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Effects of four short‐chain fatty acids or salts on the dynamics of nitrogen transformations and intrinsic protease activity of alfalfa silage
Author(s) -
Yuan XianJun,
Wen AiYou,
Desta Seare T,
Dong ZhiHao,
Shao Tao
Publication year - 2017
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.8103
Subject(s) - silage , protease , nitrogen , chemistry , dynamics (music) , food science , biochemistry , biology , enzyme , organic chemistry , physics , acoustics
BACKGROUND Short‐chain fatty salts have been widely used as food and forage preservatives because of their antimicrobial properties. This study evaluated the effects of four chemical compounds with antimicrobial properties on nitrogen transformations and intrinsic protease activity of alfalfa silage. RESULTS Potassium diformate ( PD ) and formic acid ( FA ) rapidly reduced silage pH . Silages treated with sodium diacetate ( SD ) and calcium propionate ( CAP ) had higher final peptide N concentrations than other silage. The free amino acid N contents in PD and FA treated silages were lower than other silages at all intervals of ensilage. The ammonia N concentrations in FA and PD silages were the lowest, followed by SD and CAP silages. As ensiling progressed, the aminopeptidase activity was completely lost by day 5 for FA and PD silages and inactive by day 7 for SD silage, while it remained active after day 7 for control and CAP silage. The carboxypeptidase activities in FA and PD silages were already reduced below 50% by day 1 of ensiling. CONCLUSION Potassium diformate was as effective as formic acid in depressing the proteolysis, while sodium diacetate and calcium propionate were inferior to formic acid in protecting alfalfa proteins from being hydrolysed. © 2016 Society of Chemical Industry