICC/No. 107/1 (1968), AACC/No. 56-81.03 (1972), ISO/No. ISO/DIS 3093 (1974) 和 ASBC Barley 12-A。
世界标准 - Perten降落数值仪是唯一根据国际标准AACC/No.56-81.03、ICC/No.107/1、ISO/DIS 3093经过降落数值测试验证的仪器。
应用
为什么要测量α-淀粉酶活性？庄稼收割期间多雨、恶劣天气状况会导致发芽。当发芽发生时，α-淀粉酶开始发育。α-淀粉酶活性直接影响面包和面团的质量，并对制麦工艺过程产生不利影响。哪怕只有5%的发芽颗粒与95%的完好颗粒混合，会整个混合物都不可接受。
小麦、黑麦和大麦的最终用户在谷物发芽受损时遭受损失，需要监控他们购买的原料。为了防止发芽受损的粮食进入生产链，农场主和粮食接受方应该在收割庄稼期间和交付时对粮食进行检测。
粮食贸易过程中降落数值
在庄稼收割期间多雨天气条件下，可能会发生严重的芽苗损害。在这种情况下，每一车粮食在卸货前都应在粮食进口处进行测试，并将其分装到不同的仓库，以避免将完好的谷物与发芽损坏的谷物混杂在一起。受损谷物可用于动物饲料或其他非烘焙用途，如生物燃料。分离是很重要的，因为不加控制地将高发芽的谷物与完好的谷物混合，会使整个混合物不适合面包制作或其他最终产品用途。分离还允许仔细调配谷物，以满足FN规范，特别是在面粉厂。
降落数值的变化从62秒（对于发芽严重且酶活性过大的谷物）到远远超过400秒（对于来自温暖和干燥地区的谷物）。不同国家或市场的分离限值各不相同，并取决于谷物的最终用途。在欧盟，对面包（普通）小麦的干预限制降落数值最低为220秒。例如，小麦或硬粒小麦的出口国通常采用250秒、300秒甚至350秒的分离限。黑麦的分离限值较低，低于或高于110-140秒的范围。
由于发芽受损谷物的质量影响，FN值被用于价格法规中，为了在国内和国际贸易中用于支付农农场主或贸易商，并用于验证贸易合同质量规范。通常受损的小麦只能接受到10-30%的降价，导致农场主或粮食贸易商重大经济损失。
面粉加工和烘焙中降落数值
一定量的α-淀粉酶是进行适当烘焙所必需的。α-淀粉酶分解淀粉提供糖以帮助发酵过程。酶的含量直接影响生产面包的质量。当α-淀粉酶活性正确时，可以获得细软体积大的面包（图中FN=250）。如果活性太高，可能会产生粘糊糊的面包屑且会导致面包体积变小（图中FN=62）。如果活性太低，可能会产生体积缩小的干面包屑（图中FN=400）。FN值与α-淀粉酶活性呈反比关系，即α-淀粉酶活性越高，FN值越低，反之亦然。
工厂可以使用FN值来生产具有所需或特定FN值的产品。他们可以混合不同FN值的面粉来生产具有特定淀粉酶活性的产品。可以以类似的方式添加麦芽来调整值。
所需的准确FN值取决于要生产的产品类型。面包粉和饼干粉的FN值不同。面包师可以使用FN要求他们的供应商根据其特定最终产品提供所需的产品类型。面点师也可以选择加工厂一样的方式来处理面粉。但是通过要求加工厂提供特定的产品，面点师可以得到一致的产品，而不必调整烘焙过程的这一特定方面。质量控制人员可以使用FN值作为一种质量控制工具，以帮助确保输入和输出产品的一致性。它为节省时间和金钱提供了另一个重要的工具。
面食和面条制造中降落数值
用低降落数值的面粉生产面条很困难，伴随面团的处理和剪切问题以及产品粘在机器上。这也会导致最终消费品的颜色变差，煮沸后会有粘性。使用正确降落数值®的面粉将通过提高加工和更高质量的最终产品得以节省成本。
麦芽制造领域中的降落数值
酿酒大麦的高发芽率需要健康、有活力的谷物。一些研究表明，在田间预发芽的大麦在酿酒过程中发芽能力下降，导致麦芽汁中β-葡聚糖含量高。即使是预发芽程度低的大麦也会受到影响。在贮藏过程中，发芽能力进一步降低，收割时可接受发芽率的大麦仅在几个月后显示的发芽率就明显低于一般要求的95%（见图表）。轻微的预发芽不能通过目视检查来检测，而是要通过a-淀粉酶的活性来检测。
为了避免购买预发芽大麦，降落数值分析可用于大麦入口的验收测试。该方法快速，可在5分钟内确定大麦是否预发芽。
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是最新和最现代的Falling Number®仪器型号，提供了许多新的优点和改进的功能。这是一个双分析系统，适用于任何需要可靠分析和高容量分析。
FN 1310是我们的基本型号，它允许用户以超值的价格购买一个原版的Perten系统。它是为快速、方便地进行降落数值试验而设计的自动单次分析系统。FN 1310的高质量标准为您的投资提供高回报。
