Comparison of bactericidal effects of two types of pilot-scale intense-pulsed-light devices on cassia seeds and glutinous millet

Maximizing the Nutritional Benefits and Prolonging the Shelf Life of Millets through Effective Processing Techniques: A Review

Maximizing the nutritional benefits and extending the shelf life of millets is essential due to their ancient significance, rich nutrient content, and potential health benefits, but challenges such as rapid rancidity in millet-based products underscore the need for effective processing techniques to enhance their preservation and global accessibility. In this comprehensive review, the impact of diverse processes and treatments such as mechanical processing, fermentation, germination, soaking, thermal treatments like microwave processing, infrared heating, radio frequency, nonthermal treatments like ultrasound processing, cold plasma, gamma irradiation, pulsed light processing, and high-pressure processing, on the nutritional value and the stability during storage of various millets has been examined. The review encompasses an exploration of their underlying principles, advantages, and disadvantages. The technologies highlighted in this review have demonstrated their effectiveness in maximizing and extending the shelf life of millet-based products. While traditional processes bring about alterations in nutritional and functional properties, prompting the search for alternatives, novel thermal and nonthermal techniques were identified for microbial decontamination and enzyme inactivation. Advancements in millet processing face challenges including nutrient loss, quality changes, resource intensiveness, consumer perception, environmental impact, standardization issues, regulatory compliance, and limited research on combined methods.

Modern and conventional processing technologies and their impact on the quality of different millets

Millet, the highly sustainable crop for farming and combating hunger, has recently regained a resurgence in popularity as people seek more sustainable and nutrient-dense alternatives. International organizations and research institutions have advocated for increased millet production and consumption by introducing novel technologies and machinery in response to global food security and climate change challenges. This review aims to identify the impact of modern and conventional processing technologies on the quality of different millets. A comprehensive analysis of research reviews reveals that double-stage and tabletop centrifugal dehullers, infrared roasting, pulsed light, ultrasound, high-pressure processing methods, fortification, and encapsulation are optimal for nutrient retention in various millets. Extrusion technology application in millet processing has created a diverse range of value-added products with extended shelf stability. Emphasis is needed to develop robust promotion and distribution channels and establish an export promotion forum involving all stakeholders to promote and diversify millet-based products and technologies.

Recent developments in applications of physical fields for microbial decontamination and enhancing nutritional properties of germinated edible seeds and sprouts: a review

Germinated edible seeds and sprouts have attracted consumers because of their nutritional values and health benefits. To ensure the microbial safety of the seed and sprout, emerging processing methods involving physical fields (PFs), having the characteristics of high efficiency and environmental safety, are increasingly proposed as effective decontamination processing technologies. This review summarizes recent progress on the application of PFs to germinating edible seeds, including their impact on microbial decontamination and nutritional quality and the associated influencing mechanisms in germination. The effectiveness, application scope, and limitation of the various physical techniques, including ultrasound, microwave, radio frequency, infrared heating, irradiation, pulsed light, plasma, and high-pressure processing, are symmetrically reviewed. Good application potential for improving seed germination and sprout growth is also described for promoting the accumulation of bioactive compounds in sprouts, and subsequently enhancing the antioxidant capacity under favorable PFs processing conditions. Moreover, the challenges and future directions of PFs in the application to germinated edible seeds are finally proposed. This review also attempts to provide an in-depth understanding of the effects of PFs on microbial safety and changes in nutritional properties of germinating edible seeds and a theoretical reference for the future development of PFs in processing safe sprouted seeds.

Comparison of microbial reduction effect of intense pulsed light according to growth stage and population density of Escherichia coli ATCC 25922 using a double Weibull model

This study evaluated how the efficacy of intense pulsed light (IPL) was influenced by biological factors such as the incubation time and the population of Escherichia coli. According to the 4D value, the microorganisms in the exponential phase were more susceptible to IPL (0.51 J/cm²), while those in the stationary phase were the most resistant (0.67 J/cm²). The microorganisms in the exponential phase could have more critical DNA damage. In addition, the degree of inactivation was affected by the microbial population. When the population was 10⁹ CFU/ml, a maximum 3.4-log reduction was observed after applying IPL at 12.5 J/cm². In contrast, a population with a density of 10¹⁰ CFU/ml showed maximally 0.13-log reduction when IPL was applied at 18.7 J/cm². This large difference might have been due to cell distribution and aggregation. The study is expected to contribute to the analytical confirmation of the microbial reduction mechanism through non-thermal technologies.

Decontamination of Powdery Foods Using an Intense Pulsed Light (IPL) Device for Practical Application

Controlling microbial problems when processing seeds and powdered foods is difficult due to their low water activity, irregular surfaces, and opaqueness. Moreover, existing thermal processing can readily cause various undesirable changes in sensory properties. Intense pulsed light (IPL) can be effective in nonthermal processing, and so two xenon lamps were attached to the sides of a self-designed cyclone type of pilot-scale IPL device. Each lamp was connected to its own power supply, and the following treatment conditions were applied to four sample types: lamp DC voltage of 1800–4200 V, pulse width of 0.5–1.0 ms, frequency of 2 Hz, and treatment time of 1–5 min. This device achieved reductions of 0.45, 0.66, and 0.88 log CFU/mL for ground black pepper, red pepper, and embryo buds of rice, respectively, under a total energy fluence of 12.31 J/cm2. Meanwhile, >3-log reductions were achieved for sesame seed samples under a total energy fluence of 11.26 J/cm2. In addition, analyses of color changes, water activity, and moisture content revealed no significant differences between the control and IPL-treated samples. These findings indicate that IPL treatment may be considered a feasible sterilization method for seeds and powdered foods.

Effect of pulsed light treatment on Listeria inactivation, sensory quality and oxidation in two varieties of Spanish dry-cured ham

The efficacy of pulsed light (PL) for the surface decontamination of ready-to-eat dry-cured ham was studied in two Spanish varieties, Serrano and Iberian. Listeriainnocua was inoculated on the surface of ham slices that were vacuum-packaged and flashed with 2.1, 4.2 and 8.4 J/cm². Survivors were enumerated immediately after treatment. Peroxide values, sensory analysis and volatile profile were investigated during storage at 4 and 20 °C. Inactivation of Listeria was higher in Iberian (ca. 2 log cfu/cm²) than in Serrano ham (ca. 1 log cfu/cm²) with 8.4 J/cm². PL did not increase the peroxide values above the usual levels reported in dry-cured ham, and no rancid notes were observed in the sensory analysis. PL-treated samples showed an increase in the concentration of some volatile compounds, such as methional, dimethyl disulfide and 1-octen-3-one, which imparted slight sulfur and metallic notes, although they disappeared during storage.