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The global population has rapidly expanded in the last few decades and is continuing to increase at a rapid pace. To meet this growing food demand fish is considered a balanced food source due to their high nutritious value and low cost. Fish are rich in well-balanced nutrients, a good source of polyunsaturated fatty acids and impose various health benefits. Furthermore, the most commonly used preservation technologies including cooling, freezing, super-chilling and chemical preservatives are discussed, which could prolong the shelf life. Non-thermal technologies such as pulsed electric field (PEF), fluorescence spectroscopy, hyperspectral imaging technique (HSI) and high-pressure processing (HPP) are used over thermal techniques in marine food industries for processing of most economical fish products in such a way as to meet consumer demands with minimal quality damage. Many by-products are produced as a result of processing techniques, which have caused serious environmental pollution. Therefore, highly advanced technologies to utilize these by-products for high-value-added product preparation for various applications are required. This review provides updated information on the nutritional value of fish, focusing on their preservation technologies to inhibit spoilage, improve shelf life, retard microbial and oxidative degradation while extending the new applications of non-thermal technologies, as well as reconsidering the values of by-products to obtain bioactive compounds that can be used as functional ingredients in pharmaceutical, cosmetics and food processing industries.

In this study, angiotensin-converting enzyme inhibitory peptides (ACE–IPs) derived from Muscovy duck (Cairina moschata) plasma hydrolysate (MDPH) were investigated. According to the general research protocol for bioactive peptides, the crude ACE–IPs of Muscovy duck plasma were separated and purified by ultrafiltration, gel chromatography and reversed-phase high-performance liquid chromatography (RP–HPLC). Then the components with the highest ACE inhibition potential were selected for identification. Finally, the inhibition mechanism was explored by molecular docking and in silico simulated digestion. A total of 121 peptides was detected, and five were screened for synthesis verification and molecular docking. The peptide VALSSLRP revealed high ACE inhibitory activity (91.67 ± 0.73%) because this peptide bound tightly to the S1′ pocket and formed 3 hydrogen bonds. Meaningfully, this work provides some new information about the generation of ACE–IPs derived from duck blood plasma.

IntroductionParaclostridium bifermentans is responsible for spoilage properties in vacuum-packaged meat. Ordinary heat treatment techniques are ineffective to control the extremely heat-resistant spores of P. bifermentans. Therefore, finding a new strategy to prevent the contamination of P. bifermentans spores in vacuum-packaged meat is challenging.MethodsIn this study, P. bifermentans was isolated from the vacuum-packaged chicken, and the inhibitory effects of licorice extract on the germination and outgrowth of P. bifermentans spores, as well as the key bioactive components in the licorice extract involved in inhibiting spore activity, were investigated.ResultsThe spores induced by combination-nutrient-germinant (150 mmol/L L-alanine and 20 mmol/L inosine, co-AI) did not germinate when the concentration of licorice extract was ≥ 3.13 mg/ml. The germination of P. bifermentans spores induced by non-nutrient-germinant (8 mmol/L dipicolinic acid, DPA) was completely prevented by licorice extract at least 1.56 mg/ml. While the outgrowth of P. bifermentans spores was inhibited at a concentration of 0.39 mg/ml. Licorice extract did not seem to damage the non-germinated spores but blocked the germinant sensing. Licorice extract prevented the outgrowing spores from becoming vegetable cells by disrupting the inner membrane. Furthermore, the results obtained from LC-MS data analysis exhibited 15 key bioactive compounds in licorice extract, such as glycyrrhizic acid, liquiritin, etc. Among them, glycyrrhizic acid and liquiritin apioside exerted efficient inhibitory properties on the germination and outgrowth of P. bifermentans spores.DiscussionThis present study demonstrated that licorice extract can be used as a promising inhibitor of spores and provides a new method to control the residual P. bifermentans spores in meat products. Meanwhile, this study exhibits a baseline for the better understanding of the potential application of licorice extracts to control the P. bifermentans spores in meat products.