1% carrageenan oligosaccharide solutions obtained by electron beam irradiation at the radiation doses of 9 kGy (CO-9) and 30 kGy (CO-30) were applied for shrimps before frozen, and their effects on quality of frozen shrimps were investigated by observing the microstructure of shrimp’s muscle tissue, measuring their weight loss (%), hardness and pH after thawing. Comparison with the shrimps treated by 1% tetrasodium pyrophosphate solution (Na4P2O7, positive control) and distilled water (negative control), the shrimp samples soaked in CO before frozen kept their initial properties, and the shrimps treated by CO-30 solution showed better quality than others after 3 weeks of frozen storage. Specifically, the mean distances of muscle bundles and muscle fibers in the shrimps soaked in CO-30 solution were 23.9 µm and 11.1 µm, respectively, much smaller than 37.9 µm and 14.8 µm in the shrimps treated by Na4P2O7, and 46.7 µm and 19.8 µm in the shrimps soaked in distilled water only. Our results also revealed that the weight loss after thawing and pH of the shrimps soaked in CO-30 solution were 1.55% and 6.40, much lower than that of the positive control sample (2.59% and 6.82) and negative control sample (4.83% and 6.58), respectively. In contrast, the mean of hardness of the sample soaked in CO-30 solution was 20.4, about 20.7 and 36.0% higher than those of positive control (16.9) and negative control (15.0). These results suggested that CO-30 is effective to inhibit the denaturation of shrimp during frozen storage and can be applied to prolong the shelf life and keep the quality of frozen shrimp products.

Environmental pollution, especially water pollution, is of great concern nowadays. Textile wastewater treatment by electron beam irradiation (EB) shows the advantage of not using toxic additives and not creating secondary sludge. In this study, textile wastewater was treated by electron beam irradiation in a low absorbed dose range of 0.5-2 kGy in combination with biological treatment. Besides, a study on combining EB irradiation and H2O2 oxidizing agent was also carried out to reduce the absorbed dose. The results show that after EB irradiation in the presence of oxidizing agents H2O2 combined with biological treatment, the color indicator of wastewater is within the allowed range according to column B of the national technical regulation on the effluent of the textile industry (QCVN 13–MT/2015/BTNMT), which is eligible for discharge into the environment. Research on the treatment of textile wastewater by EB irradiation combined with biological methods has shown that it increases the ability to effectively treat textile wastewater, contributing to reducing the environmental pollution.