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Graphical abstract Highlights • Effects of high pressure on pumpkin cubes was compared with thermal treatment. • The effect of three different pressures was evaluated on two pumpkin species. • After high pressure treatment parenchyma cells exhibited collapses and separations. • Treatment at 400 MPa and at 85 °C resulted the most effective on pectin methylesterase. • High pressure treatment decreased antioxidant activity that increased during storage. Abstract The effects of high pressure treatments (200, 400, 600 MPa for 5 min) and a thermal treatment (85 °C for 5 min) were evaluated on cubes of two pumpkin species (Cucurbita maxima L. var. Delica and Cucurbita moschata Duchesne var. Butternut) up to 2 months of refrigerated storage. Increasing the pressure, small parenchyma cells from the pumpkin tissue exhibited collapses and separations, especially for Butternut. This species showed a lower hardness than Delica at time 0. For both species, 400 MPa and thermal treatment were the most effective in the inactivation of pectinmethylesterase, which reactivated after 2 months, especially for Butternut. Colorimetric parameters decreased after all treatments. Antioxidant activity resulted affected by pressure, showing a significant increase during storage especially for the samples treated at 200 MPa after 2 months, comparable to the thermal treated ones. Among the tested treatments, 400 MPa may be considered as the best option for the quality retention during storage. [ABSTRACT FROM AUTHOR]

Moderate intensity pulse electric fields were applied in plum with the aim to increase bioactive compounds content of the fruit, while high-hydrostatic pressure was applied to preserve the purées. High-hydrostatic pressure treatment was compared with an equivalent thermal treatment. The addition of ascorbic acid during purée manufacture was also evaluated. The main objective of this study was to assess the effects on microorganisms, polyphenoloxidase, color and bioactive compounds of high-hydrostatic pressure, or thermal-processed plum purées made of moderate intensity pulse electric field-treated or no-moderate intensity pulse electric field-treated plums, after processing during storage. The application of moderate intensity pulse electric field to plums slightly increased the levels of anthocyanins and the antioxidant activity of purées. The application of Hydrostatic-high pressure (HHP) increased the levels of bioactive compounds in purées, while the thermal treatment preserved better the color during storage. The addition of ascorbic acid during the manufacture of plum purée was an important factor for the final quality of purées. The color and the bioactive compounds content were better preserved in purées with ascorbic acid. The no inactivation of polyphenoloxidase enzyme with treatments applied in this study affected the stability purées. Probably more intense treatments conditions (high-hydrostatic pressure and thermal treatment) would be necessary to reach better quality and shelf life during storage. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of high hydrostatic pressure (HHP) on the microbial counts, physicochemical properties, bioactive compounds, and antioxidant capacity of jujube pulp. Additionally, this study compared the shelf life of jujube pulp following HHP (600 MPa/20 min) and thermal treatment (100 °C/10 min) during 40 days of storage at 4 °C and 15 °C. The microbial count of HHP-treated jujube pulp (≥ 400 MPa/20 min) was below the detection limit. Total soluble solids and total sugars were not significantly affected by HHP processing, and > 90% ascorbic acid was retained in HHP-treated samples. HHP slightly reduced pH and browning degree and increased total phenolic content, flavonoid content, and antioxidant capacity. HHP can be used as an alternative to thermal pasteurization of freshly squeezed jujube pulp. Industrial relevance Effects of high hydrostatic pressure (HHP) processing and thermal treatment (TT) on microbiological quality, physicochemical properties, bioactive compounds and antioxidant activity in jujube pulp were investigated. Greater inhibition of microorganisms and better retention of ascorbic acid, total phenolics, flavonoid and antioxidant capacity were observed after HHP-treatment. The available data could be used to design the HHP parameters for high quality jujube juice. Further, this research would provide a useful method for preservation of jujube products and potential technical support for jujube commercial production. [ABSTRACT FROM AUTHOR]

Wild Lonicera caerulea berries were subjected to five different high hydrostatic pressure (HHP) treatments (which resemble the conditions of active component extraction and commercial sterilization). The content of anthocyanins and total phenolics increased by 6.84% and 14.35% (p < 0.05), respectively after treatment at 200 MPa for 5 and 10 min. As HHP increased, a higher loss of active component was observed. The total phenolic contents did not differ significantly between the control and the 400 MPa/20 min treated group (p > 0.05); HHP processing demonstrated better sterilization effect but severely destroyed enzymes. Polyphenol oxidase (PPO) and peroxidase (POD) activity were activated at lower HHP, such as 200 MPa, and decreased at 400–600 MPa. Superoxide dismutase (SOD) maintained good stability under HHP processing. The antioxidant capacities of anthocyanins extracts of wild L. caerulea berry were evaluated by 3 different methods (DPPH assay, oxygen radical absorbance capacity assay, and cellular antioxidant activity assay). Industrial Relevance Factors such as color, luster, and nutrition often affect consumer choice in food. However, the color and nutrition of foods tend to be destroyed during processing and storage. The demand for healthier and more nutritious food while retaining the color and flavor after processing highlights the need to develop novel and gentler technologies for fruit processing. Recently, high hydrostatic pressure (HHP) technologies have been used in different branches of the food industry. In the present study, the content of active component in blue honeysuckle fruit pulps such as anthocyanins and polyphenols showed tendency to increase and then decrease with increasing pressure at room temperature. Five different HHP treatment groups (resembling the conditions of active component extraction conditions and commercial sterilization) were compared to the control (fresh fruit) and heat-treated group to determine the effects of HHP processing on L. caerulea berry pulps. The aim of this study was to investigate the changes in active component particularly the content and composition of anthocyanins under different high-pressure treatment at room temperature; the color and physicochemical indexes were also analyzed at the same conditions. Low HHP for a long period of time (400 MPa/20 min) demonstrated better results than that with high HHP for a short time (600 MPa/10 min), as indicated by the higher contents of anthocyanins and phenols and stronger antioxidant capacities. Therefore, Low HHP conditions can be used as an auxiliary means of active component extraction. The conditions of HHP processing at low HHP for a long period of time (400 MPa/20 min) can be altered to retain active components during food processing. [ABSTRACT FROM AUTHOR]

Consumption of unpasteurised fruit/vegetable juices has increased in recent years due to their freshness, low calorie contribution and good nutritional quality. However, unpasteurised fresh juices with low acidity ( pH > 4.6) and high water activity (aw > 0.85) can support the growth of pathogens. Hence, pasteurisation is a necessary process in the production of low-acid juices. Consumer demand has required minimally processed high-quality foods that are free from additives, that are fresh tasting and microbiologically safe, and with an extended shelf life. High hydrostatic pressure (HHP) treatment is considered to be an alternative to thermal pasteurisation for fruit and vegetable juices. HHP treatment could preserve nutritional value and the sensory properties of fruits and vegetables due to its limited effect on the covalent bonds of low-molecular-mass compounds such as colour, flavour compounds and vitamins. However, inactivation of important foodborne pathogens in low-acid foods by HHP is most urgent and critical. More research should be performed in order to satisfy consumer demands for fresh-tasting products while retaining safety. [ABSTRACT FROM AUTHOR]

The article looks at mechanical aspects of tissue organogenesis and growth rates of leaf formation from plant shoot apical meristems, particularly the functions of elasticity and plasticity. The experiment promoted the deformation of apical meristem tissues through the manipulation of turgor pressure, yielding evidence of strain stiffening in the areas of the shoot tip with the slowest growth rates. These results indicate that the elastic properties of different areas of the meristem influence organogenesis by regulating growth rates and the bulging of the meristem flank, suggesting that mechanical pathways are as significant to plant development as genetic ones.