“…These stress conditions include exposure of polysorbates to evaluate the impact of e.g. temperature, iron or transition metals ( Brovč et al, 2020a ; Liu et al, 2022a ; Hvattum et al, 2012 ; Kranz et al, 2019 ; Gopalrathnam et al, 2018 ; Schröter et al, 2021 ; Bensaid et al, 2022 ; Doyle et al, 2019 ; Kranz et al, 2020 ; Klair et al, 2021 ; Prajapati et al, 2022 ), H 2 O 2 ( Kishore et al, 2011a ; Kranz et al, 2019 ; Peters et al, 2022 ), light exposure ( Ha et al, 2002 ; Doyle et al, 2019 ; Doshi et al, 2021a ; Singh et al, 2012 ; Agarkhed et al, 2013 ; Prajapati et al, 2020 , Prajapati et al, 2022 , Larson et al, 2020 ; Lei et al, 2021 ), or 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH) ( Borisov et al, 2015 ; Larson et al, 2020 ; Zhang et al, 2017 ; Schröter et al, 2021 ; Zhang et al, 2018 ), all promoting the formation of radicals resulting in oxidative degradation. As oxidation of polysorbates can occur at: (i) the POE moieties, which can also result in free fatty acids and (ii) the existing double bonds ( Donbrow et al, 1978a ; Zhang et al, 2017 ; Yao et al, 2009 ), it is discussed whether PS80 or PS20 or different subspecies are most susceptible to oxidative degradation (compare Fig.…”