Differentiation of sea buckthorn syrups processed by high pressure, pulsed electric fields, ohmic heating, and thermal pasteurization based on quality evaluation and chemical fingerprinting

Robert Sevenich; Maximilian Gratz; Beverly Hradecka; Thomas Fauster; Thomas Teufl; Felix Schottroff; Lucie Souckova Chytilova; Kamila Hurkova; Monika Tomaniova; Jana Hajslova; Cornelia Rauh; Henry Jaeger

doi:10.3389/fnut.2023.912824

Differentiation of sea buckthorn syrups processed by high pressure, pulsed electric fields, ohmic heating, and thermal pasteurization based on quality evaluation and chemical fingerprinting

Front Nutr. 2023 Feb 14:10:912824. doi: 10.3389/fnut.2023.912824. eCollection 2023.

Authors

Affiliations

¹ Department of Food Biotechnology and Food Process Engineering, Technische Universität Berlin (TU Berlin), Berlin, Germany.
² Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Potsdam, Germany.
³ Institute of Food Technology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
⁴ Department of Food Analysis and Nutrition, University of Chemistry and Technology (UCT), Prague, Czechia.
⁵ BOKU Core Facility Food and Bio Processing, University of Natural Resources and Life Sciences, Vienna, Austria.

Abstract

Introduction: Impact of processing on product characteristics, sustainability, traceability, authenticity, and public health along the food chain becomes more and more important not only to the producer but also to the customer and the trust of a consumer toward a brand. In recent years, the number of juices and smoothies containing so called super foods or fruits, which have been "gently pasteurized," has increased significantly. However, the term "gentle pasteurization" related to the application of emerging preservation technologies such as pulsed electric fields (PEF), high pressure processing (HPP) or ohmic heating (OH) is not clearly defined.

Methods: Therefore, the presented study investigated the influence of PEF, HPP, OH, and thermal treatment on quality characteristics and microbial safety of sea buckthorn syrup. Syrups from two different varieties were investigated under the following conditions HPP (600 MPa 4-8 min), OH (83°C and 90°C), PEF (29.5 kV/cm, 6 μs, 100 Hz), and thermal (88°C, hot filling). Analyses to test the influence on quality parameters like ascorbic acid (AA), flavonoids, carotenoids, tocopherols, antioxidant activity; metabolomical/chemical profiling (fingerprinting) via U-HPLC-HRMS/MS (here especially flavonoids and fatty acids); sensory evaluation, as well as microbial stability including storage, were conducted.

Results and discussion: Independent from the treatment, the samples were stable over 8 weeks of storage at 4°C. The influence on the nutrient content [Ascorbic acid (AA), total antioxidant activity (TAA), total phenolic compounds (TPC), tocopherols (Vit E)] was similar for all tested technologies. Employing statistical evaluation Principal Component Analysis (PCA) a clear clustering based on the processing technologies was observed. Flavonoids as well as fatty acids were significantly impacted by the type of used preservation technology. This was obvious during the storage time of PEF and HPP syrups, where enzyme activity was still active. The color as well as taste of the syrups were found to be more fresh-like for the HPP treated samples.

Keywords: food quality; indicator compound; innovative food technologies; sea buckthorn; untargeted chemical fingerprinting.

Grants and funding

This work was financially supported by the project “Volumetric preservation technologies for food quality improvement by retention of sensitive and mitigation of neoformed compounds (volTECH)”. We acknowledge the financial support of the German Federal Ministry of Economics and Energy (BMWi) (CORNET AIF 207 EN). This work was also partly supported by the Austrian Research Promotion Agency (FFG Project No. 859077, volTECH) and from and Innovations for Competitiveness 2014–2020 of the Czechia (registration no. CZ.01.1.02/0.0/0.0/16_079/0008876, Operational Program Enterprise), Further, from METROFOOD-CZ research infrastructure project (MEYS Grant No: LM2018100) including access to its facilities and by the grant of Specific university research–grant No A1_FPBT_2021_001. Further, we acknowledge the support by the German Research Foundation and the Open Access Publication Fund of TU Berlin.