A review on the application and safety of non-thermal techniques on fresh produce and their products

Improving ready-to-eat meat safety: Evaluating the bacterial-inactivation efficacy of microplasma-based far-UVC light treatment of food-contact surfaces and deli turkey breast

The safety of ready-to-eat (RTE) deli meats, especially those sliced in retail establishments, may be improved by light-based surface decontamination. Conventional 254 nm ultraviolet-C (UVC) systems have strong germicidal effects but pose human-health hazards that make them unsuitable for retail use. This study therefore explores the efficacy of microplasma-based 222 nm far-UVC lamps as a safer alternative for decontaminating liquid buffer, two common food-contact surfaces (polyethylene terephthalate and stainless steel), and RTE turkey breast. In all three non-meat cases, the system achieved approximately 5-log reductions of both Listeria monocytogenes and Salmonella Typhimurium. The system also caused a 1.3-log reduction of L. monocytogenes and a 1-log reduction of S. Typhimurium on turkey breast at the highest tested dose of 786.3 mJ/cm2. Color is a key quality indicator for RTE meat consumers, and treatment caused no significant change in L∗, a∗, or b∗ color values (p > 0.05) until doses reached 224.7 mJ/cm2. However, higher doses could lead to statistically significant color changes. Given that far-UVC light has been deemed human-safe by other studies, the proposed system has considerable potential to improve RTE food-related safety in retail establishments, even when consumers and workers are present.

Advances in non-thermal technologies: A revolutionary approach to controlling microbial deterioration, enzymatic activity, and maintaining other quality parameters of fresh stone fruits and their processed products

Stone fruits and their processed products are highly valued in the whole world for their flavor, aroma, rich nutritional contents, and various health benefits. While large quantities of stone fruits are produced globally, significant losses occur due to improper handling and storage, from production to consumption. This review focuses on the application of advanced non-thermal treatment techniques for whole fresh stone fruits and their processed products. It provides a comprehensive assessment of the factors contributing to spoilage, along with the mechanisms, applications, and limitations of non-thermal techniques in reducing spoilage. Compared to traditional preservation methods, such as the use of artificial food additives, chemicals, thermal treatments, and low-temperature storage, these novel techniques demonstrate better results in minimizing spoilage. Moreover, non-thermal techniques are most sustainable and eco-friendly, as they reduce energy consumption, minimize chemical use, and generate less waste than traditional methods.

Inactivation of foodborne pathogens by non-thermal technologies

Non-thermal treatments are current trends in food safety, the application of these technologies may lessen the influence of heat on food quality. The non-thermal food preservation techniques enable the food industry to meet regulations for product safety and shelf life. Common non-thermal techniques include cold plasma, ionizing radiation, ultraviolet light, pulsed electric fields, and high-pressure processing. This chapter provides a quick summary of the most current uses of these technologies for food preservation. In addition, a succinct description of the process used to inactivate foodborne microorganisms in food has been provided.

Berries as Foods: Processing, Products, and Health Implications

Berries are highly regarded as flavorful and healthy fruits that may prevent or delay some chronic diseases attributed to oxidative stress and inflammation. Berries are low in calories and harbor diverse bioactive phytochemicals, antioxidants, dietary fibers, and vitamins. This review delves into the main characteristics of fresh berries and berry products as foods and the technologies associated with their production. The main effects of processing operations and related variables on bioactive components and antioxidants are described. This review critically discusses why some health claims based on in vitro antioxidant data and clinical studies and intervention trials are difficult to assess. The review suggests that the beneficial health effects of berries are derived from a multifactorial combination of complex mixtures of abundant phenolic components, antioxidants, and their metabolites acting synergistically or additively with other nutrients like fibers and vitamins and possibly by modulating the gut microbiota.

Effects of ultra-high pressure, thermal pasteurization, and ultra-high temperature sterilization on color and nutritional components of freshly-squeezed lettuce juice

The aim of this study was to evaluate the effects of ultra-high pressure (UHP, 600 MPa/2 min), thermal pasteurization (TP, 95 °C/1 min) and ultra-high temperature (UHT, 115 °C/5 s) sterilization on the color, sensory evaluation, microorganisms, physicochemical characteristics and nutritional components of freshly-squeezed lettuce juice (FLJ). Results showed that three sterilization methods demonstrated desirable inactivation effects on total aerobic bacteria, yeast and mold, and there were no significant changes in the main nutritional components, including ash, protein, carbohydrate and total dietary fiber. However, UHT and TP significantly affected the color of FLJ from bright green to light brown and made chlorophyll, β-carotene and vitamins (VE, VC, VK1, VB6, VB12, and folic acid) contents markedly decreased. By contrast, UHP maintained the original color, fresh-like sensory qualities, vitamins, and carotene of FLJ to the greatest extent. Our results provide a promising application of UHP in the large-scale processing of FLJ.

Sterilising effect of high power pulse microwave on Listeria monocytogenes

In the present work, Listeria monocytogenes was used as the target strain to investigate the sterilising potential and mechanism of high power pulse microwave (HPPM). Results showed that the inactivation was positively correlated with the pulse frequencies and operating times. The count of Listeria monocytogenes was decreased by 5.09 log CFU/mL under 200 Hz for 9 min, which was used as the optimised condition to further explore the sterilisation mechanism. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that the L. monocytogenes cells of untreated group presented intact surfaces, clear boundary, and its intracellular contents distributed uniformly in the cytoplasm. Following treatment, the cell wall surfaces began to deform in small areas, and cell membranes were severely ruptured, thus resulting in the appearance of electron transmission areas. Extracellular protein and nucleic acid contents, represented by OD260 nm and OD280 nm, increased with the increase in operating time significantly. After treatment, SDS-PAGE profiles of whole-cell proteins displayed that the protein bands became lighter or even disappeared. Na+ K+-ATPase activities and intracellular ATP content decreased by 72.97 and 79.09%, respectively. This was consistent with the cell viability of L. monocytogenes observed by confocal laser scanning microscopy. Overall, the sterilisation mechanism of HPPM on L. monocytogenes may be caused by membrane damage, intracellular component leakage, and energy metabolism hindrance.