Chemical composition, in vitro gas production and energetic value of prickly pear fermented with and without Kluyveromyces marxianus

Abstract

The aim of this study was to characterize the chemical composition, in vitro gas production and energetic value of prickly pear during solid state fermentation (SSF) with Kluyveromyces marxianus. Prickly pear was incubated in SSF at 28°C for 0, 24, 48, 72, 96 and 120 h without and inoculation with K. marxianus. The fermented cactus pear samples were dried at 55°C for 24 h, to determine the percent of dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF). The volume of gas was recorded at 0, 3, 6, 9, 15, 24, 36, 48, 72 and 96 h and the parameters of in vitro gas production were obtained from the model: A= b*(1-e-c(t-L)). In vitro gas production at 24 h was utilized for estimation of metabolizable energy (ME) and short chain fatty acid (SCFA). Data were analyzed as a completely randomized design with a 2x6 factorial arrangement of treatments. The SSF in presence of K. marxianus increases the CP, maximum gas production (b), constant rate of gas production (c), ME and SCFA of prickly pear (P<0.05) but decreases NDF and ADF contents (P<0.05). We conclude that SSF with K. marxianus significantly improvement nutritional quality of prickly pear and may even promote animal performance.

Keywords

• prickly pear
• Kluyveromyces marxianus
• solid state fermentation
• nutritional quality
• in vitro gas production