Feed yeast powder is fermented with distiller's grains, light yellow or yellow-brown powder, with the unique aroma of yeast. Feed yeast powder is a single-cell protein with high protein content, complete amino acids, and B vitamins, trace elements and various enzymes. It can promote the metabolism of poultry and livestock, enhance the disease resistance of poultry and livestock, improve the growth rate, reproductive ability, meat quality and fur quality of poultry and livestock, and is especially suitable for feeding fish and shrimp that feed on smell.

Experimental method

1. Sample preparation

Weigh 0.2g (accurate to 0.1mg) of the pulverized and mixed sample into the digestion tube, and then add 6.4g of mixed catalyst (6gK2SO4,0.4gCuSO4), add 12mL of concentrated sulfuric acid along the wall of the digestion tube.

2. Digestion

Place the digestion tube filled with samples and reagents on the digestion instrument, cover the waste discharge cover, and set the parameters of the digestion instrument as shown in Table 1:

Table 1  Digestion parameter settings

3. Test

After the digestion is complete, the digestion tube is cooled to room temperature and then removed for use. Check whether the reagents of the azotometer are sufficient, and make a blank for the instrument at the same time.

After the blank of the instrument is stable, the digested sample can be tested on the machine. The parameters of the azotometer are set as shown in Table 2:

Table 2 Parameter settings of azotometer

Experimental results

The feed yeast powder sample selected in the experiment was digested, distilled, and titrated, and the experimental results are shown in Table 3:

Table 3 Protein content test results

Conclusion

The protein content of the feed yeast powder tested in this test was 41.021%, and the RSD value was 0.17%, and the results had good parallelism.