Storage stability of freeze-dried arazá (Eugenia stipitata Mc Vaugh) powders. Implications of carrier type and glass transition

Effect of maltodextrin weight fraction on the amorphous state and critical storage conditions of freeze‐dried juices

“…(1) predicts a sigmoid relationship between T g and a w that was consistent with experimental results, with R 2 and SSE values in the range 0.984–0.999 and 1.30–168.1 respectively. A sigmoid relationship between T g and a w has also been reported for fruit products, sugars and maltodextrins by other authors (Reyes‐Álvarez & Lanari, 2020; Camacho et al ., 2021). In some cases, also a linear relationship between T g and a w has been considered during the study of dehydrated strawberry and kiwifruit pulp and maltodextrins (Roos & Karel, 1991).…”

“…It can be seen that a wc and X wc for the juice powders ranged, respectively, from 0.077 to 0.632 and 0.013 to 0.142 (d.b.). It was found that critical values of pure juice powders and powders containing maltodextrin from this study are in the range reported in the literature (Fongin et al ., 2019; Reyes‐Álvarez & Lanari, 2020; Camacho et al ., 2021). Furthermore, X m values predicted by sorption isotherms are within the range of X wc values, confirming that both parameters can be related to the stability of these juice powders.…”

“…Polymers with high molecular weight such as maltodextrins are used to raise the T g , X wc and a wc and consequently improve critical storage conditions of the fruit powders (Fongin et al ., 2019; Reyes‐Álvarez & Lanari, 2020). Nevertheless, different results have been obtained because of various factors such as fruit composition, fruit product (pulp, juice), drying technique, W MD and the dextrose equivalent (DE) of the maltodextrin.…”

“…Recently, a w and T g concepts are complemented to evaluate the storage stability since a product is most stable at its X m or below its T g value (Reyes‐Álvarez & Lanari, 2020; Rahman et al ., 2021). Thus, T g is the most crucial structural property of amorphous powders, and it is the temperature at which an amorphous matrix changes from the glassy to the rubbery state (Camacho et al ., 2021; Rahman et al ., 2021).…”

“…T g – a w – X w diagrams are reported for several powder fruits (Fongin et al ., 2019; Reyes‐Álvarez & Lanari, 2020). The critical values of X wc and a wc defined as the water content and the a w at which the amorphous powder exhibits glass transition at room temperature (25°C) are determined from these diagrams (Kawai et al ., 2021).…”