ABSTRACT
The concepts of "green chemistry" are gaining importance in the agri-food sector due to the need to minimize pollution from toxic chemicals, improve the safety and sustainability of industrial processes, and provide "clean-labeled products" required by consumers. The application of the cloud point extraction (CPE) is considered a promising alternative to conventional organic solvents. In the CPE, the separation of compounds from the bulk solution occurs by adding a surfactant (either non-ionic or ionic). When the solution is heated to or above a critical temperature, referred to as the cloud point, two phases are formed-micellar and aqueous. Recently, the horizons of the traditional CPE have been increasingly expanding by improved procedures and integration with other techniques, such as the microwave- and ultrasonic-assisted extraction. This article provides an updated overview of the theory and research articles on the CPE from 2018 to 2023 and critically discusses the issues relevant to the potential applicability of the CPE as a promising and green technique for antioxidants recovered from plant materials. Finally, some future perspectives and research needs for improved CPE are presented.
ABSTRACT
The development of active edible coatings with improved mechanical and barrier properties is a huge challenge. In this study, active edible coatings for sliced cheese have been developed using pullulan (Pull) in combination with two different biopolymers, chitosan (CS) and gelatine (Gel), and a combination of hydrolats as a source of active compounds with antimicrobial effects. In comparison to the monolayer coating, the bilayer coating system demonstrates improved barrier and mechanical properties. A preliminary assessment of the antimicrobial effect of lemongrass and curry plant hydrolats has revealed that both hydrolats exhibited antimicrobial activity against the targeted bacterium Staphylococcus aureus, albeit at different levels. The obtained results suggest that a mixture of 1.56% lemongrass and 12.5% curry plant hydrolats yielded a lower fractional inhibitory concentration (FIC) value. Bilayer coating systems (Pull/CS and Pull/Gel) with an incorporated mixture of hydrolats have demonstrated effectiveness in both cases: artificial contamination before application of the coating system and after application of the coating system. In both contamination scenarios, the coating systems consistently effectively limited bacterial proliferation, indicating the antimicrobial effect of the hydrolat mixture in the coating layers. In the case of artificial contamination before applying the coating system, both coatings demonstrated antimicrobial effectiveness, but the formulation with chitosan had a biocide effect, while the other, with gelatine, had only a bacteriostatic effect in a long-term setting. In the second case, both Pull/CS and Pull/Gel coatings demonstrated effectiveness in inhibiting bacterial growth regardless of the moment of contamination of the sample; the Pull/CS coating showed slightly better antimicrobial activity, achieving complete elimination of bacteria earlier compared with the Pull/Gel coating system.
ABSTRACT
Biodegradable thin films based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(caprolactone diol) (PCL-diol) blend were developed using the solution casting method. PHBV is biodegradable, biocompatible, and produced naturally by bacterial activity, but its use is restricted by high crystallinity and low resistance to thermal degradation with melting temperatures close to degradation thus narrowing the processing window. Solution casting was chosen as a cost-effective method reducing energy consumption and avoiding thermal degradation during processing. The increase in PCL-diol in blend composition (40-60 wt%) enhances the film-forming ability of PHBV and the wettability along with the decrease in the roughness of the resulting materials as revealed by contact angle measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Optimal composition in terms of filmogenity and surface structure has been achieved by the addition of PCL-diol in the amount of 60 wt%. FTIR confirmed the expected chemical structures with no evidence of chemical interactions between the two polymers.
ABSTRACT
The increasing interest in microbiological food safety requires the development of sensitive and reliable analyses and technologies for preserving food products' freshness and quality. Different types of packaging systems are one of the solutions for controlling microbiological activity in foods. During the last decades, the development of biopolymer-based active packaging with essential oil incorporation systems has resulted in technologies with exceptional application potential, primarily in the food industry. There is no doubt that this principle can facilitate food status monitoring, reduce food waste, extend the shelf life, improve the overall quality of food, or indicate a larger problem during the storage, production, and distribution of foodstuffs. On the other hand, most antimicrobial packaging systems are in the development phase, while the sensitivity, selectivity, complexity, and, above all, safety of these materials are just some of the essential questions that need to be answered before they can be widely used. The incorporation of essential oils as antimicrobial substances in biopolymer-based active packaging holds significant promise for enhancing food safety, extending shelf life, and offering more sustainable packaging solutions. While challenges exist, ongoing research and innovation in this field are likely to lead to the development of effective and environmentally friendly packaging systems with enhanced antimicrobial properties.
ABSTRACT
Protein stabilized fish oil microcapsules were incorporated into chocolates in order to design fortified product which could bear the nutritional claim "source of or high omega-3 fatty acids". Protein wall material (soy, whey and potato) influenced microcapsules and chocolate performance. Soy protein resulted in the smallest microcapsules with the lowest content of surface oil. Peroxide values were low even after 14 days of microcapsules storage. Incorporation of microcapsules into chocolate led to increase in Casson viscosity and breaking force as well as decrease in melting enthalpy, due to prevalence of particle-particle over fat-fat interactions. Increase in microcapsules concentration resulted in chocolate with poorer snap and higher tendency to fat bloom formation. Whey protein microcapsules, having the largest diameter, resulted in chocolate with the lowest breaking force and melting enthalpy and the highest whitening index. In general, microcapsules addition did not require chocolate production modification and led to sensory acceptable product.
ABSTRACT
Biopolymer-based films present an ideal matrix for the incorporation of active substances such as antimicrobial agents, giving active packaging a framework of green chemistry and a step forward in food packaging technology. The chitosan-gelatine active coating has been prepared using lemongrass oil as an antimicrobial compound applying a different approach. Instead of surfactants, to achieve compatibilization of compounds, ß-cyclodextrin was used to encapsulate lemongrass oil. The antimicrobial effect was assessed using the dip-coating method on freshly harvested cherry tomatoes artificially contaminated by Penicillium aurantiogriseum during 20 days of cold storage. According to the evaluation of the antimicrobial effect of coating formulation on cherry tomato samples, which was mathematically assessed by predictive kinetic models and digital imaging, the applied coating formulation was found to be very effective since the development of fungal contamination for active-coated samples was observed for 20 days.
