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

Abstract

IntroductionImpact 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.MethodsTherefore, 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 discussionIndependent 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.

Changes in the Main Physicochemical Properties and Electrochemical Fingerprints in the Production of Sea Buckthorn Juice by Pectinase Treatment

“…Moreover, recent advances in analytical techniques have enabled the characterization of complex food systems, including the development of electrochemical fingerprinting methods [ 24 , 25 ]. Electrochemical fingerprints provide unique patterns of potential changes over time, reflecting the underlying chemical and physical interactions within the system [ 26 , 27 , 28 ].…”

Effects of Pulsed Electric Fields on the Physicochemical and Sensory Properties of Thompson Seedless Grapes

“…The applied voltage acts on the naturally occurring transmembrane voltage of cells, which is formed between the interior and exterior of the cells by ion gradients. As soon as a critical threshold value is reached, pores are formed in the membrane and cells are opened [2,3] Thus, PEF treatment is a promising technology for enhancing mass transfer during the processing of foodstuffs and is associated with many benefits, as can be seen in juices or syrups of different origins and an associated improvement in physicochemical properties [4][5][6] but without negative impact on the flavor profile [7]. This technology has been shown to produce improved peelability in various vegetables, such as tomatoes, peaches, and oranges [8], while the potato industry is investigating the use of PEFs to pretreat potatoes for the production of French fries and the degradation of starch to improve their texture [9].…”