Innovative edible films and coatings based on red color pectin obtained from the byproducts of Hibiscus sabdariffa L. for strawberry preservation

Sustainable strategies for using natural extracts in smart food packaging

The growing demand for sustainable and eco-friendly food packaging has prompted research on innovative solutions to environmental and consumer health issues. To enhance the properties of smart packaging, the incorporation of bioactive compounds derived from various natural sources has attracted considerable interest because of their functional properties, including antioxidant and antimicrobial effects. However, extracting these compounds from natural sources poses challenges because of their complex chemical structures and low concentrations. Traditional extraction methods are often environmentally harmful, expensive and time-consuming. Thus, green extraction techniques have emerged as promising alternatives, offering sustainable and eco-friendly approaches that minimise the use of hazardous solvents and reduce environmental impact. This review explores cutting-edge research on the green extraction of bioactive compounds and their incorporation into smart packaging systems in the last 10 years. Then, an overview of bioactive compounds, green extraction techniques, integrated techniques, green extraction solvents and their application in smart packaging was provided, and the impact of bioactive compounds incorporated in smart packaging on the shelf lives of food products was explored. Furthermore, it highlights the challenges and opportunities within this field and presents recommendations for future research, aiming to contribute to the advancement of sustainable and efficient smart packaging solutions.

Effects of sunflower pectin on thermal stability of purple sweet potato anthocyanins at different pH

The present study aimed to examine the impact of sunflower pectin (SFP) on the thermal stability and antioxidant activity of purple sweet potato anthocyanins (PSPA) at varying pH levels. It was observed that the pH value significantly influenced the ability of pectin to protect anthocyanins from thermal degradation, which was found to be associated with the rate of binding between PSPA and SFP. The binding rate of PSPA-SFP was observed to be highest at pH 4.0, primarily due to the influence of electrostatic interaction and hydrogen bonding. Monoacylated anthocyanins exhibited a binding rate approximately 2-4 % higher than that of diacylated anthocyanins. The PSPA-SFP demonstrated its highest thermal stability at pH 4.0, with a corresponding half-life of 14.80 h at 100 °C. Molecular dynamics simulations indicated that pectin had a greater affinity for the flavylium cation and hemiketal form of anthocyanins. The antioxidant activity of anthocyanins in PSPA and PSPA-SFP increased with increasing pH, suggesting that anthocyanins at high pH had higher antioxidant activity than anthocyanins at low pH.

Towards Valorization of Food-Waste-Derived Pectin: Recent Advances on Their Characterization and Application

Pectin, a natural biopolymer, can be extracted from food waste biomass, adding value to raw materials. Currently, commercial pectin is mostly extracted from citrus peels (85.5%) and apple pomace (14.0%), with a small segment from sugar beet pulp (0.5%). However, driven by high market demand (expected to reach 2.12 billion by 2030), alternative agro-industrial waste is gaining attention as potential pectin sources. This review summarizes the recent advances in characterizing pectin from both conventional and emerging food waste sources. The focus is the chemical properties that affect their applications, such as the degree of esterification, the neutral sugars' composition, the molecular weight, the galacturonic acid content, and technological-functional properties. The review also highlights recent updates in nutraceutical and food applications, considering the potential use of pectin as an encapsulating agent for intestinal targeting, a sustainable biopolymer for food packaging, and a functional and emulsifying agent in low-calorie products. It is clear from the considered literature that further studies are needed concerning the complexity of the pectin structure extracted from emerging food waste raw materials, in order to elucidate their most suitable commercial application.

Preparation and properties of chitosan-based bacteriostatic agents and their application in strawberry bacteriostatic preservation

The purpose of this study is to develop a green and safe chitosan-based preservative which can be applied in strawberry preservation. Chitosan (CS) was treated by 2,2,6,6-tetramethylpiperidine oxygen radical/laccase oxidation system (TEMPO/laccase oxidation system), which was mainly used to prepare TEMPO/laccase chitosan (TLCS). Furthermore, on this basis, the structure and performance of TLCS were also studied. The results showed that compared with CS, the solubility of TLCS improved, and the kinetic viscosity reduced significantly. Next, a cinnamaldehyde-TEMPO/laccase chitosan (CIN-TLCS) antibacterial agent was prepared by covalently combining the aldehyde group in cinnamaldehyde (CIN) and the amino group in CS. It was found that CIN combined with TLCS through covalent bonds, which changed the structure and crystallinity of TLCS. In addition, the total antioxidant capacity of CIN-TLCS also improved, which was necessary for the application of CIN-TLCS in extending shelf life. Cytotoxicity experiments showed that CIN-TLCS had no cytotoxicity. Furthermore, strawberries were used to explore the actual bacteriostatic and fresh-keeping effects of CIN-TLCS. The experiment found that CIN-TLCS could maintain the freshness of strawberries at room temperature (23 ± 1°C) for 5 days and had positive effects on strawberry color, loss-weight rate, hardness and pH. These results showed that CIN-TLCS could be used as a potential preserving agent for fruit storage. PRACTICAL APPLICATION: To obtain a green, safe and effective food preservative, chitosan (CS) was modified by a 2,2,6,6-tetramethylpiperidine oxygen radical/laccase oxidation system (TEMPO/laccase oxidation system) to get TEMPO/laccase chitosan (TLCS) and cinnamic aldehyde-TEMPO/laccase chitosan (CIN-TLCS). At the same time, the structure and antibacterial properties of TLCS and CIN-TLCS were analyzed, and their possibility as a new green and safe strawberry preservative was studied. Compared with oxazolidine, imidazole and triazole commercial drugs, CIN-TLCS has the advantages of low price, no pollution, no cytotoxicity and no drug resistance.

Structure and Applications of Pectin in Food, Biomedical, and Pharmaceutical Industry: A Review

Pectin is a biocompatible polysaccharide with intrinsic biological activity, which may exhibit different structures depending on its source or extraction method. The extraction of pectin from various industrial by-products presents itself as a green option for the valorization of agro-industrial residues by producing a high commercial value product. Pectin is susceptible to physical, chemical, and/or enzymatic changes. The numerous functional groups present in its structure can stimulate different functionalities, and certain modifications can enable pectin for countless applications in food, agriculture, drugs, and biomedicine. It is currently a trend to use pectin to produce edible coating to protect foodstuff, antimicrobial bio-based films, nanoparticles, healing agents, and cancer treatment. Advances in methodology, use of different sources of extraction, and knowledge about structural modification have significantly expanded the properties, yields, and applications of this polysaccharide. Recently, structurally modified pectin has shown better functional properties and bioactivities than the native one. In addition, pectin can be used in conjunction with a wide variety of biopolymers with differentiated properties and specific functionalities. In this context, this review presents the structural characteristics and properties of pectin and information on the modification of this polysaccharide, its respective applications, perspectives, and future challenges.