Cassava ( Manihot esculenta Crantz) is considered the third most important source of calories in tropical regions. Up to one third of cassava harvested worldwide is used in livestock production. The focus of this study was to characterize cassava cell wall structure to provide knowledge for a better application of cassava as an energy source in monogastric animal feed. A total of five cassava samples from different feed mills in South East Asia were investigated. On a dry matter basis, the cassava cell walls contained, on average, 640 mg g −1 glucose, 140 mg g −1 galactose, 50 mg g −1 mannose, 80 mg g −1 xylose, 60 mg g −1 arabinose, 10 mg g −1 fucose and 20 mg g −1 rhamnose. RONOZYME VP (DSM Nutritional Products, Switzerland), a non-specific multicomponent non-starch polysaccharide (NSP) degrading enzyme (NSPase) product from Aspergillus aculeatus , solubilized about 10% of cassava NSP content during 4 h incubations at 40 °C and pH 5. There was notable solubilization of polymers containing uronic acids, galactose, arabinose and rhamnose. Immuno-microscopy imaging indicated the solubilization of pectin, galactan and xyloglucan polysaccharides from cassava cell wall. As a consequence, the starch granules became more available to exogenous α-amylase degradation.

The development of stable enzymes is a key issue in both the food and feed industries. Consequently, the aim of the current study is to evaluate the impact of various additives (sodium chloride, sodium citrate, mannitol, methylparaben, polyethylene glycol 3350, ethylenediaminetetraacetic acid disodium salt, and a serine protease inhibitor) on the stability of a mushroom phytase produced by solid-state cultivation and recovery. Also observed was the effect of the additives on microbial growth inhibition by monitoring both the change in optical density over 30 days of storage and proteolytic activity. Initially, eight experimental formulations were prepared along with a control. After screening, a 3(2) factorial design was applied to define suitable concentrations of the selected additives. Among the eight formulations tested, the formulation containing NaCl, PEG 3350, and methylparaben retained all of the initial phytase activity after 50 days of storage, with no detected interference from protease activity. Sodium citrate, a metal chelation agent, presented the unusual effect of reducing protease activity in the formulations. Although all formulations presented better phytase stability when compared to the control, NaCl and PEG were both able to prolong the stability of the enzyme activity and also to inhibit microbial growth during storage, making them favorable for application as food and feed additives.