@article{0777e58eecb240dc879214b45edffbda,
title = "The combined effect of pressure and temperature on kefir production — a case study of food fermentation in unconventional conditions",
abstract = "Food fermentation under pressure has been studied in recent years as a way to produce foods with novel properties. The purpose of this work was to study kefir production under pressure (7–50 MPa) at different temperatures (17–32 ◦C), as a case study of unconventional food fermentation. The fermentation time to produce kefir was similar at all temperatures (17, 25, and 32 ◦C) up to 15 MPa, compared to atmospheric pressure. At 50 MPa, the fermentation rate was slower, but the difference was reduced as temperature increased. During fermentation, lactic and acetic acid concentration increased while citric acid decreased. The positive activation volumes (Va) obtained indicate that pressure decreased the fermentation rate, while the temperature rise led to the attenuation of the pressure effect (lower Va). On the other hand, higher activation energies (Ea) were observed with pressure increase, indicating that fermentation became more sensitive to temperature. The condition that resulted in a faster fermentation, higher titratable acidity, and higher concentration of lactic acid was 15 MPa/32 ◦C. As the authors are aware, this is the second work in the literature to study the combined effect of pressure and temperature on a fermentative process.",
keywords = "Fermentation kinetics, High pressure, Kefir, Temperature",
author = "Ribeiro, {Ana C.} and Lemos, {{\'A}lvaro T.} and Lopes, {Rita P.} and Mota, {Maria J.} and In{\'a}cio, {Rita S.} and Gomes, {Ana M. P.} and S{\'e}rgio Sousa and Ivonne Delgadillo and Saraiva, {Jorge A.}",
note = "Funding Information: Acknowledgments: Thanks are due to the University of Aveiro and FCT/MCT (Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia/Minist{\'e}rio da Ci{\^e}ncia e Tecnologia) for the financial support for the QOPNA research unit (FCT UID/QUI/00062/2019) and Associate Laboratory LAQV-REQUIMTE (UIDB/50006/2020) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement and CBQF (project UID/Multi/50016/2019). Authors Ana C. Ribeiro and {\'A}lvaro T. Lemos are also grateful for the financial support from “Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia—FCT” through the fellowship grants SFRH/BD/129540/2017 and SFRH/BD/129848/2017, respectively. Funding Information: Funding: This research received funding of FCT/MCT (Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia/Minist{\'e}rio da Ci{\^e}ncia e Tecnologia) through the financial support for the QOPNA research unit (FCT UID/QUI/00062/2019) and Associate Laboratory LAQV-REQUIMTE (UIDB/50006/2020) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement and CBQF (project UID/Multi/50016/2019), and through the fellowship grants SFRH/BD/129540/2017 (Ana C. Ribeiro) and SFRH/BD/129848/2017 ({\'A}lvaro T. Lemos). Publisher Copyright: {\textcopyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2020",
month = aug,
doi = "10.3390/foods9081133",
language = "English",
volume = "9",
journal = "Foods",
issn = "2304-8158",
publisher = "MDPI",
number = "8",
}