In this paper, remodeling the shrimp processing chain and the effects of the transformation on the biochemical and sensory qualities of fresh Pacific white shrimp ( Penaeus vannamei) under refrigeration storage were investigated. In the proposed model, a dielectric barrier discharge atmospheric cold plasma pretreatment step using a 60 kV source for 60, 90, 120, and 150 s was introduced after the first and second wash followed by refrigeration storage at 4 ± 1 °C for 12 days. Chemical, biochemical, and sensory attributes of the shrimp were monitored and compared with those of shrimp processed through the traditional method without atmospheric cold plasma pretreatment (control). Incorporating minimal dielectric barrier discharge atmospheric cold plasma pretreatment step had more desirable quality outcomes characterized by low malondialdehyde concentration, low volatile nitrogen products content, and comparable proximate composition. Texture, pH, and color were remarkably retained at 120 and 150 s of atmospheric cold plasma pretreatment and protein degradation was negligible up to 90 s than at 120 and 150 s of pretreatment. We conclude that remodeling the shrimp processing chain through incorporating minimal dielectric barrier discharge atmospheric cold plasma pretreatment with key considerations on operation parameters can maximize the beneficial biochemical and sensory quality outcomes while minimizing the negative impacts associated with traditional shrimp processing.
Cotton fabric was exposed to low-pressure capacitively coupled plasma to enhance the adsorption and adhesion of fragrance microcapsules (FCM). Two plasma-forming gases, namely oxygen (O2) and nitrogen (N2), were investigated. The untreated and plasma-treated samples were investigated for their morphological changes by scanning electron microscopy (SEM), mechanical properties (breaking force, elongation, and flexural rigidity), and wicking properties. The cotton samples were functionalized with FCM and the effect of plasma pretreatment on the adsorption and adhesion of FCM was evaluated using SEM, air permeability, fragrance intensity of unwashed and washed cotton fabrics, and Fourier transform infrared spectroscopy (FTIR). The results show that the plasma containing either of the two gases increased the wicking of the cotton fabric and that the O2 plasma caused a slight etching of the fibers, which increased the tensile strength of the cotton fabric. Both plasma gases caused changes that allowed higher adsorption of FCM. However, the adhesion of FCM was higher on the cotton treated with N2 plasma, as evidenced by a strong fragrance of the functionalized fabric after repeated washing.
In the first part of the study, dyed polyester fabric was treated with a dielectric barrier discharge (DBD) plasma at 1 W/cm2 for 15, 30, 60 and 90 s. The wicking height, tensile strength and color of the control and plasma treated fabrics were measured. Results show that the fabric capillary increases with plasma treatment time up to 90 s. However, plasma treatment time longer than 60 s caused an obvious color change and decrease in tensile strength of fabric. Plasma contact time should be such that plasma can improve the hydrophilicity of the fabric and adversely affect the properties of the fabric as little as possible. Thus, the suitable plasma contact time should be less than 60 s. Based on these results, in the second part of the study, three different time levels (15, 20 and 30 s) were selected for plasma pretreatment of this fabric. The plasma-treated fabric was then padded with the flame retardant (FR) (CETAFLAM PDP 30), dried and finally cured at 190 °C for 120 s. The limited oxygen index (LOI) of FR fabrics and the vertical fire characteristics of FR fabric after being washed 5 times also were measured. Comparison of these results with those of FR fabrics without plasma pretreatment shows that plasma pretreatment improves the fabric’s flame retardancy and FR durability. Moreover, it also reduces the heat shrinkage of PET fabric due to high temperature curing. The scanning electron microscopy (SEM) images of the fabric after plasma treatment and FR treatment and the energy-dispersive spectroscopy (EDS) spectrum of the fabric are consistent with the above results.
AbstractThe development of a simple surface barrier discharge plasma device is presented to enable more widespread access to and utilization of plasma technology. The application of the plasma device was demonstrated for pretreatment of wood prior to application of protective coatings for outdoor usage. The coatings' overall performance was increased, showing a reduction or absence of cracking due to weathering on plasma-pretreated specimens. Moreover, after ten months of outdoor weathering, the plasma-pretreated specimens showed fewer infections with biotic factors and improved adhesion performance in cross-cut tests, while the surface gloss performed independently from plasma pretreatment. In contrast to that, plasma-pretreated specimens were slightly more prone to discoloration due to outdoor weathering, whereas the plasma pretreatment did not impact the initial color after coating application.