Radical species generating technologies for decontamination of Listeria species in food: a recent review report.

Foodborne illnesses occur due to the contamination of fresh, frozen, or processed food products by some pathogens. Among several pathogens responsible for the illnesses, Listeria monocytogenes is one of the lethal bacteria that endangers public health. Several preexisting and novel technologies, especially non-thermal technologies are being studied for their antimicrobial effects, particularly toward L. monocytogenes. Some noteworthy emerging technologies include ultraviolet (UV) or light-emitting diode (LED), pulsed light, cold plasma, and ozonation. These technologies are gaining popularity since no heat is employed and undesirable deterioration of food quality, especially texture, and taste is devoided. This review aims to summarize the most recent advances in non-thermal processing technologies and their effect on inactivating L. monocytogenes in food products and on sanitizing packaging materials. These technologies use varying mechanisms, such as photoinactivation, photosensitization, disruption of bacterial membrane and cytoplasm, etc. This review can help food processing industries select the appropriate processing techniques for optimal benefits, in which the structural integrity of food can be preserved while simultaneously destroying L. monocytogenes present in foods. To eliminate Listeria spp., different technologies possess varying mechanisms such as rupturing the cell wall, formation of pyrimidine dimers in the DNA through photochemical effect, excitation of endogenous porphyrins by photosensitizers, generating reactive species, causing leakage of cellular contents and oxidizing proteins and lipids. These technologies provide an alternative to heat-based sterilization technologies and further development is still required to minimize the drawbacks associated with some technologies.

Piezoelectric dispenser printing and intense pulse light sintering of AgNW/PEDOT:PSS hybrid transparent conductive films.

A hybrid transparent conductive films (TCFs) combining silver nanowires (AgNWs) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) was fabricated using a piezoelectric dispenser printing method. The innovation lies in optimizing the ink composition and employing intense pulsed light (IPL) sintering to enhance the TCF's performance. The optimized AgNW/PEDOT:PSS mixture, with an 8:2 ratio, achieved a figure of merit (FOM) of 28.05 × 10⁻³/Ω, corresponding to a sheet resistance of 9.93 Ω/sq. and a transmittance of 88.0%. This represents a significant improvement over the pre-sintering FOM of 24.09 × 10⁻³/Ω. Additionally, the hybrid TCFs exhibited outstanding structural stability, maintaining functionality after 7000 mechanical bending cycles. The results enable applications in flexible optoelectronic devices, and highlight the potential of this method to produce high-performance, flexible, and durable transparent electrodes, advancing the development of next-generation optoelectronic devices.

Revisiting Unaddressed Safety Concerns Regarding Intense Pulsed Light Treatment: Past and Present Perspectives.

BACKGROUND: The light spectrum of intense pulsed light (IPL) comprises visible to near-infrared light. It has been widely employed in the field of aesthetics for approximately 30 years. However, several studies have demonstrated the appearance of various undesirable biomarkers on the skin after IPL irradiation, which remain elucidated. METHODS: We reviewed the evolving concepts and explored the potentially harmful effects of IPL that may have been neglected in the past. RESULTS: Increased levels of reactive oxidative stress, p53, p16, proliferating cell nuclear antigen, interleukin-6, C-reactive protein, and cleaved caspase 3 and decreased albumin levels in human or mouse skin have been observed after IPL treatment. Visible and infrared light can exert harmful and beneficial effects on human skin. CONCLUSION: If perform improperly, IPL treatment may lead to cellular senescence, photoaging, photocarcinogenesis, thermal aging, and inflammaging. Further studies are required to verify the significance of the changes in the relevant biomarkers. The selection of treatment candidates, optimal parameters, and standardized protocols for IPL therapy are necessary.

Clinical features and comprehensive treatment of persistent corneal epithelial dysfunction after cataract surgery.

OBJECTIVE: Evaluation of clinical efficacy and safety of tobramycin/dexamethasone eye ointment in treating persistent corneal epithelial dysfunction (PED) after cataract surgery. METHODS: 26 cases diagnosed as PED after cataract surgery accept the tobramycin/dexamethasone ophthalmic ointment and intense pulse light treatment in the Xiamen University of Xiamen eye center between September 2016 and April 2022 were retrospectively analyzed, mainly including clinical manifestations, characteristics of morphological changes imaged by in vivo confocal microscopy, meibomian glands infrared photography, lipid layer thickness (LLT), management and therapeutic effects. RESULTS: There were 26 eyes, include 8(35%) males and 15(65%) females with an average age of 69.6 ± 5.2 years(50 to 78 years). The mean hospitalization time was (18.4 ± 7.5) days after cataract surgery. Twenty patients had meibomian gland dysfunction. Infrared photography revealed varying loss in the meibomian glands, with a mean score of 3.8 ± 1.2 for gland loss. The mean LLT was 61.6 ± 8.4 nm. After treatment, 20 patients were cured, and 3 received amniotic membrane transplantation. After treatment, the uncorrected visual acuity (UCVA) and best-corrected vision activity (BCVA) improved (P < 0.001), and there was no significant difference in intraocular pressure (IOP) before and after treatment (P > 0.05). CONCLUSIONS: The early manifestation of PED after surgery is punctate staining of the corneal epithelium. Tobramycin and dexamethasone eye ointment bandages have a good repair effect. The meibomian gland massage combined with intense pulse light treatment can effectively shorten the course of the disease.

Combined microfocused ultrasound and delicate pulsed light for facial rejuvenation: A prospective, randomized, and split-face study.

OBJECTIVES: Public's interest in noninvasive skin rejuvenation treatments continues to grow. The advantage of combination therapy lies in that it can target different aspects of skin rejuvenation. This study aimed to assess the efficacy and safety of microfocused ultrasound (MFU) combined with delicate pulsed light (DPL) for facial rejuvenation. METHODS: Twenty-one patients with facial relaxation were enrolled. All patients received whole-face MFU treatment, and one side of the face was randomly assigned to receive DPL. MFU treatment was performed at Months 0 and 3, while DPL treatment was performed at Months 1, 2, 4, and 5. The length and angle of the nasolabial fold and perioral wrinkles, melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and follow-up time were recorded at Months 0, 3, and 6. Side effects were recorded during treatment and each follow-up visit. RESULTS: Twenty patients successfully completed the study. At the sixth month, the average length of perioral wrinkles and nasolabial folds on the combined side decreased by 11.5% (pwithin < 0.001) and 6.5% (pwithin = 0.011), while 8.3% (pwithin = 0.012) and 3.8% (pwithin = 0.02) on the MFU side. Compared with MFU treatment alone, the combined treatment also showed significant improvements in nasolabial fold angle (from 28.8 ± 3.4° to 32.7 ± 5.0°) and perioral wrinkle angle (from 39.3 ± 5.0° to 43.7 ± 5.1°). In addition, the combined side had greater benefits than the MFU side in improving MI, EI, TEWL, and skin elasticity (pbetween < 0.05). Except for one patient who withdrew due to increased skin sensitivity after MFU treatment, other subjects did not experience permanent or serious side effects. CONCLUSIONS: The combination of MFU and DPL for facial rejuvenation treatment is safe and effective. The combined treatment has better efficacy in skin firmness, and improving skin tone.

Advancing precision acne therapy using a novel photopneumatic device.

Photopneumatic therapy (PPT) combines vacuum and pulsed, broadband light to extract debris and bacteria from the pilosebaceous units; monotherapy is unexplored. Facial acne lesions and skin texture were evaluated after up to six PPT treatments, 1-2 weeks apart for 15-20 minutes per treatment using customized energy settings, in seven female patients with inflammatory, comedonal and pustular lesions. Lesion and redness reduction with improvement in skin texture and pore size were observed after 1-3 treatments; adverse effects were infrequent. PPT may optimize lesion clearance as monotherapy and/or as an adjuvant. The ability to change pulse structure, pulse duration, vacuum pressure and fluence allow for treatment that best matches skin type and acne severity.

Review of laser and energy-based devices to treat rosacea in skin of color.

The prevalence of rosacea in skin of color (SOC) populations is estimated to be as high as 10% in some countries. Traditionally, intense pulsed light (IPL) and pulsed dye laser (PDL) have been the laser and energy-based devices (EBDs) used to treat rosacea. However, not all laser and EBDs are safe for SOC (Fitzpatrick skin types IV-VI) due to increased absorption of energy in pigmented skin and increased risk of post-inflammatory hyperpigmentation and scarring. This review summarizes the use of the top seven laser and EBDs for treating rosacea in SOC.

Combined treatment of pulsed light and nisin-organic acid based antimicrobial wash for inactivation of Escherichia coli O157:H7 in Romaine lettuce, reduction of microbial loads, and retention of quality.

Microbial safety of fresh produce continues to be a major concern. Novel antimicrobial methods are needed to minimize the risk of contamination. This study investigated the antimicrobial efficacy of pulsed light (PL), a novel nisin-organic acid based antimicrobial wash (AW) and the synergy thereof in inactivating E. coli O157:H7 on Romaine lettuce. Treatment effects on background microbiota and produce quality during storage at 4 °C for 7 days was also investigated. A bacterial cocktail containing three outbreak strains of E. coli O157:H7 was used as inoculum. Lettuce leaves were spot inoculated on the surface before treating with PL (1-60 s), AW (2 min) or combinations of PL with AW. PL treatment for 10 s, equivalent to fluence dose of 10.5 J/cm2, was optimal and resulted in 2.3 log CFU/g reduction of E. coli O157:H7, while a 2 min AW treatment, provided a comparable pathogen reduction of 2.2 log CFU/g. Two possible treatment sequences of PL and AW combinations were investigated. For PL-AW combination, inoculated lettuce leaves were initially exposed to optimum PL dose followed by 2 min AW treatment, whereas for AW-PL combination, inoculated lettuce were subjected to 2 min AW treatment prior to 10 s PL treatment. Both combination treatments (PL-AW and AW-PL) resulted in synergistic inactivation as E. coli cells were not detectable after treatment, indicating >5 log pathogen reductions. Combination treatments significantly (P < 0.05) reduced spoilage microbial populations on Romaine lettuce and also hindered their growth in storage for 7 days. The firmness and visual quality appearance of lettuce were not significantly (P > 0.05) influenced due to combination treatments. Overall, the results reveal that PL and AW combination treatments can be implemented as a novel approach to enhance microbial safety, quality and shelf life of Romaine lettuce.

Comparing resistance of bacterial spores and fungal conidia to pulsed light and UVC radiation at a wavelength of 254 nm.

Pulsed light (PL) inactivates microorganisms by UV-rich, high-irradiance and short time pulses (250 µs) of white light with wavelengths from 200 nm to 1100 nm. PL is applied for disinfection of food packaging material and food-contact equipment. Spores of seven Bacillus ssp. strains and one Geobacillus stearothermophilus strain and conidia of filamentous fungi (One strain of Aspergillus brasiliensis, A. carbonarius and Penicillium rubens) were submitted to PL (fluence from 0.23 J/cm2 to 4.0 J/cm2) and UVC (at λ = 254 nm; fluence from 0.01 J/cm2 to 3.0 J/cm2). One PL flash at 3 J/cm2 allowed at least 3 log-reduction of all tested microorganisms. The emetic B. cereus strain F4810/72 was the most resistant of the tested spore-forming bacteria. The PL fluence to 3 log-reduction (F3 PL) of its spores suspended in water was 2.9 J/cm2 and F3 UVC was 0.21 J/cm2, higher than F3 PL and F3 UVC of spores of B. pumilus SAFR-032 2.0 J/cm2 and 0.15 J/cm2, respectively), yet reported as a highly UV-resistant spore-forming bacterium. PL and UVC sensitivity of bacterial spores was correlated. Aspergillus spp. conidia suspended in water were poorly sensitive to PL. In contrast, PL inactivated Aspergillus spp. conidia spread on a dry surface more efficiently than UVC. The F2 PL of A. brasiliensis DSM1988 was 0.39 J/cm2 and F2 UVC was 0.83 J/cm2. The resistance of spore-forming bacteria to PL could be reasonably predicted from the knowledge of their UVC resistance. In contrast, the sensitivity of fungal conidia to PL must be specifically explored.

A Review of Intense Pulsed Light in the Treatment of Ocular Rosacea.

INTRODUCTION: Ocular rosacea is an underdiagnosed form of rosacea that may occur with or without typical cutaneous signs of rosacea. One of the common manifestations is dry eyes. Although the use of intense pulsed light (IPL) in the treatment of rosacea-related dry eyes has been reported, a recent review is lacking. METHODS: A scoping review was performed to summarize the efficacy of IPL in the treatment of ocular rosacea. RESULTS: Five articles were included, representing 108 patients, with a mean age of 58.4 years. Based on available data, 59.2% (n = 58/98) were female. The studies detailed the use of IPL in combination with meibomian gland expression treatment. Overall, 91% (n = 89/98) of patients with ocular rosacea treated with IPL had a partial response and 9% (n = 9/98) had no response. IPL therapy did not lead to complete recovery in any of the included patients. One participant experienced an adverse event across the included studies. CONCLUSIONS: IPL is a promising treatment modality for ocular rosacea, as demonstrated by its ability to relieve dry eye symptoms with limited adverse events. Further research into this novel treatment is necessary to ascertain its role in the management of ocular rosacea.

Efficacy and safety of radiofrequency in the treatment of hidradenitis suppurativa; a systematic review.

BACKGROUND AND AIMS: Hidradenitis suppurativa (HS) is an inflammatory skin disease affecting apocrine gland-bearing sites of the body. Radiofrequency (RF) is a minimally invasive method that acts by minimizing thermal damage to the dermis, resulting in collagen synthesis and scar improvement. We systematically reviewed the efficacy and safety of RF in treating HS. METHODS: A systematic search was performed up to November 18th, 2023, in PubMed/Medline, Ovid Embase, and Web of Science. Clinical studies with English full texts were included. The National Institute of Health (NIH) Quality Assessment Tool for clinical trials and Methodological quality and synthesis of case series and case reports by Murad et al. were utilized for critical appraisal. RESULTS: Out of 55 identified studies, 11 met our inclusion criteria with 167 subjects who underwent RF therapy alone or combined with an intense pulsed laser (IPL), known as LAight®. LAight® significantly improved clinical outcomes in mild-to-moderate HS patients based on the Dermatology Life Quality Index (DLQI), International Hidradenitis Suppurativa Score System (IHS4), Pain-Numerical Rating Scale (NRS), and Hidradenitis Suppurativa Clinical Response (HiSCR). Moreover, RF therapy alone significantly alleviated the clinical manifestations in patients with mild-to-moderate HS. Additionally, fractional microneedling RF significantly decreased HS-associated inflammatory markers. RF was found to be safe with limited adverse events. However, in moderate-to-severe HS, RF has failed to yield satisfactory results. CONCLUSION: RF is a safe energy-based method with promising outcomes, especially for long-term application in mild-to-moderate HS. In moderate-to-severe cases, RF should be combined with a systemic medication for further beneficial impacts.

Efficacy and safety comparison between pulsed dye laser and intense pulsed light configured with different wavelength bands in treating erythematotelangiectatic rosacea.

Previous clinical studies have shown that pulsed dye laser (PDL) and intense pulsed light (IPL) are effective for treating erythematotelangiectatic rosacea(ETR). This article aims to compare the efficacy and safety of PDL and IPL at three different wavelength bands (broad-band, single-narrow-band, and dual-narrow-band) in treating ETR. Sixty subjects with ETR were randomly categorized into four groups and received one of the following laser treatments: PDL (595 nm), IPL with Delicate Pulse Light (DPL, 500-600 nm), IPL with M22 590 (590-1200 nm), or IPL with M22 vascular filter (530-650 nm and 900-1200 nm). Four treatment sessions were administered at 4-week intervals, with one follow-up session 4 weeks after the final treatment. The efficacy of the four lasers was evaluated by comparing the clinical symptom score, total effective rate, VISIA red area absolute score, and RosaQoL score before and after treatment. The safety was evaluated by comparing adverse reactions such as pain, purpura, erythematous edema, and blister. All 60 subjects completed the study. Within-group effects showed that the clinical symptom score, VISIA red area absolute score, and RosaQoL score of all four groups were significantly reduced compared to before treatment (p < 0.001). Between-group effects showed no statistically significant difference among the four laser groups. Safety analysis showed that all four lasers were safe, but the incidence of blister was higher in the M22 vascular group. Nonpurpurogenic PDL, DPL, M22 590, and M22 vascular were equally effective in treating ETR and were well-tolerated. ClinicalTrial.gov Identifier: NCT05360251.

Intense pulsed light therapy for ocular surface diseases.

Intense pulsed light (IPL) is a non-laser, high-intensity light source that has been shown to play a valuable role in dermatology and has been adopted in ophthalmology for treating meibomian gland dysfunction (MGD). In this review, we discuss the mechanism of action of IPL, including its benefits in ophthalmology. IPL therapy has been shown to improve tear film stability, meibomian gland (MG) function, and subjective symptoms of ocular dryness in MGD patients. Moreover, emerging evidence suggests that IPL therapy is beneficial for other ocular surface diseases, such as blepharitis and chalazia. Hence, it can be inferred that IPL has potential as a therapeutic modality in future applications. Large clinical and experimental trials are needed to exploit the full potential of IPL as a treatment for recurrent chalazia, Sjögren's syndrome, and other causes of dry eye disease (DED). This paper reviews the published literature related to the application of IPL for treating ocular surface diseases.

Effects of combined intense pulsed light and cyclosporine 0.05% eyedrops in ocular surface matrix metalloproteinase-9 levels in patients with moderate-to-severe MGD.

To investigate the changes in meibomian gland dysfunction (MGD) and tear matrix metalloproteinase-9 (MMP-9) levels in patients with moderate-to-severe MGD after combined treatment with intense pulsed light (IPL) therapy and cyclosporine 0.05%. Thirty-six patients concurrently treated with IPL and cyclosporine 0.05% ophthalmic drops were retrospectively enrolled. Tear break up time (TBUT), corneal and conjunctival staining scores, Schirmer test, and ocular surface disease index (OSDI) questionnaire responses were recorded. Meibum quality, consistency, and eyelid margin telangiectasia were evaluated. MMP-9 levels were examined by the positivity and signal intensity of red lines (scored 0-4). IPL was performed four times with a vascular filter at 2-week intervals, followed by a 1-month follow-up after treatment cessation. Immediately after each IPL treatment, gentle meibomian gland expression was performed in both the upper and lower eyelids using meibomian gland expressor forceps. TBUT (1.88 ± 1.02 s to 3.12 ± 1.08 s, p < 0.001), corneal and conjunctival staining (6.19 ± 2.11 to 3.12 ± 1.89, p < 0.001), Oxford staining grade (2.66 ± 0.89 to 1.35 ± 0.76, p < 0.001), and OSDI (52.97 ± 21.86 to 36.36 ± 22.45, p < 0.001) scores significantly improved after the combined treatment. Meibum quality, consistency and lid margin telangiectasia showed significant post-treatment improvement in both the upper and lower eyelids. MMP-9 positivity showed a significant decrease (97-69%, p = 0.026) with a reduction in signal intensity (2.72 ± 0.87 to 2.09 ± 0.95, p = 0.011). The combination of IPL therapy and 0.05% cyclosporine eye drops effectively treats moderate-to-severe MGD by reducing symptoms and signs of MGD and by decreasing ocular surface MMP-9-associated inflammation.

High Power Pulsed LED Driver for Vibration Measurements.

Vibration measurements pose specific experimental challenges to be faced. In particular, optical methods can be used to obtain full-field vibration information. In this scenario, stereo-camera systems can be developed to obtain 3D displacement measurements. As vibration frequency increases, the common approach is to reduce camera exposure time to avoid blurred images, which can lead to under-exposed images and data loss, as well as issues with the synchronization of the stereo pair. Both of these problems can be solved by using high-intensity light pulses, which can produce high-quality images and guarantee camera synchronization since data is saved by both cameras only during the short-time light pulse. To this extent, high-power Light-Emitting Diodes (LEDs) can be used, but even if the LED itself can have a fast response time, specific electronic drivers are needed to ensure the desired timing of the light pulse. In this paper, a circuit is specifically designed to achieve high-intensity short-time light pulses in the range of 1 µs. A prototype of the designed board was assembled and tested to check its capability to respect the specification. Three different measurement methods are proposed and validated to achieve short-time light pulse measurements: shunt voltage measurement, direct photodiode measurement with a low-cost sensor, and indirect pulse measurement through a low-frame-rate digital camera.

Safety and Effectiveness of Laser or Intense Pulsed Light Treatment for Early Surgical Scar: A Systematic Review and Meta-analysis.

OBJECTIVE: We aimed to investigate the safety and efficacy of laser or intense pulsed light therapy for early treatment of surgical scar. METHODS: A literature search was conducted for relevant prospective, randomized controlled trials published in PubMed, Embase, Web of Science, Cochrane Library, CNKI, WanFang Database, and VTTMS between January 2006 and January 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was used to extract literature data. The risk of bias was assessed by RevMan. Safety was assessed based on the presence of serious adverse reactions (blisters, infections, burns above the second degree), while effectiveness was assessed using the Vancouver Score Scale. RESULTS: 1512 related articles were preliminarily retrieved, including 1211 English articles and 301 Chinese articles. According to the inclusion criteria and exclusion criteria, 12 articles were selected for this analysis. In total, 475 patients were included (laser group, 238; control group, 236). All studies confirmed that the laser group was superior to the control group. In the subgroup analysis of 7 articles, the standardized mean difference was 1.99 (P = 0.0001). CONCLUSIONS: This meta-analysis demonstrates that laser or intense pulsed light therapy is a safe and effective approach for early surgical scar treatment, resulting in improved scar appearance and minimal adverse reactions. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Changes of Facial Lipidomics by Intense Pulsed Light Treatment Based on LC-MS.

BACKGROUND: Intense pulsed light (IPL) has been widely used to improve cutaneous photoaging in recent years. Several studies began to explore the changes of skin barrier function after treatment, but the changes of skin surface lipids (SSL), especially specific lipid content and types are still unclear. METHODS: A total of 25 female volunteers were included in our study, and each of them received three full-face treatments with one month apart. Before the first treatment and 1 month after the last treatment, we collected clinical photos and skin stratum corneum samples from individuals. A 5-level scale was used to evaluate the efficacy of IPL treatment, liquid chromatography-mass spectrometry (LC-MS), and Orthogonal Partial Least Squares Discrimination Analysis (OPLS-DA) were used to analyze the changes of SSL. RESULTS: Two patients got no improvement after treatment, 6 patients had poor improvement and mild improvement was achieved in 9 patients, 5 and 3 patients reported moderate and significant improvement. The overall "effective" rate was 68 % and the "significant effective" rate was 32 %. The results showed 18 lipid subclasses and 487 lipid molecules were identified. The change of total lipid volume was not statistically significant (P = 0.088>0.05), but lipid subclass analysis showed the amount of Triglyceride (TG), Phosphatidic Acid (PA), Phosphatidylglycerol (PG) and Lysophosphatidylglycerol (LPG) were significantly increased (P < 0.05). There were 55 kinds of lipid molecules with significant difference after treatment (P < 0.05), and 51 of them belong to TG. The analysis of chain saturation of TG showed that the quantity of TG with 0, 1 and 2 unsaturated bonds increased significantly (P < 0.05). CONCLUSIONS: IPL treatment does not have a significant effect on the overall amount of lipids while the amount of TG, PA, PG, LPG were significantly increased. These lipid changes may potentially improve the skin barrier function, but more high-quality and comprehensive studies are still needed. BULLET POINT: Lipidomics analysis based on LC-MS; Changes of skin surface lipid after IPL treatment; the relationships between skin surface lipid and skin barrier functions. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Pulsed light treatment enhances starch hydrolysis and improves starch physicochemical properties of germinated brown rice.

BACKGROUND: Recently, germinated brown rice (GBR) has gained substantial attention as a functional food because of its nutritional attributes. Notably, pulsed light technology (PLT) has emerged as a promising tool for enhancing rice germination and, consequently, has improved the nutritional and functional qualities of GBR-derived products. However, further research is required to comprehensively understand the impact of PLT on GBR physicochemical properties. The present study aimed to investigate the stimulating effects of PLT on starch hydrolysis, starch structure and functional properties of GBR. RESULTS: The PLT substantially boosted α-amylase activity during brown rice germination, leading to a 10.9% reduction in total starch content and a 17.3% increase in reducing sugar content, accompanied by elevated free water levels. Structural analysis indicated no changes in starch crystalline types, whereas gelatinization temperature slightly increased. Pasting properties exhibited a significant drop in peak viscosity. Scanning electron microscopy showed surface erosion of starch granules with microstructural changes. Furthermore, correlation analysis established positive links between α-amylase activity, reducing sugar accumulation, starch structure and functional properties in GBR. CONCLUSION: The present study demonstrates that PLT enhanced the physicochemical properties of GBR starch, significantly improving the stability of GBR products, thereby contributing to expanded applicability of rice starch in the food industry. © 2023 Society of Chemical Industry.

Pulsed light processing of sugarcane juice: quality evaluation and microbial load assessment.

BACKGROUND: Freshly extracted sugarcane juice is an ideal substrate for microbial fermentation and browning reactions. The present study is the first report on the potential of pulsed light (PL) processing in improving microbial stability with the retention of major bioactive. PL processing at different levels of voltage (2.1-2.7 kV) and number of pulses (100-200) was explored. The present study aimed to investigate the impact of PL processing on the quality of sugarcane juice, bioactive composition and microbial load. RESULTS: The microbial load, such as aerobic mesophiles, yeast and mold, and total coliform, was reduced to below 1 log colony-forming units mL-1 in juice samples subjected to intense PL treatment at 2.7 kV. The maximum value of the total color difference of the sugarcane juice was below 4.0, even at extreme levels of PL process parameters. In comparison with the unprocessed juice, the reduction in total phenols (Folin ciocalteu reagent assay) and the total antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay) was limited to 6% and 16.7%, respectively, when treated at 2.7 kV/200 pulses. The pH and total soluble solids of the juice remained unaffected in all the processed samples. Among the process parameters considered, the treatment voltage was found to significantly affect the quality parameters and microbial load. CONCLUSION: PL processing at 2.1 kV/170 pulses gave an optimally processed juice with a microbial load below the permissible limit and desirability value of 0.77. The results suggest that the PL treatment is effective for enhancing the microbial stability and maintaining the bioactive components of the sugarcane juice. Furthermore, the outcomes from the present study are expected to pave the way for further in-depth investigation of the effect of PL treatment on the critical quality attributes and shelf life of sugarcane juice. The technology will be useful for adoption by different stakeholders, including manufacturers and retailers in the food processing sector. © 2024 Society of Chemical Industry.

Protective Effect of Select Bacterial Species Representative of Fresh Produce on Human Norovirus Surrogates Exposed to Disinfecting Pulsed Light.

Contamination of berries and leafy greens with human norovirus (HuNoV) is a major cause of outbreaks of epidemic gastroenteritis worldwide. Using murine norovirus type 1 (MNV-1) and Tulane virus, we studied the possible extension of HuNoV persistence by biofilm-producing epiphytic bacteria on fresh produce. Nine bacterial species frequently found on the surface of berries and leafy greens (Bacillus cereus, Enterobacter cloacae, Escherichia coli, Kocuria kristinae, Lactobacillus plantarum, Pantoea agglomerans, Pseudomonas fluorescens, Raoultella terrigena, and Xanthomonas campestris) were evaluated for the ability to form biofilms in the MBEC Assay Biofilm Inoculator and in 96-well microplates. The biofilm-forming bacteria were further tested for binding MNV-1 and Tulane virus and the ability to protect them against loss of capsid integrity upon exposure to disinfecting pulsed light at a fluence of 11.52 J/cm2. Based on viral reductions, MNV-1 did not benefit from attachment to biofilm whereas Tulane virus was significantly more resistant than the control when attached to biofilms of E. cloacae (P ≤ 0.01), E. coli (P ≤ 0.01), K. kristinae (P ≤ 0.01), P. agglomerans (P ≤ 0.05), or P. fluorescens (P ≤ 0.0001). Enzymatic dispersion of biofilm and microscopic observations suggest that the biofilm matrix composition may contribute to the virus resistance. Our results indicate that direct virus-biofilm interaction protects Tulane virus against disinfecting pulsed light, and that HuNoV on fresh produce therefore might resist such treatment more than suggested by laboratory tests so far. IMPORTANCE Recent studies have shown that bacteria may be involved in the attachment of HuNoV to the surface of fresh produce. Because these foods are difficult to disinfect by conventional methods without compromising product quality, nonthermal nonchemical disinfectants such as pulsed light are being investigated. We seek to understand how HuNoV interacts with epiphytic bacteria, particularly with biofilms formed by bacterial epiphytes, with cells and extracellular polymeric substances, and to determine if it thus escapes inactivation by pulsed light. The results of this study should advance understanding of the effects of epiphytic biofilms on the persistence of HuNoV particle integrity after pulsed light treatment and thus guide the design of novel pathogen control strategies in the food industry.