Determination of Crude Fiber Content in Fish Meal by Crude Fiber Tester

Crude fiber as an important indicator to identify whether fish meal is doped with plant protein or other fillers is now commonly used in fish meal inspection. Therefore, it is necessary to further explore. Animal protein such as fish meal should not contain crude fiber. However, according to the current production process of fishmeal and general acid-alkali treatment crude fiber side determination method, there will still be a small amount of crude fiber in the normal fish meal. The problem is how much crude fiber content in the normal fish meal in the end, there is no clear standard. This has brought difficulties to monitoring, trading and so on. Therefore, more than 10 kinds of fishmeal were measured using the crude fiber analyzer, and a comprehensive discussion of the relevant literature was conducted.

Accurately weigh Ig of fishmeal sample and determine it according to the method of GB6436-86 medium and coarse fiber feed. Among the 11 samples measured by the crude fiber analyzer, there are 9 samples (No. 1-9) with a crude fiber content of 0.60%. ~1.67%, with an average of 1.06%, accounting for 82% of the total number of samples tested. However, there are 2 samples with a content greater than 2%. In addition, 2 known doping samples provided by the manufacturer after preparation (12, No. 13), the content is close to 3%.

Considering the real-scale results of the crude fiber tester and the literature values, it can be considered that the crude fiber content of most normal fishmeal does not exceed 1.5%. Considering the currently used acid-base treatment side method, there is a large error between laboratories. It is also advisable to use the specified number 2 as the limit value. However, if the crude fiber content in fishmeal is more than 2%, it may be initially identified as a rare fish meal, which should be combined with other detection methods for further confirmation.