High hydrostatic pressure (HHP) treatments affect the integrity and function of biomembranes and proteins of fresh produces. Initially, pressure affects membrane permeability, directly linked to a reversible decline in cell turgor. Reversibility reflects the restoration of intracellular solute gradients by re-established membrane semi-permeability and functionality of membrane-bound proteins. Above a certain threshold, pressure effects become irreversible resulting in tissue damage. Combining cell pressure probe and tissue impedance measurements allow differentiation between reversible and irreversible effects. Thus, these parameters were comparatively investigated in both fresh red cabbage leaves and in radish tubers, species-specifically exposed to various pre-determined relevant HHP conditions (red cabbage: 150–200 MPa at 35–55 °C for 5–20 min; radish: 100–200 MPa, at 20–40 °C for 5–10 min). These specific treatments facilitated the evaluation of the transition between reversible changes in membrane and protein properties and irreversible damages. While turgor declined immediately after HHP treatments, tissue damage occurred only delayed. The two products differed in their responses to various HHP conditions. Generally, HHP effects were limited and reversible at (and certainly also below) 100 MPa but were amplified with intensity of pressure treatments.

Industrial relevance

Increasing food security aspects but also growing concerns against conventional thermal treatments demand the application of novel and gentle nonthermal hygienisation techniques such as high hydrostatic pressure (HHP) also for the production of fresh ready-to-eat salads. However, knowledge about potential impacts of different HHP ranges on metabolic functionality and freshness of fruits and vegetables, and thus produce quality, is still only sketchy.

This study comprehensively differentiated the reversible and irreversible effects of processing conditions on the physiological and structural basis of HHP effects on fresh in fresh red cabbage leaves and radish tubers. It thus provides valuable information on the absolute limits of the applicability of HHP for safety of fresh produces. The fact that pressure treatments above 150 MPa always resulted in irreversible tissue damage indicated that even short-term HHP treatments at room temperature is not suitable for the gentle sanitation of perishable fresh produces but may probably be useful as quarantine measure against parasites and viruses.

中文翻译：

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高静水压处理对新鲜园艺产品某些组织特性的影响

高静水压（HHP）处理会影响新鲜农产品的生物膜和蛋白质的完整性和功能。最初，压力会影响膜的通透性，直接与细胞膨胀的可逆下降有关。可逆性通过重新建立的膜半透性和膜结合蛋白的功能性来反映细胞内溶质梯度的恢复。超过某个阈值，压力作用将不可逆转，从而导致组织损伤。结合细胞压力探针和组织阻抗测量值，可以区分可逆和不可逆效应。因此，在新鲜的红甘蓝叶和萝卜块茎中都对这些参数进行了比较研究，这些物种专门暴露于各种预先确定的相关HHP条件（红甘蓝：在35-55°C下150-200 MPa，持续5-20分钟；萝卜：100–200 MPa，在20–40°C下持续5-10分钟）。这些特定的处理方法有助于评估膜和蛋白质性质的可逆变化与不可逆损害之间的过渡。虽然在HHP治疗后立即出现了红肿下降，但组织损伤的发生只是延迟了。两种产品对各种HHP条件的反应不同。通常，HHP效应在100 MPa（当然也低于100 MPa）是有限且可逆的，但随着压力处理的强度而增强。两种产品对各种HHP条件的反应不同。通常，HHP效应在100 MPa（当然也低于100 MPa）是有限且可逆的，但随着压力处理的强度而增强。两种产品对各种HHP条件的反应不同。通常，HHP效应在100 MPa时（并且当然也低于100 MPa）是有限且可逆的，但随着压力处理的强度而增强。

行业相关性

越来越多的食品安全问题以及对常规热处理的越来越多的关注要求将新颖而温和的非热卫生技术应用，例如高静水压（HHP）来生产新鲜的即食色拉。但是，关于不同HHP范围对水果和蔬菜的代谢功能和新鲜度以及由此产生的品质的潜在影响的知识仍然只是一个粗略的认识。

这项研究全面区分了加工条件对鲜红卷心菜叶和萝卜块茎对新鲜的HHP效应的生理和结构基础的可逆和不可逆作用。因此，它提供了有关HHP在新鲜农产品安全性方面的绝对极限的宝贵信息。高于150 MPa的压力处理总是会导致不可逆转的组织损伤，这一事实表明，即使在室温下进行短期HHP处理，也不适合对易腐烂的新鲜农产品进行温和的卫生处理，但可能可用作隔离寄生虫和病毒的隔离措施。