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Decoupling certain material surface properties can be key to attaining critical property‐activity relationships that underpin their antibiofouling performance. Here, orthogonal nano‐engineering (ONE) is employed to decouple the influences of nanotopography and surface chemistry on surface antibiofouling. Nanotopography and surface chemistry are systematically varied with a two‐step process. Controlled nanotopography is obtained by electrochemical anodization of aluminum, which generated anodic aluminum oxide (AAO) surfaces with cylindrical nanopores (diameters: 15, 25, and 100 nm). To modify surface chemistry while preserving nanotopography, an ultrathin (≈5 nm) yet stable zwitterionic coating of poly(divinylbenzene‐4‐vinylpyridyl sulfobetaine) is deposited on these surfaces using initiated chemical vapor deposition (iCVD). Antibiofouling performance is assessed by quantifying 48‐h biomass formed by gram positive and negative bacteria. The ONE surfaces demonstrated enhanced antibiofouling performance, with small‐pore nanotopography and zwitterionic chemistry each lowered biomass accumulation by tested species, with potential additive effects. The most effective chemistry‐topography combination (ZW‐AAO15) enabled an overall reduction of 91% for Escherichia coli, 76% for Staphylococcus epidermidis, 69% for Listeria monocytogenes, and 67% for Staphylococcus aureus, relative to the uncoated nanosmooth control. Additionally, the composite ZW coating exhibited encouraging anticorrosion properties under both static and turbulent cleaning conditions, vital to antibiofouling applications in healthcare and food industries. [ABSTRACT FROM AUTHOR]

Pea protein isolate (PPI), a high‐concentration protein ingredient derived from peas, is increasingly utilized in food applications, including beverages, meat or dairy alternatives, and baked goods. The protein extraction process typically used to manufacture PPI renders the protein highly denatured, which can have a negative impact on its functionality. Therefore, it is critical to understand how to prepare and utilize PPI to maximize its functionality. The current study evaluates the effect of select reconstitution conditions on the structure and functionality of PPI, across a range of protein concentrations (4%–10%) relevant to a variety of food applications. Temperature during reconstitution with water and hydration time impacted both protein hydration and its functionality. Increasing reconstitution temperature from 20 to 60°C and increasing hydration time from 10 to 40 min decreased PPI particle size in solution and increased PPI solubility. Viscosity of PPI solutions also increased with mild heating and longer hydration time, whereas their flow behavior was highly dependent on protein concentration. Experimental data demonstrates that reconstitution conditions have a significant impact on PPI functionality. These findings can help food formulators develop high‐quality food products that utilize PPI as a functional ingredient. Practical Application: Protein in commercially available pea protein isolates (PPIs) is usually highly denatured, and thus, it is important to find ways to maximize its functionality in practical applications. The findings of this study inform food scientists how to leverage PPI at various protein concentrations with optimal reconstitution conditions to develop high‐quality products. Generally, mild heating and longer hydration times improve PPI functional performance. [ABSTRACT FROM AUTHOR]

This study establishes a correlation between dielectric properties, drying parameters, drying rate and energy demand for microwave vacuum drying (MVD) of concentrated skim milk (CSM). MVD was conducted using a EnWave nutraReV™ unit, at various specific power inputs (0.86, 1.29, 1.72 W g-1), drying pressures (30 to 147 mbar), and CSM layer thickness (1 to 4 mm). The drying rate based on moisture ratio was estimated using the Page model. The specific energy consumption was lowest as CSM dried from 50 to 15% moisture, then rapidly increased as the drying rate decreased due to a low ε" at <15% moisture. The loss factor ε" of CSM at 2.45 GHz increased up to 35% total solids, then steadily decreased up to 95% solids. The specific electrical energy demand of the MVD unit, which accounted for all utility flows at full capacity, was 2.85 kWh kg-1 water evaporated, with the magnetrons accounting for 2.14 kWh kg-1. This study provides valuable data on drying kinetics and energy demand during MVD of CSM, and an approach that can help processors assess the energy efficiency of MVD for various food applications. [ABSTRACT FROM AUTHOR]

A study is conducted to examine the influence of surface properties, particularly topography on microbicidal effect of pulsed light (PL). The results indicate that PL can be effective on both smooth and rough surfaces, but also demonstrate a complex effect of various surface properties on inactivation.

The science and technology which deals with special properties of a material which emerge from nanometer size, is called nanotechnology. Some of the current nanotechnology research that is applicable to food science and technology is reviewed and the future of newly emerging field of food technology is projected.

Bacterial attachment to material surfaces can lead to the development of biofilms that cause severe economic and health problems. The outcome of bacterial attachment is determined by a combination of bacterial sensing of material surfaces by the cell and the physicochemical factors in the near-surface environment. This paper offers a systematic review of the effects of surface topography on a range of antifouling mechanisms, with a focus on how topographical scale, from micro- to nanoscale, may influence bacterial sensing of and attachment to material surfaces. A good understanding of these mechanisms can facilitate the development of antifouling surfaces based on surface topography, with applications in various sectors of human life and activity including healthcare, food, and water treatment. [ABSTRACT FROM AUTHOR]

Thermal pasteurization can achieve the U.S. Food and Drug Administration-required 5-log reduction of pathogenic Escherichia coli O157:H7 and Cryptosporidium parvum in apple juice and cider, but it can also negatively affect the nutritional and organoleptic properties of the treated products. In addition, thermal pasteurization is only marginally effective against the acidophilic, thermophilic, and spore-forming bacteria Alicyclohacillus spp., which is known to cause off-flavors in juice products. In this study, the efficiency of a combined microfiltration (MF) and UV process as a nonthermal treatment for the reduction of pathogenic and nonpathogenic E. coli, C. parvum, and Alicyclohacillus acidoterrestris from apple cider was investigated. MF was used to physically remove suspended solids and microorganisms from apple cider, thus enhancing the effectiveness of UV and allowing a lower UV dose to be used. MF, with ceramic membranes (pore sizes, 0.8 and 1.4 µm), was performed at a temperature of 10°C and a transmembrane pressure of 155 kPa. The subsequent UV treatment was conducted using at a low UV dose of 1.75 mj/cm². The combined MF and UV achieved more than a 5-log reduction of E. coli, C. parvum, and A. acidoterrestris. MF with the 0.8-² m pore size performed better than the 1.4-²m pore size on removal of E. coli and A. acidoterrestris. The developed nonthermal hurdle treatment has the potential to significantly reduce pathogens, as well as spores, yeasts, molds, and protozoa in apple cider, and thus help juice processors improve the safety and quality of their products. [ABSTRACT FROM AUTHOR]

This work reports on a simple, robust and scientifically sound method to develop surfaces able to reduce microbial attachment and biofilm development, with possible applications in medicine, dentistry, food processing, or water treatment. Anodic surfaces with cylindrical nanopores 15 to 100 nm in diameter were manufactured and incubated withEscherichia coliATCC 25922 andListeria innocua. Surfaces with 15 and 25 nm pore diameters significantly repressed attachment and biofilm formation. Surface–bacteria interaction forces calculated using the extended Derjaguin Landau Verwey-Overbeek (XDLVO) theory indicate that reduction in attachment and biofilm formation is due to a synergy between electrostatic repulsion and surface effective free energy. An attachment study usingE. coliK12 strains unable to express appendages also suggests that the small-pore surfaces may inhibit flagella-dependent attachment. These results can have immediate, far-reaching implications and commercial applications, with substantial benefits for human health and life. [ABSTRACT FROM AUTHOR]

Pulsed light (PL) treatment can effectively inactivate a large proportion of contaminating bacteria on surfaces and in clear solutions. An important issue that needs to be investigated is whether repeated exposure to PL treatment causes any changes to the growth and resistance behavior of the bacteria surviving the treatment. To test this, three challenge microorganisms were used: Listeria monocytogenes, Listeria innocua, and Escherichia coli. Cells of the challenge bacteria were treated with either low or high PL doses. Survivors of the PL treatment were enumerated, isolated, regrown, and exposed again to PL treatment. PL inactivation curves were generated for the survivors of each exposure cycle (as well as controls) to examine possible differences induced by repeated treatments. Growth curves of L monocytogenes, L. innocua, and E. coli isolates recovered from exposure to either 1.1 or 10.1 J/cm² were not significantly different from the growth curves of untreated cells. Reduction levels of up to 4 and up to 6 log CFU were obtained after exposure to 1.1 and 10.1 J/cm², respectively, both for the controls and the repeatedly treated and recovered isolates. These results show that PL did not significantly change the growth kinetics or resistance to PL of the target microorganisms after up to 10 exposures. These findings have significance for the practical application of PL treatment, as they indicate that this technology does not select for microorganisms with increased resistance. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to investigate the effect of concentration and temperature on the rheological properties of soy proteins (SP) and micellar casein (MCN) systems. Individual and mixed (1:1) protein systems of 2–15% concentration were prepared and heat treated for 5min at 40–90°C. After cooling to 20°C, their rheological properties were determined using steady-shear rheology. Zeta potential and particle size measurements were also conducted. Both proteins were negatively charged under all experimental conditions, but the absolute values of zeta potential and thus the stability of the protein solutions decreased with temperature and concentration. For SP solutions, viscosity and apparent yield stress increased with concentration. Shear thinning behavior was prevalent, becoming more pronounced with increasing concentration. Heat treatments at T ≥80°C induced glycinin denaturation, followed by aggregation and network formation when C ≥7.5%. Heat treatment did not significantly affect viscosity of MCN systems, while increasing concentration resulted in a significant increase in apparent viscosity and apparent yield stress. Most MCN systems exhibited Newtonian flow behavior, with the exception of systems with C ≥12.5% treated at T ≥80°C, which became slightly shear thickening. Mixed SP–MCN systems mimicked the behavior of SP, with most values of rheological parameters intermediate between SP and MCN-only systems. Mixtures of 7.5–12.5% concentration treated at 90°C displayed local phase separation, low viscosity and apparent yield stress, while 15% mixtures treated at 90°C showed protein aggregation and incipient network formation. The data generated in this study can be used to develop a range of protein based products with unique flow characteristics and storage stability. [Copyright &y& Elsevier]

The main objective of this work was to evaluate the effectiveness of pulsed light (PL) treatment for the inactivation of Escherichia coli in liquids with different levels of clarity. Nonpathogenic E. coli ATCC 25922 and pathogenic E. coli O157: H7 were used as challenge organisms. Butterfield's phosphate buffer (BPB), tryptic soy broth (TSB), apple juice, and apple cider were used as substrates. The inoculated liquids were placed in a thin layer (1.3 mm) into glass chambers (23 by 53 by 11 mm) and exposed to PL doses of up to 13.1 J/cm². PL treatments were performed in a Xenon RS-3000C PL unit, both static mode and under turbulence. Survivors were determined by standard plate counting or the most-probable-number technique. For static treatments, reduction levels exceeding 8.5 log were obtained in BPB for all strains and reduction levels of about 3.5 log were obtained in TSB. For apple juice, inactivation levels of 2.66 ± 0.10 log were obtained for E. coli ATCC 25922 and 2.52 ± 0.19 log for E. coli O157:H7. In cider, inactivation levels of 2.32 ± 0.16 log and 3.22 ± 0.29 log obtained for the nonpathogenic and pathogenic strains, respectively. Inactivation kinetics was characterized using the Weibull model. Turbulent treatments resulted in 5.76 ± 0.06 log reduction in cider and 7.15 ± 0.22 log reduction in juice, which satisfies the U.S. Food and Drug Administration requirement of 5-log reduction of E. coli. These results show promise for the use of PL for the effective reduction of E. coli in apple juice and cider. [ABSTRACT FROM AUTHOR]

The risk of listeriosis associated with ready-to-eat foods is a major concern in the United States. Pulsed light (PL) treatment has been effective for killing Listeria. The possibility of enhancing the antilisterial capability of PL treatment by combining PL with an additional hurdle, the natural antimicrobial nisin, was explored in this study. First, the ability of Listeria innocua to mimic the response of Listeria monocytogenes to PL treatment was demonstrated. Subsequently, a series of inoculation studies was performed in which canned sausages were surface inoculated with L. innocua as a surrogate for L. monocytogenes and then treated with a commercial preparation of nisin (Nisaplin), PL, or a combination of the two treatments. The application of a Nisaplin dip alone resulted in an immediate reduction of L. innocua by 2.35 ± 0.09 log CFU. PL reduced L. innocua by 1.37 ± 0.30 log CFU after exposure to 9.4 J/cm². A total reduction of 4.03 ± 0.15 log CFU was recorded after the combined treatment of Nisaplin and PL for 48 h at 4°C. The long-term survival of L. innocua was evaluated on sausages stored at 4°C. Treatment with Nisaplin and PL resulted in a 4- to 5-log reduction for two replicate studies. The combination treatment resulted in no significant microbial growth during 28 and 48 days of refrigerated storage in the first and second replicates, respectively. These results suggest that this combination treatment can be used as an effective antilisterial step in the production of ready-to-eat foods. [ABSTRACT FROM AUTHOR]

Pulsed light (PL) treatment can effectively reduce microbial populations in clear substrates and on surfaces, but its effectiveness varies as a function of substrate or treatment-related factors. For PL to be successfully adopted by the food industry, all factors of influence, as well as the inactivation kinetics for the microorganisms of concern, must be elucidated. In this study, the inactivation kinetics of Listeria innocua and the effect of inoculum size on PL inactivation were investigated. Stainless steel coupons (50.8 by 101.6 mm) of defined surface properties and transparent glass chamber slides (25.4 by 50.8 by 10 mm) were each inoculated with 1 ml of aqueous suspensions of L. innocua containing inoculum populations of up to 109 CFU. The thickness of the liquid layer in the glass slides was 1.16 mm. The inoculated substrates were exposed to PL treatment of up to 17 J/cm² in a static PL chamber equipped with a pulsed Xenon lamp. Survivors were recovered and enumerated by both standard plate counting and most-probable-number procedures. The data indicated that in clear liquids, PL resulted in more than a 6-log reduction of L. innocua after a 12-J/cm² treatment, regardless of the initial inoculum size. For the stainless steel surfaces, less than a 4-log reduction after a 12-J/cm² treatment and a noticeable effect of substrate characteristics and inoculum size on inactivation were observed. The survivor curves showed pronounced tailing for all substrates used in the study. The Weibull model accurately predicted the survivor ratios for the PL treatment of L. innocua in clear liquids, with a shape and scale parameter of 0.33 and 3.01, respectively. The Weibull model resulted in significant overestimation of PL effectiveness for the stainless steel substrates, where the influence of various substrate properties and inoculum level on inactivation was significant. [ABSTRACT FROM AUTHOR]

Pulsed light (PL) treatment is an alternative to traditional thermal treatment that has the potential to achieve several log-cycle reductions in the concentration of microorganisms. One issue that is still debated is related to what specifically causes cell death after PL treatments. The main objective of this work was to elucidate which portions of the PL range are responsible for bacterial inactivation. Stainless steel coupons with controlled surface properties were inoculated with a known concentration of Listeria innocua in the stationary growth phase and treated with 1 to 12 pulses of light at a pulse rate of 3 pulses per s and a pulse width of 360 µs. The effects of the full-spectrum (λ = 180 to 1,100 nm) were compared with the effects obtained when only certain regions of UV, visible, and near-infrared light were used. The effectiveness of the treatments was determined in parallel by the standard plate count and most-probable-number techniques. At a fluence of about 6 J/cm², the full-spectrum PL treatment resulted in a 4.08-log reduction of L. innocua on a Mill finish surface, the removal of λ < 200 nm diminished the reduction to only 1.64 log, and total elimination of UV light resulted in no lethal effects on L. innocua. Overwhelmingly, the portions of the PL spectrum responsible for bacterial death are the UV-B and UV-C spectral ranges (λ < 300 nm), with some death taking place during exposure to UV-A radiation (300 < λ < 400 nm) and no observable death upon exposure to visible and near-infrared light (λ > 400 nm). This work provides additional supporting evidence that cell death in PL treatment is due to exposure to UV light. Additionally, it was shown that even a minor modification of the light path or the UV light spectrum in PL treatments can have a significant negative impact on the treatment intensity and effectiveness. [ABSTRACT FROM AUTHOR]

This work explores the structural effects of high‐pressure processing (HPP) on starch in mixed pea protein–starch systems of varying concentrations. Reconstituted pea protein concentrate containing 9, 12, and 15% (w/w) protein, without added starch or in combination with 4 or 8% (w/w) pea starch, respectively, were subjected to HPP at 600 MPa for 4 min, at 5°C. Structural changes were investigated using dynamic rheology, scanning electron microscopy, and differential scanning calorimetry (DSC). The addition of starch enabled the formation of weak gels, at protein concentrations below the minimum required for gelation. Above the minimum protein concentration for gelation, starch addition resulted in stronger gels. Starch acted mainly as a filler in the pressure‐induced protein gel matrix, and starch granules remained intact after HPP. DSC analyses confirmed that starch remained ungelatinized after HPP, likely due to the limited availability of water in the mixed systems during HPP. Practical Applications: The structure of pressure‐induced protein gels can be enhanced by adding starch. Besides being a low‐cost ingredient, starch remains ungelatinized after high‐pressure treatment, and thus can act like a fiber. Therefore, pressure‐treated protein–starch mixtures may lead to the development of low‐glycemic index, high‐protein products. [ABSTRACT FROM AUTHOR]

This work demonstrates the use of high pressure processing (HPP) to induce structural modifications in pea protein concentrates (PPC). Reconstituted PPC with 8–24 g protein /100 g water were subjected to HPP at 250–550 MPa for 15 min, at 20–33°C, or heat treatments at 95°C for 15 min. Structural changes were investigated using dynamic rheology, scanning electron microscopy, differential scanning calorimetry, and mid‐infrared spectroscopy. Gel formation occurred at 16 g protein /100 g water concentration and 250 MPa for the HPP‐treated samples, and at 12 g protein /100 g water concentration for the heat‐treated samples. Gel strength increased with both pressure level and protein concentration. Heat‐treated samples exhibited greater gel strength than pressure‐treated samples at the same protein concentration. A greater extent of protein denaturation, aggregation, and network formation occurred with increasing pressure level, due to protein tertiary and quaternary conformation changes. Starch granules present in PPC retained their structure and were not gelatinized even at 550 MPa. These findings can be used to create novel pea protein products with interesting structures and superior sensory and nutritional properties. Practical Applications: This work shows that a range of unique pea‐based products, such as puddings or tofu analogs, can be created by low temperature HPP treatment of pea protein concentrates at different pressure levels and protein concentrations. This process has the potential to better preserve the organoleptic and nutritional properties of the final products compared to traditional, heat based processing methods. These findings can be also extended to create other pulse protein products using high pressure processing. [ABSTRACT FROM AUTHOR]

Attachment and biofilm formation by bacterial pathogens on surfaces in natural, industrial, and hospital settings lead to infections and illnesses and even death. Minimizing bacterial attachment to surfaces using controlled topography could reduce the spreading of pathogens and, thus, the incidence of illnesses and subsequent human and financial losses. In this context, the attachment of key microorganisms, including Escherichia coli, Listeria innocua, and Pseudomonas fluorescens, to silica and alumina surfaces with micron and nanoscale topography was investigated. The results suggest that orientation of the attached cells occurs preferentially such as to maximize their contact area with the surface. Moreover, the bacterial cells exhibited different morphologies, including different number and size of cellular appendages, depending on the topographical details of the surface to which they attached. This suggests that bacteria may utilize different mechanisms of attachment in response to surface topography. These results are important for the design of novel microbe-repellant materials. [ABSTRACT FROM AUTHOR]

Background/objectives: Prevention of biofilm formation by bacteria is of critical importance to areas that directly affect human health and life including medicine, dentistry, food processing and water treatment. This work showcases an effective and affordable solution for reducing attachment and biofilm formation by several pathogenic bacteria commonly associated with foodborne illnesses and medical infections., Methods: Our approach exploits anodisation to create alumina surfaces with cylindrical nanopores with diameters ranging from 15 to 100 nm, perpendicular to the surface. The anodic surfaces were evaluated for attachment by Escherichia coli , Listeria monocytogenes , Staphylococcus aureus and Staphylococcus epidermidis . Cell-surface interaction forces were calculated and related to attachment., Results: We found that anodic alumina surfaces with pore diameters of 15 and 25 nm were able to effectively minimise bacterial attachment or biofilm formation by all the microorganisms tested. Using a predictive physicochemical approach on the basis of the extended Derjaguin and Landau, Verwey and Overbeek (XDLVO) theory, we attributed the observed effects largely to the repulsive forces, primarily electrostatic and acid-base forces, which were greatly enhanced by the large surface area originating from the high density, small-diameter pores. We also demonstrate how this predictive approach could be used to optimise different elements of surface topography, particularly pore diameter and density, for further enhancing the observed bacteria-repelling effects., Conclusions: We demonstrate that anodic nanoporous surfaces can effectively reduce bacterial attachment. These findings are expected to have immediate, far-reaching implications and commercial applications, primarily in health care and the food industry., Competing Interests: The authors declare no conflict of interest.