Pressure-enhanced sterilization (PES) and ohmic heating (OH) are two emerging sterilization techniques, currently lacking implementation in the food industry. However, both technologies offer significant benefits in terms of spore inactivation using reduced thermal intensity in food products, as well as minimized effects on sensory and nutritional profiles. In this study, PES and OH were tested based on possible food safety process windows in comparison to thermal retorting, to optimize the food quality of carrot-based purees. The following parameters related to food quality were tested: texture, carotenoid content, color, and detectable amount of food processing contaminants (FPC) formed. Application of the innovative sterilization techniques resulted in a better retention of color, texture, and carotenoids (for PES) as well as a reduced formation of food processing contaminants. Importantly, a significant reduction in the formation of furan and its derivates was observed, compared to the retorted samples. Hence, both sterilization technologies showed promising results in the mitigation of potential toxic processing contaminants and retention of quality attributes.

Much research has been conducted to comprehend the mechanisms of high pressure (HP) inactivation of spores in aqueous systems but for food model systems these information are scarce. In these systems spores can interact with ingredients which could lead to retarded inactivation, which can cause a problem for the sterilization process. The protective mechanism of a reduced a_W-value is still unclear. HP processing might prove valuable to overcome protective effects of solutes and achieve shorter process times for sterilization under HP. To gain insight into the underlying mechanisms five a_W-values (0.9, 0.92, 0.94, 0.96, 1) were adjusted with 2 different solutes (NaCl, sucrose). Solutions were inoculated with spores of Bacillus amyloliquefaciens and treated at 105,110°C and115°C at 600 MPa. A thermal inactivation was conducted at the same temperatures for a compraison with the high pressure data. The influence of high pressure high temperature treatment on the inactivation, the DPA-release and membrane constitution was assessed by plate count, HPLC and flow cytometry. The results show that during HP treatments sucrose and salt both have a protective effect, in which the influence of sucrose on the retarded inactivation is higher. The threshold aw, which is 0.94, here salt and sucrose have a significant influence on the inactivation. The comparison of thermal (105-115°C) and high pressure and high temperature (600 MPa, 105-115°C) treated samples showed that the time needed to achieve a 4-5 log inactivation can be reduced at 600 MPa.The release of dipicolinic acid (DPA) is the rate limiting step of the inactivation and therefore monitoring the release is of great interest. The DPA-release is slowed is slowed down in high concentrated solutions (e.g. sucrose, salt) in comparison to aw 1. Maybe as shown for vegetative microorganism the solutes can interact with membranes, e.g. inner spore membrane. FCM (flow cytometry) measurement data show a similar trend.

High-Pressure Thermal Processing (HPTP) is an emerging food preservation technology that combines elevated pressure with moderate to high temperatures to achieve microbial inactivation while preserving product quality. This review presents a comprehensive overview of the scientific principles, technological developments, and potential commercial applications of HPTP. Key mechanisms such as adiabatic compression heating and the synergistic effects of pressure and temperature are explored alongside advances in equipment design, predictive modeling, and process optimization. The manuscript also highlights applications across diverse food categories, including juices, dairy, meats, seafood, and ready-to-eat meals, and emphasizes HPTP’s ability to reduce the formation of heat-induced food processing contaminants. Recent innovations, such as multilayer canister systems enabling HPTP in conventional HPP equipment, are discussed in the context of scaling the technology from research to industrial use. As consumer demand for minimally processed, high-quality foods continue to rise, HPTP stands poised to play a transformative role in the future of food processing.

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.