The effects of allicin and antioxidant of bamboo leaves (AOB) on the quality of bullfrogs (Lithobates catesbeiana) during refrigerated storage (4 °C) were investigated. The quality changes in samples treated with deionized water (CK), allicin solution (All), antioxidant of bamboo leaves (AOB), and allicin solution combined with AOB solution (AA) in microbiological, physicochemical, and sensory evaluation were analyzed, respectively. The results demonstrated that combination treatment inhibited the increase in total viable counts, delayed the decrease in amino acid content, and retarded the sensory deterioration. Preservative treatment has an inhibitory effect on the early storage of PBC, which can reduce PBC by about 1.0 log CFU/g. The reduction in thiobarbituric acid (TBA) content and total volatile basic nitrogen (TVB-N) content indicated that combination treatment could better restrain the lipid oxidation and degradation of protein than the CK group and single-treatment group. In addition, the TVB-N content in the AA group still did not exceed the threshold on the 14th day. As a consequence, combination treatment prolonged the shelf life of bullfrogs for another six days. Therefore, allicin and AOB with excellent antioxidant and antimicrobial activity could be an effective approach to delay the biochemical reaction of refrigerated bullfrogs. This study has provided a potential approach for increasing the shelf life of bullfrogs and preserving their quality during refrigerated storage.
Yingchang Li,Qian Zou,Suzhen Song,Tong Sun,Jianrong Li
The effects of combined application of lysozyme and resveratrol with chitosan coatings on the quality of Sciaenops ocellatus during refrigerated storage were studied. Physical and chemical indices were periodically analyzed. The chitosan composite coatings were characterized, and the mechanical properties and gas permeability were also measured. The results showed that chitosan coatings could significantly reduce the total viable count (TVC), maintain tissue hardness, chewiness and sensory quality, slow the rate of fat oxidation, and restrain the increases in pH and total volatile basic nitrogen (TVB-N). Compared with chitosan coatings, the addition of resveratrol and lysozyme had increased the tensile strength and reduced the gas permeability. The lysozyme–resveratrol–chitosan coatings had good preservation properties. The study indicated that the 0.1% lysozyme + 0.2% resveratrol + 1% chitosan group of composite coatings could maintain the quality and extend the shelf life for 8 days compared with the control group during refrigerated storage.
Tianhao Ying,Chenghong Jiang,Sadia Munir,Ru Liu,Tao Yin,Juan You,Jianhua Rong,Shanbai Xiong,Yang Hu
This work aimed to synthesize oregano essential oil/β-cyclodextrin microcapsules (OEO/β-CDs) and then prepare gelatin-based controlled-release antibacterial films with different OEO/β-CDs contents (0%–2%) for chilling preservation of grass carp fillets. The results of FTIR , XRD, DSC and accelerated release ratio showed that OEO was successfully encapsulated in OEO/β-CDs and its thermal stability was effectively improved. Moreover, at 2% of addition amount of OEO/β-CDs, the tensile strength of the films increased from 14.43 MPa to 18.72 MPa. In addition, the films showed significant antibacterial activity against Pseudomonas (61.52%), Aeromonas (62.87%), and Shewanella putrefaciens (66.67%). Preservation experiments showed that the films effectively prevented the increase of TVB-N, and TBA value of the refrigerated fillets and significantly suppressed the growth of spoilage organisms , thus extending the shelf life by 2–3 days. Therefore, the synthesized film has promising potential as an active packaging material for the preservation of grass carp.