Improving the digestibility of cereal fractions of wheat, maize, and rice by a carbohydrase complex rich in xylanases and arabinofuranosidases: an in vitro digestion study

Abstract

BACKGROUND Cereal co‐products rich in dietary fibres are increasingly used in animal feed. The high fibre content decreases the digestibility and reduces the nutrient and energy availability, resulting in lower nutritive value. Therefore, this study investigated the ability of two carbohydrase complexes to solubilize cell‐wall polysaccharides, in particular arabinoxylan (AX), from different cereal fractions of wheat, maize, and rice using an in vitro digestion model of the pig gastric and small intestinal digestive system. The first complex (NSPase 1) was rich in cell‐wall‐degrading enzymes, whereas the second complex (NSPase 2) was additionally enriched with xylanases and arabinofuranosidases. The extent of solubilization of insoluble cell‐wall polysaccharides after in vitro digestion was evaluated with gas–liquid chromatography and an enzymatic fingerprint of the AX oligosaccharides was obtained with high‐performance anion‐exchange chromatography with pulsed amperometric detection. RESULTS The addition of carbohydrase increased the digestibility of dry matter and solubilized AX in particular, with the greatest effect in wheat fractions and less effect in maize and rice fractions. The solubilization of AX (expressed as xylose release) ranged from 6% to 41%, and there was an increased effect when enriching with xylanases and arabinofuranosidases in wheat aleurone and bran of 19% and 14% respectively. The enzymatic fingerprint of AX oligosaccharides revealed several non‐final hydrolysis products of the enzymes applied, indicating that the hydrolysis of AX was not completed during in vitro digestion. CONCLUSION These results indicate that the addition of a carbohydrase complex can introduce structural alterations under in vitro digestion conditions, and that enrichment with additional xylanases and arabinofuranosidases can boost this effect in wheat, maize, and rice. © 2020 Society of Chemical Industry

Combination of Xylan Depolymerizing and Debranching Enzymes Improves Digestion, Growth Performance and Intestinal Volatile Fatty Acid Profile of Piglets

“…Nevertheless, this steric hindrance can be alleviated by the usage of Afd that removes arabinose groups from side chains, thus providing a convenience for further action of Xyn on Abx [3,10]. In support of this view, we noted that combination of Xyn and Afd at a ratio ranging from 3000:1 to 100:1 resulted in a more pronounced (P < 0.05) RRS from DSWB relative to Xyn acting alone (Figure 3), validating a synergistic interaction between Xyn and Afd on degradation of Abx in DSWB [31,32]. Intriguingly, there was almost no elevation in the RRS with the increased ratio of Xyn dose to Afd dose.…”

Methodologies for energy evaluation of pig and poultry feeds: A review

“…In other words, the effect of any technological (pellet vs mash) or animal (adult vs young) factor on in vivo digestion could not be measured using the dOMv method. This also means that in vitro digestion methods may not be able to quantify the effects of factors such as supplemental enzymes, while it is rather frequently used for a rapid evaluation of their effects, either in pigs or in poultry ( Vangsøe et al, 2021 ). Finally, the in vitro prediction of energy values should be used with caution when it is applied to feeds where preparation (pelleting, enzymes, etc.)…”

Dietary Soluble Non-Starch Polysaccharide Level Influences Performance, Nutrient Utilisation and Disappearance of Non-Starch Polysaccharides in Broiler Chickens

“…Thus, it appears that it is beneficial to supplement diets containing poor fermentable NSP substrates, such as corn, with a fermentable NSP substrate, to enhance intestinal fermentation activities. Arabinoxylans (AX) are the predominant NSP in both wheat and corn, but the structure of AX in corn is more complex than that in wheat, with a higher degree of substitution and arabinose: xylose ratio [ 46 ], meaning corn AX is less readily fermentable than wheat AX [ 47 ]. In addition, the poor ileal and total tract starch digestibility observed at d 14 in birds fed the low sNSP diets could be attributed to production of high molecular weight viscous AX, from insoluble NSP degradation, exceeding their hydrolysis rate in the gastrointestinal tract in this treatment group.…”