The effects of microalgae (Spirulina platensis and Chlorella vulgaris) extracts on the quality of vacuum packaged sardine during chilled storage

New insights into Chlorella vulgaris applications

Environmental pollution is a big challenge that has been faced by humans in contemporary life. In this context, fossil fuel, cement production, and plastic waste pose a direct threat to the environment and biodiversity. One of the prominent solutions is the use of renewable sources, and different organisms to valorize wastes into green energy and bioplastics such as polylactic acid. Chlorella vulgaris, a microalgae, is a promising candidate to resolve these issues due to its ease of cultivation, fast growth, carbon dioxide uptake, and oxygen production during its growth on wastewater along with biofuels, and other productions. Thus, in this article, we focused on the potential of Chlorella vulgaris to be used in wastewater treatment, biohydrogen, biocement, biopolymer, food additives, and preservation, biodiesel which is seen to be the most promising for industrial scale, and related biorefineries with the most recent applications with a brief review of Chlorella and polylactic acid market size to realize the technical/nontechnical reasons behind the cost and obstacles that hinder the industrial production for the mentioned applications. We believe that our findings are important for those who are interested in scientific/financial research about microalgae.

Antimicrobial activity of Spirulina platensis extract on total mesophilic and psychrophilic bacteria of fresh tilapia fillet

Spirulina platensis has a wide range of activities, notably antibacterial property against food pathogens. This study investigates the antibacterial activity of S. platensis extract on Total Mesophilic and Psychrophilic Aerobic Bacteria. The results were compared using statistical analysis and the predicted model values using artificial intelligence-based models such as artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS) Models. The extraction of spirulina was done by using the freeze-thaw method with a concentration of 0.5, 1 and 5% w/v. Before the application of the extract, initial microbial load of fillets was analyzed the and the results were used as control. After application analysis was performed at 1, 24 and 48 h of storage at 4 °C. Based on the statistical analysis result the S. platensis extracts' antimicrobial activity over TMAB of fresh tilapia fish fillets at 1, 24 and 48 h was using EA from 2.5 log10 CFU/g during the control stage to 1.8, 1.1 and 0.7 log10 CFU/g respectively whereas EB and EC was from 2.1 and 2.2 log10 CFU/g at control to 1.5, 0.8, 0.5 log10 CFU/g and 1.23, 0.6 and 0.32 log10 CFU/g respectively at the specified hour interval. Similarly, the three extracts over TPAB were from 2.8 log10 CFU/g at control time to 2.1, 1.5 and 0.9 in EA, while using EB reduces from 2.8 log10 CFU/g to 1.9, 1.3 and 0.8 log10 CFU/g at 1, 24 and 48 h respectively. Although EC presented the reduction from 1.9 log10 CFU/g to 1.4, 1 and 0.5 log10 CFU/g. This was supported by ANN and ANFIS models prediction.

Effects of ellagic acid and ε-polylysine hydrochloride on the content of biogenic amines, volatile compounds and quality of salmon slices during chilled storage

This study aimed to investigate effects of ellagic acid (EA) and ε-polylysine hydrochloride (ε-PL) on biogenic amines (BAs), volatile compounds and quality of salmon slices stored at 4 °C. The results showed that EA and ε-PL attenuated the production of BAs, retarded the increase of TVC, TVB-N and TBARS. Additionally, water mobility, texture properties of salmon slices were also stabilized by the EA and ε-PL. Volatile compounds including aldehydes, alcohols and hydrocarbons were identified and spoilage-related compounds reduced by the EA and ε-PL, which was related to the inhibition of bacterial, TVB-N and TBA growth by EA and ε-PL. The content of phencthylamine, putrescine, cadaverine, histamine and tyramine in EA-s-PL groups reduced by 46.53%, 54.1%, 26.42%, 31.98% and 45.37% compared to the control group at the end of storage, respectively. Therefore, EA and ε-PL can be applied for inhibiting the increase of BAs and delaying quality deterioration of salmon slices.

Technological strategies for the use of plant-derived compounds in the preservation of fish products

New approaches to reducing synthetic preservatives in the preservation of foods draw the attention of plant-derived bioactive compounds, especially for application in foods highly susceptible to spoilage, such as fish products. The review presents relevant data from procurement, application, and methodological research trends to investigate the potential effects of plant-derived bioactive compounds on shelf life extension in fish products. The systematization of data allowed observation that the different methods of extraction and application of bioactive plant compounds result in different effects, such as the reduction of lipid oxidation, antimicrobial effects, and maintenance of sensory characteristics, benefiting the extension of shelf life. In general, plant-derived bioactive compounds are an alternative for the preservation of fish products; however, approaches to the composition of the compounds can contribute to the optimization and efficiency of the process from a technical point of view and industrial viability.