# Antioxidant and Antimicrobial Properties of Selected Phytogenics for Sustainable Poultry Production
## 7 Amelioration of Antinutritional Effects in Poultry Consuming Phytogenics  
As aforementioned, the utility of phytogenics is hindered by the presence of ANFs, which could be ameliorated using a variety of techniques. Solid-state fermentation, alkali treatments, tannin-binding agents, thermal processes, exogenous feed enzymes, and plant breeding are some of the strategies that can be used to ameliorate ANFs. Solid-state fermentation (SSF) is a process that takes place in a solid matrix in the absence or near absence of free water with the aid of the metabolic activity of microorganisms [165]. When fermenting phytogenics to reduce ANFs, it is also important to use microorganisms, such as lactic acid bacteria, that will promote beneficial intestinal microbiota while acting against pathogenic enteric microbes [166]. Microbial activity during SSF can reduce the levels of ANFs in potential phytogenic substrates. Indeed, [PERSON] et al. [167] reported a significant reduction in the phytic acid content in fermented lupins flour using _Aspergillus sojue_ and _A. ficuum_. Similarly, [PERSON] et al. [168] reported a reduction in the concentrations of crude fiber, tannins, hemicellulose, and phytate in fermented _M. oleifera_ inoculated with _A. niger_, _Candidia utilis_, and _Bacillus subtilis_ at a ratio of 1:1:2. Similarly, _M. oliefera_ seed flour was reported to have reduced tannin, phytic, phenol, flavonoid, saponin, and alkaloid contents after fermentation and germination processes compared to unprocessed flour [169].  
Thermal processing is also an effective means of inactivating thermo-labile ANFs in phytogenic products [170]. Heat-based methods include autoclaving, pressure cooking, microwaving, extrusion cooking, and toasting. [PERSON] et al. [171] reported that autoclaving reduced the contents of trypsin and \(\alpha\)-amylase inhibitors and resistant starch in _Phuseolus vulgaris_. Toasting the seeds from _Senna obtusifolia_ at 80 \({}^{\circ}\)C for one hour significantly lowered the hemagglutinin, phytate, oxalate, saponin, and tannin contents [172]. Thermal application has been shown to partially hydrolyze tannic acid and release gallic acid molecules, and these newly produced gallic acid and galloyl groups had enhanced antimicrobial and antioxidant effects compared to fresh tannic acid [172]. Moreover, boiling, steaming, stir-frying, and roasting were reported to decrease the total polyphenols contents of _Capsicum annuum_ L. [173].  
Exogenous enzymes have the potential to improve the utility of phytogenics for sustainable poultry production [174]. Proteases and carbohydrates (xylanases and cellulases) are exogenous enzymes commonly used in poultry feeds. [PERSON] et al. [175] successfully used exogenous _ulvan lyase_ to boost the meat nutritional value of birds by feeding them _Ulva lactuca_ supplemented with carbohydrates. Abou-Arab and Abu-Salem [176] treated _Jatropha curcas_ seeds with sodium bicarbonate (NaHCO\({}_{3}\)) and sodium hydroxide (NaOH) and successfully inactivated the phytic acid, trypsin inhibitors, total phenols, and saponins. This review shows that ANFs in phytogenic products could hinder their utility as sources of beneficial bioactive compounds. However, there are several methods that could be used to reduce the ANF content of phytogenic products and improve their utilization in poultry nutrition. Nonetheless, factors such as costs and the ease of application often guide the preferable processing method of farmers.