Kinetics of Formation of Butyric and Pyroglutamic Acid during the Shelf Life of Probiotic, Prebiotic and Synbiotic Yoghurt

Butyric acid (C4) and pyroglutamic (pGlu) exert significant beneficial effects on human health. In this study, the influence of probiotics (Lactobacillus acidophilus Bifidobacteria) and/or prebiotics (1 3% inulin fructo-oligosaccharides) content C4 pGlu in yoghurt during shelf-life period was evaluated. The contents were determined probiotic, prebiotic synbiotic yoghurts 30 days storage at 4 °C by solid-phase microextraction coupled with gas chromatography/mass spectrometry HPLC analysis. Traditional uninoculated milk used as control. Prebiotic contained more (2.2–2.4 mg/kg) than milk, no increase detected respect to traditional yoghurt. However, probiotic showed 10% Adding fibre (synbiotic yoghurt) increased 30%. Regarding pGlu, presented highest approximately 130 mg/100 g. Fibre did not affect content. Finally, generally up 20 then decreased storage. results might be useful for preparation other functional foods rich using lactic bacteria.